http://rise4fun.com/Alive/i8Q
A narrow bitwise logic op is obviously better than math for value tracking,
and zext is better than sext. Typically, the 'not' will be folded into an
icmp predicate.
The IR difference would even survive through codegen for x86, so we would see
worse code:
https://godbolt.org/g/C14HMF
one_or_zero(int, int): # @one_or_zero(int, int)
xorl %eax, %eax
cmpl %esi, %edi
setle %al
retq
one_or_zero_alt(int, int): # @one_or_zero_alt(int, int)
xorl %ecx, %ecx
cmpl %esi, %edi
setg %cl
movl $1, %eax
subl %ecx, %eax
retq
llvm-svn: 306243
Summary:
InstCombine replaces large allocas with small globals consts causing buffer overflows
on valid code, see PR33372.
This fix permits this optimization only if the global is dereference for alloca size.
Fixes PR33372
Reviewers: eugenis, majnemer, chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34311
llvm-svn: 306194
This reverts commit r306157.
It caused some timeouts in clang tests. Perhaps unreachable loops have
far too many phi nodes.
Reverting and investigating.
llvm-svn: 306162
Currently, the implementation of delete dead loops has a special case
when the loop being deleted is never executed. This special case
(updating of exit block's incoming values for phis) can be
run as a prepass for non-executable loops before performing
the actual deletion.
llvm-svn: 306157
Summary:
Many languages have a three way comparison idiom where comparing two values
produces not a boolean, but a tri-state value. Typical values (e.g. as used in
the lcmp/fcmp bytecodes from Java) are -1 for less than, 0 for equality, and +1
for greater than.
We actually do a great job already of converting three way comparisons into
binary comparisons when the result produced has one a single use. Unfortunately,
such values can have more than one use, and in that case, our existing
optimizations break down.
The patch adds a peephole which converts a three-way compare + test idiom into a
binary comparison on the original inputs. It focused on replacing the test on
the result of the three way compare and does nothing about removing the three
way compare itself. That's left to other optimizations (which do actually kick
in commonly.)
We currently recognize one idiom on signed integer compare. In the future, we
plan to recognize and simplify other comparison idioms on
other signed/unsigned datatypes such as floats, vectors etc.
This is a resurrection of Philip Reames' original patch:
https://reviews.llvm.org/D19452
Reviewers: majnemer, apilipenko, reames, sanjoy, mkazantsev
Reviewed by: mkazantsev
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34278
llvm-svn: 306100
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
I want to use the same logic as LoopSimplify to form dedicated exits in
another pass (SimpleLoopUnswitch) so I wanted to factor it out here.
I also noticed that there is a pretty significantly more efficient way
to implement this than the way the code in LoopSimplify worked. We don't
need to actually retain the set of unique exit blocks, we can just
rewrite them as we find them and use only a set to deduplicate.
This did require changing one part of LoopSimplify to not re-use the
unique set of exits, but it only used it to check that there was
a single unique exit. That part of the code is about to walk the exiting
blocks anyways, so it seemed better to rewrite it to use those exiting
blocks to compute this property on-demand.
I also had to ditch a statistic, but it doesn't seem terribly valuable.
Differential Revision: https://reviews.llvm.org/D34049
llvm-svn: 306081
Summary:
Currently, we incorrectly update exit blocks of loops when there are multiple
edges from a single exiting block to the exit block. This can happen when we
have switches as the terminator of the exiting blocks.
The fix here is to correctly update the phi nodes in the exit block, and remove
all incoming values *except* for one which is from the preheader.
Note: Currently, this error can manifest only while deleting non-executed loops. However, it
is possible to trigger this error in invariant loops, once we enhance the logic
around the exit conditions for the loop check.
Reviewers: chandlerc, dberlin, sanjoy, efriedma
Reviewed by: efriedma
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D34516
llvm-svn: 306048
Summary:
InstCombine likes to turn (icmp eq (and X, C1), 0) into (icmp slt (trunc (X)), 0) sometimes. This breaks foldSelectICmpAndOr's ability to recognize (select (icmp eq (and X, C1), 0), Y, (or Y, C2))->(or (shl (and X, C1), C3), y).
This patch tries to recover this. I had to flip around some of the early out checks so that I could create a new And instruction during the compare processing without it possibly never getting used.
Reviewers: spatel, majnemer, davide
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34184
llvm-svn: 306029
If the components of the and/or had multiple uses, this transform created an additional instruction.
This patch makes sure we remove one of the components.
Differential Revision: https://reviews.llvm.org/D34498
llvm-svn: 306027
There are 2 parts to this patch made simultaneously to avoid a regression.
We're reversing the canonicalization that moves bitwise vector ops before bitcasts.
We're moving bitwise vector ops *after* bitcasts instead. That's the 1st and 3rd hunks
of the patch. The motivation is that there's only one fold that currently depends on
the existing canonicalization (see next), but there are many folds that would
automatically benefit from the new canonicalization.
PR33138 ( https://bugs.llvm.org/show_bug.cgi?id=33138 ) shows why/how we have these
patterns in IR.
There's an or(and,andn) pattern that requires an adjustment in order to continue matching
to 'select' because the bitcast changes position. This match is unfortunately complicated
because it requires 4 logic ops with optional bitcast and sext ops.
Test diffs:
1. The bitcast.ll and bitcast-bigendian.ll changes show the most basic difference -
bitcast comes before logic.
2. There are also tests with no diffs in bitcast.ll that verify that we're still doing
folds that were enabled by the previous canonicalization.
3. icmp-xor-signbit.ll shows the payoff. We don't need to adjust existing icmp patterns
to look through bitcasts.
4. logical-select.ll contains several tests for the or(and,andn) --> select fold to
verify that we are still handling those cases. The lone diff shows the movement of
the bitcast from the new canonicalization rule.
Differential Revision: https://reviews.llvm.org/D33517
llvm-svn: 306011
Summary:
vectorizer-maximize-bandwidth is generally useful in terms of performance. I've tested the impact of changing this to default on speccpu benchmarks on sandybridge machines. The result shows non-negative impact:
spec/2006/fp/C++/444.namd 26.84 -0.31%
spec/2006/fp/C++/447.dealII 46.19 +0.89%
spec/2006/fp/C++/450.soplex 42.92 -0.44%
spec/2006/fp/C++/453.povray 38.57 -2.25%
spec/2006/fp/C/433.milc 24.54 -0.76%
spec/2006/fp/C/470.lbm 41.08 +0.26%
spec/2006/fp/C/482.sphinx3 47.58 -0.99%
spec/2006/int/C++/471.omnetpp 22.06 +1.87%
spec/2006/int/C++/473.astar 22.65 -0.12%
spec/2006/int/C++/483.xalancbmk 33.69 +4.97%
spec/2006/int/C/400.perlbench 33.43 +1.70%
spec/2006/int/C/401.bzip2 23.02 -0.19%
spec/2006/int/C/403.gcc 32.57 -0.43%
spec/2006/int/C/429.mcf 40.35 +0.27%
spec/2006/int/C/445.gobmk 26.96 +0.06%
spec/2006/int/C/456.hmmer 24.4 +0.19%
spec/2006/int/C/458.sjeng 27.91 -0.08%
spec/2006/int/C/462.libquantum 57.47 -0.20%
spec/2006/int/C/464.h264ref 46.52 +1.35%
geometric mean +0.29%
The regression on 453.povray seems real, but is due to secondary effects as all hot functions are bit-identical with and without the flag.
I started this patch to consult upstream opinions on this. It will be greatly appreciated if the community can help test the performance impact of this change on other architectures so that we can decided if this should be target-dependent.
Reviewers: hfinkel, mkuper, davidxl, chandlerc
Reviewed By: chandlerc
Subscribers: rengolin, sanjoy, javed.absar, bjope, dorit, magabari, RKSimon, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D33341
llvm-svn: 305960
Summary: r305009 disables recursive inlining for indirect calls in sample loader pass. The same logic applies to direct recursive calls.
Reviewers: iteratee, davidxl
Reviewed By: iteratee
Subscribers: sanjoy, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D34456
llvm-svn: 305934
Summary:
I noticed that passing known bits across these intrinsics isn't great at capturing the information we really know. Turning known bits of the input into known bits of a count output isn't able to convey a lot of what we really know.
This patch adds range metadata to these intrinsics based on the known bits.
Currently the patch punts if we already have range metadata present.
Reviewers: spatel, RKSimon, davide, majnemer
Reviewed By: RKSimon
Subscribers: sanjoy, hfinkel, llvm-commits
Differential Revision: https://reviews.llvm.org/D32582
llvm-svn: 305927
Summary:
Previously this folding had no checks to see if it was going to result in less instructions. This was pointed out during the review of D34184
This patch adds code to count how many instructions its going to create vs how many its going to remove so we can make a proper decision.
Reviewers: spatel, majnemer
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34437
llvm-svn: 305926
We weren't actually checking for duplicated stores, as the condition
was always actually false. This was found by Coverity, and I have
no clue how to trigger this in real-world code (although I
tried for a bit).
llvm-svn: 305867
We have a large portfolio of folds for and-of-icmps and or-of-icmps in InstSimplify and InstCombine,
but hardly anything for xor-of-icmps. Rather than trying to rethink and translate all of those folds,
we can use the truth table definition of xor:
X ^ Y --> (X | Y) & !(X & Y)
...to see if we can convert the xor to and/or and then use the existing folds.
http://rise4fun.com/Alive/J9v
Differential Revision: https://reviews.llvm.org/D33342
llvm-svn: 305792
With PR33517, it became apparent that symbol table creation can fail
when presented with malformed inputs. This patch makes that sort of
error detectable, so llvm-cov etc. can fail more gracefully.
Specifically, we now check that function names within the symbol table
aren't empty.
Testing: check-{llvm,clang,profile}, some unit test updates.
llvm-svn: 305765
Summary:
Existing heuristic uses the ratio between the function entry
frequency and the loop invocation frequency to find cold loops. However,
even if the loop executes frequently, if it has a small trip count per
each invocation, vectorization is not beneficial. On the other hand,
even if the loop invocation frequency is much smaller than the function
invocation frequency, if the trip count is high it is still beneficial
to vectorize the loop.
This patch uses estimated trip count computed from the profile metadata
as a primary metric to determine coldness of the loop. If the estimated
trip count cannot be computed, it falls back to the original heuristics.
Reviewers: Ayal, mssimpso, mkuper, danielcdh, wmi, tejohnson
Reviewed By: tejohnson
Subscribers: tejohnson, mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D32451
llvm-svn: 305729
Summary:
Some optimizations in AddReachableCodeToWorklist did not update
the MadeIRChange state. This could happen both when removing
trivially dead instructions (DCE) and at constant folds.
It is essential that changes to the IR is reported correctly,
since for example InstCombinePass::run() will indicate that all
analyses are preserved otherwise.
And the CGPassManager determines if the CallGraph is up-to-date
based on status from InstructionCombiningPass::runOnFunction().
The new test case early_dce_clobbers_callgraph.ll is a reproducer
for some asserts that started to trigger after changes in the
inliner in r305245. With this patch the test case passes again.
Reviewers: sanjoy, craig.topper, dblaikie
Reviewed By: craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34346
llvm-svn: 305725
This seems to be interacting badly with ASan somehow, causing false reports of
heap-buffer overflows: PR33514.
> Summary:
> The patch makes instruction count the highest priority for
> LSR solution for X86 (previously registers had highest priority).
>
> Reviewers: qcolombet
>
> Differential Revision: http://reviews.llvm.org/D30562
>
> From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 305720
Summary:
These 4 patterns have the same one use check repeated twice for each. Once without a cast and one with. But the cast has no effect on what method is called.
For the OR case I believe it is always profitable regardless of the number of uses since we'll never increase the instruction count.
For the AND case I believe it is profitable if the pair of xors has one use such that we'll get rid of it completely. Or if the C value is something freely invertible, in which case the not doesn't cost anything.
Reviewers: spatel, majnemer
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34308
llvm-svn: 305705
Summary:
Currently we don't try to do anything with vector xors.
This patch adds support for removing duplicate pairs from a chain of vector xors as its pretty easy to support. We still dont' try to combine the xors with and/ors, but I might try that in a future patch.
Reviewers: mcrosier, davide, resistor
Reviewed By: mcrosier
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34338
llvm-svn: 305704
Summary:
After a single predecessor is merged into a basic block, we need to invalidate
the LVI information for the new merged block, when LVI is not provably true for
all of instructions in the new block.
The test cases added show the correct LVI information using the LVI printer
pass.
Reviewers: reames, dberlin, davide, sanjoy
Reviewed by: dberlin, davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34108
llvm-svn: 305699
Summary: use AA to tell whether a load can be moved before a call that writes to memory.
Reviewers: dberlin, davide, sanjoy, hfinkel
Reviewed By: hfinkel
Subscribers: hfinkel, llvm-commits
Differential Revision: https://reviews.llvm.org/D34115
llvm-svn: 305698
Summary:
This allows strlen to be moved out of the loop in case its argument is
not modified in the loop in LICM.
Reviewers: hfinkel, davide, sanjoy, dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34323
llvm-svn: 305641
Summary:
When we fold vector constants that are operands of phi's that feed into select,
we need to set the correct insertion point for the *new* selects that get generated.
The correct insertion point is the incoming block for the phi.
Such cases can occur with patch r298845, which fixed folding of
vector constants, but the new selects could be inserted incorrectly (as the added
test case shows).
Reviewers: majnemer, spatel, sanjoy
Reviewed by: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34162
llvm-svn: 305591
The recommit fixes two bugs: The first one is to use CurrentBlock instead of
PREInstr's Parent as param of performScalarPREInsertion because the Parent
of a clone instruction may be uninitialized. The second one is stop PRE when
CurrentBlock to its predecessor is a backedge and an operand of CurInst is
defined inside of CurrentBlock. The same value defined inside of loop in last
iteration can not be regarded as available.
Right now scalarpre doesn't have phi-translate support, so it will miss some
simple pre opportunities. Like the following testcase, current scalarpre cannot
recognize the last "a * b" is fully redundent because a and b used by the last
"a * b" expr are both defined by phis.
long a[100], b[100], g1, g2, g3;
__attribute__((pure)) long goo();
void foo(long a, long b, long c, long d) {
g1 = a * b;
if (__builtin_expect(g2 > 3, 0)) {
a = c;
b = d;
g2 = a * b;
}
g3 = a * b; // fully redundant.
}
The patch adds phi-translate support in scalarpre. This is only a temporary
solution before the newpre based on newgvn is available.
Differential Revision: https://reviews.llvm.org/D32252
llvm-svn: 305578
Summary:
Background: http://lists.llvm.org/pipermail/llvm-dev/2017-May/112779.html
This change is to alter the prototype for the atomic memcpy intrinsic. The prototype itself is being changed to more closely resemble the semantics and parameters of the llvm.memcpy intrinsic -- to ease later combination of the llvm.memcpy and atomic memcpy intrinsics. Furthermore, the name of the atomic memcpy intrinsic is being changed to make it clear that it is not a generic atomic memcpy, but specifically a memcpy is unordered atomic.
Reviewers: reames, sanjoy, efriedma
Reviewed By: reames
Subscribers: mzolotukhin, anna, llvm-commits, skatkov
Differential Revision: https://reviews.llvm.org/D33240
llvm-svn: 305558
Summary: This is the demorganed version of the case we already handle for the OR of iszero.
Reviewers: spatel
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34244
llvm-svn: 305548
Summary:
Split the PGOMemOPSizeOpt pass out from IndirectCallPromotion.cpp into
its own file.
Reviewers: davidxl
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D34248
llvm-svn: 305501
Currently we expect A to be on the same side in both Ands but nothing guarantees that.
While there also switch to using matchers for some of the code.
Differential Revision: https://reviews.llvm.org/D34230
llvm-svn: 305487
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
This way we end up not looking at PHI args already removed.
MemSSA now goes through the updater so we can prune
it to avoid having redundant MemoryPHI arguments, but that
doesn't quite work for the general case.
Discussed with Daniel Berlin, fixes PR33406.
llvm-svn: 305409
Doing so breaks compilation of the following C program
(under -fprofile-instr-generate):
__attribute__((always_inline)) inline int foo() { return 0; }
int main() { return foo(); }
At link time, we fail because taking the address of an
available_externally function creates an undefined external reference,
which the TU cannot provide.
Emitting the function definition into the object file at all appears to
be a violation of the langref: "Globals with 'available_externally'
linkage are never emitted into the object file corresponding to the LLVM
module."
Differential Revision: https://reviews.llvm.org/D34134
llvm-svn: 305327
Summary:
Leave an updated VP metadata on the fallback memcpy intrinsic after
specialization. This can be used for later possible expansion based on
the average of the remaining values.
Reviewers: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34164
llvm-svn: 305321
Summary: Fixes an issue using RegisterStandardPasses from a statically linked object before PassManagerBuilder::addGlobalExtension is called from a dynamic library.
Reviewers: efriedma, theraven
Reviewed By: efriedma
Subscribers: mehdi_amini, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D33515
llvm-svn: 305303
This restores the order of evaluation (& conditionalized evaluation) of
isTriviallyDeadInstruction, InlineHistoryIncludes, and shouldInline
(with the addition of a shouldInline call after
isTriviallyDeadInstruction) from before r305245.
llvm-svn: 305267
Summary:
After RS4GC, we should drop metadata that is no longer valid. These metadata
is used by optimizations scheduled after RS4GC, and can cause a miscompile.
One such metadata is invariant.load which is used by LICM sinking transform.
After rewriting statepoints, the address of a load maybe relocated. With
invariant.load metadata on a load instruction, LICM sinking assumes the
loaded value (from a dererenceable address) to be invariant, and
rematerializes the load operand and the load at the exit block.
This transforms the IR to have an unrelocated use of the
address after a statepoint, which is incorrect.
Other metadata we conservatively remove are related to
dereferenceability and noalias metadata.
This patch drops such metadata on store and load instructions after
rewriting statepoints.
Reviewers: reames, sanjoy, apilipenko
Reviewed by: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33756
llvm-svn: 305234
Summary:
Use MemorySSA for memory dependency checking in the EarlyCSE pass at the
start of the function simplification portion of the pipeline. We rely
on the fact that GVNHoist runs just after this pass of EarlyCSE to
amortize the MemorySSA construction cost since GVNHoist uses MemorySSA
and EarlyCSE preserves it.
This is turned off by default. A follow-up change will turn it on to
allow for easier reversion in case it breaks something.
llvm-svn: 305146
Currently there is a bug in SROA::presplitLoadsAndStores which causes assertion in
GEPOperator::accumulateConstantOffset.
Basically it does not consider the situation that the pointer operand of load or store
may be in a non-zero address space and its size may be different from the size of
a pointer in address space 0.
This patch fixes assertion when compiling Blender Cycles kernels for amdgpu backend.
Diffferential Revision: https://reviews.llvm.org/D33298
llvm-svn: 305107
Summary:
isSafeToSpeculativelyExecute is the wrong predicate to use here.
All that checks for is whether it is safe to hoist a value due to
unaligned/un-dereferencable accesses. However, not only are we doing
sinking rather than hoisting, our concern is that the location
we're loading from may have been modified. Instead forbid sinking
any load across a critical edge.
Reviewers: majnemer
Subscribers: davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D33179
llvm-svn: 305102
This change adds an option disable-lftr to be able to disable Linear Function Test Replace optimization.
By default option is off so current behavior is not changed.
Reviewers: reames, sanjoy, wmi, andreadb, apilipenko
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33979
llvm-svn: 305055
If we're shrinking a binary operation, it may be the case that the new
operations wraps where the old didn't. If this happens, the behavior
should be well-defined. So, we can't always carry wrapping flags with us
when we shrink operations.
If we do, we get incorrect optimizations in cases like:
void foo(const unsigned char *from, unsigned char *to, int n) {
for (int i = 0; i < n; i++)
to[i] = from[i] - 128;
}
which gets optimized to:
void foo(const unsigned char *from, unsigned char *to, int n) {
for (int i = 0; i < n; i++)
to[i] = from[i] | 128;
}
Because:
- InstCombine turned `sub i32 %from.i, 128` into
`add nuw nsw i32 %from.i, 128`.
- LoopVectorize vectorized the add to be `add nuw nsw <16 x i8>` with a
vector full of `i8 128`s
- InstCombine took advantage of the fact that the newly-shrunken add
"couldn't wrap", and changed the `add` to an `or`.
InstCombine seems happy to figure out whether we can add nuw/nsw on its
own, so I just decided to drop the flags. There are already a number of
places in LoopVectorize where we rely on InstCombine to clean up.
llvm-svn: 305053
Other comments/implications are that this isn't intended behavior (nor
perserved/reimplemented in the new inliner) & complicates fixing the
'inlining' of trivially dead calls without consulting the cost function
first.
llvm-svn: 305052
Summary: This matches the behavior we already had for compares and makes us consistent everywhere.
Reviewers: dberlin, hfinkel, spatel
Reviewed By: dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33604
llvm-svn: 305049
Since D17854 LinkerSubsectionsViaSymbols is unnecessary.
It is interfering with ThinLTO implementation of CFI-ICall, where
the aliases used on the !LinkerSubsectionsViaSymbols branch are
needed to export jump tables to ThinLTO backends.
This is the second attempt to land this change after fixing PR33316.
llvm-svn: 305031
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
Summary: Early-inlining of recursive call makes the code size bloat exponentially. We should not disable it.
Reviewers: davidxl, dnovillo, iteratee
Reviewed By: iteratee
Subscribers: iteratee, llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D34017
llvm-svn: 305009
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
This was discussed in D33338. We have larger pattern-matching ending in a truncate that
we can reduce or remove by handling these smaller patterns first. Further motivation is
that narrower shift ops are easier for value tracking and zext is better than sext.
http://rise4fun.com/Alive/rhh
Name: boolshift
%sext = sext i1 %x to i8
%r = lshr i8 %sext, 7
=>
%r = zext i1 %x to i8
Name: noboolshift
%sext = sext i3 %x to i8
%r = lshr i8 %sext, 7
=>
%sh = lshr i3 %x, 2
%r = zext i3 %sh to i8
Differential Revision: https://reviews.llvm.org/D33879
llvm-svn: 304939
This makes it so that the code quality for CFI checks when compiling
with -O2 and linking with --lto-O0 is similar to that of the rest of
the code.
Reduces the size of a chrome binary built with -O2/--lto-O0 by
about 750KB.
Differential Revision: https://reviews.llvm.org/D33925
llvm-svn: 304921
I believe this code used to use APInt references which would have worked. But then they were changed to pointers to allow m_APInt to be used.
llvm-svn: 304875
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
Summary:
The patch makes instruction count the highest priority for
LSR solution for X86 (previously registers had highest priority).
Reviewers: qcolombet
Differential Revision: http://reviews.llvm.org/D30562
From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 304824
1. When there is no perfect iteration order, we can't let phi nodes
put themselves in terms of things that come later in the iteration
order, or we will endlessly cycle (the normal RPO algorithm clears the
hashtable to avoid this issue).
2. We are sometimes erasing the wrong expression (causing pessimism)
because our equality says loads and stores are the same.
We introduce an exact equality function and use it when erasing to
make sure we erase only identical expressions, not equivalent ones.
llvm-svn: 304807
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
Summary:
We were canonizalizing the pre loop (into loop-simplify form) before
the post loop blocks were added into parent loop. This is incorrect when IRCE is
done on a subloop. The post-loop blocks are created, but not yet added to the
parent loop. So, loop-simplification on the pre-loop incorrectly updates
LoopInfo.
This patch corrects the ordering so that pre and post loop blocks are added to
parent loop (if any), and then the loops are canonicalized to LCSSA and
LoopSimplifyForm.
Reviewers: reames, sanjoy, apilipenko
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33846
llvm-svn: 304800
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
Summary:
This problem stems from the fact that instructions are allocated using new
in LLVM, i.e. there is no relationship that can be derived by just looking
at the pointer value.
This interface dispatches to appropriate dominance check given 2 instructions,
i.e. in case the instructions are in the same basic block, ordered basicblock
(with instruction numbering and caching) are used. Otherwise, dominator tree
is used.
This is a preparation patch for https://reviews.llvm.org/D32720
Reviewers: dberlin, hfinkel, davide
Subscribers: davide, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D33380
llvm-svn: 304764
Summary:
The patch guard all instruction cost calculations with InsnCosts (-lsr-insns-cost) option.
Currently even if the option set to false we calculate and print (in debug mode) instruction costs.
Reviewers: qcolombet
Differential Revision: http://reviews.llvm.org/D33914
From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 304746
This fixes a bug that can cause extractelements with operands that
haven't been defined yet to be inserted at a wrong point when
optimising insertelements.
Patch by Karl Hylen.
Differential Revision: https://reviews.llvm.org/D33449
llvm-svn: 304701
Following the request made in https://reviews.llvm.org/D32871,
scalarizeInstruction() which is no longer overridden by InnerLoopUnroller is
hereby made non-virtual in InnerLoopVectorizer.
Should have been part of r297580 originally.
llvm-svn: 304685
Fixed some comments, added an additional description of the algorithms,
improved readability of the code.
Differential revision: https://reviews.llvm.org/D33320
llvm-svn: 304616
We'd called this "vm state" in the early days, but have long since standardized on calling it "deopt" in line with the operand bundle tag. Fix a few cases we'd missed.
llvm-svn: 304607
Minor optimization but mostly simplifies my debugging so I'm not dealing
with empty SCCNodeSets while investigating issues in this optimization.
llvm-svn: 304597
Summary:
Fixed some comments, added an additional description of the algorithms,
improved readability of the code.
Reviewers: anemet
Subscribers: llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D33320
llvm-svn: 304593
Summary:
As shown in the test case, SROA was crashing when trying to split
stores (to the alloca) of loads (from anywhere), because it assumed
the pointer operand to the loads and stores had to have the same
address space. This isn't the case. Make sure to use the correct
pointer type for both the load and the store.
Reviewed By: yaxunl
Differential Revision: https://reviews.llvm.org/D32593
llvm-svn: 304585
Since D17854 LinkerSubsectionsViaSymbols is unnecessary.
It is interfering with ThinLTO implementation of CFI-ICall, where
the aliases used on the !LinkerSubsectionsViaSymbols branch are
needed to export jump tables to ThinLTO backends.
llvm-svn: 304582
Summary:
Optimization passes may remove llvm.coro.suspend intrinsic while leaving matching llvm.coro.save intrinsic orphaned.
Make sure we clean up orphaned coro.saves. The bug manifested with a crash similar to this:
```
llvm_unreachable("Unknown type!");
llvm::MVT::getVT (Ty=0x489518, HandleUnknown=false)
llvm::EVT::getEVT
llvm::TargetLoweringBase::getValueType
llvm::ComputeValueVTs
llvm::SelectionDAGBuilder::visitTargetIntrinsic
```
Reviewers: GorNishanov
Subscribers: EricWF, llvm-commits
Differential Revision: https://reviews.llvm.org/D33817
llvm-svn: 304518
builtin_expect applied on && or || expressions were not
handled properly before. With this patch, the problem is fixed.
Differential Revision: http://reviews.llvm.org/D33164
llvm-svn: 304517
This was rL304226, reverted in 304228 due to a clang assertion failure
on the build bots. That problem should have been addressed by clang
commit rL304470.
llvm-svn: 304488
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
The lowerer wrongly assumes the ICMP instruction
1) always has a constant operand;
2) the operand has value 0.
It also assumes the expected value can only be one, thus
other values other than one will be considered 'zero'.
This leads to wrong profile annotation when other integer values
are used other than 0, 1 in the comparison or in the expect intrinsic.
Also missing is handling of equal predicate.
This patch fixes all the above problems.
Differential Revision: http://reviews.llvm.org/D33757
llvm-svn: 304453
Summary:
Sort OpsToRename before iterating to make iteration order deterministic.
Thanks to Daniel Berlin for the sorting logic.
Reviewers: dberlin, RKSimon, efriedma, davide
Reviewed By: dberlin, davide
Subscribers: sanjoy, davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D33265
llvm-svn: 304447
Summary: Also see D33429 for other ThinLTO + New PM related changes.
Reviewers: davide, chandlerc, tejohnson
Subscribers: mehdi_amini, Prazek, cfe-commits, inglorion, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D33525
llvm-svn: 304378
Summary:
Fairly straightforward patch to fill in some of the holes in the
attributes API with respect to accessing parameter/argument attributes.
The patch aims to step further towards encapsulating the
idx+FirstArgIndex pattern to access these attributes to within the
AttributeList.
Patch by Daniel Neilson!
Reviewers: rnk, chandlerc, pete, javed.absar, reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33355
llvm-svn: 304329
This reverts commit r304310.
It caused build failures in polly and mingw
due to undefined reference to
llvm::RTLIB::getMEMCPY_ELEMENT_ATOMIC.
llvm-svn: 304315
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
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
Subscribers: llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D33243
llvm-svn: 304310
r303763 caused build failures in some out-of-tree tests due to an assertion in
TTI. The original patch updated cost estimates for induction variable update
instructions marked for scalarization. However, it didn't consider that the
incoming value of an induction variable phi node could be a cast instruction.
This caused queries for cast instruction costs with a mix of vector and scalar
types. This patch includes a fix for cast instructions and the test case from
PR33193.
The fix was suggested by Jonas Paulsson <paulsson@linux.vnet.ibm.com>.
Reference: https://bugs.llvm.org/show_bug.cgi?id=33193
Original Differential Revision: https://reviews.llvm.org/D33457
llvm-svn: 304235
Summary:
In rL302576, DISubprograms gained the constraint that a !dbg attachments to functions must
have a 1:1 mapping to DISubprograms. As part of that change, the function cloning support
was adjusted to attempt to enforce this invariant during cloning. However, there
were several problems with the implementation. Part of these were fixed in rL304079.
However, there was a more fundamental problem with these changes, namely that it
bypasses the matadata value map, causing the cloned metadata to be a mix of metadata
pointing to the new suprogram (where manual code was added to fix those up) and the
old suprogram (where this was not the case). This mismatch could cause a number of
different assertion failures in the DWARF emitter. Some of these are given at
https://github.com/JuliaLang/julia/issues/22069, but some others have been observed
as well. Attempt to rectify this by partially reverting the manual DI metadata fixup,
and instead using the standard value map approach. To retain the desired semantics
of not duplicating the compilation unit and inlined subprograms, explicitly freeze
these in the value map.
Reviewers: dblaikie, aprantl, GorNishanov, echristo
Reviewed By: aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33655
llvm-svn: 304226
Summary:
I believe https://reviews.llvm.org/rL302576 introduced two bugs:
1) it produces duplicate distinct variables for every: dbg.value describing the same variable.
To fix the problme I switched form getDistinct() to get() in DebugLoc.cpp: auto reparentVar = [&](DILocalVariable *Var) {
return DILocalVariable::getDistinct(
2) It passes NewFunction plain name as a linkagename parameter to Subprogram constructor. Breaks assert in:
|| DeclLinkageName.empty()) || LinkageName == DeclLinkageName) && "decl has a linkage name and it is different"' failed.
#9 0x00007f5010261b75 llvm::DwarfUnit::applySubprogramDefinitionAttributes(llvm::DISubprogram const*, llvm::DIE&) /home/gor/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp:1173:3
#
(Edit: reproducer added)
Here how https://reviews.llvm.org/rL302576 broke coroutine debug info.
Coroutine body of the original function is split into several parts by cloning and removing unneeded code.
All parts describe the original function and variables present in the original function.
For a simple case, prior to Split, original function has these two blocks:
```
PostSpill: ; preds = %AllocaSpillBB
call void @llvm.dbg.value(metadata i32 %x, i64 0, metadata !14, metadata !15), !dbg !13
store i32 %x, i32* %x.addr, align 4
...
and
sw.epilog: ; preds = %sw.bb
%x.addr.reload.addr = getelementptr inbounds %f.Frame, %f.Frame* %FramePtr, i32 0, i32 4, !dbg !20
%4 = load i32, i32* %x.addr.reload.addr, align 4, !dbg !20
call void @llvm.dbg.value(metadata i32 %4, i64 0, metadata !14, metadata !15), !dbg !13!14 = !DILocalVariable(name: "x", arg: 1, scope: !6, file: !7, line: 55, type: !11)
```
Note that in two blocks different expression represent the same original user variable X.
Before rL302576, for every cloned function there was exactly one cloned DILocalVariable(name: "x" as in:
```
define i8* @f(i32 %x) #0 !dbg !6 {
...
!6 = distinct !DISubprogram(name: "f", scope: !7, file: !7, line: 55, type: !8, isLocal: false, isDefinition: true, scopeLine: 55, flags: DIFlagPrototyped,
...
!14 = !DILocalVariable(name: "x", arg: 1, scope: !6, file: !7, line: 55, type: !11)
define internal fastcc void @f.resume(%f.Frame* %FramePtr) #0 !dbg !25 {
...
!25 = distinct !DISubprogram(name: "f", scope: !7, file: !7, line: 55, type: !8, isLocal: false, isDefinition: true, scopeLine: 55, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
!28 = !DILocalVariable(name: "x", arg: 1, scope: !25, file: !7, line: 55, type: !11)
```
After rL302576, for every cloned function there were as many DILocalVariable(name: "x" as there were "call void @llvm.dbg.value" for that variable.
This was causing asserts in VerifyDebugInfo and AssemblyPrinter.
Example:
```
!27 = distinct !DISubprogram(name: "f", linkageName: "f.resume", scope: !7, file: !7, line: 55, type: !8, isLocal: false, isDefinition: true, scopeLine: 55,
!29 = distinct !DILocalVariable(name: "x", arg: 1, scope: !27, file: !7, line: 55, type: !11)
!39 = distinct !DILocalVariable(name: "x", arg: 1, scope: !27, file: !7, line: 55, type: !11)
!41 = distinct !DILocalVariable(name: "x", arg: 1, scope: !27, file: !7, line: 55, type: !11)
```
Second problem:
Prior to rL302576, all clones were described by DISubprogram referring to original function.
```
define i8* @f(i32 %x) #0 !dbg !6 {
...
!6 = distinct !DISubprogram(name: "f", scope: !7, file: !7, line: 55, type: !8, isLocal: false, isDefinition: true, scopeLine: 55, flags: DIFlagPrototyped,
define internal fastcc void @f.resume(%f.Frame* %FramePtr) #0 !dbg !25 {
...
!25 = distinct !DISubprogram(name: "f", scope: !7, file: !7, line: 55, type: !8, isLocal: false, isDefinition: true, scopeLine: 55, flags: DIFlagPrototyped,
```
After rL302576, DISubprogram for clones is of two minds, plain name refers to the original name, linkageName refers to plain name of the clone.
```
!27 = distinct !DISubprogram(name: "f", linkageName: "f.resume", scope: !7, file: !7, line: 55, type: !8, isLocal: false, isDefinition: true, scopeLine: 55,
```
I think the assumption in AsmPrinter is that both name and linkageName should refer to the same entity. It asserts here when they are not:
```
|| DeclLinkageName.empty()) || LinkageName == DeclLinkageName) && "decl has a linkage name and it is different"' failed.
#9 0x00007f5010261b75 llvm::DwarfUnit::applySubprogramDefinitionAttributes(llvm::DISubprogram const*, llvm::DIE&) /home/gor/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp:1173:3
```
After this fix, behavior (with respect to coroutines) reverts to exactly as it was before and therefore making them debuggable again, or even more importantly, compilable, with "-g"
Reviewers: dblaikie, echristo, aprantl
Reviewed By: dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33614
llvm-svn: 304079
The recommit is to fix a bug about ExtractValue and InsertValue ops. For those
ops, some varargs inside GVN::Expression are not value numbers but raw index
numbers. It is wrong to do phi-translate for raw index numbers, and the fix is
to stop doing that.
Right now scalarpre doesn't have phi-translate support, so it will miss some
simple pre opportunities. Like the following testcase, current scalarpre cannot
recognize the last "a * b" is fully redundent because a and b used by the last
"a * b" expr are both defined by phis.
long a[100], b[100], g1, g2, g3;
__attribute__((pure)) long goo();
void foo(long a, long b, long c, long d) {
g1 = a * b;
if (__builtin_expect(g2 > 3, 0)) {
a = c;
b = d;
g2 = a * b;
}
g3 = a * b; // fully redundant.
}
The patch adds phi-translate support in scalarpre. This is only a temporary
solution before the newpre based on newgvn is available.
Differential Revision: https://reviews.llvm.org/D32252
llvm-svn: 304050
The whole-program-devirt pass needs to run at -O0 because only it
knows about the llvm.type.checked.load intrinsic: it needs to both
lower the intrinsic itself and handle it in the summary.
Differential Revision: https://reviews.llvm.org/D33571
llvm-svn: 304019
Every other place in InstCombine that uses these methods in ValueTracking already pass this information. This makes the remaining sites consistent.
Differential Revision: https://reviews.llvm.org/D33567
llvm-svn: 304018
We have wrappers for several other ValueTracking methods that take care of passing all of the analysis and assumption cache parameters. This extends it to isKnownToBeAPowerOfTwo.
llvm-svn: 303924
Right now scalarpre doesn't have phi-translate support, so it will miss some
simple pre opportunities. Like the following testcase, current scalarpre cannot
recognize the last "a * b" is fully redundent because a and b used by the last
"a * b" expr are both defined by phis.
long a[100], b[100], g1, g2, g3;
__attribute__((pure)) long goo();
void foo(long a, long b, long c, long d) {
g1 = a * b;
if (__builtin_expect(g2 > 3, 0)) {
a = c;
b = d;
g2 = a * b;
}
g3 = a * b; // fully redundant.
}
The patch adds phi-translate support in scalarpre. This is only a temporary
solution before the newpre based on newgvn is available.
Differential Revision: https://reviews.llvm.org/D32252
llvm-svn: 303923
There's probably a lot more like this (see also comments in D33338 about responsibility),
but I suspect we don't usually get a visible manifestation.
Given the recent interest in improving InstCombine efficiency, another potential micro-opt
that could be repeated several times in this function: morph the existing icmp pred/operands
instead of creating a new instruction.
llvm-svn: 303860
This patch provides an initial prototype for a pass that sinks instructions based on GVN information, similar to GVNHoist. It is not yet ready for commiting but I've uploaded it to gather some initial thoughts.
This pass attempts to sink instructions into successors, reducing static
instruction count and enabling if-conversion.
We use a variant of global value numbering to decide what can be sunk.
Consider:
[ %a1 = add i32 %b, 1 ] [ %c1 = add i32 %d, 1 ]
[ %a2 = xor i32 %a1, 1 ] [ %c2 = xor i32 %c1, 1 ]
\ /
[ %e = phi i32 %a2, %c2 ]
[ add i32 %e, 4 ]
GVN would number %a1 and %c1 differently because they compute different
results - the VN of an instruction is a function of its opcode and the
transitive closure of its operands. This is the key property for hoisting
and CSE.
What we want when sinking however is for a numbering that is a function of
the *uses* of an instruction, which allows us to answer the question "if I
replace %a1 with %c1, will it contribute in an equivalent way to all
successive instructions?". The (new) PostValueTable class in GVN provides this
mapping.
This pass has some shown really impressive improvements especially for codesize already on internal benchmarks, so I have high hopes it can replace all the sinking logic in SimplifyCFG.
Differential revision: https://reviews.llvm.org/D24805
llvm-svn: 303850
pass.
The original logic only considered direct successors of the hoisted
domtree nodes, but that isn't really enough. If there are other basic
blocks that are completely within the subtree, their successors could
just as easily be impacted by the hoisting.
The more I think about it, the more I think the correct update here is
to hoist every block on the dominance frontier which has an idom in the
chain we hoist across. However, this is subtle enough that I'd
definitely appreciate some more eyes on it.
Sadly, if this is the correct algorithm, it requires computing a (highly
localized) dominance frontier. I've done this in the simplest (IE, least
code) way I could come up with, but that may be too naive. Suggestions
welcome here, dominance update algorithms are not an area I've studied
much, so I don't have strong opinions.
In good news, with this patch, turning on simple unswitch passes the
LLVM test suite for me with asserts enabled.
Differential Revision: https://reviews.llvm.org/D32740
llvm-svn: 303843
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
Coverage instrumentation which does not instrument full post-dominators
and full-dominators may skip valid paths, as the reasoning for skipping
blocks may become circular.
This patch fixes that, by only skipping
full post-dominators with multiple predecessors, as such predecessors by
definition can not be full-dominators.
llvm-svn: 303827
Summary:
Frontend generates store instructions after allocas, for example:
```
define i8* @f(i64 %this) "coroutine.presplit"="1" personality i32 0 {
entry:
%this.addr = alloca i64
store i64 %this, i64* %this.addr
..
%hdl = call i8* @llvm.coro.begin(token %id, i8* %alloc)
```
Such instructions may require spilling into coro.frame, but, coro-frame address is only available after coro.begin and thus needs to be moved after coro.begin.
The only instructions that should not be moved are the arguments of coro.begin and all of their operands.
Reviewers: GorNishanov, majnemer
Reviewed By: GorNishanov
Subscribers: llvm-commits, EricWF
Differential Revision: https://reviews.llvm.org/D33527
llvm-svn: 303825
The swapped operands in the first test is a manifestation of an
inefficiency for vectors that doesn't exist for scalars because
the IRBuilder checks for an all-ones mask for scalars, but not
vectors.
llvm-svn: 303818
While there avoid resizing the DemandedMask twice. Make a copy into a separate variable instead. This potentially removes an allocation on large bit widths.
With the use of the zextOrTrunc methods on APInt and KnownBits these can be made almost source identical. The only difference is the zero of the upper bits for ZExt. This is similar to how its done in computeKnownBits in ValueTracking.
llvm-svn: 303791
The current code created a NewBits mask and used it as a mask several times. One of them just before a call to trunc making it unnecessary. A call to getActiveBits can get us the same information for the case. We also ORed with this mask later when we should have just sign extended the known bits.
We also called trunc on the guaranteed to be zero KnownZeros/Ones masks entering this code. Creating appropriately sized temporary APInts is probably better.
Differential Revision: https://reviews.llvm.org/D32098
llvm-svn: 303779
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
For non-uniform instructions marked for scalarization, we should update
`VectorTy` when computing instruction costs to reflect the scalar type. In
addition to determining instruction costs, this type is also used to signal
that all instructions in the loop will be scalarized. This currently affects
memory instructions and non-pointer induction variables and their updates. (We
also mark GEPs scalar after vectorization, but their cost is computed together
with memory instructions.) For scalarized induction updates, this patch also
scales the scalar cost by the vectorization factor, corresponding to each
induction step.
llvm-svn: 303763
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
Otherwise we don't revisit an instruction that could be simplified,
and when we verify, we discover there's something that changed, i.e.
what we had wasn't a maximal fixpoint.
Fixes PR32836.
llvm-svn: 303715
Instead of using the SCCP homegrown one. We should eventually
make the private SCCP version disappear, but that wont' be today.
PR33143 tracks this issue.
Add braces for consistency while here. No functional change intended.
llvm-svn: 303706
Daniel Jasper