Usually the frontend communicates the size of wchar_t via metadata and
we can optimize wcslen (and possibly other calls in the future). In
cases without the wchar_size metadata we would previously try to guess
the correct size based on the target triple; however this is fragile to
keep up to date and may miss users manually changing the size via flags.
Better be safe and stop guessing and optimizing if the frontend didn't
communicate the size.
Differential Revision: https://reviews.llvm.org/D38106
llvm-svn: 314185
Summary:
Right now there are two functions with the same name, one does the work
and the other one returns true if expansion is needed. Rename
TargetTransformInfo::expandMemCmp to make it more consistent with other
members of TargetTransformInfo.
Remove the unused Instruction* parameter.
Differential Revision: https://reviews.llvm.org/D38165
llvm-svn: 314096
Summary:
A SCEV such as:
{%v2,+,((-1 * (trunc i64 (-1 * %v1) to i32)) + (-1 * (trunc i64 %v1 to i32)))}<%loop>
can be folded into, simply, {%v2,+,0}. However, the current code in ::getAddExpr()
will not try to apply the simplification m*trunc(x)+n*trunc(y) -> trunc(trunc(m)*x+trunc(n)*y)
because it only keys off having a non-multiplied trunc as the first term in the simplification.
This patch generalizes this code to try to do a more generic fold of these trunc
expressions.
Reviewers: sanjoy
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37888
llvm-svn: 313988
This broke the buildbots, e.g.
http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/391
> Summary:
> This patch tries to vectorize loads of consecutive memory accesses, accessed
> in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
> which was reverted back due to some basic issue with representing the 'use mask'
> jumbled accesses.
>
> This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
>
> Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
>
> Subscribers: mzolotukhin
>
> Reviewed By: ayal
>
> Differential Revision: https://reviews.llvm.org/D36130
>
> Review comments updated accordingly
>
> Change-Id: I22ab0a8a9bac9d49d74baa81a08e1e486f5e75f0
>
> Added a TODO for sortLoadAccesses API
>
> Change-Id: I3c679bf1865422d1b45e17ea28f1992bca660b58
>
> Modified the TODO for sortLoadAccesses API
>
> Change-Id: Ie64a66cb5f9e2a7610438abb0e750c6e090f9565
>
> Review comment update for using OpdNum to insert the mask in respective location
>
> Change-Id: I016d0c1b29874e979efc0205bbf078991f92edce
>
> Fixes '-Wsign-compare warning' in LoopAccessAnalysis.cpp and code rebase
>
> Change-Id: I64b2ea5e68c1d7b6a028f5ef8251c5a97333f89b
llvm-svn: 313781
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask'
jumbled accesses.
This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
Subscribers: mzolotukhin
Reviewed By: ayal
Differential Revision: https://reviews.llvm.org/D36130
Review comments updated accordingly
Change-Id: I22ab0a8a9bac9d49d74baa81a08e1e486f5e75f0
Added a TODO for sortLoadAccesses API
Change-Id: I3c679bf1865422d1b45e17ea28f1992bca660b58
Modified the TODO for sortLoadAccesses API
Change-Id: Ie64a66cb5f9e2a7610438abb0e750c6e090f9565
Review comment update for using OpdNum to insert the mask in respective location
Change-Id: I016d0c1b29874e979efc0205bbf078991f92edce
Fixes '-Wsign-compare warning' in LoopAccessAnalysis.cpp and code rebase
Change-Id: I64b2ea5e68c1d7b6a028f5ef8251c5a97333f89b
llvm-svn: 313771
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask' of
jumbled accesses.
This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh
Reviewed By: Ayal
Subscribers: mzolotukhin
Differential Revision: https://reviews.llvm.org/D36130
Commit after rebase for patch D36130
Change-Id: I8add1c265455669ef288d880f870a9522c8c08ab
llvm-svn: 313736
Summary:
With this change:
- Methods in LoopBase trip an assert if the receiver has been invalidated
- LoopBase::clear frees up the memory held the LoopBase instance
This change also shuffles things around as necessary to work with this stricter invariant.
Reviewers: chandlerc
Subscribers: mehdi_amini, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D38055
llvm-svn: 313708
Summary:
See comment for why I think this is a good idea.
This change also:
- Removes an SCEV test case. The SCEV test was not testing anything useful (most of it was `#if 0` ed out) and it would need to be updated to deal with a private ~Loop::Loop.
- Updates the loop pass manager test case to deal with a private ~Loop::Loop.
- Renames markAsRemoved to markAsErased to contrast with removeLoop, via the usual remove vs. erase idiom we already have for instructions and basic blocks.
Reviewers: chandlerc
Subscribers: mehdi_amini, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D37996
llvm-svn: 313695
This should bring signed div/rem analysis up to the same level as unsigned.
We use icmp simplification to determine when the divisor is known greater than the dividend.
Each positive test is followed by a negative test to show that we're not overstepping the boundaries of the known bits.
There are extra tests for the signed-min-value special cases.
Alive proofs:
http://rise4fun.com/Alive/WI5
Differential Revision: https://reviews.llvm.org/D37713
llvm-svn: 313264
The idea to make an 'isDivZero' helper was suggested for the signed case in D37713:
https://reviews.llvm.org/D37713
This clean-up makes it clear that D37713 is just filling the gap for signed div/rem,
removes unnecessary code, and allows us to remove a bit of duplicated code from the
planned improvement in D37713.
llvm-svn: 313261
invalidated SCCs even when we do not have an updated SCC to redirect
towards.
This comes up in a fairly subtle and surprising circumstance: we need to
have a connected but internal node in the call graph which later becomes
a disconnected island, and then gets deleted. All of this needs to
happen mid-CGSCC walk. Because it is disconnected, we have no way of
computing a new "current" SCC when it gets deleted. Instead, we need to
explicitly check for a deleted "current" SCC and bail out of the current
CGSCC step. This will bubble all the way up to the post-order walk and
then resume correctly.
I've included minimal tests for this bug. The specific behavior
matches something we've seen in the wild with the new PM combined with
ThinLTO and sample PGO, but I've not yet confirmed whether this is the
only issue there.
llvm-svn: 313242
This patch fixes pr34283, which exposed that the computation of
maximum legal width for vectorization was wrong, because it relied
on MaxInterleaveFactor to obtain the maximum stride used in the loop,
however not all strided accesses in the loop have an interleave-group
associated with them.
Instead of recording the maximum stride in the loop, which can be over
conservative (e.g. if the access with the maximum stride is not involved
in the dependence limitation), this patch tracks the actual maximum legal
width imposed by accesses that are involved in dependencies.
Differential Revision: https://reviews.llvm.org/D37507
llvm-svn: 313237
Summary:
Full inline cost is computed when -inline-cost-full is true or ORE is
non-null. This patch adds another way to compute full inline cost by
adding a field to InlineParams. This will be used by SampleProfileLoader
to check legality of inlining a callee that it wants to inline.
Reviewers: danielcdh, haicheng
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37819
llvm-svn: 313185
Summary:
Added text options to -pgo-view-counts and -pgo-view-raw-counts that dump block frequency and branch probability info in text.
This is useful when the graph is very large and complex (the dot command crashes, lines/edges too close to tell apart, hard to navigate without textual search) or simply when text is preferred.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37776
llvm-svn: 313159
Summary: References should only be on the aliasee.
Reviewers: pcc
Subscribers: llvm-commits, inglorion
Differential Revision: https://reviews.llvm.org/D37814
llvm-svn: 313158
Summary:
LAA can only emit run-time alias checks for pointers with affine AddRec
SCEV expressions. However, non-AddRecExprs can be now be converted to
affine AddRecExprs using SCEV predicates.
This change tries to add the minimal set of SCEV predicates in order
to enable run-time alias checking.
Reviewers: anemet, mzolotukhin, mkuper, sanjoy, hfinkel
Reviewed By: hfinkel
Subscribers: mssimpso, Ayal, dorit, roman.shirokiy, mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D17080
llvm-svn: 313012
forgetLoop() has pretty bad performance because it goes over
the same instructions over and over again in particular when
nested loop are involved.
The refactoring changes the function to a not-recursive function
and reusing the allocation for data-structures and the Visited
set.
NFCI
Differential Revision: https://reviews.llvm.org/D37659
llvm-svn: 312920
I'm trying to refactor some shared code for integer div/rem,
but I keep having to scroll through fdiv. The FP ops have
nothing in common with the integer ops, so I'm moving FP
below everything else.
While here, improve a couple of comments and fix some formatting.
llvm-svn: 312913
This removes some duplicated code and makes it easier to support signed div/rem
in a similar way if we want to do that. Note that the existing comments were not
accurate - we don't need a constant divisor to simplify; icmp simplification does
more than that. But as the added tests show, it could go even further.
llvm-svn: 312885
It now knows the tricks of both functions.
Also, fix a bug that considered allocas of non-zero address space to be always non null
Differential Revision: https://reviews.llvm.org/D37628
llvm-svn: 312869
This is intended to be a superset of the functionality from D31037 (EarlyCSE) but implemented
as an independent pass, so there's no stretching of scope and feature creep for an existing pass.
I also proposed a weaker version of this for SimplifyCFG in D30910. And I initially had almost
this same functionality as an addition to CGP in the motivating example of PR31028:
https://bugs.llvm.org/show_bug.cgi?id=31028
The advantage of positioning this ahead of SimplifyCFG in the pass pipeline is that it can allow
more flattening. But it needs to be after passes (InstCombine) that could sink a div/rem and
undo the hoisting that is done here.
Decomposing remainder may allow removing some code from the backend (PPC and possibly others).
Differential Revision: https://reviews.llvm.org/D37121
llvm-svn: 312862
Current TargetTransformInfo can support throughput cost model and code size model, but sometimes we also need instruction latency cost model in different optimizations. Hal suggested we need a single public interface to query the different cost of an instruction. So I proposed following interface:
enum TargetCostKind {
TCK_RecipThroughput, ///< Reciprocal throughput.
TCK_Latency, ///< The latency of instruction.
TCK_CodeSize ///< Instruction code size.
};
int getInstructionCost(const Instruction *I, enum TargetCostKind kind) const;
All clients should mainly use this function to query the cost of an instruction, parameter <kind> specifies the desired cost model.
This patch also provides a simple default implementation of getInstructionLatency.
The default getInstructionLatency provides latency numbers for only small number of instruction classes, those latency numbers are only reasonable for modern OOO processors. It can be extended in following ways:
Add more detail into this function.
Add getXXXLatency function and call it from here.
Implement target specific getInstructionLatency function.
Differential Revision: https://reviews.llvm.org/D37170
llvm-svn: 312832
SLP vectorizer supports horizontal reductions for Add/FAdd binary
operations. Patch adds support for horizontal min/max reductions.
Function getReductionCost() is split to getArithmeticReductionCost() for
binary operation reductions and getMinMaxReductionCost() for min/max
reductions.
Patch fixes PR26956.
Differential revision: https://reviews.llvm.org/D27846
llvm-svn: 312791
The current code that handles personality functions when creating a
module summary does not correctly handle the case where a function's
personality function operand refers to the function indirectly
(e.g. via a bitcast). This patch handles such cases by treating
personality function references like any other reference, i.e. by
adding them to the function's reference list. This has the minor side
benefit of allowing personality functions to participate in early
dead stripping.
We do this by calling findRefEdges on the function itself. This way
we also end up handling other function operands (specifically prefix
data and prologue data) for free.
Differential Revision: https://reviews.llvm.org/D37553
llvm-svn: 312698
Remove code that assumed that a nullptr of address space != 0 couldnt alias with a non-null pointer. This is incorrect, since nothing can be concluded about a null pointer in an address space != 0.
This code was written before address spaces were introduced
Differential Revision: https://reviews.llvm.org/D37518
llvm-svn: 312648
This is a preliminary step towards solving the remaining part of PR27145 - IR for isfinite():
https://bugs.llvm.org/show_bug.cgi?id=27145
In order to solve that one more generally, we need to add matching for and/or of fcmp ord/uno
with a constant operand.
But while looking at those patterns, I realized we were missing a canonicalization for nonzero
constants. Rather than limiting to just folds for constants, we're adding a general value
tracking method for this based on an existing DAG helper.
By transforming everything to 0.0, we can simplify the existing code in foldLogicOfFCmps()
and pick up missing vector folds.
Differential Revision: https://reviews.llvm.org/D37427
llvm-svn: 312591
Summary:
When constructing the predicate P1 in ScalarEvolution::createAddRecFromPHIWithCastsImpl() it is possible
for the PHISCEV from which the predicate is constructed to be a SCEVConstant instead of a SCEVAddRec. If
this happens, then the cast<SCEVAddRec>(PHISCEV) in the code will assert.
Such a PHISCEV is possible if either the start value or the accumulator value is a constant value
that not equal to its truncated value, and if the truncated value is zero.
This patch adds tests that demonstrate the cast<> assertion, and fixes this problem by checking
whether the PHISCEV is a constant before constructing the P1 predicate; if it is, then P1 is
equivalent to one of P2 or P3. Additionally, if we know that the start value or accumulator
value are constants then we check whether the P2 and/or P3 predicates are known false at compile
time; if either is, then we bail out of constructing the AddRec.
Reviewers: sanjoy, mkazantsev, silviu.baranga
Reviewed By: mkazantsev
Subscribers: mkazantsev, llvm-commits
Differential Revision: https://reviews.llvm.org/D37265
llvm-svn: 312568
This patch teaches decomposeBitTestICmp to look through truncate instructions on the input to the compare. If a truncate is found it will now return the pre-truncated Value and appropriately extend the APInt mask.
This allows some code to be removed from InstSimplify that was doing this functionality.
This allows InstCombine's bit test combining code to match a pre-truncate Value with the same Value appear with an 'and' on another icmp. Or it allows us to combine a truncate to i16 and a truncate to i8. This also required removing the type check from the beginning of getMaskedTypeForICmpPair, but I believe that's ok because we still have to find two values from the input to each icmp that are equal before we'll do any transformation. So the type check was really just serving as an early out.
There was one user of decomposeBitTestICmp that didn't want to look through truncates, so I've added a flag to prevent that behavior when necessary.
Differential Revision: https://reviews.llvm.org/D37158
llvm-svn: 312382
If a function contains inline asm and the module-level inline asm
contains the definition of a local symbol, prevent the function from
being imported in case the function-level inline asm refers to a
symbol in the module-level inline asm.
Differential Revision: https://reviews.llvm.org/D37370
llvm-svn: 312332
In LLVM IR the following code:
%r = urem <ty> %t, %b
is equivalent to
%q = udiv <ty> %t, %b
%s = mul <ty> nuw %q, %b
%r = sub <ty> nuw %t, %q ; (t / b) * b + (t % b) = t
As UDiv, Mul and Sub are already supported by SCEV, URem can be implemented
with minimal effort using that relation:
%r --> (-%b * (%t /u %b)) + %t
We implement two special cases:
- if %b is 1, the result is always 0
- if %b is a power-of-two, we produce a zext/trunc based expression instead
That is, the following code:
%r = urem i32 %t, 65536
Produces:
%r --> (zext i16 (trunc i32 %a to i16) to i32)
Note that while this helps get a tighter bound on the range analysis and the
known-bits analysis, this exposes some normalization shortcoming of SCEVs:
%div = udim i32 %a, 65536
%mul = mul i32 %div, 65536
%rem = urem i32 %a, 65536
%add = add i32 %mul, %rem
Will usually not be reduced.
llvm-svn: 312329
Summary:
Remove redundant explicit template instantiation.
This was reported by Andrew Kelley building release_50 with gcc7.2.0 on MacOS: duplicate symbol llvm::DominatorTreeBase.
Reviewers: kuhar, andrewrk, davide, hans
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37185
llvm-svn: 311835
Summary:
Add options -print-bfi/-print-bpi that dump block frequency and branch
probability info like -view-block-freq-propagation-dags and
-view-machine-block-freq-propagation-dags do but in text.
This is useful when the graph is very large and complex (the dot command
crashes, lines/edges too close to tell apart, hard to navigate without textual
search) or simply when text is preferred.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37165
llvm-svn: 311822
Change the early exit condition from Cost > Threshold to Cost >= Threshold
because the inline condition is Cost < Threshold.
Differential Revision: https://reviews.llvm.org/D37087
llvm-svn: 311791
Summary: We need to have accurate-sample-profile in function attribute so that it works with LTO.
Reviewers: davidxl, rsmith
Reviewed By: davidxl
Subscribers: sanjoy, mehdi_amini, javed.absar, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D37113
llvm-svn: 311706
Summary:
We add the precise cache sizes and associativity for the following Intel
architectures:
- Penry
- Nehalem
- Westmere
- Sandy Bridge
- Ivy Bridge
- Haswell
- Broadwell
- Skylake
- Kabylake
Polly uses since several months a performance model for BLAS computations that
derives optimal cache and register tile sizes from cache and latency
information (based on ideas from "Analytical Modeling Is Enough for High-Performance BLIS", by Tze Meng Low published at TOMS 2016).
While bootstrapping this model, these target values have been kept in Polly.
However, as our implementation is now rather mature, it seems time to teach
LLVM itself about cache sizes.
Interestingly, L1 and L2 cache sizes are pretty constant across
micro-architectures, hence a set of architecture specific default values
seems like a good start. They can be expanded to more target specific values,
in case certain newer architectures require different values. For now a set
of Intel architectures are provided.
Just as a little teaser, for a simple gemm kernel this model allows us to
improve performance from 1.2s to 0.27s. For gemm kernels with less optimal
memory layouts even larger speedups can be reported.
Reviewers: Meinersbur, bollu, singam-sanjay, hfinkel, gareevroman, fhahn, sebpop, efriedma, asb
Reviewed By: fhahn, asb
Subscribers: lsaba, asb, pollydev, llvm-commits
Differential Revision: https://reviews.llvm.org/D37051
llvm-svn: 311647
Current PGO only annotates the edge weight for branch and switch instructions
with profile counts. We should also annotate the indirectbr instruction as
all the information is there. This patch enables the annotating for indirectbr
instructions. Also uses this annotation in branch probability analysis.
Differential Revision: https://reviews.llvm.org/D37074
llvm-svn: 311604
This is PR33245.
Case I am fixing is next:
Imagine we have 2 BC files, one defines and uses personality routine,
second has only declaration and also uses it.
Previously algorithm computing dead symbols (llvm::computeDeadSymbols) did
not know about personality routines and leaved them dead even if function that
has routine was live.
As a result thinLTOInternalizeAndPromoteGUID() method changed binding for
such symbol to local. Later when LLD tried to link these objects it failed
because one object had undefined global symbol for routine and second
object contained local definition instead of global.
Patch set the live root flag on the corresponding FunctionSummary
for personality routines when we build the per-module summaries
during the compile step.
Differential revision: https://reviews.llvm.org/D36834
llvm-svn: 311432
The function does an equality check later to terminate the recursion, but that won't work if its starts out too high. Similar assert already exists in computeKnownBits.
llvm-svn: 311400
Currently, the inline cost model will bail once the inline cost exceeds the
inline threshold in order to avoid unnecessary compile-time. However, when
debugging it is useful to compute the full cost, so this command line option
is added to override the default behavior.
I took over this work from Chad Rosier (mcrosier@codeaurora.org).
Differential Revision: https://reviews.llvm.org/D35850
llvm-svn: 311371
This adds support non-canonical compare predicates. InstSimplify can't rely on canonicalization to have occurred.
Differential Revision: https://reviews.llvm.org/D36646
llvm-svn: 310893
This recommits r310869, with the moved files and no extra changes.
Original commit message:
This addresses a fixme in InstSimplify about using decomposeBitTest. This also fixes InstSimplify to handle ugt and ult compares too.
I've modified the interface a little to return only the APInt version of the mask that InstSimplify needs. InstCombine now has a small wrapper routine to create a Constant out of it. I've also dropped the returning of 0 since InstSimplify doesn't need that. So InstCombine creates a zero constant itself.
I also had to make decomposeBitTest support vectors since InstSimplify needs that.
As InstSimplify can't use something from the Transforms library, I've moved the CmpInstAnalysis code to the Analysis library.
Differential Revision: https://reviews.llvm.org/D36593
llvm-svn: 310889
localized to the code that uses those analyses.
Technically, this can change behavior as we no longer require the
existence of the ProfileSummaryInfo analysis to use local profile
information via BFI. We didn't actually require the PSI to have an
interesting profile though, so this only really impacts the behavior in
non-default pass pipelines.
IMO, this makes it substantially less surprising how everything works --
before an analysis that wasn't actually used had to exist to trigger
*any* profile aware inlining. I think the new organization makes it more
obvious where various checks for profile signals happen.
Differential Revision: https://reviews.llvm.org/D36710
llvm-svn: 310888
Failed to add the two files that moved. And then added an extra change I didn't mean to while trying to fix that. Reverting everything.
llvm-svn: 310873
This addresses a fixme in InstSimplify about using decomposeBitTest. This also fixes InstSimplify to handle ugt and ult compares too.
I've modified the interface a little to return only the APInt version of the mask that InstSimplify needs. InstCombine now has a small wrapper routine to create a Constant out of it. I've also dropped the returning of 0 since InstSimplify doesn't need that. So InstCombine creates a zero constant itself.
I also had to make decomposeBitTest support vectors since InstSimplify needs that.
As InstSimplify can't use something from the Transforms library, I've moved the CmpInstAnalysis code to the Analysis library.
Differential Revision: https://reviews.llvm.org/D36593
llvm-svn: 310869
ValueTracking has to strike a balance when attempting to propagate information
backwards from assumes, because if the information is trivially propagated
backwards, it can appear to LLVM that the assumption is known to be true, and
therefore can be removed.
This is sound (because an assumption has no semantic effect except for causing
UB), but prevents the assume from allowing further optimizations.
The isEphemeralValueOf check exists to try and prevent this issue by not
removing the source of an assumption. This tries to make it a little bit more
general to handle the case of side-effectful instructions, such as in
%0 = call i1 @get_val()
%1 = xor i1 %0, true
call void @llvm.assume(i1 %1)
Patch by Ariel Ben-Yehuda, thanks!
Differential Revision: https://reviews.llvm.org/D36590
llvm-svn: 310859
causing compile time issues.
Moreover, the patch *deleted* the flag in addition to changing the
default, and links to a code review that doesn't even discuss the flag
and just has an update to a Clang test case.
I've followed up on the commit thread to ask for numbers on compile time
at this point, leaving the flag in place until things stabilize, and
pointing at specific code that seems to exhibit excessive compile time
with this patch.
Original commit message for r310583:
"""
[ValueTracking] Enabling ValueTracking patch by default (recommit). Part 2.
The original patch was an improvement to IR ValueTracking on
non-negative integers. It has been checked in to trunk (D18777,
r284022). But was disabled by default due to performance regressions.
Perf impact has improved. The patch would be enabled by default.
""""
llvm-svn: 310816
printing techniques with a DEBUG_TYPE controlling them.
It was a mistake to start re-purposing the pass manager `DebugLogging`
variable for generic debug printing -- those logs are intended to be
very minimal and primarily used for testing. More detailed and
comprehensive logging doesn't make sense there (it would only make for
brittle tests).
Moreover, we kept forgetting to propagate the `DebugLogging` variable to
various places making it also ineffective and/or unavailable. Switching
to `DEBUG_TYPE` makes this a non-issue.
llvm-svn: 310695
The original patch was an improvement to IR ValueTracking on non-negative
integers. It has been checked in to trunk (D18777, r284022). But was disabled by
default due to performance regressions.
Perf impact has improved. The patch would be enabled by default.
Reviewers: reames, hfinkel
Differential Revision: https://reviews.llvm.org/D34101
Patch by: Olga Chupina <olga.chupina@intel.com>
llvm-svn: 310583
of the returned value.
Checking the returned value from inside of a scoped exit isn't actually
valid. It happens to work when NRVO fires and the stars align, which
they reliably do with Clang but don't, for example, on MSVC builds.
llvm-svn: 310547
Summary:
Avoid checking each operand and calling getValueFromCondition() before calling
constantFoldUser() when the instruction type isn't supported by
constantFoldUser().
This fixes a large compile time regression in an internal build.
Reviewers: sanjoy
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36552
llvm-svn: 310545
must-alias(p, sz_p, p, sz_q) irrespective of access sizes sz_p, sz_q
As discussed a couple of weeks ago on the ML.
This makes the behavior consistent with that of BasicAA.
AA clients already check the obj size themselves and may not require the
obj size to match exactly the access size (e.g., in case of store forwarding)
llvm-svn: 310495
The recently improved support for `icmp` in ValueTracking
(r307304) exposes the fact that `isImplied` condition doesn't
really bail out if we hit the recursion limit (and calls
`computeKnownBits` which increases the depth and asserts).
Differential Revision: https://reviews.llvm.org/D36512
llvm-svn: 310481
isLegalAddressingMode() has recently gained the extra optional Instruction*
parameter, and therefore it can now do the job that previously only
isFoldableMemAccess() could do.
The SystemZ implementation of isLegalAddressingMode() has gained the
functionality of checking for offsets, which used to be done with
isFoldableMemAccess().
The isFoldableMemAccess() hook has been removed everywhere.
Review: Quentin Colombet, Ulrich Weigand
https://reviews.llvm.org/D35933
llvm-svn: 310463
to Nodes when removing ref edges from a RefSCC.
This map based association turns out to be pretty expensive for large
RefSCCs and pointless as we already have embedded data members inside
nodes that we use to track the DFS state. We can reuse one of those and
the map becomes unnecessary.
This also fuses the update of those numbers into the scan across the
pending stack of nodes so that we don't walk the nodes twice during the
DFS.
With this I expect the new PM to be faster than the old PM for the test
case I have been optimizing. That said, it also seems simpler and more
direct in many ways. The side storage was always pretty awkward.
The last remaining hot-spot in the profile of the LCG once this is done
will be the edge iterator walk in the DFS. I'll take a look at improving
that next.
llvm-svn: 310456
that RefSCC still connected.
This is common and can be handled much more efficiently. As soon as we
know we've covered every node in the RefSCC with the DFS, we can simply
reset our state and return. This avoids numerous data structure updates
and other complexity.
On top of other changes, this appears to get new PM back to parity with
the old PM for a large protocol buffer message source code. The dense
map updates are very hot in this function.
llvm-svn: 310451
limited batch updates.
Specifically, allow removing multiple reference edges starting from
a common source node. There are a few constraints that play into
supporting this form of batching:
1) The way updates occur during the CGSCC walk, about the most we can
functionally batch together are those with a common source node. This
also makes the batching simpler to implement, so it seems
a worthwhile restriction.
2) The far and away hottest function for large C++ files I measured
(generated code for protocol buffers) showed a huge amount of time
was spent removing ref edges specifically, so it seems worth focusing
there.
3) The algorithm for removing ref edges is very amenable to this
restricted batching. There are just both API and implementation
special casing for the non-batch case that gets in the way. Once
removed, supporting batches is nearly trivial.
This does modify the API in an interesting way -- now, we only preserve
the target RefSCC when the RefSCC structure is unchanged. In the face of
any splits, we create brand new RefSCC objects. However, all of the
users were OK with it that I could find. Only the unittest needed
interesting updates here.
How much does batching these updates help? I instrumented the compiler
when run over a very large generated source file for a protocol buffer
and found that the majority of updates are intrinsically updating one
function at a time. However, nearly 40% of the total ref edges removed
are removed as part of a batch of removals greater than one, so these
are the cases batching can help with.
When compiling the IR for this file with 'opt' and 'O3', this patch
reduces the total time by 8-9%.
Differential Revision: https://reviews.llvm.org/D36352
llvm-svn: 310450
Summary: Currently, ICP checks the count against a fixed value to see if it is hot enough to be promoted. This does not work for SamplePGO because sampled count may be much smaller. This patch uses PSI to check if the count is hot enough to be promoted.
Reviewers: davidxl, tejohnson, eraman
Reviewed By: davidxl
Subscribers: sanjoy, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D36341
llvm-svn: 310416
I want to reuse this code in SimplifyDemandedBits handling of Add/Sub. This will make that easier.
Wonder if we should use it in SelectionDAG's computeKnownBits too.
Differential Revision: https://reviews.llvm.org/D36433
llvm-svn: 310378
This was just a bad oversight on my part. The code in question should
never have worked without this fix. But it turns out, there are
relatively few places that involve libfunctions that participate in
a single SCC, and unless they do, this happens to not matter.
The effect of not having this correct is that each time through this
routine, the edge from write_wrapper to write was toggled between a call
edge and a ref edge. First time through, it becomes a demoted call edge
and is turned into a ref edge. Next time it is a promoted call edge from
a ref edge. On, and on it goes forever.
I've added the asserts which should have always been here to catch silly
mistakes like this in the future as well as a test case that will
actually infloop without the fix.
The other (much scarier) infinite-inlining issue I think didn't actually
occur in practice, and I simply misdiagnosed this minor issue as that
much more scary issue. The other issue *is* still a real issue, but I'm
somewhat relieved that so far it hasn't happened in real-world code
yet...
llvm-svn: 310342
After the previous series of patches, this is now trivial and deletes
a pretty astonishing amount of complexity. This has been a long time
coming, as the move toward a PO sequence of RefSCCs started eroding the
underlying use cases for this half of the data structure.
Among the biggest advantages here is that now there aren't two
independent data structures that need to stay in sync.
Some of my profiling has also indicated that updating the parent sets
was among the most expensive parts of the lazy call graph. Eliminating
it whole sale is likely to be a nice win in terms of compile time.
Last but not least, I had discussed with some folks previously keeping
it around for asserts and other correctness checking, but once the
fundamentals of the parent and child checking were implemented without
the parent sets their value in correctness checking was tiny and no
where near worth the cost of the complexity required to keep everything
up-to-date.
llvm-svn: 310171
isDescendantOf methods on RefSCCs in terms of the forward edges rather
than the parent sets.
This is technically slower, but probably not interestingly slower, and
all of these routines were already so expensive that they're guarded
behind both !NDEBUG and EXPENSIVE_CHECKS.
This removes another non-critical usage of parent sets.
I've also added some comments to try and help clarify to any potential
users the costs of these routines. They're mostly useful for debugging,
asserts, or other queries.
llvm-svn: 310170
walk over the parent set.
When removing a single function from the call graph, we previously would
walk the entire RefSCC's parent set and then walk every outgoing edge
just to find the ones to remove. In addition to this being quite high
complexity in theory, it is also the last fundamental use of the parent
sets.
With this change, when we remove a function we transform the node
containing it to be recognizably "dead" and then teach the edge
iterators to recognize edges to such nodes and skip them the same way
they skip null edges.
We can't move fully to using "dead" nodes -- when disconnecting two live
nodes we need to null out the edge. But the complexity this adds to the
edge sequence isn't too bad and the simplification of lazily handling
this seems like a significant win.
llvm-svn: 310169
The definition of 'false' here was already pretty vague and debatable,
and I'm about to add another potential 'false' that would actually make
much more sense in a bool operator. Especially given how rarely this is
used, a nicely named method seems better.
llvm-svn: 310165
structures, actually null out the graph pointers as well. We won't ever
update these, and we certainly shouldn't be calling any methods on them,
so it seems good to defensively nuke them.
llvm-svn: 310164
pointers in node objects, just walk the map from function to node.
It doesn't have stable ordering, but works just as well and is much
simpler. We don't need ordering when just updating internal pointers.
llvm-svn: 310163
merging RefSCCs.
The logic to directly use the reference edges is simpler and not
substantially slower (despite the comments to the contrary) because this
is not actually an especially hot part of LCG in practice.
llvm-svn: 310161
Pushes the sext onto the operands of a Sub if NSW is present.
Also adds support for propagating the nowrap flags of the
llvm.ssub.with.overflow intrinsic during analysis.
Differential Revision: https://reviews.llvm.org/D35256
llvm-svn: 310117
Summary: We originally set the hotness threshold as 99.9% to be consistent with gcc FDO. But because the inline heuristic is different between 2 compilers: llvm uses bottom-up algorithm while gcc uses priority based. The LLVM algorithm tends to inline too much early that prevents hot callsites from further inlined into its caller. Due to this restriction, we think it is reasonable to lower the hotness threshold to give priority to those that are really hot. Our experiments show that this change would improve performance on large applications. Note that the inline heuristic has great room for further tuning. Once the inline heuristics are refined, we could adjust this threshold to allow inlining for less hot callsites.
Reviewers: davidxl, tejohnson, eraman
Reviewed By: tejohnson
Subscribers: sanjoy, llvm-commits
Differential Revision: https://reviews.llvm.org/D36317
llvm-svn: 310065
Adds function attributes to index: ReadNone, ReadOnly, NoRecurse, NoAlias. This attributes will be used for future ThinLTO optimizations that will propagate function attributes across modules.
llvm-svn: 310061
Summary:
This commit allows matchSelectPattern to recognize clamp of float
arguments in the presence of FMF the same way as already done for
integers.
This case is a little different though. With integers, given the
min/max pattern is recognized, DAGBuilder starts selecting MIN/MAX
"automatically". That is not the case for float, because for them only
full FMINNAN/FMINNUM/FMAXNAN/FMAXNUM ISD nodes exist and they do care
about NaNs. On the other hand, some backends (e.g. X86) have only
FMIN/FMAX nodes that do not care about NaNS and the former NAN/NUM
nodes are illegal thus selection is not happening. So I decided to do
such kind of transformation in IR (InstCombiner) instead of
complicating the logic in the backend.
Reviewers: spatel, jmolloy, majnemer, efriedma, craig.topper
Reviewed By: efriedma
Subscribers: hiraditya, javed.absar, n.bozhenov, llvm-commits
Patch by Andrei Elovikov <andrei.elovikov@intel.com>
Differential Revision: https://reviews.llvm.org/D33186
llvm-svn: 310054
Summary:
Detect when the working set size of a profiled application is huge,
by comparing the number of counts required to reach the hot percentile
in the profile summary to a large threshold*.
When the working set size is determined to be huge, disable peeling
to avoid bloating the working set further.
*Note that the selected threshold (15K) is significantly larger than the
largest working set value in SPEC cpu2006 (which is gcc at around 11K).
Reviewers: davidxl
Subscribers: mehdi_amini, mzolotukhin, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D36288
llvm-svn: 310005
Summary:
This increases the inlining threshold for hot callsites. Hotness is
defined in terms of block frequency of the callsite relative to the
caller's entry block's frequency. Since this requires BFI in the
inliner, this only affects the new PM pipeline. This is enabled by
default at -O3.
This improves the performance of some internal benchmarks. Notably, an
internal benchmark for Gipfeli compression
(https://github.com/google/gipfeli) improves by ~7%. Povray in SPEC2006
improves by ~2.5%. I am running more experiments and will update the
thread if other benchmarks show improvement/regression.
In terms of text size, LLVM test-suite shows an 1.22% text size
increase. Diving into the results, 13 of the benchmarks in the
test-suite increases by > 10%. Most of these are small, but
Adobe-C++/loop_unroll (17.6% increases) and tramp3d(20.7% size increase)
have >250K text size. On a large application, the text size increases by
2%
Reviewers: chandlerc, davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36199
llvm-svn: 309994
Summary:
(This is a second attempt as https://reviews.llvm.org/D34822 was reverted.)
LazyValueInfo currently computes the constant value of the switch condition through case edges, which allows the constant value to be propagated through the case edges.
But we have seen a case where a zero-extended value of the switch condition is used past case edges for which the constant propagation doesn't occur.
This patch adds a small logic to handle such a case in getEdgeValueLocal().
This is motivated by the Python 2.7 eval loop in PyEval_EvalFrameEx() where the lack of the constant propagation causes longer live ranges and more spill code than necessary.
With this patch, we see that the code size of PyEval_EvalFrameEx() decreases by ~5.4% and a performance test improves by ~4.6%.
Reviewers: sanjoy
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36247
llvm-svn: 309986
Summary: For SamplePGO, we already record the callsite count in the call instruction itself. So we do not want to use BFI to get profile count as it is less accurate.
Reviewers: tejohnson, davidxl, eraman
Reviewed By: eraman
Subscribers: sanjoy, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D36025
llvm-svn: 309964
The patch rL309080 was reverted because it did not clean up the cache on "forgetValue"
method call. This patch re-enables this change, adds the missing check and introduces
two new unit tests that make sure that the cache is cleaned properly.
Differential Revision: https://reviews.llvm.org/D36087
llvm-svn: 309925
This patch is update after the first patch (https://reviews.llvm.org/rL309651) based on the post-commit comments.
Stack coloring pass need to maintain AliasAnalysis information when merging stack slots of different types.
Actually, there is a FIXME comment in StackColoring.cpp
// FIXME: In order to enable the use of TBAA when using AA in CodeGen,
// we'll also need to update the TBAA nodes in MMOs with values
// derived from the merged allocas.
But, TBAA has been already enabled in CodeGen without fixing this pass.
The incorrect TBAA metadata results in recent failures in bootstrap test on ppc64le (PR33928) by allowing unsafe instruction scheduling.
Although we observed the problem on ppc64le, this is a platform neutral issue.
This patch makes the stack coloring pass maintains AliasAnalysis information when merging multiple stack slots.
This patch fixes PR33928.
llvm-svn: 309849
If SCEV can prove that the backedge taken count for a loop is zero, it does not
need to "understand" a recursive PHI to compute its exiting value.
This should fix PR33885.
llvm-svn: 309758
This causes assertion failures in (a somewhat old version of) SpiderMonkey.
I have already forwarded reproduction instructions to the patch author.
llvm-svn: 309659
Stack coloring pass need to maintain AliasAnalysis information when merging stack slots of different types.
Actually, there is a FIXME comment in StackColoring.cpp
// FIXME: In order to enable the use of TBAA when using AA in CodeGen,
// we'll also need to update the TBAA nodes in MMOs with values
// derived from the merged allocas.
But, TBAA has been already enabled in CodeGen without fixing this pass.
The incorrect TBAA metadata results in recent failures in bootstrap test on ppc64le (PR33928) by allowing unsafe instruction scheduling.
Although we observed the problem on ppc64le, this is a platform neutral issue.
This patch makes the stack coloring pass maintains AliasAnalysis information when merging multiple stack slots.
llvm-svn: 309651
Summary:
Adding part of the changes in D30369 (needed to make progress):
Current patch updates AliasAnalysis and MemoryLocation, but does _not_ clean up MemorySSA.
Original summary from D30369, by dberlin:
Currently, we have instructions which affect memory but have no memory
location. If you call, for example, MemoryLocation::get on a fence,
it asserts. This means things specifically have to avoid that. It
also means we end up with a copy of each API, one taking a memory
location, one not.
This starts to fix that.
We add MemoryLocation::getOrNone as a new call, and reimplement the
old asserting version in terms of it.
We make MemoryLocation optional in the (Instruction, MemoryLocation)
version of getModRefInfo, and kill the old one argument version in
favor of passing None (it had one caller). Now both can handle fences
because you can just use MemoryLocation::getOrNone on an instruction
and it will return a correct answer.
We use all this to clean up part of MemorySSA that had to handle this difference.
Note that literally every actual getModRefInfo interface we have could be made private and replaced with:
getModRefInfo(Instruction, Optional<MemoryLocation>)
and
getModRefInfo(Instruction, Optional<MemoryLocation>, Instruction, Optional<MemoryLocation>)
and delegating to the right ones, if we wanted to.
I have not attempted to do this yet.
Reviewers: dberlin, davide, dblaikie
Subscribers: sanjoy, hfinkel, chandlerc, llvm-commits
Differential Revision: https://reviews.llvm.org/D35441
llvm-svn: 309641
Summary:
Inlining threshold is increased by application of bonuses when the
callee has a single reachable basic block or is rich in vector
instructions. Similarly, inlining cost is reduced by applying a large
bonus when the last call to a static function is considered for
inlining. This patch disables the application of these bonuses when the
callsite or the callee is cold. The intention here is to prevent a large
cold callsite from being inlined to a non-cold caller that could prevent
the caller from being inlined. This is especially important when the
cold callsite is a last call to a static since the associated bonus is
very high.
Reviewers: chandlerc, davidxl
Subscribers: danielcdh, llvm-commits
Differential Revision: https://reviews.llvm.org/D35823
llvm-svn: 309441
Summary:
LazyValueInfo currently computes the constant value of the switch condition through case edges, which allows the constant value to be propagated through the case edges.
But we have seen a case where a zero-extended value of the switch condition is used past case edges for which the constant propagation doesn't occur.
This patch adds a small logic to handle such a case in getEdgeValueLocal().
This is motivated by the Python 2.7 eval loop in PyEval_EvalFrameEx() where the lack of the constant propagation causes longer live ranges and more spill code than necessary.
With this patch, we see that the code size of PyEval_EvalFrameEx() decreases by ~5.4% and a performance test improves by ~4.6%.
Reviewers: wmi, dberlin, sanjoy
Reviewed By: sanjoy
Subscribers: davide, davidxl, llvm-commits
Differential Revision: https://reviews.llvm.org/D34822
llvm-svn: 309415
This patch reworks the function that searches constants in Add and Mul SCEV expression
chains so that now it does not visit a node more than once, and also renames this function
for better correspondence between its implementation and semantics.
Differential Revision: https://reviews.llvm.org/D35931
llvm-svn: 309367
This reverts commit r309080. The patch needs to clear out the
ScalarEvolution::ExitLimits cache in forgetMemoizedResults.
I've replied on the commit thread for the patch with more details.
llvm-svn: 309357
Summary: In performance tuning, we see performance benefits when enlarge the maximum num promotion targets to 3. This is safe as soon as we have total percentage threshold properly setup (https://reviews.llvm.org/D35962)
Reviewers: davidxl, tejohnson
Reviewed By: tejohnson
Subscribers: llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D35966
llvm-svn: 309346
Summary: In the current implementation, isPromotionProfitable only checks if the call count to a direct target is no less than a certain percentage threshold of the remaining call counts that have not been promoted. This causes code size problems when the target count is small but greater than a large portion of remaining counts. E.g. target1 takes 99.9%, while target2 takes 0.1%. Both targets will be promoted and inlined, makes the function size too large, which potentially prevents it from further inlining into its callers. This patch adds another percentage threshold against the total indirect call count. If the target count needs to be no less than both thresholds in order to be promoted speculatively.
Reviewers: davidxl, tejohnson
Reviewed By: tejohnson
Subscribers: sanjoy, llvm-commits
Differential Revision: https://reviews.llvm.org/D35962
llvm-svn: 309345
Currently CallAnalyzer::isGEPFree uses TTI::getGEPCost to check if GEP is free.
TTI::getGEPCost cannot handle cases when GEPs participate in Def-Use dependencies
(see https://reviews.llvm.org/D31186 for example).
There is TTI::getUserCost which can calculate the cost more accurately by
taking dependencies into account.
Differential Revision: https://reviews.llvm.org/D33685
llvm-svn: 309268
This patch adds a cache for computeExitLimit to save compilation time. A lot of examples of
tests that take extensive time to compile are attached to the bug 33494.
Differential Revision: https://reviews.llvm.org/D35827
llvm-svn: 309080
`SCEVUnknown::allUsesReplacedWith` does not need to call `forgetMemoizedResults`
since RAUW does a value-equivalent replacement by assumption. If this
assumption was false then the later setValPtr(New) call would be incorrect too.
This is a non-trivial performance optimization for functions with a large number
of loops since `forgetMemoizedResults` walks all loop backedge taken counts to
see if any of them use the SCEVUnknown being RAUWed. However, this improvement
is difficult to demonstrate without checking in an excessively large IR file.
llvm-svn: 309072
When SCEV calculates product of two SCEVAddRecs from the same loop, it
tries to combine them into one big AddRecExpr. If the sizes of the initial
SCEVs were `S1` and `S2`, the size of their product is `S1 + S2 - 1`, and every
operand of the resulting SCEV is combined from operands of initial SCEV and
has much higher complexity than they have.
As result, if we try to calculate something like:
%x1 = {a,+,b}
%x2 = mul i32 %x1, %x1
%x3 = mul i32 %x2, %x1
%x4 = mul i32 %x3, %x2
...
The size of such SCEVs grows as `2^N`, and the arguments
become more and more complex as we go forth. This leads
to long compilation and huge memory consumption.
This patch sets a limit after which we don't try to combine two
`SCEVAddRecExpr`s into one. By default, max allowed size of the
resulting AddRecExpr is set to 16.
Differential Revision: https://reviews.llvm.org/D35664
llvm-svn: 308847
This patch makes LSR generate better code for SystemZ in the cases of memory
intrinsics, Load->Store pairs or comparison of immediate with memory.
In order to achieve this, the following common code changes were made:
* New TTI hook: LSRWithInstrQueries(), which defaults to false. Controls if
LSR should do instruction-based addressing evaluations by calling
isLegalAddressingMode() with the Instruction pointers.
* In LoopStrengthReduce: handle address operands of memset, memmove and memcpy
as address uses, and call isFoldableMemAccessOffset() for any LSRUse::Address,
not just loads or stores.
SystemZ changes:
* isLSRCostLess() implemented with Insns first, and without ImmCost.
* New function supportedAddressingMode() that is a helper for TTI methods
looking at Instructions passed via pointers.
Review: Ulrich Weigand, Quentin Colombet
https://reviews.llvm.org/D35262https://reviews.llvm.org/D35049
llvm-svn: 308729
functions.
In the prior commit, we provide ordering to the LCG between functions
and library function definitions that they might begin to call through
transformations. But we still would delete these library functions from
the call graph if they became dead during inlining.
While this immediately crashed, it also exposed a loss of information.
We shouldn't remove definitions of library functions that can still
usefully participate in the LCG-powered CGSCC optimization process. If
new call edges are formed, we want to have definitions to be called.
We can still remove these functions if truly dead using global-dce, etc,
but removing them during the CGSCC walk is premature.
This fixes a crash in the new PM when optimizing some unusual libraries
that end up with "internal" lib functions such as the code in the "R"
language's libraries.
llvm-svn: 308417
using runtime checks
Extend the SCEVPredicateRewriter to work a bit harder when it encounters an
UnknownSCEV for a Phi node; Try to build an AddRecurrence also for Phi nodes
whose update chain involves casts that can be ignored under the proper runtime
overflow test. This is one step towards addressing PR30654.
Differential revision: http://reviews.llvm.org/D30041
llvm-svn: 308299
Summary:
Previously, we counted TotalMemInst by reading certain instruction counters before and after calling visit and then finding the difference. But that wouldn't be thread safe if this same pass was being ran on multiple threads.
This list of "memory instructions" doesn't make sense to me as it includes call/invoke and is missing atomics.
This patch removes the counter all together.
Reviewers: hfinkel, chandlerc, davide
Reviewed By: davide
Subscribers: davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D33608
llvm-svn: 308260
function to every defined function known to LLVM as a library function.
LLVM can introduce calls to these functions either by replacing other
library calls or by recognizing patterns (such as memset_pattern or
vector math patterns) and replacing those with calls. When these library
functions are actually defined in the module, we need to have reference
edges to them initially so that we visit them during the CGSCC walk in
the right order and can effectively rebuild the call graph afterward.
This was discovered when building code with Fortify enabled as that is
a common case of both inline definitions of library calls and
simplifications of code into calling them.
This can in extreme cases of LTO-ing with libc introduce *many* more
reference edges. I discussed a bunch of different options with folks but
all of them are unsatisfying. They either make the graph operations
substantially more complex even when there are *no* defined libfuncs, or
they introduce some other complexity into the callgraph. So this patch
goes with the simplest possible solution of actual synthetic reference
edges. If this proves to be a memory problem, I'm happy to implement one
of the clever techniques to save memory here.
llvm-svn: 308088
Now, getUserCost() only checks the src and dst types of EXT to decide it is free
or not. This change first checks the types, then calls isExtFreeImpl(), and
check if EXT can form ExtLoad at last. Currently, only AArch64 has customized
implementation of isExtFreeImpl() to check if EXT can be folded into its use.
Differential Revision: https://reviews.llvm.org/D34458
llvm-svn: 308076
Summary:
DominatorTreeBase used to have IsPostDominators (bool) member to indicate if the tree is a dominator or a postdominator tree. This made it possible to switch between the two 'modes' at runtime, but it isn't used in practice anywhere.
This patch makes IsPostDominator a template argument. This way, it is easier to switch between different algorithms at compile-time based on this argument and design external utilities around it. It also makes it impossible to incidentally assign a postdominator tree to a dominator tree (and vice versa), and to further simplify template code in GenericDominatorTreeConstruction.
Reviewers: dberlin, sanjoy, davide, grosser
Reviewed By: dberlin
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D35315
llvm-svn: 308040
I used the wrong variable to update. This was even covered by a unittest
I wrote, and the comments for the unittest were correct (if confusing)
but the test itself just matched the buggy behavior. =[
llvm-svn: 307764
Summary:
Solves PR33689.
If the pointer size is less than the size of the type used for the array
size in an alloca (the <ty> type below) then we could trigger the assert in
the PR. In that example we have pointer size i16 and <ty> is i32.
<result> = alloca [inalloca] <type> [, <ty> <NumElements>] [, align <alignment>]
Handle the situation by allowing truncation as well as zero extension in
ObjectSizeOffsetVisitor::visitAllocaInst().
Also, we now detect overflow in visitAllocaInst(), similar to how it was
already done in visitCallSite().
Reviewers: craig.topper, rnk, george.burgess.iv
Reviewed By: george.burgess.iv
Subscribers: davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D35003
llvm-svn: 307754
invalidation of analyses when merging SCCs.
While I've added a bunch of testing of this, it takes something much
more like the inliner to really trigger this as you need to have
partially-analyzed SCCs with updates at just the right time. So I've
added a direct test for this using the inliner and verifying the
domtree. Without the changes here, this test ends up finding a stale
dominator tree.
However, to handle this properly, we need to invalidate analyses
*before* merging the SCCs. After talking to Philip and Sanjoy about this
they convinced me this was the right approach. To do this, we need
a callback mechanism when merging SCCs so we can observe the cycle that
will be merged before the merge happens. This API update ended up being
surprisingly easy.
With this commit, the new PM passes the test-suite again. It hadn't
since MemorySSA was enabled for EarlyCSE as that also will find this bug
very quickly.
llvm-svn: 307498
dependencies between analyses.
This uncovers even more issues with the proxies and the splitting apart
of SCCs which are fixed in this patch. I discovered this while trying to
add more rigorous testing for a change I'm making to the call graph
update invalidation logic.
llvm-svn: 307497
the invalidation propagation logic from an SCC to a Function.
I wrote the infrastructure to test this but didn't actually use it in
the unit test where it was designed to be used. =[ My bad. Once
I actually added it to the test case I discovered that it also hadn't
been properly implemented, so I've implemented it. The logic in the FAM
proxy for an SCC pass to propagate invalidation follows the same ideas
as the FAM proxy for a Module pass, but the implementation is a bit
different to reflect the fact that it is forwarding just for an SCC.
However, implementing this correctly uncovered a surprising "bug" (it
was conservatively correct but relatively very expensive) in how we
handle invalidation when splitting one SCC into multiple SCCs. We did an
eager invalidation when in reality we should be deferring invaliadtion
for the *current* SCC to the CGSCC pass manager and just invaliating the
newly constructed SCCs. Otherwise we end up invalidating too much too
soon. This was exposed by the inliner test case that I've updated. Now,
we invalidate *just* the split off '(test1_f)' SCC when doing the CG
update, and then the inliner finishes and invalidates the '(test1_g,
test1_h)' SCC's analyses. The first few attempts at fixing this hit
still more bugs, but all of those are covered by existing tests. For
example, the inliner should also preserve the FAM proxy to avoid
unnecesasry invalidation, and this is safe because the CG update
routines it uses handle any necessary adjustments to the FAM proxy.
Finally, the unittests for the CGSCC pass manager needed a bunch of
updates where we weren't correctly preserving the FAM proxy because it
hadn't been fully implemented and failing to preserve it didn't matter.
Note that this doesn't yet fix the current crasher due to MemSSA finding
a stale dominator tree, but without this the fix to that crasher doesn't
really make any sense when testing because it relies on the proxy
behavior.
llvm-svn: 307487
Summary: For interative sample-pgo, if a hot call site is inlined in the profiling binary, we should inline it in before profile annotation in the backend. Before that, the compile phase first collects all GUIDs that needs to be imported and creates virtual "hot" call edge in the summary. However, "hot" is not good enough to guarantee the callsites get inlined. This patch introduces "critical" call edge, and assign much higher importing threshold for those edges.
Reviewers: tejohnson
Reviewed By: tejohnson
Subscribers: sanjoy, mehdi_amini, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D35096
llvm-svn: 307439
Prior to this commit both of the added test cases were passing. However, in the
latter case (test7) we were doing a lot more work to arrive at the same answer
(i.e., we were using isImpliedCondMatchingOperands() to determine the
implication.).
llvm-svn: 307400
Adds loop expansions for known-size and unknown-sized memcpy calls, allowing the
target to provide the operand types through TTI callbacks. The default values
for the TTI callbacks use int8 operand types and matches the existing behaviour
if they aren't overridden by the target.
Differential revision: https://reviews.llvm.org/D32536
llvm-svn: 307346
This patch adds support for handling some forms of ands and ors in
ValueTracking's isImpliedCondition API.
PR33611
https://reviews.llvm.org/D34901
llvm-svn: 307304
Going through the Constant methods requires redetermining that the Constant is a ConstantInt and then calling isZero/isOne/isMinusOne.
llvm-svn: 307292
The dependence analysis was returning incorrect information when using the GEPs
to compute dependences. The analysis uses the GEP indices under certain
conditions, but was doing it incorrectly when the base objects of the GEP are
aliases, but pointing to different locations in the same array.
This patch adds another check for the base objects. If the base pointer SCEVs
are not equal, then the dependence analysis should fall back on the path
that uses the whole SCEV for the dependence check. This fixes PR33567.
Differential Revision: https://reviews.llvm.org/D34702
llvm-svn: 307203
This reverts commit r306907 and reapplies the patches in the title.
The patches used to make one of the
CodeGen/ARM/2011-02-07-AntidepClobber.ll test to fail because of a
missing null check.
llvm-svn: 306919
Summary:
Add an option to prevent diagnostics that do not meet a minimum hotness
threshold from being output. When generating optimization remarks for
large codebases with a ton of cold code paths, this option can be used
to limit the optimization remark output at a reasonable size. Discussion of
this change can be read here:
http://lists.llvm.org/pipermail/llvm-dev/2017-June/114377.html
Reviewers: anemet, davidxl, hfinkel
Reviewed By: anemet
Subscribers: qcolombet, javed.absar, fhahn, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D34867
llvm-svn: 306912
This reverts commit r306894.
Revert "[Dominators] Add NearestCommonDominator verification"
This reverts commit r306893.
Revert "[Dominators] Keep tree level in DomTreeNode and use it to find NCD and answer dominance queries"
This reverts commit r306892.
llvm-svn: 306907
Summary: This patch teaches IteratedDominanceFrontier to use the level information stored in DomTreeNodes instead of calculating it manually.
Reviewers: dberlin, sanjoy, davide
Reviewed By: davide
Subscribers: davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D34703
llvm-svn: 306894
Summary:
To enable profile hotness information in diagnostics output, Clang takes
the option `-fdiagnostics-show-hotness` -- that's "diagnostics", with an
"s" at the end. Clang also defines `CodeGenOptions::DiagnosticsWithHotness`.
LLVM, on the other hand, defines
`LLVMContext::getDiagnosticHotnessRequested` -- that's "diagnostic", not
"diagnostics". It's a small difference, but it's confusing, typo-inducing, and
frustrating.
Add a new method with the spelling "diagnostics", and "deprecate" the
old spelling.
Reviewers: anemet, davidxl
Reviewed By: anemet
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D34864
llvm-svn: 306848
In rL300494 there was an attempt to deal with excessive compile time on
invocations of getSign/ZeroExtExpr using local caching. This approach only
helps if we request the same SCEV multiple times throughout recursion. But
in the bug PR33431 we see a case where we request different values all the time,
so caching does not help and the size of the cache grows enormously.
In this patch we remove the local cache for this methods and add the recursion
depth limit instead, as we do for arithmetics. This gives us a guarantee that the
invocation sequence is limited and reasonably short.
Differential Revision: https://reviews.llvm.org/D34273
llvm-svn: 306785
In LLVM IR the following code:
%r = urem <ty> %t, %b
is equivalent to:
%q = udiv <ty> %t, %b
%s = mul <ty> nuw %q, %b
%r = sub <ty> nuw %t, %q ; (t / b) * b + (t % b) = t
As UDiv, Mul and Sub are already supported by SCEV, URem can be
implemented with minimal effort this way.
Note: While SRem and SDiv are also related this way, SCEV does not
provides SDiv yet.
llvm-svn: 306695
The changes are a result of discussion of https://reviews.llvm.org/D33685.
It solves the following problem:
1. We can inform getGEPCost about simplified indices to help it with
calculating the cost. But getGEPCost does not take into account the
context which GEPs are used in.
2. We have getUserCost which can take the context into account but we cannot
inform about simplified indices.
With the changes getUserCost will have access to additional information
as getGEPCost has.
The one parameter getUserCost is also provided.
Differential Revision: https://reviews.llvm.org/D34057
llvm-svn: 306674
The original patch was an improvement to IR ValueTracking on non-negative
integers. It has been checked in to trunk (D18777, r284022). But was disabled by
default due to performance regressions.
Perf impact has improved. The patch would be enabled by default.
Reviewers: reames
Differential Revision: https://reviews.llvm.org/D34101
Patch by: Olga Chupina <olga.chupina@intel.com>
llvm-svn: 306528
Summary:
This commit allows matchSelectPattern to recognize clamp of float
arguments in the presence of FMF the same way as already done for
integers.
This case is a little different though. With integers, given the
min/max pattern is recognized, DAGBuilder starts selecting MIN/MAX
"automatically". That is not the case for float, because for them only
full FMINNAN/FMINNUM/FMAXNAN/FMAXNUM ISD nodes exist and they do care
about NaNs. On the other hand, some backends (e.g. X86) have only
FMIN/FMAX nodes that do not care about NaNS and the former NAN/NUM
nodes are illegal thus selection is not happening. So I decided to do
such kind of transformation in IR (InstCombiner) instead of
complicating the logic in the backend.
Reviewers: spatel, jmolloy, majnemer, efriedma, craig.topper
Reviewed By: efriedma
Subscribers: hiraditya, javed.absar, n.bozhenov, llvm-commits
Patch by Andrei Elovikov <andrei.elovikov@intel.com>
Differential Revision: https://reviews.llvm.org/D33186
llvm-svn: 306525
Using Optional<> here doesn't seem to be terribly valuable, but
this is not the main point of this change. The change enables
us to merge the (now) two identical copies of parentFunctionOfValue()
that Steensgaard's and Andersens' provide.
llvm-svn: 306351
Summary:
Make sure we are comparing the unknown instructions in the alias set and the instruction interested in.
I believe this is clearly a bug (missed opportunity). I can also add some test cases if desired.
Reviewers: hfinkel, davide, dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34597
llvm-svn: 306241
Summary:
This patch changes getRange to getRangeRef and returns a reference to the ConstantRange object stored inside the DenseMap caches. We then take advantage of that to add new helper methods that can return min/max value of a signed or unsigned ConstantRange using that reference without first copying the ConstantRange.
getRangeRef calls itself recursively and I believe the reference return is fine for those calls.
I've left getSignedRange and getUnsignedRange returning a ConstantRange object so they will make a copy now. This is to ensure safety since the reference will be invalidated if the DenseMap changes.
I'm sure there are still more places that can take advantage of the reference and I'll submit future patches as I find them.
Reviewers: sanjoy, davide
Reviewed By: sanjoy
Subscribers: zzheng, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D32978
llvm-svn: 306229
Summary:
m_CombineOr isn't very efficient. The code using it is also quite verbose.
This patch adds m_Shift and m_BitwiseLogic matchers to make the using code more concise and improve the match efficiency.
Reviewers: spatel, davide
Reviewed By: davide
Subscribers: davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D34593
llvm-svn: 306206
Summary: visitSwitchInst should not take INT_MAX when Cost is negative. Instead of INT_MAX , we also use a valid upperbound cost when overflow occurs in Cost.
Reviewers: hans, echristo, dmgreen
Reviewed By: dmgreen
Subscribers: mcrosier, javed.absar, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D34436
llvm-svn: 306118
Currently JumpThreading can use LazyValueInfo to analyze an 'and' or 'or' of compare if the compare is fed by a livein of a basic block. This can be used to to prove the condition can't be met for some predecessor and the jump from that predecessor can be moved to the false path of the condition.
But if the compare is something that InstCombine turns into an add and a single compare, it can't be analyzed because the livein is now an input to the add and not the compare.
This patch adds a new method to LVI to get a ConstantRange on an edge. Then we teach jump threading to detect the add livein feeding a compare and to get the ConstantRange and propagate it.
Differential Revision: https://reviews.llvm.org/D33262
llvm-svn: 306085
Summary: LVI can reason about an AND of icmps on the true dest of a branch. I believe we can do similar for the false dest of ORs. This allows us to get the same answer for the demorganed versions of some of the AND test cases as you can see.
Reviewers: anna, reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34431
llvm-svn: 306076
This matches the checks done at the beginning of isKnownNonEqual that this code is partially emulating.
Without this we can get assertion failures due to the bit widths of the KnownBits not matching.
llvm-svn: 306044
Using various methods, BasicAA tries to determine whether two
GetElementPtr memory locations alias when its base pointers are known
to be equal. When none of its heuristics are applicable, it falls back
to PartialAlias to, according to a comment, protect TBAA making a wrong
decision in case of unions and malloc. PartialAlias is not correct,
because a PartialAlias result implies that some, but not all, bytes
overlap which is not necessarily the case here.
AAResults returns the first analysis result that is not MayAlias.
BasicAA is always the first alias analysis. When it returns
PartialAlias, no other analysis is queried to give a more exact result
(which was the intention of returning PartialAlias instead of MayAlias).
For instance, ScopedAA could return a more accurate result.
The PartialAlias hack was introduced in r131781 (and re-applied in
r132632 after some reverts) to fix llvm.org/PR9971 where TBAA returns a
wrong NoAlias result due to a union. A test case for the malloc case
mentioned in the comment was not provided and I don't think it is
affected since it returns an omnipotent char anyway.
Since r303851 (https://reviews.llvm.org/D33328) clang does emit specific
TBAA for unions anymore (but "omnipotent char" instead). Hence, the
PartialAlias workaround is not required anymore.
This patch passes the test-suite and check-llvm/check-clang of a
self-hoisted build on x64.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D34318
llvm-svn: 305938
MulOpsInlineThreshold option of SCEV is defaulted to 1000, which is inadequately high.
When constructing SCEVs of expressions like:
x1 = a * a
x2 = x1 * x1
x3 = x2 * x2
...
We actually have huge SCEVs with max allowed amount of operands inlined.
Such expressions are easy to get from unrolling of loops looking like
x = a
for (i = 0; i < n; i++)
x = x * x
Or more tricky cases where big powers are involved. If some non-linear analysis
tries to work with a SCEV that has 1000 operands, it may lead to excessively long
compilation. The attached test does not pass within 1 minute with default threshold.
This patch decreases its default value to 32, which looks much more reasonable if we
use analyzes with complexity O(N^2) or O(N^3) working with SCEV.
Differential Revision: https://reviews.llvm.org/D34397
llvm-svn: 305882
The description of this option was copy-pasted from another one and does not
correspond to reality.
Differential Revision: https://reviews.llvm.org/D34390
llvm-svn: 305782
Current implementation of SCEVExpander demonstrates a very naive behavior when
it deals with power calculation. For example, a SCEV for x^8 looks like
(x * x * x * x * x * x * x * x)
If we try to expand it, it generates a very straightforward sequence of muls, like:
x2 = mul x, x
x3 = mul x2, x
x4 = mul x3, x
...
x8 = mul x7, x
This is a non-efficient way of doing that. A better way is to generate a sequence of
binary power calculation. In this case the expanded calculation will look like:
x2 = mul x, x
x4 = mul x2, x2
x8 = mul x4, x4
In some cases the code size reduction for such SCEVs is dramatic. If we had a loop:
x = a;
for (int i = 0; i < 3; i++)
x = x * x;
And this loop have been fully unrolled, we have something like:
x = a;
x2 = x * x;
x4 = x2 * x2;
x8 = x4 * x4;
The SCEV for x8 is the same as in example above, and if we for some reason
want to expand it, we will generate naively 7 multiplications instead of 3.
The BinPow expansion algorithm here allows to keep code size reasonable.
This patch teaches SCEV Expander to generate a sequence of BinPow multiplications
if we have repeating arguments in SCEVMulExpressions.
Differential Revision: https://reviews.llvm.org/D34025
llvm-svn: 305663
This is a fix for the test case in PR32314.
Basic Alias Analysis can ask if two nodes are known non-equal after looking through a phi node to find a GEP. isAddOfNonZero saw an add of a constant from the same phi and said that its output couldn't be equal. But Basic Alias Analysis was really asking about the value from the previous loop iteration.
This patch at least makes that case not happen anymore, I'm not sure if there were still other ways this can fail. As was discussed in the bug, it looks like fixing BasicAA would be difficult so this patch seemed like a possible workaround
Differential Revision: https://reviews.llvm.org/D33136
llvm-svn: 305481
This is a fix for PR33292 that shows a case of extremely long compilation
of a single .c file with clang, with most time spent within SCEV.
We have a mechanism of limiting recursion depth for getAddExpr to avoid
long analysis in SCEV. However, there are calls from getAddExpr to getMulExpr
and back that do not propagate the info about depth. As result of this, a chain
getAddExpr -> ... .> getAddExpr -> getMulExpr -> getAddExpr -> ... -> getAddExpr
can be extremely long, with every segment of getAddExpr's being up to max depth long.
This leads either to long compilation or crash by stack overflow. We face this situation while
analyzing big SCEVs in the test of PR33292.
This patch applies the same limit on max expression depth for getAddExpr and getMulExpr.
Differential Revision: https://reviews.llvm.org/D33984
llvm-svn: 305463
There's an early out that's trying to detect when we don't know any bits that make up the legal range of a shift. The code subtracts one from BitWidth which creates a mask in the lower bits for power of 2 bit widths. This is then ANDed with the known bits to see if any of those bits are known. If the bit width isn't a power of 2 this creates a non-sensical mask.
This patch corrects this by rounding up to a power of 2 before doing the subtract and mask.
Differential Revision: https://reviews.llvm.org/D34165
llvm-svn: 305400
Previously it was non-const reference named Result which would tend to make someone think that it was an outparam when really its an input.
llvm-svn: 305114
Summary:
Unless I'm mistaken, the special handling for EQ/NE should cover everything and there is no reason to fallthrough to the more complex code. For that matter I'm not sure there's any reason to special case EQ/NE other than avoiding creating temporary ConstantRanges.
This patch moves the complex code into an else so we only do it when we are handling a predicate other than EQ/NE.
Reviewers: anna, reames, resistor, Farhana
Reviewed By: anna
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34000
llvm-svn: 305086
This is to prepare to allow for dead stripping of globals in the
merged modules.
Differential Revision: https://reviews.llvm.org/D33921
llvm-svn: 305027
The zero heuristic assumes that integers are more likely positive than negative,
but this also has the effect of assuming that strcmp return values are more
likely positive than negative. Given that for nonzero strcmp return values it's
the ordering of arguments that determines the sign of the result there's no
reason to assume that's true.
Fix this by inspecting the LHS of the compare and using TargetLibraryInfo to
decide if it's strcmp-like, and if so only assume that nonzero is more likely
than zero i.e. strings are more often different than the same. This causes a
slight code generation change in the spec2006 benchmark 403.gcc, but with no
noticeable performance impact. The intent of this patch is to allow better
optimisation of dhrystone on Cortex-M cpus, but currently it won't as there are
also some changes that need to be made to if-conversion.
Differential Revision: https://reviews.llvm.org/D33934
llvm-svn: 304970
Summary:
Check that the first access before one being tested is valid.
Before this patch, if there was no definition prior to the Use being tested,
the first time Iter was deferenced, it hit the sentinel.
Reviewers: dberlin, gbiv
Subscribers: sanjoy, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D33950
llvm-svn: 304926
Seems like at least one reasonable interpretation of optnone is that the
optimizer never "looks inside" a function. This fix is consistent with
that interpretation.
Specifically this came up in the situation:
f3 calls f2 calls f1
f2 is always_inline
f1 is optnone
The application of readnone to f1 (& thus to f2) caused the inliner to
kill the call to f2 as being trivially dead (without even checking the
cost function, as it happens - not sure if that's also a bug).
llvm-svn: 304833
Summary:
LVIPrinter pass was previously relying on the LVICache. We now directly call the
the LVI functions which solves the value if the LVI information is not already
available in the cache. This has 2 benefits over the printing of LVI cache:
1. higher coverage (i.e. catches errors) in LVI code when cache value is
invalidated.
2. relies on the core functions, and not dependent on the LVI cache (which may
be scrapped at some point).
It would still catch any cache invalidation errors, since we first go through
the cache.
Reviewers: reames, dberlin, sanjoy
Reviewed by: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32135
llvm-svn: 304819
Summary:
Expanding the loop idiom test for memcpy to also recognize
unordered atomic memcpy. The only difference for recognizing
an unordered atomic memcpy and instead of a normal memcpy is
that the loads and/or stores involved are unordered atomic operations.
Background: http://lists.llvm.org/pipermail/llvm-dev/2017-May/112779.html
Patch by Daniel Neilson!
Reviewers: reames, anna, skatkov
Reviewed By: reames, anna
Subscribers: llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D33243
llvm-svn: 304806
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.
I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.
This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.
Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).
llvm-svn: 304787
isKnownNonEqual is called a little earlier in this function and can handle the case that we were checking here as well as more complex cases.
llvm-svn: 304775
This will be used by another commit to remove some code from InstSimplify that is redundant for scalars, but was needed for vectors due to this issue.
llvm-svn: 304774
This is actually NFC because the next case starts with the same if statement as this case did. So the result will be the same and it will fallthrough to the end of the switch. But there's no reason to rely on that so we should just break.
llvm-svn: 304680
Summary:
This is to enable the new switch inline cost heuristic (r301649) by removing the
old heuristic as well as the flag itself.
In my experiment for LLVM test suite and spec2000/2006, +17.82% performance and
8% code size reduce was observed in spec2000/vertex with O3 LTO in AArch64.
No significant code size / performance regression was found in O3/O2/Os. No
significant complain was reported from the llvm-dev thread.
Reviewers: hans, chandlerc, eraman, haicheng, mcrosier, bmakam, eastig, ddibyend, echristo
Reviewed By: echristo
Subscribers: javed.absar, kristof.beyls, echristo, aemerson, rengolin, mehdi_amini
Differential Revision: https://reviews.llvm.org/D32653
llvm-svn: 304594
Summary:
The constant folding code currently assumes that the constant expression will always be on the left and the simple null will be on the right. But that's not true at least on the path from InstSimplify.
This patch adds support to ConstantFolding to detect the reversed case.
Reviewers: spatel, dberlin, majnemer, davide, joey
Reviewed By: joey
Subscribers: joey, llvm-commits
Differential Revision: https://reviews.llvm.org/D33801
llvm-svn: 304559
Summary:
Reduce min percent required for indirect call promotion from 33% to 30%,
which matches gcc's threshold and catches the same hot opportunities.
Reviewers: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33798
llvm-svn: 304469
Replace GVFlags::LiveRoot with GVFlags::Live and use that instead of
all the DeadSymbols sets. This is refactoring in order to make
liveness information available in the RegularLTO pipeline.
llvm-svn: 304466
This patch does an inline expansion of memcmp.
It changes the memcmp library call into an inline expansion when the size is
known at compile time and is under a target specified threshold.
This expansion is implemented in CodeGenPrepare and expands into straight line
code. The target specifies a maximum load size and the expansion works by using
this size to load the two sources, compare, and exit early if a difference is
found. It also has a special case when the memcmp result is used in a compare
to zero equality.
Differential Revision: https://reviews.llvm.org/D28637
llvm-svn: 304313
Thanks to Galina Kistanova for finding the missing break!
When trying to make a test for this, I realized our logic for handling
extractvalue/insertvalue/... is somewhat broken. This makes constructing
a test-case for this missing break nontrivial.
llvm-svn: 304275
Params DT and LI are redundant, because these values are contained in fields anyways.
Differential Revision: https://reviews.llvm.org/D33668
llvm-svn: 304204
The optimistic delinearization implemented in LLVM detects array sizes by
looking for non-linear products between parameters and induction variables.
In OpenCL code, such products often look like:
A[get_global_id(0) * N + get_global_id(1)]
Hence, the IV is hidden in the get_global_id() call and consequently
delinearization would fail as no induction variable is available that helps
us to identify N as array size parameter.
We now use a very simple heuristic to change this. We assume that each parameter
that comes directly from a function call is a hidden induction variable. As
a result, we can delinearize the access above to:
A[get_global_id(0)][get_global_id(1]
llvm-svn: 304073
Summary:
This fixes introduction of an incorrect inttoptr/ptrtoint pair in
the included test case which makes use of non-integral pointers. I
suspect there are more cases like this left, but this takes care of
the one I was seeing at the moment.
Reviewers: sanjoy
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D33129
llvm-svn: 304058
Previously, we called simplifyPossiblyCastedAndOrOfICmps twice with the operands commuted, but the call to simplifyAndOrOfICmpsWithConstants further down already handles commuting and doesn't need to be called both ways.
This patch pushes double calls further down to just the individual routines that need to be called twice.
Differential Revision: https://reviews.llvm.org/D33603
llvm-svn: 304044
This code was replicated two additional times to handle commuted cases, but I think a commutable matcher can take care of it.
Differential Revision: https://reviews.llvm.org/D33585
llvm-svn: 304022
The tests here are have operands commuted to provide more coverage. I also commuted one of the instructions in the scalar tests so the 4 tests cover the 4 commuted variations
Differential Revision: https://reviews.llvm.org/D33599
llvm-svn: 304021
The patch rL303730 was reverted because test lsr-expand-quadratic.ll failed on
many non-X86 configs with this patch. The reason of this is that the patch
makes a correctless fix that changes optimizer's behavior for this test.
Without the change, LSR was making an overconfident simplification basing on a
wrong SCEV. Apparently it did not need the IV analysis to do this. With the
change, it chose a different way to simplify (that wasn't so confident), and
this way required the IV analysis. Now, following the right execution path,
LSR tries to make a transformation relying on IV Users analysis. This analysis
is target-dependent due to this code:
// LSR is not APInt clean, do not touch integers bigger than 64-bits.
// Also avoid creating IVs of non-native types. For example, we don't want a
// 64-bit IV in 32-bit code just because the loop has one 64-bit cast.
uint64_t Width = SE->getTypeSizeInBits(I->getType());
if (Width > 64 || !DL.isLegalInteger(Width))
return false;
To make a proper transformation in this test case, the type i32 needs to be
legal for the specified data layout. When the test runs on some non-X86
configuration (e.g. pure ARM 64), opt gets confused by the specified target
and does not use it, rejecting the specified data layout as well. Instead,
it uses some default layout that does not treat i32 as a legal type
(currently the layout that is used when it is not specified does not have
legal types at all). As result, the transformation we expect to happen does
not happen for this test.
This re-enabling patch does not have any source code changes compared to the
original patch rL303730. The only difference is that the failing test is
moved to X86 directory and now has requirement of running on x86 only to comply
with the specified target triple and data layout.
Differential Revision: https://reviews.llvm.org/D33543
llvm-svn: 303971
having it internally allocate the loop.
This is a much more flexible API and necessary in the new loop unswitch
to reasonably support both new and old PMs in common code. It also just
seems like a cleaner separation of concerns.
NFC, this should just be a pure refactoring.
Differential Revision: https://reviews.llvm.org/D33528
llvm-svn: 303834
Summary: This code was migrated from InstCombine a few years ago. InstCombine had nearby code that would move Constants to the RHS for these, but InstSimplify doesn't have such code on this path.
Reviewers: spatel, majnemer, davide
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33473
llvm-svn: 303774
This continues the changes started when computeSignBit was replaced with this new version of computeKnowBits.
Differential Revision: https://reviews.llvm.org/D33431
llvm-svn: 303773
The loop vectorizer usually vectorizes any instruction it can and then
extracts the elements for a scalarized use. On SystemZ, all elements
containing addresses must be extracted into address registers (GRs). Since
this extraction is not free, it is better to have the address in a suitable
register to begin with. By forcing address arithmetic instructions and loads
of addresses to be scalar after vectorization, two benefits result:
* No need to extract the register
* LSR optimizations trigger (LSR isn't handling vector addresses currently)
Benchmarking show improvements on SystemZ with this new behaviour.
Any other target could try this by returning false in the new hook
prefersVectorizedAddressing().
Review: Renato Golin, Elena Demikhovsky, Ulrich Weigand
https://reviews.llvm.org/D32422
llvm-svn: 303744
When folding arguments of AddExpr or MulExpr with recurrences, we rely on the fact that
the loop of our base recurrency is the bottom-lost in terms of domination. This assumption
may be broken by an expression which is treated as invariant, and which depends on a complex
Phi for which SCEVUnknown was created. If such Phi is a loop Phi, and this loop is lower than
the chosen AddRecExpr's loop, it is invalid to fold our expression with the recurrence.
Another reason why it might be invalid to fold SCEVUnknown into Phi start value is that unlike
other SCEVs, SCEVUnknown are sometimes position-bound. For example, here:
for (...) { // loop
phi = {A,+,B}
}
X = load ...
Folding phi + X into {A+X,+,B}<loop> actually makes no sense, because X does not exist and cannot
exist while we are iterating in loop (this memory can be even not allocated and not filled by this moment).
It is only valid to make such folding if X is defined before the loop. In this case the recurrence {A+X,+,B}<loop>
may be existant.
This patch prohibits folding of SCEVUnknown (and those who use them) into the start value of an AddRecExpr,
if this instruction is dominated by the loop. Merging the dominating unknown values is still valid. Some tests that
relied on the fact that some SCEVUnknown should be folded into AddRec's are changed so that they no longer
expect such behavior.
llvm-svn: 303730
When presented with an icmp/select pair, we can end up asking what would happen
if we replaced one constant with another in an instruction. This is a mistake,
while non-constant Values could become a constant, constants cannot change and
trying to do so can lead to completely invalid IR (a GEP referencing a
non-existant field in the original case).
llvm-svn: 303580
This is a re-application of a r303497 that was reverted in r303498.
I thought it had broken a bot when it had not (the breakage did not
go away with the revert).
This change makes the split between the "exact" backedge taken count
and the "maximum" backedge taken count a bit more obvious. Both of
these are upper bounds on the number of times the loop header
executes (since SCEV does not account for most kinds of abnormal
control flow), but the latter is guaranteed to be a constant.
There were a few places where the max backedge taken count *was* a
non-constant; I've changed those to compute constants instead.
At this point, I'm not sure if the constant max backedge count can be
computed by calling `getUnsignedRange(Exact).getUnsignedMax()` without
losing precision. If it can, we can simplify even further by making
`getMaxBackedgeTakenCount` a thin wrapper around
`getBackedgeTakenCount` and `getUnsignedRange`.
llvm-svn: 303531
This change makes the split between the "exact" backedge taken count
and the "maximum" backedge taken count a bit more obvious. Both of
these are upper bounds on the number of times the loop header
executes (since SCEV does not account for most kinds of abnormal
control flow), but the latter is guaranteed to be a constant.
There were a few places where the max backedge taken count *was* a
non-constant; I've changed those to compute constants instead.
At this point, I'm not sure if the constant max backedge count can be
computed by calling `getUnsignedRange(Exact).getUnsignedMax()` without
losing precision. If it can, we can simplify even further by making
`getMaxBackedgeTakenCount` a thin wrapper around
`getBackedgeTakenCount` and `getUnsignedRange`.
llvm-svn: 303497
Summary: This allows pthread_self to be pulled out of a loop by LICM.
Reviewers: hfinkel, arsenm, davide
Reviewed By: davide
Subscribers: davide, wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D32782
llvm-svn: 303495
Refactor the strlen optimization code to work for both strlen and wcslen.
This especially helps with programs in the wild where people pass
L"string"s to const std::wstring& function parameters and the wstring
constructor gets inlined.
This also fixes a lingerind API problem/bug in getConstantStringInfo()
where zeroinitializers would always give you an empty string (without a
length) back regardless of the actual length of the initializer which
did not work well in the TrimAtNul==false causing the PR mentioned
below.
Note that the fixed getConstantStringInfo() needed fixes to SelectionDAG
memcpy lowering and may lead to some cases for out-of-bounds
zeroinitializer accesses not getting optimized anymore. So some code
with UB may produce out of bound memory reads now instead of just
producing zeros.
The refactoring "accidentally" fixes http://llvm.org/PR32124
Differential Revision: https://reviews.llvm.org/D32839
llvm-svn: 303461
Summary:
Implements PR889
Removing the virtual table pointer from Value saves 1% of RSS when doing
LTO of llc on Linux. The impact on time was positive, but too noisy to
conclusively say that performance improved. Here is a link to the
spreadsheet with the original data:
https://docs.google.com/spreadsheets/d/1F4FHir0qYnV0MEp2sYYp_BuvnJgWlWPhWOwZ6LbW7W4/edit?usp=sharing
This change makes it invalid to directly delete a Value, User, or
Instruction pointer. Instead, such code can be rewritten to a null check
and a call Value::deleteValue(). Value objects tend to have their
lifetimes managed through iplist, so for the most part, this isn't a big
deal. However, there are some places where LLVM deletes values, and
those places had to be migrated to deleteValue. I have also created
llvm::unique_value, which has a custom deleter, so it can be used in
place of std::unique_ptr<Value>.
I had to add the "DerivedUser" Deleter escape hatch for MemorySSA, which
derives from User outside of lib/IR. Code in IR cannot include MemorySSA
headers or call the MemoryAccess object destructors without introducing
a circular dependency, so we need some level of indirection.
Unfortunately, no class derived from User may have any virtual methods,
because adding a virtual method would break User::getHungOffOperands(),
which assumes that it can find the use list immediately prior to the
User object. I've added a static_assert to the appropriate OperandTraits
templates to help people avoid this trap.
Reviewers: chandlerc, mehdi_amini, pete, dberlin, george.burgess.iv
Reviewed By: chandlerc
Subscribers: krytarowski, eraman, george.burgess.iv, mzolotukhin, Prazek, nlewycky, hans, inglorion, pcc, tejohnson, dberlin, llvm-commits
Differential Revision: https://reviews.llvm.org/D31261
llvm-svn: 303362
Replace two places that duplicate the code of isLoopInvariant method with
the invocation of this method.
Differential Revision: https://reviews.llvm.org/D33313
llvm-svn: 303336
The probability of edge coming to unreachable block should be as low as possible.
The change reduces the probability to minimal value greater than zero.
The bug https://bugs.llvm.org/show_bug.cgi?id=32214 show the example when
the probability of edge coming to unreachable block is greater than for edge
coming to out of the loop and it causes incorrect loop rotation.
Please note that with this change the behavior of unreachable heuristic is a bit different
than others. Specifically, before this change the sum of probabilities
coming to unreachable blocks have the same weight for all branches
(it was just split over all edges of this block coming to unreachable blocks).
With this change it might be slightly different but not to much due to probability of
taken branch to unreachable block is really small.
Reviewers: chandlerc, sanjoy, vsk, congh, junbuml, davidxl, dexonsmith
Reviewed By: chandlerc, dexonsmith
Subscribers: reames, llvm-commits
Differential Revision: https://reviews.llvm.org/D30633
llvm-svn: 303327
Summary:
There are several places in the codebase that try to calculate a maximum value in a Statistic object. We currently do this in one of two ways:
MaxNumFoo = std::max(MaxNumFoo, NumFoo);
or
MaxNumFoo = (MaxNumFoo > NumFoo) ? MaxNumFoo : NumFoo;
The first version reads from MaxNumFoo one time and uncontionally rwrites to it. The second version possibly reads it twice depending on the result of the first compare. But we have no way of knowing if the value was changed by another thread between the reads and the writes.
This patch adds a method to the Statistic object that can ensure that we only store if our value is the max and the previous max didn't change after we read it. If it changed we'll recheck if our value should still be the max or not and try again.
This spawned from an audit I'm trying to do of all places we uses the implicit conversion to unsigned on the Statistics objects. See my previous thread on llvm-dev https://groups.google.com/forum/#!topic/llvm-dev/yfvxiorKrDQ
Reviewers: dberlin, chandlerc, hfinkel, dblaikie
Reviewed By: chandlerc
Subscribers: llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D33301
llvm-svn: 303318
We already handled all of the new tests identically, but several
of those went through a lot of unnecessary processing before
getting folded.
Another motivation for grouping these cases together is that
InstCombine needs a similar fold. Currently, it handles the
'not' cases inefficiently which can lead to bugs as described
in the post-commit comments of:
https://reviews.llvm.org/D32143
llvm-svn: 303295
Sorting of AddRecExprs by loop nesting does not make sense since we only invoke
the CompareSCEVComplexity for AddRecExprs that are used by one SCEV. This
guarantees that there is always a dominance relationship between them. This
patch removes the sorting by nesting which is a dead code in current usage of
this function.
Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D33228
llvm-svn: 303235
We would eventually catch these via demanded bits and computing known bits in InstCombine,
but I think it's better to handle the simple cases as soon as possible as a matter of efficiency.
This fold allows further simplifications based on distributed ops transforms. eg:
%a = lshr i8 %x, 7
%b = or i8 %a, 2
%c = and i8 %b, 1
InstSimplify can directly fold this now:
%a = lshr i8 %x, 7
Differential Revision: https://reviews.llvm.org/D33221
llvm-svn: 303213
Update threshold based on callee's hotness only when BFI is not available.
Otherwise use only callsite's hotness. This makes it easier to reason about
hotness related threshold updates.
Differential revision: https://reviews.llvm.org/D33157
llvm-svn: 303210
ProfileSummaryInfo already checks whether the module has sample profile
in determining profile counts. This will also be useful in inliner to
clean up threshold updates.
llvm-svn: 303204
The existing sorting order in defined CompareSCEVComplexity sorts AddRecExprs
by loop depth, but does not pay attention to dominance of loops. This can
lead us to the following buggy situation:
for (...) { // loop1
op1 = {A,+,B}
}
for (...) { // loop2
op2 = {A,+,B}
S = add op1, op2
}
In this case there is no guarantee that in operand list of S the op2 comes
before op1 (loop depth is the same, so they will be sorted just
lexicographically), so we can incorrectly treat S as a recurrence of loop1,
which is wrong.
This patch changes the sorting logic so that it places the dominated recs
before the dominating recs. This ensures that when we pick the first recurrency
in the operands order, it will be the bottom-most in terms of domination tree.
The attached test set includes some tests that produce incorrect SCEV
estimations and crashes with oldlogic.
Reviewers: sanjoy, reames, apilipenko, anna
Reviewed By: sanjoy
Subscribers: llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D33121
llvm-svn: 303148
This function gives the wrong answer on some non-ELF platforms in some
cases. The function that does the right thing lives in Mangler.h. To try to
discourage people from using this function, give it a different name.
Differential Revision: https://reviews.llvm.org/D33162
llvm-svn: 303134
ARM Neon has native support for half-sized vector registers (64 bits). This
is beneficial for example for 2D and 3D graphics. This patch adds the option
to lower MinVecRegSize from 128 via a TTI in the SLP Vectorizer.
*** Performance Analysis
This change was motivated by some internal benchmarks but it is also
beneficial on SPEC and the LLVM testsuite.
The results are with -O3 and PGO. A negative percentage is an improvement.
The testsuite was run with a sample size of 4.
** SPEC
* CFP2006/482.sphinx3 -3.34%
A pretty hot loop is SLP vectorized resulting in nice instruction reduction.
This used to be a +22% regression before rL299482.
* CFP2000/177.mesa -3.34%
* CINT2000/256.bzip2 +6.97%
My current plan is to extend the fix in rL299482 to i16 which brings the
regression down to +2.5%. There are also other problems with the codegen in
this loop so there is further room for improvement.
** LLVM testsuite
* SingleSource/Benchmarks/Misc/ReedSolomon -10.75%
There are multiple small SLP vectorizations outside the hot code. It's a bit
surprising that it adds up to 10%. Some of this may be code-layout noise.
* MultiSource/Benchmarks/VersaBench/beamformer/beamformer -8.40%
The opt-viewer screenshot can be seen at F3218284. We start at a colder store
but the tree leads us into the hottest loop.
* MultiSource/Applications/lambda-0.1.3/lambda -2.68%
* MultiSource/Benchmarks/Bullet/bullet -2.18%
This is using 3D vectors.
* SingleSource/Benchmarks/Shootout-C++/Shootout-C++-lists +6.67%
Noise, binary is unchanged.
* MultiSource/Benchmarks/Ptrdist/anagram/anagram +4.90%
There is an additional SLP in the cold code. The test runs for ~1sec and
prints out over 2000 lines. This is most likely noise.
* MultiSource/Applications/aha/aha +1.63%
* MultiSource/Applications/JM/lencod/lencod +1.41%
* SingleSource/Benchmarks/Misc/richards_benchmark +1.15%
Differential Revision: https://reviews.llvm.org/D31965
llvm-svn: 303116
Summary:
Merge overflow computation for signed add,
appearing both in InstCombine and ValueTracking.
As part of the merge,
cleanup the interface for overflow checks in InstCombine.
Patch by Yoav Ben-Shalom.
Reviewers: craig.topper, majnemer
Reviewed By: craig.topper
Subscribers: takuto.ikuta, llvm-commits
Differential Revision: https://reviews.llvm.org/D32946
llvm-svn: 303029
This patch adds min/max population count, leading/trailing zero/one bit counting methods.
The min methods return answers based on bits that are known without considering unknown bits. The max methods give answers taking into account the largest count that unknown bits could give.
Differential Revision: https://reviews.llvm.org/D32931
llvm-svn: 302925
This is a follow up patch for https://reviews.llvm.org/rL300440
to address a comment.
To make implementation to be consistent with other cases we just
ignore the remainder after distribution of remaining probability between
reachable edges.
If we reduced the probability of some edges coming to unreachable
blocks we should distribute the remaining part across other edges
coming to reachable blocks to satisfy the condition that sum of all
probabilities should be equal to one. If this remaining part is not
divided by number of "reachable" edges then we get this remainder.
This remainder probability should be pretty small. Other cases just ignore
if the sum of probabilities is not equal to one so we do the same.
Reviewers: chandlerc, sanjoy, vsk, junbuml, reames
Reviewed By: reames
Subscribers: reames, llvm-commits
Differential Revision: https://reviews.llvm.org/D32124
llvm-svn: 302883
Summary:
Don't use the metadata on call instructions for determining hotness
unless we are in sample PGO mode, where it is needed because profile
counts are not accurate. In instrumentation mode this is not necessary
and does more harm than good when calls have VP metadata that hasn't
been properly scaled after transformations or dropped after constant
prop based devirtualization (both should be fixed, but we don't need
to do this in the first place for instrumentation PGO).
This required adjusting a number of tests to distinguish between sample
and instrumentation PGO handling, and to add in profile summary metadata
so that getProfileCount can get the summary.
Reviewers: davidxl, danielcdh
Subscribers: aemerson, rengolin, mehdi_amini, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D32877
llvm-svn: 302844
I ran the test-suite (including SPEC 2006) in PGO mode comparing cold
thresholds of 225 and 45. Here are some stats on the text size:
Out of 904 tests that ran, 197 see a change in text size. The average
text size reduction (of all the 904 binaries) is 1.07%. Of the 197
binaries, 19 see a text size increase, as high as 18%, but most of them
are small single source benchmarks. There are 3 multisource benchmarks
with a >0.5% size increase (0.7, 1.3 and 2.1 are their % increases). On
the other side of the spectrum, 31 benchmarks see >10% size reduction
and 6 of them are MultiSource.
I haven't run the test-suite with other values of inlinecold-threshold.
Since we have a cold callsite threshold of 45, I picked this value.
Differential revision: https://reviews.llvm.org/D33106
llvm-svn: 302829
This fixes a ubsan bot failure after r302597, which made getProfileCount
non-static, but ended up invoking it on a null ProfileSummaryInfo object
in some cases from buildModuleSummaryIndex.
Most testing passed because the non-static getProfileCount currently
doesn't access any member variables, but I found this when testing a
follow on patch (D32877) that adds a member variable access.
llvm-svn: 302705
This pass uses a new target hook to decide whether or not to expand a particular
intrinsic to the shuffevector sequence.
Differential Revision: https://reviews.llvm.org/D32245
llvm-svn: 302631
This change is required because the notion of count is different for
sample profiling and getProfileCount will need to determine the
underlying profile type.
Differential revision: https://reviews.llvm.org/D33012
llvm-svn: 302597
- This change allows targets to opt-in to using them instead of the log2
shufflevector algorithm.
- The SLP and Loop vectorizers have the common code to do shuffle reductions
factored out into LoopUtils, and now have a unified interface for generating
reductions regardless of the preference of the target. LoopUtils now uses TTI
to determine what kind of reductions the target wants to handle.
- For CodeGen, basic legalization support is added.
Differential Revision: https://reviews.llvm.org/D30086
llvm-svn: 302514
This patch uses KnownOnes of the input of ctlz/cttz to bound the value that can be returned from these intrinsics. This makes these intrinsics more similar to the handling for ctpop which already uses known bits to produce a similar bound.
Differential Revision: https://reviews.llvm.org/D32521
llvm-svn: 302444
This introduces a new interface for computeKnownBits that returns the KnownBits object instead of requiring it to be pre-constructed and passed in by reference.
This is a much more convenient interface as it doesn't require the caller to figure out the BitWidth to pre-construct the object. It's so convenient that I believe we can use this interface to remove the special ComputeSignBit flavor of computeKnownBits.
As a step towards that idea, this patch replaces all of the internal usages of ComputeSignBit with this new interface. As you can see from the patch there were a couple places where we called ComputeSignBit which really called computeKnownBits, and then called computeKnownBits again directly. I've reduced those places to only making one call to computeKnownBits. I bet there are probably external users that do it too.
A future patch will update the external users and remove the ComputeSignBit interface. I'll also working on moving more locations to the KnownBits returning interface for computeKnownBits.
Differential Revision: https://reviews.llvm.org/D32848
llvm-svn: 302437
Summary:
Minor refactoring of foldIdentityShuffles() which allows the removal of a
ConstantDataVector::get() in SimplifyShuffleVectorInstruction.
Reviewers: spatel
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32955
Conflicts:
lib/Analysis/InstructionSimplify.cpp
llvm-svn: 302433
Summary:
Following up on Sanjay's suggetion in D32955, move this functionality
into ShuffleVectornstruction.
Reviewers: spatel, RKSimon
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32956
llvm-svn: 302420
Summary:
Re-applying r301766 with a fix to a typo and a regression test.
The log message for r301766 was:
==================================================================================
InstructionSimplify: Canonicalize shuffle operands. NFC-ish.
Summary:
Apply canonicalization rules:
1. Input vectors with no elements selected from can be replaced with undef.
2. If only one input vector is constant it shall be the second one.
This allows constant-folding to cover more ad-hoc simplifications that
were in place and avoid duplication for RHS and LHS checks.
There are more rules we may want to add in the future when we see a
justification. e.g. mask elements that select undef elements can be
replaced with undef.
==================================================================================
Reviewers: spatel, RKSimon
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32863
llvm-svn: 302373
Summary: This makes setRange take ConstantRange by rvalue reference since most callers were passing an unnamed temporary ConstantRange. We can then move that ConstantRange into the DenseMap caches. For the callers that weren't passing a temporary, I've added std::move to to the local variable being passed.
Reviewers: sanjoy, mzolotukhin, efriedma
Reviewed By: sanjoy
Subscribers: takuto.ikuta, llvm-commits
Differential Revision: https://reviews.llvm.org/D32943
llvm-svn: 302371
We can simplify (or (icmp X, C1), (icmp X, C2)) to 'true' or one of the icmps in many cases.
I had to check some of these with Alive to prove to myself it's right, but everything seems
to check out. Eg, the deleted code in instcombine was completely ignoring predicates with
mismatched signedness.
This is a follow-up to:
https://reviews.llvm.org/rL301260https://reviews.llvm.org/D32143
llvm-svn: 302370
This changes one parameter to be a const APInt& since we only read from it. Use std::move on local APInts once they are no longer needed so we can reuse their allocations. Lastly, use operator+=(uint64_t) instead of adding 1 to an APInt twice creating a new APInt each time.
llvm-svn: 302335
Summary:
ConstantRange contains two APInts which can allocate memory if their width is larger than 64-bits. So we shouldn't copy it when we can avoid it.
This changes LVILatticeVal::getConstantRange() to return its internal ConstantRange by reference. This allows many places that just need a ConstantRange reference to avoid making a copy.
Several places now capture the return value of getConstantRange() by reference so they can call methods on it that don't need a new object.
Lastly it adds std::move in one place to capture to move a local ConstantRange into an LVILatticeVal.
Reviewers: reames, dberlin, sanjoy, anna
Reviewed By: reames
Subscribers: grandinj, llvm-commits
Differential Revision: https://reviews.llvm.org/D32884
llvm-svn: 302331
wcslen is part of the C99 and C++98 standards.
- This introduces the function to TargetLibraryInfo.
- Also set attributes for wcslen in llvm::inferLibFuncAttributes().
Differential Revision: https://reviews.llvm.org/D32837
llvm-svn: 302278
This adds routines for reseting KnownBits to unknown, making the value all zeros or all ones. It also adds methods for querying if the value is zero, all ones or unknown.
Differential Revision: https://reviews.llvm.org/D32637
llvm-svn: 302262
The sibling folds for 'and' with casts were added with https://reviews.llvm.org/rL273200.
This is a preliminary step for adding the 'or' variants for the folds added with https://reviews.llvm.org/rL301260.
The reason for the strange form with constant LHS in the 1st test is because there's another missing fold in that
case for the inverted predicate. That should be fixed when we add the ConstantRange functionality for 'or-of-icmps'
that already exists for 'and-of-icmps'.
I'm hoping to share more code for the and/or cases, so we won't have these differences. This will allow us to remove
code from InstCombine. It's also possible that we can remove some code here in InstSimplify. I think we have some
duplicated folds because patterns are not matched in a general way.
Differential Revision: https://reviews.llvm.org/D32876
llvm-svn: 302189
Putting these next to each other should make it easier to see
what's missing from each side. Patch to plug one of those holes
should be posted soon.
llvm-svn: 302178
When profiling a no-op incremental link of Chromium I found that the functions
computeImportForFunction and computeDeadSymbols were consuming roughly 10% of
the profile. The goal of this change is to improve the performance of those
functions by changing the map lookups that they were previously doing into
pointer dereferences.
This is achieved by changing the ValueInfo data structure to be a pointer to
an element of the global value map owned by ModuleSummaryIndex, and changing
reference lists in the GlobalValueSummary to hold ValueInfos instead of GUIDs.
This means that a ValueInfo will take a client directly to the summary list
for a given GUID.
Differential Revision: https://reviews.llvm.org/D32471
llvm-svn: 302108
Summary:
The existing implementation creates a symbolic SCEV expression every
time we analyze a phi node and then has to remove it, when the analysis
is finished. This is very expensive, and in most of the cases it's also
unnecessary. According to the data I collected, ~60-70% of analyzed phi
nodes (measured on SPEC) have the following form:
PN = phi(Start, OP(Self, Constant))
Handling such cases separately significantly speeds this up.
Reviewers: sanjoy, pete
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32663
llvm-svn: 302096
This patch adds isConstant and getConstant for determining if KnownBits represents a constant value and to retrieve the value. Use them to simplify code.
Differential Revision: https://reviews.llvm.org/D32785
llvm-svn: 302091
I don't believe its possible to have non-zero values here since DataLayout became required. The APInt constructor inside of the KnownBits object will assert if this ever happens.
llvm-svn: 302089
This patch adds zext, sext, and trunc methods to KnownBits and uses them where possible.
Differential Revision: https://reviews.llvm.org/D32784
llvm-svn: 302088
Summary:
Do three things to help with that:
- Add AttributeList::FirstArgIndex, which is an enumerator currently set
to 1. It allows us to change the indexing scheme with fewer changes.
- Add addParamAttr/removeParamAttr. This just shortens addAttribute call
sites that would otherwise need to spell out FirstArgIndex.
- Remove some attribute-specific getters and setters from Function that
take attribute list indices. Most of these were only used from
BuildLibCalls, and doesNotAlias was only used to test or set if the
return value is malloc-like.
I'm happy to split the patch, but I think they are probably easier to
review when taken together.
This patch should be NFC, but it sets the stage to change the indexing
scheme to this, which is more convenient when indexing into an array:
0: func attrs
1: retattrs
2...: arg attrs
Reviewers: chandlerc, pete, javed.absar
Subscribers: david2050, llvm-commits
Differential Revision: https://reviews.llvm.org/D32811
llvm-svn: 302060
We should always expect values to be named before running the module summary
analysis (see NameAnonGlobals pass), so it's fine if we crash in that case.
llvm-svn: 301991
Turns out this wasn't NFC-ish at all because there's a bug processing shuffles
that change the size of their input vectors (that case always seems to trip us
up).
This should fix PR32872 while we investigate how it failed and reduce a testcase:
https://bugs.llvm.org/show_bug.cgi?id=32872
llvm-svn: 301977
This change caused buildbot failures, apparently because we're not
passing around types that InstSimplify is used to seeing. I'm not overly
familiar with InstSimplify, so I'm reverting this until I can figure out
what exactly is wrong.
llvm-svn: 301885
In particular (since it wouldn't fit nicely in the summary):
(select (icmp eq V 0) P (getelementptr P V)) -> (getelementptr P V)
Differential Revision: https://reviews.llvm.org/D31435
llvm-svn: 301880
Summary:
programUndefinedIfPoison makes more sense, given what the function
does; and I'm about to add a function with a name similar to
isKnownNotFullPoison (so do the rename to avoid confusion).
Reviewers: broune, majnemer, bjarke.roune
Reviewed By: broune
Subscribers: mcrosier, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D30444
llvm-svn: 301776
Summary:
Apply canonicalization rules:
1. Input vectors with no elements selected from can be replaced with undef.
2. If only one input vector is constant it shall be the second one.
This allows constant-folding to cover more ad-hoc simplifications that
were in place and avoid duplication for RHS and LHS checks.
There are more rules we may want to add in the future when we see a
justification. e.g. mask elements that select undef elements can be
replaced with undef.
Reviewers: spatel, RKSimon, andreadb, davide
Reviewed By: spatel, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32338
llvm-svn: 301766
Summary: This patch adds isNegative, isNonNegative for querying whether the sign bit is known. It also adds makeNegative and makeNonNegative for controlling the sign bit.
Reviewers: RKSimon, spatel, davide
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32651
llvm-svn: 301747
This eliminates many extra 'Idx' induction variables in loops over
arguments in CodeGen/ and Target/. It also reduces the number of places
where we assume that ReturnIndex is 0 and that we should add one to
argument numbers to get the corresponding attribute list index.
NFC
llvm-svn: 301666
Summary:
The motivation example is like below which has 13 cases but only 2 distinct targets
```
lor.lhs.false2: ; preds = %if.then
switch i32 %Status, label %if.then27 [
i32 -7012, label %if.end35
i32 -10008, label %if.end35
i32 -10016, label %if.end35
i32 15000, label %if.end35
i32 14013, label %if.end35
i32 10114, label %if.end35
i32 10107, label %if.end35
i32 10105, label %if.end35
i32 10013, label %if.end35
i32 10011, label %if.end35
i32 7008, label %if.end35
i32 7007, label %if.end35
i32 5002, label %if.end35
]
```
which is compiled into a balanced binary tree like this on AArch64 (similar on X86)
```
.LBB853_9: // %lor.lhs.false2
mov w8, #10012
cmp w19, w8
b.gt .LBB853_14
// BB#10: // %lor.lhs.false2
mov w8, #5001
cmp w19, w8
b.gt .LBB853_18
// BB#11: // %lor.lhs.false2
mov w8, #-10016
cmp w19, w8
b.eq .LBB853_23
// BB#12: // %lor.lhs.false2
mov w8, #-10008
cmp w19, w8
b.eq .LBB853_23
// BB#13: // %lor.lhs.false2
mov w8, #-7012
cmp w19, w8
b.eq .LBB853_23
b .LBB853_3
.LBB853_14: // %lor.lhs.false2
mov w8, #14012
cmp w19, w8
b.gt .LBB853_21
// BB#15: // %lor.lhs.false2
mov w8, #-10105
add w8, w19, w8
cmp w8, #9 // =9
b.hi .LBB853_17
// BB#16: // %lor.lhs.false2
orr w9, wzr, #0x1
lsl w8, w9, w8
mov w9, #517
and w8, w8, w9
cbnz w8, .LBB853_23
.LBB853_17: // %lor.lhs.false2
mov w8, #10013
cmp w19, w8
b.eq .LBB853_23
b .LBB853_3
.LBB853_18: // %lor.lhs.false2
mov w8, #-7007
add w8, w19, w8
cmp w8, #2 // =2
b.lo .LBB853_23
// BB#19: // %lor.lhs.false2
mov w8, #5002
cmp w19, w8
b.eq .LBB853_23
// BB#20: // %lor.lhs.false2
mov w8, #10011
cmp w19, w8
b.eq .LBB853_23
b .LBB853_3
.LBB853_21: // %lor.lhs.false2
mov w8, #14013
cmp w19, w8
b.eq .LBB853_23
// BB#22: // %lor.lhs.false2
mov w8, #15000
cmp w19, w8
b.ne .LBB853_3
```
However, the inline cost model estimates the cost to be linear with the number
of distinct targets and the cost of the above switch is just 2 InstrCosts.
The function containing this switch is then inlined about 900 times.
This change use the general way of switch lowering for the inline heuristic. It
etimate the number of case clusters with the suitability check for a jump table
or bit test. Considering the binary search tree built for the clusters, this
change modifies the model to be linear with the size of the balanced binary
tree. The model is off by default for now :
-inline-generic-switch-cost=false
This change was originally proposed by Haicheng in D29870.
Reviewers: hans, bmakam, chandlerc, eraman, haicheng, mcrosier
Reviewed By: hans
Subscribers: joerg, aemerson, llvm-commits, rengolin
Differential Revision: https://reviews.llvm.org/D31085
llvm-svn: 301649
This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit.
Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch.
I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases.
Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with.
Differential Revision: https://reviews.llvm.org/D32376
llvm-svn: 301432
Commits were:
"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTrackingVH; NFC"
The changes assumed pointers are 8 byte aligned on all architectures.
llvm-svn: 301429
Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.
Reviewers: dblaikie, davide
Reviewed By: davide
Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle
Differential Revision: https://reviews.llvm.org/D32266
llvm-svn: 301424
Summary:
Expose the internal query structure, start using it.
Note: This is the most minimal change possible i could create. I have
trivial followups, like fixing the one use of const FastMathFlags &,
the renaming of CtxI to be consistent, etc.
This should be NFC.
Reviewers: majnemer, davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32448
llvm-svn: 301379
This patch uses various APInt methods to reduce temporary APInt creation.
This should be all of the unrelated cleanups that got buried in D32376(creating a KnownBits struct) as well as some pointed out by Simon during the review of that. Plus a few improvements to use counting instead of masking.
I've left out any places where we do something like (KnownZero & KnownOne) != 0 as I plan to add a helper method to KnownBits to ask that question and didn't want to thrash that code an additional time.
Differential Revision: https://reviews.llvm.org/D32495
llvm-svn: 301338
The code Sanjay Patel moved over from InstCombine doesn't work properly if the 'and' has both inputs as nots because we used a commuted op matcher on the 'and' first. But this will bind to the first 'not' on 'and' when there could be two 'not's. InstCombine could rely on DeMorgan to ensure the 'and' wouldn't have two 'not's eventually, but InstSimplify can't rely on that.
This patch matches the xor first then checks for the ands and allows a not of either operand of the xor.
Differential Revision: https://reviews.llvm.org/D32458
llvm-svn: 301329
This is a pre-commit for a patch I'm working on to turn KnownZero/One into a struct. Once I do that the type here will be less obvious.
llvm-svn: 301324
This is a pre-commit for a patch that I'm working on to merge KnownZero/KnownOne into a KnownBits struct which would have had to touch this line.
llvm-svn: 301323
Summary:
In a previous change I changed SCEV's normalization / denormalization
to work with non-affine add recs. So the bailout in IVUsers can be
removed.
Reviewers: atrick, efriedma
Reviewed By: atrick
Subscribers: davide, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D32105
llvm-svn: 301298
Summary:
Before this change, SCEV Normalization would incorrectly normalize
non-affine add recurrences. To work around this there was (still is)
a check in place to make sure we only tried to normalize affine add
recurrences.
We recently found a bug in aforementioned check to bail out of
normalizing non-affine add recurrences. However, instead of fixing
the bailout, I have decided to teach SCEV normalization to work
correctly with non-affine add recurrences, making the bailout
unnecessary (I'll remove it in a subsequent change).
I've also added some unit tests (which would have failed before this
change).
Reviewers: atrick, sunfish, efriedma
Reviewed By: atrick
Subscribers: mcrosier, mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D32104
llvm-svn: 301281
We can simplify (and (icmp X, C1), (icmp X, C2)) to one of the icmps in many cases.
I had to check some of these with Alive to prove to myself it's right, but everything
seems to check out. Eg, the code in instcombine was completely ignoring predicates with
mismatched signedness.
Handling or-of-icmps would be a follow-up step.
Differential Revision: https://reviews.llvm.org/D32143
llvm-svn: 301260
Summary:
llvm.invariant.group.barrier returns pointer that mustalias
pointer it takes. It can't be marked with `returned` attribute,
because it would be remove easily. The other reason is that
only Alias Analysis can know about this, because if any other
pass would know it, then the result would be replaced with it's
argument, which would be invalid.
We can think about returned pointer as something that mustalias, but
it doesn't have to be bitwise the same as the argument.
Reviewers: dberlin, chandlerc, hfinkel, sanjoy
Subscribers: reames, nlewycky, rsmith, anna, amharc
Differential Revision: https://reviews.llvm.org/D31585
llvm-svn: 301227
This is a straight cut and paste, but there's a bigger problem: if this
fold exists for simplifyOr, there should be a DeMorganized version for
simplifyAnd. But more than that, we have a patchwork of ad hoc logic
optimizations in InstCombine. There should be some structure to ensure
that we're not missing sibling folds across and/or/xor.
llvm-svn: 301213
This change reboots SCEV's current (off by default) verification logic
to avoid false failures. Instead of stringifying trip counts, it maps
old and new trip counts to the same ScalarEvolution "universe" and
asks ScalarEvolution to compute the difference between them. If the
difference comes out to be a non-zero constant, then (barring some
corner cases) we *know* we messed up.
I've not yet enabled this by default since it hits an exponential time
issue in SCEV, but once I fix that, I'll flip it on by default in
EXPENSIVE_CHECKS builds.
llvm-svn: 301146
- Mark an internal function static
- Remove the llvm namespace (just holding on to the `using namespace
llvm;` Works on My Machine(TM))
llvm-svn: 300947
There have been multiple reports of this causing problems: a
compile-time explosion on the LLVM testsuite, and a stack
overflow for an opencl kernel.
llvm-svn: 300928
getSignBit is a static function that creates an APInt with only the sign bit set. getSignMask seems like a better name to convey its functionality. In fact several places use it and then store in an APInt named SignMask.
Differential Revision: https://reviews.llvm.org/D32108
llvm-svn: 300856
This is preparation for a clang change to improve the [[nodiscard]] warning to not be ignored on methods that return a class marked [[nodiscard]] that are defined in the class itself. See D32207.
We should consider adding wrapper methods to APInt that return the overflow flag directly and discard the APInt result. This would eliminate the void casts and the need to create a bool before the call to pass to the out param.
llvm-svn: 300758
Use haveNoCommonBitsSet to figure out whether an "or" instruction
is equivalent to addition. This handles more cases than just
checking for a constant on the RHS.
Differential Revision: https://reviews.llvm.org/D32239
llvm-svn: 300746
This patch simplifies the examples from D31509 and D31927 (PR30630) and catches
the basic identity shuffle tests that Zvi recently added.
I'm not sure if we have something like this in DAGCombiner, but we should?
It's worth noting that "MaxRecurse / RecursionLimit" is only 3 on entry at the moment.
We might want to bump that up if there are longer shuffle chains like this in the wild.
For now, we're ignoring shuffles that have undef mask elements because it's not
clear how those should be handled.
Differential Revision: https://reviews.llvm.org/D31960
llvm-svn: 300714
InstSimplify returned the wrong type when simplifying a vector GEP
and we ended up crashing when trying to replace all uses with the
new value. Fixes PR32697.
Differential Revision: https://reviews.llvm.org/D32180
llvm-svn: 300693
BasicAA wants to know if a function is either a malloc or calloc like function. Currently we have to check both separately. This means both calls check if its an intrinsic, query TLI, check the nobuiltin attribute, scan the AllocationFnData, etc.
This patch adds a isMallocOrCallocLikeFn so we can go through all of the checks once per call.
This also changes the one other location I saw that called both together.
Differential Revision: https://reviews.llvm.org/D32188
llvm-svn: 300608
This patch uses lshrInPlace to replace code where the object that lshr is called on is being overwritten with the result.
This adds an lshrInPlace(const APInt &) version as well.
Differential Revision: https://reviews.llvm.org/D32155
llvm-svn: 300566
the exponential behavior.
The patch is to fix PR32043. Functions getZeroExtendExpr and getSignExtendExpr
may call themselves recursively more than once. This is potentially a 2^N
complexity behavior. The exponential behavior was not commonly exposed before
because of existing global cache mechnism like UniqueSCEVs or some early return
mechanism when flags FlagNSW or FlagNUW are seen. However, we still have case
which can expose the exponential behavior, like the case in PR32043, so we add
a local cache in getZeroExtendExpr and getSignExtendExpr. If the input of the
functions -- SCEV and type pair have been seen before, we can find the extended
expression directly in the local cache.
Differential Revision: https://reviews.llvm.org/D30350
llvm-svn: 300494
This is non-functional change to re-order if statements to bail out earlier
from unreachable and ColdCall heuristics.
Reviewers: sanjoy, reames, junbuml, vsk, chandlerc
Reviewed By: chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31704
llvm-svn: 300442
Metadata potentially is more precise than any heuristics we use, so
it makes sense to use first metadata info if it is available. However it makes
sense to examine it against other strong heuristics like unreachable one.
If edge coming to unreachable block has higher probability then it is expected
by unreachable heuristic then we use heuristic and remaining probability is
distributed among other reachable blocks equally.
An example where metadata might be more strong then unreachable heuristic is
as follows: it is possible that there are two branches and for the branch A
metadata says that its probability is (0, 2^25). For the branch B
the probability is (1, 2^25).
So the expectation is that first edge of B is hotter than first edge of A
because first edge of A did not executed at least once.
If first edge of A points to the unreachable block then using the unreachable
heuristics we'll set the probability for A to (1, 2^20) and now edge of A
becomes hotter than edge of B.
This is unexpected behavior.
This fixed the biggest part of https://bugs.llvm.org/show_bug.cgi?id=32214
Reviewers: sanjoy, junbuml, vsk, chandlerc
Reviewed By: chandlerc
Subscribers: llvm-commits, reames, davidxl
Differential Revision: https://reviews.llvm.org/D30631
llvm-svn: 300440
If we already called computeKnownBits for the RHS being a constant power of 2, we've already computed everything we can and should just stop. I think previously we would still recurse if we had determined the result was negative or had not determined the sign bit at all.
llvm-svn: 300432
The ConstantInt version has the same assert, and using null/allOnes is likely less efficient.
The only advantage of these local variants (and there's probably a better way to achieve this?)
is to save typing "ConstantInt::" over and over.
llvm-svn: 300426
This avoids the confusing 'CS.paramHasAttr(ArgNo + 1, Foo)' pattern.
Previously we were testing return value attributes with index 0, so I
introduced hasReturnAttr() for that use case.
llvm-svn: 300367
It won't compile after the recent changes I've made, and I think
keeping it in provides very little value.
Instead I've added (in an earlier commit) a C++ unit test to check the
Denormalize(Normalized(X)) == X property for specific instances of X,
which is what the assert was trying to do anyway.
llvm-svn: 300339
The PostIncTransform class was not pulling its weight, so delete it
and use free functions instead.
This also makes the use of `function_ref` more idiomatic. We were
storing an instance of function_ref in the PostIncTransform class
before, which was fine in that specific case, but the usage after this
change is more obviously okay.
llvm-svn: 300338
It is cleaner to have a callback based system where the logic of
whether an add recurrence is normalized or not lives on IVUsers.
This is one step in a multi-step cleanup.
llvm-svn: 300330
The APInt was created from an 'unsigned' and we just wanted to know how many bits the value needed to represent it. We can just use Log2_32 from MathExtras.h to get the info.
llvm-svn: 300309
We call it unconditionally on the operands of the select. Then decide if its a min/max and call it on the min/max operands or on the select operands again. Either of those second calls will overwrite the results of the initial call so we can just delete the first call.
llvm-svn: 300256
Summary:
* Add a bitreverse case in the demanded bits analysis pass.
* Add tests for the bitreverse (and bswap) intrinsic in the
demanded bits pass.
* Add a test case to the BDCE tests: that manipulations to
high-order bits are eliminated once the bits are reversed
and then right-shifted.
Reviewers: mkuper, jmolloy, hfinkel, trentxintong
Reviewed By: jmolloy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31857
llvm-svn: 300215
Previously it tried to call SimplifyInstruction which doesn't know anything about alloca so defers to constant folding which also doesn't do anything with alloca. This results in wasted cycles making calls that won't do anything. Given the frequency with which this function is called this time adds up.
llvm-svn: 300118
Since SystemZ supports vector element load/store instructions, there is no
need for extracts/inserts if a vector load/store gets scalarized.
This patch lets Target specify that it supports such instructions by means of
a new TTI hook that defaults to false.
The use for this is in the LoopVectorizer getScalarizationOverhead() method,
which will with this patch produce a smaller sum for a vector load/store on
SystemZ.
New test: test/Transforms/LoopVectorize/SystemZ/load-store-scalarization-cost.ll
Review: Adam Nemet
https://reviews.llvm.org/D30680
llvm-svn: 300056
getArithmeticInstrCost(), getShuffleCost(), getCastInstrCost(),
getCmpSelInstrCost(), getVectorInstrCost(), getMemoryOpCost(),
getInterleavedMemoryOpCost() implemented.
Interleaved access vectorization enabled.
BasicTTIImpl::getCastInstrCost() improved to check for legal extending loads,
in which case the cost of the z/sext instruction becomes 0.
Review: Ulrich Weigand, Renato Golin.
https://reviews.llvm.org/D29631
llvm-svn: 300052
and to expose a handle to represent the actual case rather than having
the iterator return a reference to itself.
All of this allows the iterator to be used with common STL facilities,
standard algorithms, etc.
Doing this exposed some missing facilities in the iterator facade that
I've fixed and required some work to the actual iterator to fully
support the necessary API.
Differential Revision: https://reviews.llvm.org/D31548
llvm-svn: 300032
Collection of PostDominatedByUnreachable and PostDominatedByColdCall have been
split out of heuristics itself. Update of the data happens now for each basic
block (before update for PostDominatedByColdCall might be skipped if
unreachable or matadata heuristic handled this basic block).
This separation allows re-ordering of heuristics without loosing
the post-domination information.
Reviewers: sanjoy, junbuml, vsk, chandlerc, reames
Reviewed By: chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31701
llvm-svn: 300029
Analysis, it has Analysis passes, and once NewGVN is made an Analysis,
this removes the cross dependency from Analysis to Transform/Utils.
NFC.
llvm-svn: 299980
Summary:
getModRefInfo is meant to answer the question "what impact does this
instruction have on a given memory location" (not even another
instruction).
Long debate on this on IRC comes to the conclusion the answer should be "nothing special".
That is, a noalias volatile store does not affect a memory location
just by being volatile. Note: DSE and GVN and memdep currently
believe this, because memdep just goes behind AA's back after it says
"modref" right now.
see line 635 of memdep. Prior to this patch we would get modref there, then check aliasing,
and if it said noalias, we would continue.
getModRefInfo *already* has this same AA check, it just wasn't being used because volatile was
lumped in with ordering.
(I am separately testing whether this code in memdep is now dead except for the invariant load case)
Reviewers: jyknight, chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31726
llvm-svn: 299741
We have dedicated handlers for every opcode so nothing can get here anymore. The switch doesn't get detected as fully covered because Opcode is an unsigned. Casting to Instruction::BinaryOps still doesn't detect it because BinaryOpsEnd is in the enum and 1 past the last opcode.
llvm-svn: 299687
This is a latent bug that's been hanging around for a while. For a loop-invariant
pointer, expandBounds would return the range {Ptr, Ptr}, but this was interpreted
as a half-open range, not a closed range. So we ended up planting incorrect
bounds checks. Even worse, they were tautological, so we ended up incorrectly
executing the optimized loop.
llvm-svn: 299526
Summary:
Add a hook for simplification of shufflevector's with the following rules:
- Constant folding - NFC, as it was already being done by the default handler.
- If only one of the operands is constant, constant fold the shuffle if the
mask does not select elements from the variable operand - to show the hook is firing and affecting the test-cases.
Reviewers: RKSimon, craig.topper, spatel, sanjoy, nlopes, majnemer
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31525
llvm-svn: 299393
Summary:
Move the aarch64-type-promotion pass within the existing type promotion framework in CGP.
This change also support forking sexts when a new sext is required for promotion.
Note that change is based on D27853 and I am submitting this out early to provide a better idea on D27853.
Reviewers: jmolloy, mcrosier, javed.absar, qcolombet
Reviewed By: qcolombet
Subscribers: llvm-commits, aemerson, rengolin, mcrosier
Differential Revision: https://reviews.llvm.org/D28680
llvm-svn: 299379
This moves the isMask and isShiftedMask functions to be class methods. They now use the MathExtras.h function for single word size and leading/trailing zeros/ones or countPopulation for the multiword size. The previous implementation made multiple temorary memory allocations to do the bitwise arithmetic operations to match the MathExtras.h implementation.
Differential Revision: https://reviews.llvm.org/D31565
llvm-svn: 299362
The patch rL298481 was reverted due to crash on clang-with-lto-ubuntu build.
The reason of the crash was type mismatch between either a or b and RHS in the following situation:
LHS = sext(a +nsw b) > RHS.
This is quite rare, but still possible situation. Normally we need to cast all {a, b, RHS} to their widest type.
But we try to avoid creation of new SCEV that are not constants to avoid initiating recursive analysis that
can take a lot of time and/or cache a bad value for iterations number. To deal with this, in this patch we
reject this case and will not try to analyze it if the type of sum doesn't match with the type of RHS. In this
situation we don't need to create any non-constant SCEVs.
This patch also adds an assertion to the method IsProvedViaContext so that we could fail on it and not
go further into range analysis etc (because in some situations these analyzes succeed even when the passed
arguments have wrong types, what should not normally happen).
The patch also contains a fix for a problem with too narrow scope of the analysis caused by wrong
usage of predicates in recursive invocations.
The regression test on the said failure: test/Analysis/ScalarEvolution/implied-via-addition.ll
Reviewers: reames, apilipenko, anna, sanjoy
Reviewed By: sanjoy
Subscribers: mzolotukhin, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D31238
llvm-svn: 299205
SimplifyDemandedUseBits for Add/Sub already recursed down LHS and RHS for simplifying bits. If that didn't provide any simplifications we fall back to calling computeKnownBits which will recurse again. Instead just take the known bits for LHS and RHS we already have and call into a new function in ValueTracking that can calculate the known bits given the LHS/RHS bits.
llvm-svn: 298711
The patch rL298481 was reverted due to crash on clang-with-lto-ubuntu build.
The reason of the crash was type mismatch between either a or b and RHS in the following situation:
LHS = sext(a +nsw b) > RHS.
This is quite rare, but still possible situation. Normally we need to cast all {a, b, RHS} to their widest type.
But we try to avoid creation of new SCEV that are not constants to avoid initiating recursive analysis that
can take a lot of time and/or cache a bad value for iterations number. To deal with this, in this patch we
reject this case and will not try to analyze it if the type of sum doesn't match with the type of RHS. In this
situation we don't need to create any non-constant SCEVs.
This patch also adds an assertion to the method IsProvedViaContext so that we could fail on it and not
go further into range analysis etc (because in some situations these analyzes succeed even when the passed
arguments have wrong types, what should not normally happen).
The patch also contains a fix for a problem with too narrow scope of the analysis caused by wrong
usage of predicates in recursive invocations.
The regression test on the said failure: test/Analysis/ScalarEvolution/implied-via-addition.ll
llvm-svn: 298690
Summary: The current prefix based function layout algorithm only looks at function's entry count, which is not sufficient. A function should be grouped together if its entry count or any call edge count is hot.
Reviewers: davidxl, eraman
Reviewed By: eraman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31225
llvm-svn: 298656
Using AssemblyAnnotationWriter for LVI printer prints
for instructions and basic blocks.
So, we explicitly need to print LVI info for the arguments of the function (these
are values and not instructions).
llvm-svn: 298640
Given below case:
%y = shl %x, n
%z = ashr %y, m
when n = m, SCEV models it as sext(trunc(x)). This patch tries to handle
the case where n > m by using sext(mul(trunc(x), 2^(n-m)))) as the SCEV
expression.
llvm-svn: 298631
Summary:
Adding a printer pass for printing the LVI cache values after transformations
that use LVI.
This will help us in identifying cases where LVI
invariants are violated, or transforms that leave LVI in an incorrect state.
Right now, I have added two test cases to show that the printer pass is working.
I will be adding more test cases in a later change, once this change is
checked in upstream.
Reviewers: reames, dberlin, sanjoy, apilipenko
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30790
llvm-svn: 298542
This patch allows SCEV predicate analysis to prove implication of some expression predicates
from context predicates related to arguments of those expressions.
It introduces three new rules:
For addition:
(A >X && B >= 0) || (B >= 0 && A > X) ===> (A + B) > X.
For division:
(A > X) && (0 < B <= X + 1) ===> (A / B > 0).
(A > X) && (-B <= X < 0) ===> (A / B >= 0).
Using these rules, SCEV is able to prove facts like "if X > 1 then X / 2 > 0".
They can also be combined with the same context, to prove more complex expressions like
"if X > 1 then X/2 + 1 > 1".
Diffirential Revision: https://reviews.llvm.org/D30887
Reviewed by: sanjoy
llvm-svn: 298481
This adds a parameter to @llvm.objectsize that makes it return
conservative values if it's given null.
This fixes PR23277.
Differential Revision: https://reviews.llvm.org/D28494
llvm-svn: 298430
Summary: Because SamplePGO passes will be invoked twice in ThinLTO build: once at compile phase, the other at backend. We want to make sure the IR at the 2nd phase matches the hot part in profile, thus we do not want to inline hot callsites in the first phase.
Reviewers: tejohnson, eraman
Reviewed By: tejohnson
Subscribers: mehdi_amini, llvm-commits, Prazek
Differential Revision: https://reviews.llvm.org/D31201
llvm-svn: 298428
Summary: ModuleSummary should use the standard interface of ProfileSummary::getProfileCount.
Reviewers: eraman, tejohnson
Reviewed By: tejohnson
Subscribers: tejohnson, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D31154
llvm-svn: 298404
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.
Rename AttributeSetImpl to AttributeListImpl to follow suit.
It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.
Reviewers: sanjoy, javed.absar, chandlerc, pete
Reviewed By: pete
Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits
Differential Revision: https://reviews.llvm.org/D31102
llvm-svn: 298393
After the loop unroll threshold was increased in r295538, very
large constant expressions can be created. This prevents them
from having to be recursively scanned, leading to a compile
time blow-up.
Differential Revision: https://reviews.llvm.org/D30689
llvm-svn: 298356
If loop bound containing calculations like min(a,b), the Scalar
Evolution API getSmallConstantTripMultiple returns 4294967295 "-1"
as the trip multiple. The problem is that, SCEV use -1 * umax to
represent umin. The multiple constant -1 was returned, and the logic
of guarding against huge trip counts was skipped. Because -1 has 32
active bits.
The fix attempt to factor more general cases. First try to get the
greatest power of two divisor of trip count expression. In case
overflow happens, the trip count expression is still divisible by the
greatest power of two divisor returned. Returns 1 if not divisible by 2.
Patch by Huihui Zhang <huihuiz@codeaurora.org>
Differential Revision: https://reviews.llvm.org/D30840
llvm-svn: 298301
Summary:
Extract FindAvailablePtrLoadStore out of FindAvailableLoadedValue.
Prepare for upcoming change which will do phi-translation for load on
phi pointer in jump threading SimplifyPartiallyRedundantLoad.
This is in preparation for https://reviews.llvm.org/D30543
Reviewers: efriedma, sanjoy, davide, dberlin
Reviewed By: davide
Subscribers: junbuml, davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D30524
llvm-svn: 298216
Summary:
The reverse of an artbitrary bitpattern is also an arbitrary
bitpattern.
Reviewers: trentxintong, arsenm, majnemer
Reviewed By: majnemer
Subscribers: majnemer, wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D31118
llvm-svn: 298201
The code assigned to KnownZero, but later code unconditionally assigned over it. I'm pretty sure the later code can handle the same cases and more equally well.
llvm-svn: 298190
Summary:
This approach has two major advantages over the existing one:
1. We don't need to extend bitwidth in our computations. Extending
bitwidth is a big issue for compile time as we often end up working with
APInts wider than 64bit, which is a slow case for APInt.
2. When we zero extend a wrapped range, we lose some information (we
replace the range with [0, 1 << src bit width)). Thus, avoiding such
extensions better preserves information.
Correctness testing:
I ran 'ninja check' with assertions that the new implementation of
getRangeForAffineAR gives the same results as the old one (this
functionality is not present in this patch). There were several failures
- I inspected them manually and found out that they all are caused by
the fact that we're returning more accurate results now (see bullet (2)
above).
Without such assertions 'ninja check' works just fine, as well as
SPEC2006.
Compile time testing:
CTMark/Os:
- mafft/pairlocalalign -16.98%
- tramp3d-v4/tramp3d-v4 -12.72%
- lencod/lencod -11.51%
- Bullet/bullet -4.36%
- ClamAV/clamscan -3.66%
- 7zip/7zip-benchmark -3.19%
- sqlite3/sqlite3 -2.95%
- SPASS/SPASS -2.74%
- Average -5.81%
Performance testing:
The changes are expected to be neutral for runtime performance.
Reviewers: sanjoy, atrick, pete
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30477
llvm-svn: 297992
If it is possible for the RHS of a shift operation to be greater than or equal
to the bit-width, then the result might be undef, and we can't report any known
bits.
In some cases, this was allowing a transformation in instcombine which widened
an undef value from i1 to i32, increasing the range of values that a function
could return.
Differential revision: https://reviews.llvm.org/D30781
llvm-svn: 297724
getIntrinsicInstrCost() used to only compute scalarization cost based on types.
This patch improves this so that the actual arguments are checked when they are
available, in order to handle only unique non-constant operands.
Tests updates:
Analysis/CostModel/X86/arith-fp.ll
Transforms/LoopVectorize/AArch64/interleaved_cost.ll
Transforms/LoopVectorize/ARM/interleaved_cost.ll
The improvement in getOperandsScalarizationOverhead() to differentiate on
constants made it necessary to update the interleaved_cost.ll tests even
though they do not relate to intrinsics.
Review: Hal Finkel
https://reviews.llvm.org/D29540
llvm-svn: 297705
Summary:
This change solves the same problem as D30726, except that this only
throws out the bathwater.
AST was not correctly tracking and deleting UnknownInstructions via
handles. The existing code only tracks "pointers" in its
`ASTCallbackVH`, so an UnknownInstruction (that isn't also def'ing a
pointer used by another memory instruction) never gets a
`ASTCallbackVH`.
There are two other ways to solve this problem:
- Use the `PointerRec` scheme for both known and unknown instructions.
- Use a `CallbackVH` that erases the offending Instruction from the
UnknownInstruction list.
Both of the above changes seemed to be significantly (and unnecessarily
IMO) more complex than this.
Reviewers: chandlerc, dberlin, hfinkel, reames
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D30849
llvm-svn: 297539
Summary: There is no need to check profile count as only CallInst will have metadata attached.
Reviewers: eraman
Reviewed By: eraman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30799
llvm-svn: 297500
This reverts r293386, r294027, r294029 and r296411.
Turns out the SLP tree isn't actually a "tree" and we don't handle
accessing the same packet of loads in several different orders well,
causing miscompiles.
Revert until we can fix this properly.
llvm-svn: 297493
Summary: We should not use that to check basic block hotness as optimization may mess it up.
Reviewers: eraman
Reviewed By: eraman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30800
llvm-svn: 297437
Summary:
In a .symver assembler directive like:
.symver name, name2@@nodename
"name2@@nodename" should get the same symbol binding as "name".
While the ELF object writer is updating the symbol binding for .symver
aliases before emitting the object file, not doing so when the module
inline assembly is handled by the RecordStreamer is causing the wrong
behavior in *LTO mode.
E.g. when "name" is global, "name2@@nodename" must also be marked as
global. Otherwise, the symbol is skipped when iterating over the LTO
InputFile symbols (InputFile::Symbol::shouldSkip). So, for example,
when performing any *LTO via the gold-plugin, the versioned symbol
definition is not recorded by the plugin and passed back to the
linker. If the object was in an archive, and there were no other symbols
needed from that object, the object would not be included in the final
link and references to the versioned symbol are undefined.
The llvm-lto2 tests added will give an error about an unused symbol
resolution without the fix.
Reviewers: rafael, pcc
Reviewed By: pcc
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D30485
llvm-svn: 297332
A block with an UnreachableInst does not transfer execution to a successor.
The problem was exposed by GVN-hoist. This patch fixes bug 32153.
Patch by Aditya Kumar.
Differential Revision: https://reviews.llvm.org/D30667
llvm-svn: 297254
Fixes PR32142.
r287232 accidentally increased the recursion threshold for
CompareValueComplexity from 2 to 32. This change reverses that change
by introducing a separate flag for CompareValueComplexity's threshold.
llvm-svn: 296992
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.It also needs to recompute the proper Lane for
external use of vectorizable scalars based on shuffle mask.
Reviewers: mkuper
Differential Revision: https://reviews.llvm.org/D30159
Change-Id: Ide8773ce0ad3562f3cf4d1a0ad0f487e2f60ce5d
llvm-svn: 296863
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.
Reviewers: mkuper
Differential Revision: https://reviews.llvm.org/D30159
Change-Id: Id1e287f073fa4959713ba545fa4254db5da8b40d
llvm-svn: 296575
Summary: For SamplePGO, the profile may contain cross-module inline stacks. As we need to make sure the profile annotation happens when all the hot inline stacks are expanded, we need to pass this info to the module importer so that it can import proper functions if necessary. This patch implemented this feature by emitting cross-module targets as part of function entry metadata. In the module-summary phase, the metadata is used to build call edges that points to functions need to be imported.
Reviewers: mehdi_amini, tejohnson
Reviewed By: tejohnson
Subscribers: davidxl, llvm-commits
Differential Revision: https://reviews.llvm.org/D30053
llvm-svn: 296498
Summary:
Previously we used to return a bogus result, 0, for IR like `ashr %val,
-1`.
I've also added an assert checking that `ComputeNumSignBits` at least
returns 1. That assert found an already checked in test case where we
were returning a bad result for `ashr %val, -1`.
Fixes PR32045.
Reviewers: spatel, majnemer
Reviewed By: spatel, majnemer
Subscribers: efriedma, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D30311
llvm-svn: 296273
Last use was killed in my previous patch. The preferred way is now to
construct the remark, pipe things to it and pass it to ORE.emit.
llvm-svn: 296019
This needed a const_cast for the dominator tree recalculation in
OptimizationRemarkEmitter, but we do that all over the place already
and it's safe.
llvm-svn: 295812
Summary:
Motivation: fix PR31181 without regression (the actual fix is still in
progress). However, the actual content of PR31181 is not relevant
here.
This change makes poison propagation more aggressive in the following
cases:
1. poision * Val == poison, for any Val. In particular, this changes
existing intentional and documented behavior in these two cases:
a. Val is 0
b. Val is 2^k * N
2. poison << Val == poison, for any Val
3. getelementptr is poison if any input is poison
I think all of these are justified (and are axiomatically true in the
new poison / undef model):
1a: we need poison * 0 to be poison to allow transforms like these:
A * (B + C) ==> A * B + A * C
If poison * 0 were 0 then the above transform could not be allowed
since e.g. we could have A = poison, B = 1, C = -1, making the LHS
poison * (1 + -1) = poison * 0 = 0
and the RHS
poison * 1 + poison * -1 = poison + poison = poison
1b: we need e.g. poison * 4 to be poison since we want to allow
A * 4 ==> A + A + A + A
If poison * 4 were a value with all of their bits poison except the
last four; then we'd not be able to do this transform since then if A
were poison the LHS would only be "partially" poison while the RHS
would be "full" poison.
2: Same reasoning as (1b), we'd like have the following kinds
transforms be legal:
A << 1 ==> A + A
Reviewers: majnemer, efriedma
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D30185
llvm-svn: 295809
The change to InstCombine in:
https://reviews.llvm.org/D29729
...exposes this missing fold in InstSimplify, so adding this
first to avoid a regression.
llvm-svn: 295573
Several visitors check if operands to the instruction are constants,
either as it is or after looking up SimplifiedValues, check if the
result is a constant and update the SimplifiedValues map. This
refactoring splits it into a common function that does the checking of
whether the operands are constants and updating of the SimplifiedValues
table, and an instruction specific part that is implemented by each
instruction visitor as a lambda and passed to the common function.
Differential revision: https://reviews.llvm.org/D30104
llvm-svn: 295552
This creates and uses a DiagnosticLocation type rather than using
DebugLoc for this purpose in the backend diagnostics. This is NFC for
now, but will allow us to create locations for diagnostics without
having to create new metadata nodes when we don't have a DILocation.
llvm-svn: 295519
This is a short term solution to the problem that many passes currently fail
to update the assumption cache. In the long term the verifier should not
be controllable with a flag. We should either fix all passes to correctly
update the assumption cache and enable the verifier unconditionally or
somehow arrange for the assumption list to be updated automatically by passes.
Differential Revision: https://reviews.llvm.org/D30003
llvm-svn: 295236
proven larger than the loop-count
This fixes PR31098: Try to resolve statically data-dependences whose
compile-time-unknown distance can be proven larger than the loop-count,
instead of resorting to runtime dependence checking (which are not always
possible).
For vectorization it is sufficient to prove that the dependence distance
is >= VF; But in some cases we can prune unknown dependence distances early,
and even before selecting the VF, and without a runtime test, by comparing
the distance against the loop iteration count. Since the vectorized code
will be executed only if LoopCount >= VF, proving distance >= LoopCount
also guarantees that distance >= VF. This check is also equivalent to the
Strong SIV Test.
Reviewers: mkuper, anemet, sanjoy
Differential Revision: https://reviews.llvm.org/D28044
llvm-svn: 294892
The summary information includes all uses of llvm.type.test and
llvm.type.checked.load intrinsics that can be used to devirtualize calls,
including any constant arguments for virtual constant propagation.
Differential Revision: https://reviews.llvm.org/D29734
llvm-svn: 294795
Somewhat amazingly, this only requires teaching it to clean them up when
deleting a dead function from the graph. And we already have exactly the
necessary data structures to do that in the parent RefSCCs.
This allows ArgPromote to work in a much simpler way be merely letting
reference edges linger in the graph after the causing IR is deleted. We
will clean up these edges when we run any function pass over the IR, but
don't remove them eagerly.
This avoids all of the quadratic update issues both in the current pass
manager and in my previous attempt with the new pass manager.
Differential Revision: https://reviews.llvm.org/D29579
llvm-svn: 294663
disturbing the graph or having to update edges.
This is motivated by porting argument promotion to the new pass manager.
Because of how LLVM IR Function objects work, in order to change their
signature a new object needs to be created. This is efficient and
straight forward in the IR but previously was very hard to implement in
LCG. We could easily replace the function a node in the graph
represents. The challenging part is how to handle updating the edges in
the graph.
LCG previously used an edge to a raw function to represent a node that
had not yet been scanned for calls and references. This was the core
of its laziness. However, that model causes this kind of update to be
very hard:
1) The keys to lookup an edge need to be `Function*`s that would all
need to be updated when we update the node.
2) There will be some unknown number of edges that haven't transitioned
from `Function*` edges to `Node*` edges.
All of this complexity isn't necessary. Instead, we can always build
a node around any function, always pointing edges at it and always using
it as the key to lookup an edge. To maintain the laziness, we need to
sink the *edges* of a node into a secondary object and explicitly model
transitioning a node from empty to populated by scanning the function.
This design seems much cleaner in a number of ways, but importantly
there is now exactly *one* place where the `Function*` has to be
updated!
Some other cleanups that fall out of this include having something to
model the *entry* edges more accurately. Rather than hand rolling parts
of the node in the graph itself, we have an explicit `EdgeSequence`
object that gives us exactly the functionality needed. We also have
a consistent place to define the edge iterators and can use them for
both the entry edges and the internal edges of the graph.
The API used to model the separation between a node and its edges is
intentionally very thin as most clients are expected to deal with nodes
that have populated edges. We model this exactly as an optional does
with an additional method to populate the edges when that is
a reasonable thing for a client to do. This is based on API design
suggestions from Richard Smith and David Blaikie, credit goes to them
for helping pick how to model this without it being either too explicit
or too implicit.
The patch is somewhat noisy due to shifting around iterator types and
new syntax for walking the edges of a node, but most of the
functionality change is in the `Edge`, `EdgeSequence`, and `Node` types.
Differential Revision: https://reviews.llvm.org/D29577
llvm-svn: 294653
Summary:
Convert all obvious node_begin/node_end and child_begin/child_end
pairs to range based for.
Sending for review in case someone has a good idea how to make
graph_children able to be inferred. It looks like it would require
changing GraphTraits to be two argument or something. I presume
inference does not happen because it would have to check every
GraphTraits in the world to see if the noderef types matched.
Note: This change was 3-staged with clang as well, which uses
Dominators/etc from LLVM.
Reviewers: chandlerc, tstellarAMD, dblaikie, rsmith
Subscribers: arsenm, llvm-commits, nhaehnle
Differential Revision: https://reviews.llvm.org/D29767
llvm-svn: 294620
Summary:
LVI is now depth first, which is optimal for iteration strategy in
terms of work per call. However, the way the results get cached means
it can still go very badly N^2 or worse right now. The overdefined
cache is per-block, because LVI wants to try to get different results
for the same name in different blocks (IE solve the problem
PredicateInfo solves). This means even if we discover a value is
overdefined after going very deep, it doesn't cache this information,
causing it to end up trying to rediscover it again and again. The
same is true for values along the way. In practice, overdefined
anywhere should mean overdefined everywhere (this is how, for example,
SCCP works).
Until we get around to reworking the overdefined cache, we need to
limit the worklist size we process. Note that permanently reverting
the DFS strategy exploration seems the wrong strategy (temporarily
seems fine if we really want). BFS is clearly the wrong approach, it
just gets luckier on some testcases. It's also very hard to design
an effective throttle for BFS. For DFS, the throttle is directly related
to the depth of the CFG. So really deep CFGs will get cutoff, smaller
ones will not. As the CFG simplifies, you get better results.
In BFS, the limit is it's related to the fan-out times average block size,
which is harder to reason about or make good choices for.
Bug being filed about the overdefined cache, but it will require major
surgery to fix it (plumbing predicateinfo through CVP or LVI).
Note: I did not make this number configurable because i'm not sure
anyone really needs to tweak this knob. We run CVP 3 times. On the
testcases i have the slow ones happen in the middle, where CVP is
doing cleanup work other things are effective at. Over the course of
3 runs, we don't see to have any real loss of performance.
I haven't gotten a minimized testcase yet, but just imagine in your
head a testcase where, going *up* the CFG, you have branches, one of
which leads 50000 blocks deep, and the other, to something where the
answer is overdefined immediately. BFS would discover the overdefined
faster than DFS, but do more work to do so. In practice, the right
answer is "once DFS discovers overdefined for a value, stop trying to
get more info about that value" (and so, DFS would normally cache the
overdefined results for every value it passed through in those 50k
blocks, and never do that work again. But it don't, because of the
naming problem)
Reviewers: chandlerc, djasper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29715
llvm-svn: 294463
The patch committed in r293017, as discussed on the list, doesn't really
make sense but was causing an actual issue to go away.
The issue turns out to be that in one place the extra template arguments
were dropped from the OuterAnalysisManagerProxy. This in turn caused the
types used in one set of places to access the key to be completely
different from the types used in another set of places for both Loop and
CGSCC cases where there are extra arguments.
I have literally no idea how anything seemed to work with this bug in
place. It blows my mind. But it did except for mingw64 in a DLL build.
I've added a really handy static assert that helps ensure we don't break
this in the future. It immediately diagnoses the issue with a compile
failure and a very clear error message. Much better that staring at
backtraces on a build bot. =]
llvm-svn: 294267
This patch changes the order in which LVI explores previously unexplored paths.
Previously, the code used an BFS strategy where each unexplored input was added to the search queue before any of them were explored. This has the effect of causing all inputs to be explored before returning to re-evaluate the merge point (non-local or phi node). This has the unfortunate property of doing redundant work if one of the inputs to the merge is found to be overdefined (i.e. unanalysable). If any input is overdefined, the result of the merge will be too; regardless of the values of other inputs.
The new code uses a DFS strategy where we re-evaluate the merge after evaluating each input. If we discover an overdefined input, we immediately return without exploring other inputs.
We have reports of large (4-10x) improvements of compile time with this patch and some reports of more precise analysis results as well. See the review discussion for details. The original motivating case was pr10584.
Differential Revision: https://reviews.llvm.org/D28190
llvm-svn: 294264
iteration.
The lazy formation of RefSCCs isn't really the most important part of
the laziness here -- that has to do with walking the functions
themselves -- and isn't essential to maintain. Originally, there were
incremental update algorithms that relied on updates happening
predominantly near the most recent RefSCC formed, but those have been
replaced with ones that have much tighter general case bounds at this
point. We do still perform asserts that only scale well due to this
incrementality, but those are easy to place behind EXPENSIVE_CHECKS.
Removing this simplifies the entire analysis by having a single up-front
step that builds all of the RefSCCs in a direct Tarjan walk. We can even
easily replace this with other or better algorithms at will and with
much less confusion now that there is no iterator-based incremental
logic involved. This removes a lot of complexity from LCG.
Another advantage of moving in this direction is that it simplifies
testing the system substantially as we no longer have to worry about
observing and mutating the graph half-way through the RefSCC formation.
We still need a somewhat special iterator for RefSCCs because we want
the iterator to remain stable in the face of graph updates. However,
this now merely involves relative indexing to the current RefSCC's
position in the sequence which isn't too hard.
Differential Revision: https://reviews.llvm.org/D29381
llvm-svn: 294227
for a quite big function with source like
%add = add nsw i32 %mul, %conv
%mul1 = mul nsw i32 %add, %conv
%add2 = add nsw i32 %mul1, %add
%mul3 = mul nsw i32 %add2, %add
; repeat couple of thousands times
that can be produced by loop unroll, getAddExpr() tries to recursively construct SCEV and runs almost infinite time.
Added recursion depth restriction (with new parameter to set it)
Reviewers: sanjoy
Subscribers: hfinkel, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D28158
llvm-svn: 294181
This generalizes memory access sorting to use differences between SCEVs,
instead of relying on constant offsets. That allows us to properly do
SLP vectorization of non-sequentially ordered loads within loops bodies.
Differential Revision: https://reviews.llvm.org/D29425
llvm-svn: 294027
This reverts commit r293970.
After more discussion, this belongs to the linker side and
there is no added value to do it at this level.
llvm-svn: 293993
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.
This is a recommit of r293912 after fixing build failures,
and a recommit of r293918 after fixing LLD tests.
Differential Revision: https://reviews.llvm.org/D28978
llvm-svn: 293970
1. Added comments for options
2. Added missing option cl::desc field
3. Uniified function filter option for graph viewing.
Now PGO count/raw-counts share the same
filter option: -view-bfi-func-name=.
llvm-svn: 293938
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.
This is a recommit of r293912 after fixing build failures.
Differential Revision: https://reviews.llvm.org/D28978
llvm-svn: 293918
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.
Differential Revision: https://reviews.llvm.org/D28978
llvm-svn: 293912
Summary: While scanning predecessors to find an available loaded value, if the predecessor has a single predecessor, we can continue scanning through the single predecessor.
Reviewers: mcrosier, rengolin, reames, davidxl, haicheng
Reviewed By: rengolin
Subscribers: zzheng, llvm-commits
Differential Revision: https://reviews.llvm.org/D29200
llvm-svn: 293896
This patch moves some helper functions related to interleaved access
vectorization out of LoopVectorize.cpp and into VectorUtils.cpp. We would like
to use these functions in a follow-on patch that improves interleaved load and
store lowering in (ARM/AArch64)ISelLowering.cpp. One of the functions was
already duplicated there and has been removed.
Differential Revision: https://reviews.llvm.org/D29398
llvm-svn: 293788
A program may contain llvm.assume info that disagrees with other analysis.
This may be caused by UB in the program, so we must not crash because of that.
As noted in the code comments:
https://llvm.org/bugs/show_bug.cgi?id=31809
...we can do better, but this at least avoids the assert/crash in the bug report.
Differential Revision: https://reviews.llvm.org/D29395
llvm-svn: 293773
Make SolveLinEquationWithOverflow take the start as a SCEV, so we can
solve more cases. With that implemented, get rid of the special case
for powers of two.
The additional functionality probably isn't particularly useful,
but it might help a little for certain cases involving pointer
arithmetic.
Differential Revision: https://reviews.llvm.org/D28884
llvm-svn: 293576
The jumbled scalar loads will be sorted while building the tree and these accesses will be marked to generate shufflevector after the vectorized load with proper mask.
Reviewers: hfinkel, mssimpso, mkuper
Differential Revision: https://reviews.llvm.org/D26905
Change-Id: I9c0c8e6f91a00076a7ee1465440a3f6ae092f7ad
llvm-svn: 293386
We had various variants of defining dump() functions in LLVM. Normalize
them (this should just consistently implement the things discussed in
http://lists.llvm.org/pipermail/cfe-dev/2014-January/034323.html
For reference:
- Public headers should just declare the dump() method but not use
LLVM_DUMP_METHOD or #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
- The definition of a dump method should look like this:
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void MyClass::dump() {
// print stuff to dbgs()...
}
#endif
llvm-svn: 293359
This is fixing pr31761: BasicAA is deducing NoAlias
on the result of the GEP if the base pointer is itself NoAlias.
This is possible only if the NoAlias on the base pointer is
deduced with a non-sized query: this should guarantee that
the pointers are belonging to different memory allocation
and that the GEP can't legally jump from one to another.
Differential Revision: https://reviews.llvm.org/D29216
llvm-svn: 293293
Summary:
CannotBeOrderedLessThanZero(powi(x, exp)) returns true if
CannotBeOrderedLessThanZero(x). But powi(-0, exp) is negative if exp is
odd, so we actually want to return SignBitMustBeZero(x).
Except that also isn't right, because we want to return true if x is
NaN, even if x has a negative sign bit.
What we really need in order to fix this is a consistent approach in
this function to handling the sign bit of NaNs. Without this it's very
difficult to say what the correct behavior here is.
Reviewers: hfinkel, efriedma, sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28927
llvm-svn: 293243
Inlining in getAddExpr() can cause abnormal computational time in some cases.
New parameter -scev-addops-inline-threshold is intruduced with default value 500.
Reviewers: sanjoy
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D28812
llvm-svn: 293176
with it.
This code was dereferencing the PoisoningVH which isn't allowed once it
is poisoned. But the code itself really doesn't need to access the
pointer, it is just doing the safe stuff of clearing out data structures
keyed on the pointer value.
Change the code to use iterators to erase directly from a DenseMap. This
is also substantially more efficient as it avoids lots of hashing and
lookups to do the erasure. DenseMap supports iterating behind the
iteration which is fairly easy to implement.
Sadly, I don't have a test case here. I'm not even close and I don't
know that I ever will be. The issue is that several of the tricky
aspects of fixing this only show up when you cause the stack's
SmallVector to be in *EXACTLY* the right location. I only ever got
a reproduction for those with Clang, and only with *exactly* the right
command line flags. Any adjustment, even to seemingly unrelated flags,
would make partial and half-way solutions magically start to "work". In
good news, all of this was caught with the LLVM test suite. Also, there
is no *specific* code here that is untested, just that the old pattern
of code won't immediately fail on any test case I've managed to
contrive.
llvm-svn: 293160
Refactoring to remove duplications of this method.
New method getOperandsScalarizationOverhead() that looks at the present unique
operands and add extract costs for them. Old behaviour was to just add extract
costs for one operand of the type always, which still happens in
getArithmeticInstrCost() if no operands are provided by the caller.
This is a good start of improving on this, but there are more places
that can be improved by using getOperandsScalarizationOverhead().
Review: Hal Finkel
https://reviews.llvm.org/D29017
llvm-svn: 293155
Summary:
Previously we assumed that the result of sqrt(x) always had 0 as its
sign bit. But sqrt(-0) == -0.
Reviewers: hfinkel, efriedma, sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28928
llvm-svn: 293115
This allows MIR passes to emit optimization remarks with the same level
of functionality that is available to IR passes.
It also hooks up the greedy register allocator to report spills. This
allows for interesting use cases like increasing interleaving on a loop
until spilling of registers is observed.
I still need to experiment whether reporting every spill scales but this
demonstrates for now that the functionality works from llc
using -pass-remarks*=<pass>.
Differential Revision: https://reviews.llvm.org/D29004
llvm-svn: 293110
Code region is the only part of this class that is IR-specific. Code
region is moved down in the inheritance tree to a new derived class,
called DiagnosticInfoIROptimization.
All the existing remarks are derived from this new class now.
This allows the new MIR pass-remark classes to be derived from
DiagnosticInfoOptimizationBase.
Also because we keep the name DiagnosticInfoOptimizationBase, the clang
parts don't need any adjustment.
Differential Revision: https://reviews.llvm.org/D29003
llvm-svn: 293109
Floating point intrinsics in LLVM are generally not speculatively
executed, since most of them are defined to behave the same as libm
functions, which set errno.
However, the @llvm.powi.* intrinsics do not correspond to any libm
function, and lacks any defined error handling semantics in LangRef.
It most certainly does not alter errno.
llvm-svn: 293041
I found root class should be instantiated for variadic tempate to instantiate static member explicitly.
This will fix failures in mingw DLL build.
llvm-svn: 293017
a lazy-asserting PoisoningVH.
AssertVH is fundamentally incompatible with cache-invalidation of
analysis results. The invaliadtion happens after the AssertingVH has
already fired. Instead, use a PoisoningVH that will assert if the
dangling handle is ever used rather than merely be assigned or
destroyed.
This patch also removes all of the (numerous) doomed attempts to work
around this fundamental incompatibility. It is a pretty significant
simplification IMO.
The most interesting change is in the Inliner where we still do some
clearing because we don't want to rely on the coarse grained
invalidation strategy of the containing pass manager. However, I prefer
the approach that contains this logic to the cleanup phase of the
Inliner, and I think we could enhance the CGSCC analysis management
layer to make this even better in the future if desired.
The rest is straight cleanup.
I've also added a test for one of the harder cases to work around: when
a *module analysis* contains many AssertingVHes pointing at functions.
Differential Revision: https://reviews.llvm.org/D29006
llvm-svn: 292928
Verifications of dominator tree and loop info are expensive operations
so they are disabled by default. They can be enabled by command line
options -verify-dom-info and -verify-loop-info. These options however
enable checks only in files Dominators.cpp and LoopInfo.cpp. If some
transformation changes dominaror tree and/or loop info, it would be
convenient to place similar checks to the files implementing the
transformation.
This change makes corresponding flags global, so they can be used in
any file to optionally turn verification on.
llvm-svn: 292889
Summary:
The LibFunc::Func enum holds enumerators named for libc functions.
Unfortunately, there are real situations, including libc implementations, where
function names are actually macros (musl uses "#define fopen64 fopen", for
example; any other transitively visible macro would have similar effects).
Strictly speaking, a conforming C++ Standard Library should provide any such
macros as functions instead (via <cstdio>). However, there are some "library"
functions which are not part of the standard, and thus not subject to this
rule (fopen64, for example). So, in order to be both portable and consistent,
the enum should not use the bare function names.
The old enum naming used a namespace LibFunc and an enum Func, with bare
enumerators. This patch changes LibFunc to be an enum with enumerators prefixed
with "LibFFunc_". (Unfortunately, a scoped enum is not sufficient to override
macros.)
There are additional changes required in clang.
Reviewers: rsmith
Subscribers: mehdi_amini, mzolotukhin, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D28476
llvm-svn: 292848
become unavailable.
The AssumptionCache is now immutable but it still needs to respond to
DomTree invalidation if it ended up caching one.
This lets us remove one of the explicit invalidates of LVI but the
other one continues to avoid hitting a latent bug.
llvm-svn: 292769
This is similar to what the caller (matchSelectPattern()) does. In all
cases where we succeed in matching a min/max pattern, the values in
that pattern will be the values of the 'select', so hoist that and
remove a bunch of duplicated code.
llvm-svn: 292725
Daniel Berlin