Summary:
When salvaging a dead zext instruction, append a convert operation to
the DIExpressions of the debug uses of the instruction, to prevent the
salvaged value from being sign-extended.
I confirmed that lldb prints out the correct unsigned result for "f" in
the example from PR45923 with this changed applied.
rdar://63246143
Reviewers: aprantl, jmorse, chrisjackson, davide
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80034
Along the lines of D77454 and D79968. Unlike loads and stores, the
default alignment is getPrefTypeAlign, to match the existing handling in
various places, including SelectionDAG and InstCombine.
Differential Revision: https://reviews.llvm.org/D80044
This reverts commit 454de99a6f.
The problem was that one of the ctor arguments of CallAnalyzer was left
to be const std::function<>&. A function_ref was passed for it, and then
the ctor stored the value in a function_ref field. So a std::function<>
would be created as a temporary, and not survive past the ctor
invocation, while the field would.
Tested locally by following https://github.com/google/sanitizers/wiki/SanitizerBotReproduceBuild
Original Differential Revision: https://reviews.llvm.org/D79917
This is D77454, except for stores. All the infrastructure work was done
for loads, so the remaining changes necessary are relatively small.
Differential Revision: https://reviews.llvm.org/D79968
This has been duplicated since before
2372a193ba, but that commit has it
appearing twice in the space of 10 lines of the same function body. It
could also be hoisted up to the point just after where the last
special-case is considered, but I want to keep the intent of the
original authors.
Committed as obvious without a review.
The "null-pointer-is-valid" attribute needs to be checked by many
pointer-related combines. To make the check more efficient, convert
it from a string into an enum attribute.
In the future, this attribute may be replaced with data layout
properties.
Differential Revision: https://reviews.llvm.org/D78862
Summary:
This change exposes the vector name mangling with LLVM ISA (used as part
of vector-function-abi-variant) as a utility.
This can then be used by front-ends that add this attribute.
Note that all parameters passed in to the function will be mangled with
the "v" token to identify that they are of of vector type. So, it is the
responsibility of the caller to confirm that all parameters in the
vectorized variant is of vector type.
Added unit test to show vector name mangling.
Reviewed-By: fpetrogalli, simoll
Differential Revision: https://reviews.llvm.org/D79867
Summary:
Replacing uses of std::function pointers or refs, or Optional, to
function_ref, since the usage pattern allows that. If the function is
optional, using a default parameter value (nullptr). This led to a few
parameter reshufles, to push all optionals to the end of the parameter
list.
Reviewers: davidxl, dblaikie
Subscribers: arsenm, jvesely, nhaehnle, eraman, hiraditya, haicheng, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79917
Summary:
Analyses that are statefull should not be retrieved through a proxy from
an outer IR unit, as these analyses are only invalidated at the end of
the inner IR unit manager.
This patch disallows getting the outer manager and provides an API to
get a cached analysis through the proxy. If the analysis is not
stateless, the call to getCachedResult will assert.
Reviewers: chandlerc
Subscribers: mehdi_amini, eraman, hiraditya, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72893
Hide the method that allows setting probability for particular
edge and introduce a public method that sets probabilities for
all outgoing edges at once.
Setting individual edge probability is error prone. More over
it is difficult to check that the total probability is 1.0
because there is no easy way to know when the user finished
setting all the probabilities.
Reviewers: yamauchi, ebrevnov
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79396
We want to add a way to avoid merging identical calls so as to keep the
separate debug-information for those calls. There is also an asan
usecase where having this attribute would be beneficial to avoid
alternative work-arounds.
Here is the link to the feature request:
https://bugs.llvm.org/show_bug.cgi?id=42783.
`nomerge` is different from `noline`. `noinline` prevents function from
inlining at callsites, but `nomerge` prevents multiple identical calls
from being merged into one.
This patch adds `nomerge` to disable the optimization in IR level. A
followup patch will be needed to let backend understands `nomerge` and
avoid tail merge at backend.
Reviewed By: asbirlea, rnk
Differential Revision: https://reviews.llvm.org/D78659
Summary:
this patch fixe crash/asserts found in the test-suite.
the AssumeptionCache cannot be assumed to have all assumes contrary to what i tought.
prevent generation of information for terminators, because this can create broken IR in transfromation where we insert the new terminator before removing the old one.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79458
don't span their entire scope.
The previous commit (6d1c40c171) is an older version of the test.
Reviewed By: aprantl, vsk
Differential Revision: https://reviews.llvm.org/D79573
Summary:
The assume builder was non-deterministic when working on unamed values.
this patch fixes this.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, mgrang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78616
Summary: with this patch the assume salvageKnowledge will not generate assume if all knowledge is already available in an assume with valid context. assume bulider can also in some cases update an existing assume with better information.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78014
Currently LAA's uses of ScalarEvolutionExpander blocks moving the
expander from Analysis to Transforms. Conceptually the expander does not
fit into Analysis (it is only used for code generation) and
runtime-check generation also seems to be better suited as a
transformation utility.
Reviewers: Ayal, anemet
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D78460
Summary:
If the only use of a value is a start or end lifetime intrinsic then mark the intrinsic as trivially dead. This should allow for that value to then be removed as well.
Currently, this only works for allocas, globals, and arguments.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79355
FoldBranchToCommonDest clones instructions to a different basic block,
but handles debug intrinsics in a separate path. Previously, when
cloning debug intrinsics, their operands were not updated to reference
the correct cloned values. As a result, we would emit debug.value
intrinsics with broken operand references which are discarded in later
passes. This leads to incorrect debuginfo that reports incorrect values
for variables.
Fix this by remapping debug intrinsic operands when cloning them.
Fixes https://bugs.llvm.org/show_bug.cgi?id=45667.
Differential Revision: https://reviews.llvm.org/D79602
Splitting critical edges for indirect branches
the SplitIndirectBrCriticalEdges() function may break branch
probabilities if target basic block happens to have unset
a probability for any of its successors. That is because in
such cases the getEdgeProbability(Target) function returns
probability 1/NumOfSuccessors and it is called after Target
was split (thus Target has a single successor). As the result
the correspondent successor of the split block gets
probability 100% but 1/NumOfSuccessors is expected (or better
be left unset).
Reviewers: yamauchi
Differential Revision: https://reviews.llvm.org/D78806
loop nest.
Summary: As discussed in https://reviews.llvm.org/D73129.
Example
Before unroll and jam:
for
A
for
B
for
C
D
E
After unroll and jam (currently):
for
A
A'
for
B
for
C
D
B'
for
C'
D'
E
E'
After unroll and jam (Ideal):
for
A
A'
for
B
B'
for
C
C'
D
D'
E
E'
This is the first patch to change unroll and jam to work in the ideal
way.
This patch change the safety checks needed to make sure is safe to
unroll and jam in the ideal way.
Reviewer: dmgreen, jdoerfert, Meinersbur, kbarton, bmahjour, etiotto
Reviewed By: Meinersbur
Subscribers: fhahn, hiraditya, zzheng, llvm-commits, anhtuyen, prithayan
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D76132
Summary:
If the only use of a value is a start or end lifetime intrinsic then mark the intrinsic as trivially dead. This should allow for that value to then be removed as well.
Currently, this only works for allocas, globals, and arguments.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79355
We check that C is finite and strictly positive, but there's no need to
check that it's normal too. exp2 should be just as accurate on denormals
as pow is.
Differential Revision: https://reviews.llvm.org/D79413
I don't think there's any good reason not to do this transformation when
the pow has multiple uses.
Differential Revision: https://reviews.llvm.org/D79407
optimizePow does not create any new calls to pow, so it should work
regardless of whether the pow library function is available. This allows
it to optimize the llvm.pow intrinsic on targets with no math library.
Based on a patch by Tim Renouf.
Differential Revision: https://reviews.llvm.org/D68231
When the shufflevector mask operand was converted into special
instruction data, the FunctionComparator was not updated to
account for this. As such, MergeFuncs will happily merge
shufflevectors with different masks.
This fixes https://bugs.llvm.org/show_bug.cgi?id=45773.
Differential Revision: https://reviews.llvm.org/D79261
In D74183 clang started emitting alignment for sret parameters
unconditionally. This caused a 1.5% compile-time regression on
tramp3d-v4. The reason is that we now generate many instance of IR like
%ptrint = ptrtoint %class.GuardLayers* %guards_m to i64
%maskedptr = and i64 %ptrint, 3
%maskcond = icmp eq i64 %maskedptr, 0
tail call void @llvm.assume(i1 %maskcond)
to preserve the alignment information during inlining. Based on IR
analysis, these assumptions also regress optimization. The attached
phase ordering test case illustrates two issues: One are instruction
count based optimization heuristics, which are affected by the four
additional instructions of the assumption. The other is blocking of
SROA due to ptrtoint casts (PR45763).
We already encountered the same problem in Rust, where we (unlike
Clang) generally prefer to emit alignment information absolutely
everywhere it is available. We were only able to do this after
hardcoding -preserve-alignment-assumptions-during-inlining=false,
because we were seeing significant optimization and compile-time
regressions otherwise.
This patch disables -preserve-alignment-assumptions-during-inlining
by default, because we should not be punishing people for adding
more alignment annotations.
Once the assume bundle work shakes out and we can represent (and use)
alignment assumptions using assume bundles, it should be possible to
re-enable this with reduced overhead.
Differential Revision: https://reviews.llvm.org/D76886
This allows forward declarations of PointerCheck, which in turn reduce
the number of times LoopAccessAnalysis needs to be included.
Ultimately this helps with moving runtime check generation to
Transforms/Utils/LoopUtils.h, without having to include it there.
Reviewers: anemet, Ayal
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D78458
There are several different types of cost that TTI tries to provide
explicit information for: throughput, latency, code size along with
a vague 'intersection of code-size cost and execution cost'.
The vectorizer is a keen user of RecipThroughput and there's at least
'getInstructionThroughput' and 'getArithmeticInstrCost' designed to
help with this cost. The latency cost has a single use and a single
implementation. The intersection cost appears to cover most of the
rest of the API.
getUserCost is explicitly called from within TTI when the user has
been explicit in wanting the code size (also only one use) as well
as a few passes which are concerned with a mixture of size and/or
a relative cost. In many cases these costs are closely related, such
as when multiple instructions are required, but one evident diverging
cost in this function is for div/rem.
This patch adds an argument so that the cost required is explicit,
so that we can make the important distinction when necessary.
Differential Revision: https://reviews.llvm.org/D78635
This method has been commented as deprecated for a while. Remove
it and replace all uses with the equivalent getCalledOperand().
I also made a few cleanups in here. For example, to removes use
of getElementType on a pointer when we could just use getFunctionType
from the call.
Differential Revision: https://reviews.llvm.org/D78882
Add llvm.call.preallocated.{setup,arg} instrinsics.
Add "preallocated" operand bundle which takes a token produced by llvm.call.preallocated.setup.
Add "preallocated" parameter attribute, which is like byval but without the copy.
Verifier changes for these IR constructs.
See https://github.com/rnk/llvm-project/blob/call-setup-docs/llvm/docs/CallSetup.md
Subscribers: hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74651
Summary:
refactor assume bulider for the next patch.
the assume builder now generate only one assume per attribute kind and per value they are on. to do this it takes the highest. this is desirable because currently, for all attributes the higest value is the most valuable.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78013
We should only skip `lifetime` and `dbg` intrinsics when searching for users.
Other intrinsics are legit users that can't be ignored.
Without this fix, the testcase would result in an invalid IR. `memcpy`
will have a reference to the, now, external value (local to the
extracted loop function).
Fix PR42194
Differential Revision: https://reviews.llvm.org/D78749
Summary:
Teach MachineDebugify how to insert DBG_VALUE instructions. This can
help find bugs causing CodeGen differences when debug info is present.
DBG_VALUE instructions are only emitted when -debugify-level is set to
locations+variables.
There is essentially no attempt made to match up DBG_VALUE register
operands with the local variables they ought to correspond to. I'm not
sure how to improve the situation. In some cases (MachineMemOperand?)
it's possible to find the IR instruction a MachineInstr corresponds to,
but in general this seems to call for "undoing" the work done by ISel.
Reviewers: dsanders, aprantl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78135
Summary:
When an irreducible SCC is converted into a new natural loop, existing
loops included in that SCC now become children of the new loop. The
logic that moves these loops from the parent loop to the new loop
invoked undefined behaviour when it modified the container that it was
iterating over. Fixed this by first extracting all the loops that are
to be removed from the parent.
Fixes bug 45623.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D78544
With clang option -funique-internal-linkage-symbols, symbols with
internal linkage get names with the module hash appended.
Differential Revision: https://reviews.llvm.org/D78243
The recently added Instruction::comesBefore can be used instead of
OrderedInstructions.
Reviewers: rnk, nikic, efriedma
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D78452
Most of the includes in LoopUtils.h are not required in the header and
they can be replaced by forward declarations.
Unfortunately includes of TargetTransformInfo.h and IVDescriptors.h pull
in a bunch of additional things, but there is no easy way to get rid of
them at the moment I think.
When running IPSCCP on a module with many small functions, memory
usage is dominated by PredicateInfo, which is a huge structure
(partially due to some unfortunate nested SmallVector use). However,
most of it is actually only temporary state needed to build
predicate info, and does not need to be retained after initial
construction.
This patch factors out the predicate building logic and state
into a separate PrediceInfoBuilder, with the extra bonus that
it does not need to live in the header anymore.
Differential Revision: https://reviews.llvm.org/D78326
We previously clamped the trailing zero count to 31 bits. And
then clamped the final alignment to MaximumAlignment which is
1 << 29.
This patch simplifies this to just clamp the trailing zero to
29 using MaxAlignmentExponent.
I was looking into changing this function to use Align/MaybeAlign
and noticed this.
Differential Revision: https://reviews.llvm.org/D78418
I uploaded the old version accidentally instead of the one with these
minor adjustments requested by the reviewers.
Differential Revision: https://reviews.llvm.org/D77855
Summary:
We can and should remove deleted nodes from their respective SCCs. We
did not do this before and this was a potential problem even though I
couldn't locally trigger an issue. Since the `DeleteNode` would assert
if the node was not in the SCC, we know we only remove nodes from their
SCC and only once (when run on all the Attributor tests).
Reviewers: lebedev.ri, hfinkel, fhahn, probinson, wristow, loladiro, sstefan1, uenoku
Subscribers: hiraditya, bollu, uenoku, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77855
Summary:
While it is uncommon that the ExternalCallingNode needs to be updated,
it can happen. It is uncommon because most functions listed as callees
have external linkage, modifying them is usually not allowed. That said,
there are also internal functions that have, or better had, their
"address taken" at construction time. We conservatively assume various
uses cause the address "to be taken". Furthermore, the user might have
become dead at some point. As a consequence, transformations, e.g., the
Attributor, might be able to replace a function that is listed
as callee of the ExternalCallingNode.
Since there is no function corresponding to the ExternalCallingNode, we
did just remove the node from the callee list if we replaced it (so
far). Now it would be preferable to replace it if needed and remove it
otherwise. However, removing the node has implications on the CGSCC
iteration. Locally, that caused some other nodes to be never visited
but it is for sure possible other (bad) side effects can occur. As it
seems conservatively safe to keep the new node in the callee list we
will do that for now.
Reviewers: lebedev.ri, hfinkel, fhahn, probinson, wristow, loladiro, sstefan1, uenoku
Subscribers: hiraditya, bollu, uenoku, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77854
Summary:
The old code did eliminate references from and to functions that were
about to be deleted only just before we deleted them. This can cause
references from other functions that are supposed to be deleted to still
exist, depending on the order. If the functions form a strongly
connected component the problem manifests regardless of the order in
which we try to actually delete the functions.
This patch introduces a two step deletion. First we remove all
references and then we delete the function. Note that this only affects
the old call graph. There should not be any functional changes if no old
style call graph was given.
To test this we delete two strongly connected functions instead of one
in an existing test.
Reviewers: hfinkel
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77975
This is related to commit 8c11bc0cd0
which introduces the FixIrreducible pass. The warning seems hard to
reproduce locally. The latest attempt ought to work.
An irreducible SCC is one which has multiple "header" blocks, i.e., blocks
with control-flow edges incident from outside the SCC. This pass converts an
irreducible SCC into a natural loop by introducing a single new header
block and redirecting all the edges on the original headers to this
new block.
This is a useful workaround for a limitation in the structurizer
which, which produces incorrect control flow in the presence of
irreducible regions. The AMDGPU backend provides an option to
enable this pass before the structurizer, which may eventually be
enabled by default.
Reviewed By: nhaehnle
Differential Revision: https://reviews.llvm.org/D77198
This restores commit 2ada8e2525.
Originally reverted with commit 44e09b59b8.
This reverts commit 2ada8e2525.
Buildbots produced compilation errors which I was not able to quickly
reproduce locally. Need more time to investigate.
An irreducible SCC is one which has multiple "header" blocks, i.e., blocks
with control-flow edges incident from outside the SCC. This pass converts an
irreducible SCC into a natural loop by introducing a single new header
block and redirecting all the edges on the original headers to this
new block.
This is a useful workaround for a limitation in the structurizer
which, which produces incorrect control flow in the presence of
irreducible regions. The AMDGPU backend provides an option to
enable this pass before the structurizer, which may eventually be
enabled by default.
Reviewed By: nhaehnle
Differential Revision: https://reviews.llvm.org/D77198
Summary:
Share logic to strip debugify metadata between the IR and MIR level
debugify passes. This makes it simpler to hunt for bugs by diffing IR
with vs. without -debugify-each turned on.
As a drive-by, fix an issue causing CallGraphNodes to become invalid
when a dead llvm.dbg.value prototype is deleted.
Reviewers: dsanders, aprantl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77915
Summary: change assumption cache to store an assume along with an index to the operand bundle containing the knowledge.
Reviewers: jdoerfert, hfinkel
Reviewed By: jdoerfert
Subscribers: hiraditya, mgrang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77402
Summary:
Updated CallPromotionUtils and impacted sites. Parameters that are
expected to be non-null, and return values that are guranteed non-null,
were replaced with CallBase references rather than pointers.
Left FIXME in places where more changes are facilitated by CallBase, but
aren't CallSites: Instruction* parameters or return values, for example,
where the contract that they are actually CallBase values.
Reviewers: davidxl, dblaikie, wmi
Reviewed By: dblaikie
Subscribers: arsenm, jvesely, nhaehnle, eraman, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77930
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.
Reviewers: rriddle, sdesmalen, efriedma
Reviewed By: sdesmalen
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77260
Dead constants might be left when a function is replaced, we can
gracefully handle this case and avoid complexity for the users who would
see an assertion otherwise.
Summary:
Re-used the IR-level debugify for the most part. The MIR-level code then
adds locations to the MachineInstrs afterwards based on the LLVM-IR debug
info.
It's worth mentioning that the resulting locations make little sense as
the range of line numbers used in a Function at the MIR level exceeds that
of the equivelent IR level function. As such, MachineInstrs can appear to
originate from outside the subprogram scope (and from other subprogram
scopes). However, it doesn't seem worth worrying about as the source is
imaginary anyway.
There's a few high level goals this pass works towards:
* We should be able to debugify our .ll/.mir in the lit tests without
changing the checks and still pass them. I.e. Debug info should not change
codegen. Combining this with a strip-debug pass should enable this. The
main issue I ran into without the strip-debug pass was instructions with MMO's and
checks on both the instruction and the MMO as the debug-location is
between them. I currently have a simple hack in the MIRPrinter to
resolve that but the more general solution is a proper strip-debug pass.
* We should be able to test that GlobalISel does not lose debug info. I
recently found that the legalizer can be unexpectedly lossy in seemingly
simple cases (e.g. expanding one instr into many). I have a verifier
(will be posted separately) that can be integrated with passes that use
the observer interface and will catch location loss (it does not verify
correctness, just that there's zero lossage). It is a little conservative
as the line-0 locations that arise from conflicts do not track the
conflicting locations but it can still catch a fair bit.
Depends on D77439, D77438
Reviewers: aprantl, bogner, vsk
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77446
dso_local leads to direct access even if the definition is not within this compilation unit (it is
still in the same linkage unit). On ELF, such a relocation (e.g. R_X86_64_PC32) referencing a
STB_GLOBAL STV_DEFAULT object can cause a linker error in a -shared link.
If the linkage is changed to available_externally, the dso_local flag should be dropped, so that no
direct access will be generated.
The current behavior is benign, because -fpic does not assume dso_local
(clang/lib/CodeGen/CodeGenModule.cpp:shouldAssumeDSOLocal).
If we do that for -fno-semantic-interposition (D73865), there will be an
R_X86_64_PC32 linker error without this patch.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D74751
Now that we have scalable vectors, there's a distinction that isn't
getting captured in the original SequentialType: some vectors don't have
a known element count, so counting the number of elements doesn't make
sense.
In some cases, there's a better way to express the commonality using
other methods. If we're dealing with GEPs, there's GEP methods; if we're
dealing with a ConstantDataSequential, we can query its element type
directly.
In the relatively few remaining cases, I just decided to write out
the type checks. We're talking about relatively few places, and I think
the abstraction doesn't really carry its weight. (See thread "[RFC]
Refactor class hierarchy of VectorType in the IR" on llvmdev.)
Differential Revision: https://reviews.llvm.org/D75661
Summary:
It can be helpful to test behaviour w.r.t locations without having DEBUG_VALUE
around. In particular, because DEBUG_VALUE has the potential to change CodeGen
behaviour (e.g. hasOneUse() vs hasOneNonDbgUse()) while locations generally
don't.
Reviewers: aprantl, bogner
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77438
This patch builds upon D76140 by updating metadata on pointer typed
loads in inlined functions, when the load is the return value, and the
callsite contains return attributes which can be updated as metadata on
the load.
Added test cases show this for nonnull, dereferenceable,
dereferenceable_or_null
Reviewed-By: jdoerfert
Differential Revision: https://reviews.llvm.org/D76792
As discussed in post-commit review in https://reviews.llvm.org/D73501
if the goal of this is to help vectorizer, then we should actually
be teaching vectorizer to do this, because right now this rewrite
is still budget-limited, which isn't what we'd want.
Additionally, while the rest of the patch series was universally profitable,
this particular patch is reportedly (https://reviews.llvm.org/D73501#1905171)
exposing cost-modeling issues on ARM.
So let's just back this particular patch out. Once there's an undo transform,
this could be considered for reintegration.
This reverts commit 44edc6fd2c.
Consider a callee function that has a call (C) within it which feeds
into the return. When we inline that callee into a callsite that has
return attributes, we can backward propagate valid attributes to the
call (C) within that inlined callee body.
This is safe to do so only if we can guarantee transfer of execution to
successor in the window of instructions between return value (i.e. the
call C) and the return instruction.
Also, this is valid only for attributes which are a property of a
callsite and not those that are not dependent on the ABI, or a property
of the call itself.
Reviewed-By: reames, jdoerfert
Differential Revision: https://reviews.llvm.org/D76140
Summary:
Splitting Knowledge retention into Queries in Analysis and Builder into Transform/Utils
allows Queries and Transform/Utils to use Analysis.
Reviewers: jdoerfert, sstefan1
Reviewed By: jdoerfert
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77171
This reverts commit 28518d9ae3.
There is a failure in MsgPackReader.cpp when built with clang. It
complains about "signext and zeroext" are incompatible. Investigating
offline if it is infact a UB in the MsgPackReader code.
Consider a callee function that has a call (C) within it which feeds
into the return. When we inline that callee into a callsite that has
return attributes, we can backward propagate those attributes to the
call (C) within that inlined callee body.
This is safe to do so only if we can guarantee transfer of execution to
successor in the window of instructions between return value (i.e. the
call C) and the return instruction.
See added test cases.
Reviewed-By: reames, jdoerfert
Differential Revision: https://reviews.llvm.org/D76140
For each natural loop with multiple exit blocks, this pass creates a
new block N such that all exiting blocks now branch to N, and then
control flow is redistributed to all the original exit blocks.
The bulk of the tranformation is a new function introduced in
BasicBlockUtils that an redirect control flow from a set of incoming
blocks to a set of outgoing blocks via a common "hub".
This is a useful workaround for a limitation in the structurizer which
incorrectly orders blocks when processing a nest of loops. This pass
bypasses that issue by ensuring that each natural loop is recognized
as a separate region. Since the structurizer is a region pass, it no
longer sees a nest of loops in a single region, and instead processes
each "level" in the nesting as a separate region.
The AMDGPU backend provides a new option to enable this pass before
the structurizer, which may eventually be enabled by default.
Reviewers: madhur13490, arsenm, nhaehnle
Reviewed By: nhaehnle
Differential Revision: https://reviews.llvm.org/D75865
Aligned_alloc is a standard lib function and has been in glibc since
2.16 and in the C11 standard. It has semantics similar to malloc/calloc
for several analyses/transforms. This patch introduces aligned_alloc
in target library info and memory builtins. Subsequent ones will
make other passes aware and fix https://bugs.llvm.org/show_bug.cgi?id=44062
This change will also be useful to LLVM generators that need to allocate
buffers of vector elements larger than 16 bytes (for eg. 256-bit ones),
element boundary alignment for which is not typically provided by glibc malloc.
Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>
Differential Revision: https://reviews.llvm.org/D76970
Since intrinsics can now specify when an argument is required to be
constant, it is now OK to replace arguments with variables if they
aren't. This means intrinsics must now be accurately marked with
immarg.
Summary: Prevent InstCombine from removing llvm.assume for which the arguement is true when they have operand bundles with usefull information.
Reviewers: jdoerfert, nikic, lebedev.ri
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76147
Summary:
during inling Create and insert an llvm.assume with attributes to preserve them.
to prevent any changes for now generation of llvm.assume is under a flag disabled by default.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75825
Summary:
This patch replaces incorrectt assert with a check. Previously it asserts that
if SCEV cannot prove `isKnownPredicate(A != B)`, then it should be able to prove
`isKnownPredicate(A == B)`.
Both these fact may be not provable. It is shown in the provided test:
Could not prove: `{-294,+,-2}<%bb1> != 0`
Asserting: `{-294,+,-2}<%bb1> == 0`
Obviously, this SCEV is not equal to zero, but 0 is in its range so we cannot
also prove that it is not zero.
Instead of assert, we should be checking the required conditions explicitly.
Reviewers: lebedev.ri, fhahn, sanjoy, fedor.sergeev
Reviewed By: lebedev.ri
Subscribers: hiraditya, zzheng, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76050
This essentially reverts some of the SimplifyLibcalls part changes of D45736 [SimplifyLibcalls] Replace locked IO with unlocked IO.
C11 7.21.5.2 The fflush function
> If stream is a null pointer, the fflush function performs this flushing action on all streams for which the behavior is defined above.
i.e. fopen'ed FILE* is inherently captured.
POSIX.1-2017 getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - stdio with explicit client locking
> These functions can safely be used in a multi-threaded program if and only if they are called while the invoking thread owns the ( FILE *) object, as is the case after a successful call to the flockfile() or ftrylockfile() functions.
After a thread fopen'ed a FILE*, when it is calling foobar() which is now replaced by foobar_unlocked(),
if another thread is concurrently calling fflush(0), the behavior is undefined.
C11 7.22.4.4 The exit function
> Next, all open streams with unwritten buffered data are flushed, all open streams are closed, and all files created by the tmpfile function are removed.
The replacement is only feasible if the program is single threaded, or exit or fflush(0) is never called.
See also http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20180528/556615.html
for how the replacement makes libc interceptors difficult to implement.
dalias: in a worst case, it's unbounded data corruption because of concurrent access to pointers
without synchronization. f->wpos or rpos could get outside of the buffer, thread A could do
f->wpos += j after knowing j is in bounds, while thread B also changes it concurrently.
This can produce exploitable conditions depending on libc internals.
Revert the SimplifyLibcalls part change because the cons obviously
overweigh the pros. Even when the replacement is feasible, the benefit
is indemonstrable, more so in an application instead of an artificial
glibc benchmark. Theoretically the replacement could be beneficial when
calling getc_unlocked/putc_unlocked in a loop, but then it is better
using a blocked IO operation and the user is likely aware of that.
The function attribute inference is still useful and thus kept.
Reviewed By: xbolva00
Differential Revision: https://reviews.llvm.org/D75933
Summary:
Assume bundles need to be usable by Analysis and Transforms/Utils isn't.
so this commit moves utilities to deal with asusme bundles to IR.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75618
Summary: Finding what information is know about a value from a use is generally useful and can be done quickly.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75616
Summary:
This performs better for sample PGO.
NFC as PGSOColdCodeOnlyForSamplePGO is still true.
Reviewers: davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75550
As the test case shows if there is an ExtractValueInst in the Ret block, function dupRetToEnableTailCallOpts can't duplicate it into the block containing call. So later no tail call is generated in CodeGen.
This patch adds the ExtractValueInst handling code in function dupRetToEnableTailCallOpts and FoldReturnIntoUncondBranch, and later tail call can be generated for this case.
Differential Revision: https://reviews.llvm.org/D74242
Spin-off from D75407. As described there, ConstantFoldConstant()
currently returns null for non-ConstantExpr/ConstantVector inputs,
but otherwise always returns non-null, independently of whether
any folding has happened or not.
This is confusing and makes consumer code more complicated.
I would expect either that ConstantFoldConstant() returns only if
it actually folded something, or that it always returns non-null.
I'm going to the latter possibility here, which appears to be more
useful considering existing usage.
Differential Revision: https://reviews.llvm.org/D75543
Summary:
https://gist.github.com/modocache/ed7c62f6e570766c0f39b35dad675c2f
is an example of a small C++ program that uses C++20 coroutines that
is difficult to debug, due to the loss of debug info for variables that
"spill" across coroutine suspension boundaries. This patch addresses
that issue by inserting 'llvm.dbg.declare' intrinsics that point the
debugger to the variables' location at an offset to the coroutine frame.
With this patch, I confirmed that running the 'frame variable' commands in
https://gist.github.com/modocache/ed7c62f6e570766c0f39b35dad675c2f at
the specified breakpoints results in the correct values being printed
for coroutine frame variables 'i' and 'j' when using an lldb built from
trunk, as well as with gdb 8.3 (lldb 9.0.1, however, could not print the
values). The added test case also verifies this improved behavior.
The existing coro-debug.ll test case is also modified to reflect the
locations at which Clang actually places calls to 'dbg.declare', and
additional checks are added to ensure this patch works as intended in that
example as well.
Reviewers: vsk, jmorse, GorNishanov, lewissbaker, wenlei
Subscribers: EricWF, aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75338
Summary: This patch adds a new way to query operand bundles of an llvm.assume that is much better suited to some users like the Attributor that need to do many queries on the operand bundles of llvm.assume. Some modifications of the IR like replaceAllUsesWith can cause information in the map to be outdated, so this API is more suited to analysis passes and passes that don't make modification that could invalidate the map.
Reviewers: jdoerfert, sstefan1, uenoku
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75020
Also adds a force-reduction-intrinsics option for testing, for forcing
the generation of reduction intrinsics even when the backend is not
requesting them.
Summary:
This is to avoid generating duplicate llvm.dbg.value instrinsic if it already exists after the Instruction.
Before inserting llvm.dbg.value instruction, LLVM checks if the same instruction is already present before the instruction to avoid duplicates.
Currently it misses to check if it already exists after the instruction.
flang generates IR like this.
%4 = load i32, i32* %i1_311, align 4, !dbg !42
call void @llvm.dbg.value(metadata i32 %4, metadata !35, metadata !DIExpression()), !dbg !33
When this IR is processed in llvm, it ends up inserting duplicates.
%4 = load i32, i32* %i1_311, align 4, !dbg !42
call void @llvm.dbg.value(metadata i32 %4, metadata !35, metadata !DIExpression()), !dbg !33
call void @llvm.dbg.value(metadata i32 %4, metadata !35, metadata !DIExpression()), !dbg !33
We have now updated LdStHasDebugValue to include the cases when instruction is already
followed by same dbg.value instruction we intend to insert.
Now,
Definition and usage of function LdStHasDebugValue are deleted.
RemoveRedundantDbgInstrs is called for the cleanup of duplicate dbg.value's
Testing:
Added unit test for validation
check-llvm
check-debuginfo (the debug info integration tests)
Reviewers: aprantl, probinson, dblaikie, jmorse, jini.susan.george
SouraVX, awpandey, dstenb, vsk
Reviewed By: aprantl, jmorse, dstenb, vsk
Differential Revision: https://reviews.llvm.org/D74030
Summary:
Current peeling implementation bails out in case of loop nests.
The patch introduces a field in TargetTransformInfo structure that
certain targets can use to relax the constraints if it's
profitable (disabled by default).
Also additional option is added to enable peeling manually for
experimenting and testing purposes.
Reviewers: fhahn, lebedev.ri, xbolva00
Reviewed By: xbolva00
Subscribers: RKSimon, xbolva00, hiraditya, zzheng, llvm-commits
Differential Revision: https://reviews.llvm.org/D70304
Summary: This fixes the crash that led to the revert of D69591.
Reviewers: davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75307
Summary:
Replacing uses of IV outside of the loop is likely generally useful,
but `rewriteLoopExitValues()` is cautious, and if it isn't told to always
perform the replacement, and there are hard uses of IV in loop,
it doesn't replace.
In [[ https://bugs.llvm.org/show_bug.cgi?id=44668 | PR44668 ]],
that prevents `-indvars` from replacing uses of induction variable
after the loop, which might be one of the optimization failures
preventing that code from being vectorized.
Instead, now that the cost model is fixed, i believe we should be
a little bit more optimistic, and also perform replacement
if we believe it is within our budget.
Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=44668 | PR44668 ]].
Reviewers: reames, mkazantsev, asbirlea, fhahn, skatkov
Reviewed By: mkazantsev
Subscribers: nikic, hiraditya, zzheng, javed.absar, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73501
Summary:
In future patches`SCEVExpander::isHighCostExpansionHelper()` will respect the budget allocated by performing TTI cost modelling.
This is a fully NFC patch to make things reviewable.
Reviewers: reames, mkazantsev, wmi, sanjoy
Reviewed By: mkazantsev
Subscribers: hiraditya, zzheng, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73705
Summary:
Future patches will make use of TTI to perform cost-model-driven `SCEVExpander::isHighCostExpansionHelper()`
This is a fully NFC patch to make things reviewable.
Reviewers: reames, mkazantsev, wmi, sanjoy
Reviewed By: mkazantsev
Subscribers: hiraditya, zzheng, javed.absar, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73704
Summary:
Blocks in a loop can be in any order as long as the loop header is the
first block in Blocks.
With some order of Blocks, cloneLoopWithPreheader would trigger the
assertion in addBasicBlockToLoop.
Example:
define void @test(i64 %N) {
preheader.i:
br label %header.i
header.i:
%i = phi i64 [ 0, %preheader.i ], [ %inc.i, %latch.i ]
br label %header.j
header.j:
%j = phi i64 [ 0, %header.i ], [ %inc.j, %latch.j ]
br label %header.k
header.k:
%k = phi i64 [ 0, %header.j ], [ %inc.k, %latch.k ]
call void @baz(i64 %i, i64 %j, i64 %k)
br label %latch.k
latch.k:
%inc.k = add nsw i64 %k, 1
%cmp.k = icmp slt i64 %inc.k, %N
br i1 %cmp.k, label %header.k, label %latch.j
latch.j:
%inc.j = add nsw i64 %j, 1
%cmp.j = icmp slt i64 %inc.j, %N
br i1 %cmp.j, label %header.j, label %latch.i
latch.i:
%inc.i = add nsw i64 %i, 1
%cmp.i = icmp slt i64 %inc.i, %N
br i1 %cmp.i, label %header.i, label %exit.i
exit.i:
ret void
}
declare void @baz(i64, i64, i64)
If the blocks of loop-i is in the order: header.i, latch.k, header.k,
header.j, latch.j, latch.i,
then cloneLoopWithPreheader would trigger the assertion in
addBasicBlockToLoop
assert(contains(SameHeader) && getHeader() == SameHeader->getHeader() &&
"Incorrect LI specified for this loop!");
As latch.k is in both loop-j and loop-k, it would be set as the header
of both loops after adding latch.k.
If we update loop headers during cloning blocks, then after adding
header.k,
the header of loop-k would be updated with header.k,
while the header of loop-j stays as latch.k.
When adding header.j, SameHeader is loop-k, SameHeader->getHeader() is
header.k, but getHeader() is latch.k, which trigger the assertion.
Reviewer: jdoerfert, Meinersbur, fhahn, kbarton, hfinkel, bmahjour,
etiotto
Reviewed By: Meinersbur
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D74382
ToVectorTy is defined and used in multiple places. Hoist it to
VectorUtils.h to avoid duplication and improve re-usability.
Reviewers: rengolin, hsaito, Ayal, gilr, fpetrogalli
Reviewed By: fpetrogalli
Differential Revision: https://reviews.llvm.org/D74959
This changes the SimplifyLibCalls utility to accept an IRBuilderBase,
which allows us to pass through the IRBuilder used by InstCombine.
This will ensure that new instructions get added to the worklist.
The annotated test-case drops from 4 to 2 InstCombine iterations thanks
to this.
To achieve this, I'm adding an IRBuilderBase::OperandBundlesGuard,
which is basically the same as the existing InsertPointGuard and
FastMathFlagsGuard, but for operand bundles. Also add a
setDefaultOperandBundles() method so these can be set outside the
constructor.
Differential Revision: https://reviews.llvm.org/D74792
In addition to memory behavior attributes (readonly/writeonly) we now
derive memory location attributes (argmemonly/inaccessiblememonly/...).
The former is part of AAMemoryBehavior and the latter part of
AAMemoryLocation. While they are similar in nature it got messy when
they were put in a single AA. Location attributes for arguments and
floating values will follow later.
Note that both memory attributes kinds can derive readnone. If there are
no accesses AAMemoryBehavior will derive readnone. If there are accesses
but only to stack (=local) locations AAMemoryLocation will derive
readnone.
Reviewed By: uenoku
Differential Revision: https://reviews.llvm.org/D73426
replaceDbgDeclare is used to update the descriptions of stack variables
when they are moved (e.g. by ASan or SafeStack). A side effect of
replaceDbgDeclare is that it moves dbg.declares around in the
instruction stream (typically by hoisting them into the entry block).
This behavior was introduced in llvm/r227544 to fix an assertion failure
(llvm.org/PR22386), but no longer appears to be necessary.
Hoisting a dbg.declare generally does not create problems. Usually,
dbg.declare either describes an argument or an alloca in the entry
block, and backends have special handling to emit locations for these.
In optimized builds, LowerDbgDeclare places dbg.values in the right
spots regardless of where the dbg.declare is. And no one uses
replaceDbgDeclare to handle things like VLAs.
However, there doesn't seem to be a positive case for moving
dbg.declares around anymore, and this reordering can get in the way of
understanding other bugs. I propose getting rid of it.
Testing: stage2 RelWithDebInfo sanitized build, check-llvm
rdar://59397340
Differential Revision: https://reviews.llvm.org/D74517
This reverts commit 61b35e4111.
This commit causes a timeout in chromium builds; likely to have a
similar cause to the previous timeout issue caused by this commit (see
6ded69f294 for more details). It is possible that there is no way to
fix this bug that will not cause this issue; further investigations as
to the efficiency of handling large amounts of debug info will be
necessary.
Reapply 8a56d64d76 with minor fixes.
The problem was that cancellation can cause new edges to the parallel
region exit block which is not outlined. The CodeExtractor will encode
the information which "exit" was taken as a return value. The fix is to
ensure we do not return any value from the outlined function, to prevent
control to value conversion we ensure a single exit block for the
outlined region.
This reverts commit 3aac953afa.
In order to fix PR44560 and to prepare for loop transformations we now
finalize a function late, which will also do the outlining late. The
logic is as before but the actual outlining step happens now after the
function was fully constructed. Once we have loop transformations we
can apply them in the finalize step before the outlining.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D74372
This reverts commit 636c93ed11.
The original patch caused build failures on TSan buildbots. Commit 6ded69f294
fixes this issue by reducing the rate at which empty debug intrinsics
propagate, reducing the memory footprint and preventing a fatal spike.
Summary: It attempts to devirtualize a call on alloca through vtable loads.
Reviewers: davidxl
Subscribers: mgorny, Prazek, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71308
The CallGraphUpdater is a helper that simplifies the process of updating
the call graph, both old and new style, while running an CGSCC pass.
The uses are contained in different commits, e.g. D70767.
More functionality is added as we need it.
Reviewed By: modocache, hfinkel
Differential Revision: https://reviews.llvm.org/D70927
Bionic has had `__strlen_chk` for a while. Optimizing that into a
constant is quite profitable, when possible.
Differential Revision: https://reviews.llvm.org/D74079
Summary:
This enables it for large working set size cases only.
This does not enable it under sample PGO.
Reviewers: davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74073
Summary:
Tune the profile threshold flag value for instrumentation PGO based on internal
benchmarks.
Also, add flags to allow profile guided size optimizations for non-cold code
to be enabled separately for instrumentation and sample PGSO.
Neither changes the default behavior (yet) as it's disabled for non-cold code.
Reviewers: davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72937
Summary:
Method appendLoopsToWorklist is duplicate in LoopUnroll and in the
LoopPassManager as an internal method. Make it an utility.
Reviewers: dmgreen, chandlerc, fedor.sergeev, yamauchi
Subscribers: mehdi_amini, hiraditya, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73569
If we had `noalias` on an argument the inliner created alias scope
metadata already. However, the call site `noalias` annotation was not
considered. Since the Attributor can derive such call site `noalias`
annotation we should treat them the same as argument annotations.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D73528
Fix attempt
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Some code gen passes use MBFIWrapper to keep track of the frequency of new
blocks. This was not taken into account and could lead to incorrect frequencies
as MBFI silently returns zero frequency for unknown/new blocks.
Add a variant for MBFIWrapper in the PGSO query interface.
Depends on D73494.
We may calculate reassociable math ops in arbitrary order when creating a shuffle reduction,
so there's no guarantee that things like 'nsw' hold on those intermediate values. Drop all
poison-generating flags for safety.
This change is limited to shuffle reductions because I don't think we have a problem in the
general case (where we intersect flags of each scalar op that goes into a vector op), but if
there's evidence of other cases being wrong, we can extend this fix to cover those cases.
https://bugs.llvm.org/show_bug.cgi?id=44536
Differential Revision: https://reviews.llvm.org/D73727
Summary:
This patch makes sure that the field VFShape.VF is greater than zero
when demangling the vector function name of scalable vector functions
encoded in the "vector-function-abi-variant" attribute.
This change is required to be able to provide instances of VFShape
that can be used to query the VFDatabase for the vectorization passes,
as such passes always require a positive value for the Vectorization Factor (VF)
needed by the vectorization process.
It is not possible to extract the value of VFShape.VF from the mangled
name of scalable vector functions, because it is encoded as
`x`. Therefore, the VFABI demangling function has been modified to
extract such information from the IR declaration of the vector
function, under the assumption that _all_ vectors in the signature of
the vector function have the same number of lanes. Such assumption is
valid because it is also assumed by the Vector Function ABI
specifications supported by the demangling function (x86, AArch64, and
LLVM internal one).
The unit tests that demangle scalable names have been modified by
adding the IR module that carries the declaration of the vector
function name being demangled.
In particular, the demangling function fails in the following cases:
1. When the declaration of the scalable vector function is not
present in the module.
2. When the value of VFSHape.VF is not greater than 0.
Reviewers: jdoerfert, sdesmalen, andwar
Reviewed By: jdoerfert
Subscribers: mgorny, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73286
proven safe.
Summary:
Currently LoopFusion give up when the second loop nest preheader is
not empty. For example:
for (int i = 0; i < 100; ++i) {}
x+=1;
for (int i = 0; i < 100; ++i) {}
The above example should be safe to fuse.
This PR moves instructions in FC1 preheader (e.g. x+=1; ) to
FC0 preheader, which then LoopFusion is able to fuse them.
Reviewer: kbarton, Meinersbur, jdoerfert, dmgreen, fhahn, hfinkel,
bmahjour, etiotto
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D71821
During extraction, stale llvm.assume handles may be retained in the
original function. The setup is:
1) CodeExtractor unregisters assumptions in the blocks that are to be
extracted.
2) Extraction happens. There are now two functions: f1 and f1.extracted.
3) Leftover assumptions in f1 (/not/ removed as they were not in the set of
blocks to be extracted) now have affected-value llvm.assume handles in
f1.extracted.
When assumptions for a value used in f1 are looked up, ValueTracking can assert
as some of the handles are in the wrong function. To fix this, simply erase the
llvm.assume calls in the extracted function.
Alternatives include flushing the assumption cache in the original function, or
walking all values used in the original function to prune stale affected-value
handles. Both seem more expensive.
Testing: check-llvm, LNT run with -mllvm -hot-cold-split enabled
rdar://58460728
Previously, the enums didn't account for all the possible cases, which
could cause misleading results (particularly for a "switch" on
FunctionModRefBehavior).
Fixes regression in polly from recent patch to add writeonly to memset.
While I'm here, also fix a few dubious uses of the FMRB_* enum values.
Differential Revision: https://reviews.llvm.org/D73154
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Summary:
Currently IsControlFlowEquivalent determine if two blocks are control
flow equivalent by checking if A dominates B and B post dominates A.
There exists blocks that are control flow equivalent even if they don't
satisfy the A dominates B and B post dominates A condition.
For example,
if (cond)
A
if (cond)
B
In the PR, we determine if two blocks are control flow equivalent by
also checking if the two sets of conditions A and B depends on are
equivalent.
Reviewer: jdoerfert, Meinersbur, dmgreen, etiotto, bmahjour, fhahn,
hfinkel, kbarton
Reviewed By: fhahn
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D71578
Summary:
LoopUnroll can reuse the RemapInstruction() in ValueMapper, or
remapInstructionsInBlocks() in CloneFunction, depending on the needs.
There is no need to have its own version in LoopUnroll.
By calling RemapInstruction() without TypeMapper or Materializer and
with Flags (RF_NoModuleLevelChanges | RF_IgnoreMissingLocals), it does
the same as remapInstruction(). remapInstructionsInBlocks() calls
RemapInstruction() exactly as described.
Looking at the history, I cannot find any obvious reason to have its own
version.
Reviewer: dmgreen, jdoerfert, Meinersbur, kbarton, bmahjour, etiotto,
foad, aprantl
Reviewed By: jdoerfert
Subscribers: hiraditya, zzheng, llvm-commits, prithayan, anhtuyen
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D73277
Summary:
This is a follow up on https://reviews.llvm.org/D71473#inline-647262.
There's a caveat here that `Align(1)` relies on the compiler understanding of `Log2_64` implementation to produce good code. One could use `Align()` as a replacement but I believe it is less clear that the alignment is one in that case.
Reviewers: xbolva00, courbet, bollu
Subscribers: arsenm, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, Jim, kerbowa, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73099
This fixes a bug where a PHI node that is only referenced by a lifetime.end intrinsic in an otherwise empty cleanuppad can cause SimplyCFG to create an SSA violation while removing the empty cleanuppad. Theoretically the same problem can occur with debug intrinsics.
Differential Revision: https://reviews.llvm.org/D72540
Create a utility wrapper for the RecursivelyDeleteTriviallyDeadInstructions utility
method, which sets to nullptr the instructions that are not trivially
dead. Use the new method in LoopStrengthReduce.
Alternative: add a bool to the same method; this option adds a marginal
amount of overhead to the other callers, and the method needs to be
updated to return a bool status when it removes/doesn't remove
instructions.
The utility method RecursivelyDeleteTriviallyDeadInstructions receives
as input a vector of Instructions, where all inputs are valid
instructions. This same vector is used as a scratch storage (per the
header comment) to recursively delete instructions. If an instruction is
added as an operand of multiple other instructions, it may be added twice,
then deleted once, then the second reference in the vector is invalid.
Switch to using a Vector<WeakTrackingVH>.
This change facilitates a clean-up in LoopStrengthReduction.
Calling `operator*` on a WeakVH with a null value yields a null
reference, which is UB. Avoid this by implicitly converting the WeakVH
to a `Value *` rather than dereferencing and then taking the address
for the type conversion.
Differential Revision: https://reviews.llvm.org/D73280
In case of loops with multiple exit where all-but-one exit are deoptimizing
it might happen that the first rotation will end up with latch having a deoptimizing
exit. This makes the loop unsuitable for trip-count analysis (say, getLoopEstimatedTripCount)
as well as for loop transformations that know how to handle multple deoptimizing exits.
It pretty much means that canonical form in multple-deoptimizing-exits case should be
with non-deoptimizing exit at latch.
Teach loop-rotation to reach this canonical form by repeating rotation.
-loop-rotate-multi option introduced to control this behavior, currently disabled by default.
Reviewers: skatkov, asbirlea, reames, fhahn
Reviewed By: skatkov
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73058
It is incorrect to call ValueHandleBase::ValueIsRAUWd when only one use
is replaced since it simply violates semantics of the callback and leads
to bugs like PR44320.
Previously this call was used specifically to keep LICM's cache of
AliasSetTrackers up to date across passes (as PR36801 showed, even for
that purpose it didn't work properly), but since LICM doesn't have that
cache anymore, we can safely remove this incorrect call with no
repercussions.
This patch fixes https://bugs.llvm.org/show_bug.cgi?id=44320
Reviewers: asbirlea, fhahn, efriedma, reames
Reviewed-By: asbirlea
Differential Revision: https://reviews.llvm.org/D73089
Summary: Vectorized loop processes VFxUF number of elements in one iteration thus total number of iterations decreases proportionally. In addition epilog loop may not have more than VFxUF - 1 iterations. This patch updates profile information accordingly.
Reviewers: hsaito, Ayal, fhahn, reames, silvas, dcaballe, SjoerdMeijer, mkuper, DaniilSuchkov
Reviewed By: Ayal, DaniilSuchkov
Subscribers: fedor.sergeev, hiraditya, rkruppe, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67905
Summary: Current implementation of getLoopEstimatedTripCount returns 1 iteration less than it should. The reason is that in bottom tested loop first iteration is executed before first back branch is taken. For example for loop with !{!"branch_weights", i32 1 // taken, i32 1 // exit} metadata getLoopEstimatedTripCount gives 1 while actual number of iterations is 2.
Reviewers: Ayal, fhahn
Reviewed By: Ayal
Subscribers: mgorny, hiraditya, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71990
This moves `rewriteLoopExitValues()` from IndVarSimplify to LoopUtils thus
making it a generic loop utility function. This allows to rewrite loop exit
values by just calling this function without running the whole IndVarSimplify
pass.
We use this in D72714 to rematerialise the iteration count in exit blocks, so
that we can clean-up loop update expressions inside the hardware-loops later.
Differential Revision: https://reviews.llvm.org/D72602
Static method MemoryDependenceResults::getLoadLoadClobberFullWidthSize
does not have or use any info specific to MemoryDependenceResults.
Move it to its only user: VNCoercion.
This reverts commit 3f3017e because there's a failure on peel-loop-nests.ll
with LLVM_ENABLE_EXPENSIVE_CHECKS on.
Differential Revision: https://reviews.llvm.org/D70304
Summary:
This commits is a rework of the patch in
https://reviews.llvm.org/D67572.
The rework was requested to prevent out-of-tree performance regression
when vectorizing out-of-tree IR intrinsics. The vectorization of such
intrinsics is enquired via the static function `isTLIScalarize`. For
detail see the discussion in https://reviews.llvm.org/D67572.
Reviewers: uabelho, fhahn, sdesmalen
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72734
Summary:
This change implements the expansion in two parts:
- Add a utility function emitAMDGPUPrintfCall() in LLVM.
- Invoke the above function from Clang CodeGen, when processing a HIP
program for the AMDGPU target.
The printf expansion has undefined behaviour if the format string is
not a compile-time constant. As a sufficient condition, the HIP
ToolChain now emits -Werror=format-nonliteral.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D71365
After extracting, fix up debug info in both the old and new functions by
1) Pointing line locations and debug intrinsics to the new subprogram
scope, and
2) Deleting intrinsics which point to values outside of the new
function.
Depends on https://reviews.llvm.org/D72795.
Testing: check-llvm, check-clang, a build of LNT in the `-Os -g` config
with "-mllvm -hot-cold-split=1" set, and end-to-end debugging of a toy
program which undergoes splitting to verify that lldb can find
variables, single step, etc. in extracted code.
rdar://45507940
Differential Revision: https://reviews.llvm.org/D72801
Summary:
InlineResult is used both in APIs assessing whether a call site is
inlinable (e.g. llvm::isInlineViable) as well as in the function
inlining utility (llvm::InlineFunction). It means slightly different
things (can/should inlining happen, vs did it happen), and the
implicit casting may introduce ambiguity (casting from 'false' in
InlineFunction will default a message about hight costs,
which is incorrect here).
The change renames the type to a more generic name, and disables
implicit constructors.
Reviewers: eraman, davidxl
Reviewed By: davidxl
Subscribers: kerbowa, arsenm, jvesely, nhaehnle, eraman, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72744
Factor out the logic needed to update debug locations contained within
MD_loop metadata.
This refactor is preparation for a future change that also needs to
rewrite MD_loop metadata.
rdar://45507940
Summary:
Current peeling implementation bails out in case of loop nests.
The patch introduces a field in TargetTransformInfo structure that
certain targets can use to relax the constraints if it's
profitable (disabled by default).
Also additional option is added to enable peeling manually for
experimenting and testing purposes.
Reviewers: fhahn, lebedev.ri, xbolva00
Reviewed By: xbolva00
Subscribers: xbolva00, hiraditya, zzheng, llvm-commits
Differential Revision: https://reviews.llvm.org/D70304
SCEVExpander modifies the underlying function so it is more suitable in
Transforms/Utils, rather than Analysis. This allows using other
transform utils in SCEVExpander.
Reviewers: sanjoy.google, efriedma, reames
Reviewed By: sanjoy.google
Differential Revision: https://reviews.llvm.org/D71537
As discussed in PR44330:
https://bugs.llvm.org/show_bug.cgi?id=44330
...the transform from pow(X, -0.5) libcall/intrinsic to
reciprocal square root can result in small deviations from
the expected result due to differences in the pow()
implementation and/or the extra rounding step from the division.
This patch proposes to allow that difference with either the
'approximate functions' or 'reassociate' FMF:
http://llvm.org/docs/LangRef.html#fast-math-flags
In practice, this likely means that the code is compiled with
all of 'fast' (-ffast-math), but I have preserved the existing
specializations for -0.0/-INF that enable generating safe code
if those special values are allowed simultaneously with
allowing approximation/reassociation.
The question about whether a similar restriction is needed for
the non-reciprocal case -- pow(X, 0.5) -- is deferred. That
transform is allowed without FMF currently, and this patch does
not change that behavior.
Differential Revision: https://reviews.llvm.org/D71706
This reverts commit 1f3dd83cc1, reapplying
commit bb1b0bc4e5.
The original commit failed on some builds seemingly due to the use of a
bracketed constructor with an std::array, i.e. `std::array<> arr({...})`.
Previously, LLVM had no functional way of performing casts inside of a
DIExpression(), which made salvaging cast instructions other than Noop
casts impossible. This patch enables the salvaging of casts by using the
DW_OP_LLVM_convert operator for SExt and Trunc instructions.
There is another issue which is exposed by this fix, in which fragment
DIExpressions (which are preserved more readily by this patch) for
values that must be split across registers in ISel trigger an assertion,
as the 'split' fragments extend beyond the bounds of the fragment
DIExpression causing an error. This patch also fixes this issue by
checking the fragment status of DIExpressions which are to be split, and
dropping fragments that are invalid.
Summary:This PR move instructions from FC0.Latch bottom up to the
beginning of FC1.Latch as long as they are proven safe.
To illustrate why this is beneficial, let's consider the following
example:
Before Fusion:
header1:
br header2
header2:
br header2, latch1
latch1:
br header1, preheader3
preheader3:
br header3
header3:
br header4
header4:
br header4, latch3
latch3:
br header3, exit3
After Fusion (before this PR):
header1:
br header2
header2:
br header2, latch1
latch1:
br header3
header3:
br header4
header4:
br header4, latch3
latch3:
br header1, exit3
Note that preheader3 is removed during fusion before this PR.
Notice that we cannot fuse loop2 with loop4 as there exists block latch1
in between.
This PR move instructions from latch1 to beginning of latch3, and remove
block latch1. LoopFusion is now able to fuse loop nest recursively.
After Fusion (after this PR):
header1:
br header2
header2:
br header3
header3:
br header4
header4:
br header2, latch3
latch3:
br header1, exit3
Reviewer: kbarton, jdoerfert, Meinersbur, dmgreen, fhahn, hfinkel,
bmahjour, etiotto
Reviewed By: kbarton, Meinersbur
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D71165
Summary:
This is a resubmit of D71473.
This patch introduces a set of functions to enable deprecation of IRBuilder functions without breaking out of tree clients.
Functions will be deprecated one by one and as in tree code is cleaned up.
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: aaron.ballman, courbet
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71547
Summary:
This patch introduces a set of functions to enable deprecation of IRBuilder functions without breaking out of tree clients.
Functions will be deprecated one by one and as in tree code is cleaned up.
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: arsenm, jvesely, nhaehnle, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71473
Summary:
In commit d60f34c20a (llvm-svn 317128,
PR35113) MergeBlockIntoPredecessor was changed into
discarding some dbg.value intrinsics referring to
PHI values, post-splice due to loop rotation.
That elimination of dbg.value intrinsics did not
consider which dbg.value to keep depending on the
context (e.g. if the variable is changing its value
several times inside the basic block).
In the past that hasn't been such a big problem since
CodeGenPrepare::placeDbgValues has moved the dbg.value
to be next to the PHI node anyway. But after commit
00e238896c CodeGenPrepare isn't doing that
any longer, so we need to be more careful when avoiding
duplicate dbg.value intrinsics in MergeBlockIntoPredecessor.
This patch replaces the code that tried to avoid duplicate
dbg.values by using the RemoveRedundantDbgInstrs helper.
Reviewers: aprantl, jmorse, vsk
Reviewed By: aprantl, vsk
Subscribers: jholewinski, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71480
Summary:
Add a RemoveRedundantDbgInstrs to BasicBlockUtils with the
goal to remove redundant dbg intrinsics from a basic block.
This can be useful after various transforms, as it might
be simpler to do a filtering of dbg intrinsics after the
transform than during the transform.
One primary use case would be to replace a too aggressive
removal done by MergeBlockIntoPredecessor, seen at loop
rotate (not done in this patch).
The elimination algorithm currently focuses on dbg.value
intrinsics and is doing two iterations over the BB.
First we iterate backward starting at the last instruction
in the BB. Whenever a consecutive sequence of dbg.value
instructions are found we keep the last dbg.value for
each variable found (variable fragments are identified
using the {DILocalVariable, FragmentInfo, inlinedAt}
triple as given by the DebugVariable helper class).
Next we iterate forward starting at the first instruction
in the BB. Whenever we find a dbg.value describing a
DebugVariable (identified by {DILocalVariable, inlinedAt})
we save the {DIValue, DIExpression} that describes that
variables value. But if the variable already was mapped
to the same {DIValue, DIExpression} pair we instead drop
the second dbg.value.
To ease the process of making lit tests for this utility a
new pass is introduced called RedundantDbgInstElimination.
It can be executed by opt using -redundant-dbg-inst-elim.
Reviewers: aprantl, jmorse, vsk
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71478
This reverts commit 0be81968a2.
The VFDatabase needs some rework to be able to handle vectorization
and subsequent scalarization of intrinsics in out-of-tree versions of
the compiler. For more details, see the discussion in
https://reviews.llvm.org/D67572.
GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.
This fixes the buildbot failures.
Differential Revision: https://reviews.llvm.org/D68328
Patch by Joseph Faulls!
GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.
Differential Revision: https://reviews.llvm.org/D68328
Patch by Joseph Faulls!
This patch introduced the VFDatabase, the framework proposed in
http://lists.llvm.org/pipermail/llvm-dev/2019-June/133484.html. [*]
In this patch the VFDatabase is used to bridge the TargetLibraryInfo
(TLI) calls that were previously used to query for the availability of
vector counterparts of scalar functions.
The VFISAKind field `ISA` of VFShape have been moved into into VFInfo,
under the assumption that different vector ISAs may provide the same
vector signature. At the moment, the vectorizer accepts any of the
available ISAs as long as the signature provided by the VFDatabase
matches the one expected in the vectorization process. For example,
when targeting AVX or AVX2, which both have 256-bit registers, the IR
signature of the two vector functions associated to the two ISAs is
the same. The `getVectorizedFunction` method at the moment returns the
first available match. We will need to add more heuristics to the
search system to decide which of the available version (TLI, AVX,
AVX2, ...) the system should prefer, when multiple versions with the
same VFShape are present.
Some of the code in this patch is based on the work done by Sumedh
Arani in https://reviews.llvm.org/D66025.
[*] Notice that in the proposal the VFDatabase was called SVFS. The
name VFDatabase is more in line with LLVM recommendations for
naming classes and variables.
Differential Revision: https://reviews.llvm.org/D67572
basic blocks
Originally applied in 72ce759928.
Fixed a build failure caused by incorrect use of cast instead of
dyn_cast.
This reverts commit 8b0780f795.
AssumptionCache can be null in SimplifyCFGOptions. However, FoldCondBranchOnPHI() was not properly handling that when passing a null AssumptionCache to simplifyCFG.
Patch by Rodrigo Caetano Rocha <rcor.cs@gmail.com>
Reviewers: fhahn, lebedev.ri, spatel
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D69963
In general ValueHandleBase::ValueIsRAUWd shouldn't be called when not
all uses of the value were actually replaced, though, currently
formLCSSAForInstructions calls it when it inserts LCSSA-phis.
Calls of ValueHandleBase::ValueIsRAUWd were added to LCSSA specifically
to update/invalidate SCEV. In the best case these calls duplicate some
of the work already done by SE->forgetValue, though in case when SCEV of
the value is SCEVUnknown, SCEV replaces the underlying value of
SCEVUnknown with the new value (i.e. acts like LCSSA-phi actually fully
replaces the value it is created for), which leads to SCEV being
corrupted because LCSSA-phi rarely dominates all uses of its inputs.
Fixes bug https://bugs.llvm.org/show_bug.cgi?id=44058.
Reviewers: fhahn, efriedma, reames, sanjoy.google
Reviewed By: fhahn
Subscribers: hiraditya, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70593
Summary:
Emit a value debug intrinsic (with OP_deref) when an alloca address is
passed to a function call after going through a bitcast.
This generates an FP or SP-relative location for the local variable in
the following case:
int x;
use((void *)&x;
Reviewers: aprantl, vsk, pcc
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70752
Summary:
D69561/dde5893 enabled importing of readonly variables with references,
however, it introduced a bug relating to importing/internalization of
writeonly variables with references.
A fix for this was added in D70006/7f92d66. But this didn't work in
distributed ThinLTO mode. The reason is that the fix (importing the
writeonly var with a zeroinitializer) was only applied when there were
references on the writeonly var summary. In distributed ThinLTO mode,
where we only have a small slice of the index, we will not have the
references on the importing side if we are not importing those
referenced values. Rather than changing this handshaking (which will
require a lot of other changes, since that's how we know what to import
in the distributed backend clang invocation), we can simply always give
the writeonly variable a zero initializer.
Reviewers: evgeny777, steven_wu
Subscribers: mehdi_amini, inglorion, hiraditya, dexonsmith, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70977
Summary:
This is one more prep step necessary before the code gen pass instrumentation
code could go in.
Reviewers: davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70988
When basic blocks are killed, either due to being empty or to being an if.then
or if.else block whose complement contains identical instructions, some of the
debug intrinsics in that block are lost. This patch sinks those intrinsics
into the single successor block, setting them Undef if necessary to
prevent debug info from falling out-of-date.
Differential Revision: https://reviews.llvm.org/D70318
Vedant Kumar