This was reverted because it was breaking when targeting Darwin which
tried to export these symbols which are now hidden. It should be safe
to just stop attempting to export these symbols in the clang driver,
though Apple folks will need to change their TAPI allow list described
in the commit where these symbols were originally exported
f538018562
Bug: https://github.com/llvm/llvm-project/issues/58265
Differential Revision: https://reviews.llvm.org/D135340
Move logic to check and replace conditions to a helper function. This
isolates the code, allows using early returns, reduces the
indentation and simplifies eliminateConstraints.
When generating masked gathers nodes, SLP vectorizer accounts the cost
of the GEPs for loads as part of the scalar-vector transformation cost
estimation. But it does not do it for vectorized loads/stores, while it
may completely remove some of the GEPs completely. Because of this in
some cases masked gather operation can be much more profitable rather
than regular vectorization (masked-gather cost + vector GEP - scalar
loads + GEPs comparing to vectorized loads - scalar loads).
Added the analysis of the removed scalarGEPs for vectorized load/store nodes for better cost estimation.
Differential Revision: https://reviews.llvm.org/D135282
This reverts commit b05f5b90a1.
There are thread sanitizer buildbot failures in simple_stack.c.
I think that's because this ended up affecting the handling of
volatile accesses to allocas. Reverting for now.
Don't add argmem if the pointer is clearly not an argument (e.g.
a global). I don't think this makes a difference right now, but
gives more obvious results with D135780.
Limit pointer decomposition to pointers with index sizes of at most 64
bits. int64_t is used for coefficients, so as long as the index size <=
64 bits we should be able to represent all pointer offsets.
Pointer decomposition is limited to inbounds GEPs, so if a index
computation would overflow the result is poison, so it doesn't matter
that the coefficient overflows.
This allows replacing MulOverflow with regular multiplications.
We have to account for accesses to argument memory via captures.
I don't think there's any way to make this produce incorrect
results right now (because as soon as "other" is set, we lose the
ability to infer argmemonly), but this avoids incorrect results
once we have more precise representation.
The code for inferring memory attributes on arguments claims that
inalloca/preallocated arguments are always clobbered:
d71ad41080/llvm/lib/Transforms/IPO/FunctionAttrs.cpp (L640-L642)
However, we would still infer memory attributes for the whole
function without taking this into account, so we could still end
up inferring readnone for the function. This adds an argument
clobber if there are any inalloca/preallocated arguments.
Differential Revision: https://reviews.llvm.org/D135783
Add a check (can be disabled via a flag) that the pipeline we generate is actually parsable.
Can be disabled because we don't expect to handle every pass in -print-pipeline-passes.
Fixes#58280.
Reviewed By: ChuanqiXu
Differential Revision: https://reviews.llvm.org/D135703
(X << Z) / (Y << Z) --> X / Y
https://alive2.llvm.org/ce/z/CLKzqT
This requires a surprising "nuw" constraint because we have
to guard against immediate UB via signed-div overflow with
-1 divisor.
This extends 008a89037a and is another transform
derived from issue #58137.
Need to set the insertpoint for extractelement to point to the first
instruction in the node to avoid possible crash during external uses
combine process. Without it we may endup with the incorrect
transformation.
Differential Revision: https://reviews.llvm.org/D135591
(X << Z) / (Y << Z) --> X / Y
https://alive2.llvm.org/ce/z/E5eaxU
This fixes the motivating example from issue #58137,
but it is not the most general transform. We should
probably also convert left-shift in the divisor to
right-shift in the dividend for that, but that exposes
another missed canonicalization for shifts and adds.
Freeze instruction in some cases makes codegen worse, so need to be very
careful when emitting it. Instead improve analysis in isUndefVector
function to generate mask of unused elements and use it in the analysis.
Differential Revision: https://reviews.llvm.org/D135382
optimizeInductions may leave dead recipes which can prevent sinking.
Sinking on the other hand should not introduce new dead recipes, so
clean up dead recipes before sinking.
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D133762
They have been scattered over the code. For better structuring, perform
them in one place. Potential CT drop is possible because we collect exit
blocks twice, but it's small price to pay for much better code structure.
These are semantically two different stages, but were entwined in the
old implementation. Now cost computation does not do legality checks,
and they all are done beforehead.
For a local linkage GlobalObject in a non-prevailing COMDAT, it remains defined while its
leader has been made available_externally. This violates the COMDAT rule that
its members must be retained or discarded as a unit.
To fix this, update the regular LTO change D34803 to track local linkage
GlobalValues, and port the code to ThinLTO (GlobalAliases are not handled.)
This fixes two problems.
(a) `__cxx_global_var_init` in a non-prevailing COMDAT group used to
linger around (unreferenced, hence benign), and is now correctly discarded.
```
int foo();
inline int v = foo();
```
(b) Fix https://github.com/llvm/llvm-project/issues/58215:
as a size optimization, we place private `__profd_` in a COMDAT with a
`__profc_` key. When FuncImport.cpp makes `__profc_` available_externally due to
a non-prevailing COMDAT, `__profd_` incorrectly remains private. This change
makes the `__profd_` available_externally.
```
cat > c.h <<'eof'
extern void bar();
inline __attribute__((noinline)) void foo() {}
eof
cat > m1.cc <<'eof'
int main() {
bar();
foo();
}
eof
cat > m2.cc <<'eof'
__attribute__((noinline)) void bar() {
foo();
}
eof
clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto=thin -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
```
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D135427
((Op1 * X) / Y) / Op1 --> X / Y
https://alive2.llvm.org/ce/z/JYxWjA
InstSimplify handles the more basic mul+div pattern with
shared operand, but we don't seem to have any reassociation
folds to handle cases where the common op is further away.
This is a generalization of 9cff4711ac and another
transform derived from issue #58137.
When Index is variable but still trivially known to be equal we can use Value
from before the insertion, possibly eliminating the vector.
Reverts a functional change from:
Author: Philip Reames <listmail@philipreames.com>
Date: Wed Dec 8 12:21:10 2021 -0800
[instcombine] A couple style tweaks to visitExtractElementInst [nfc]
Thanks to Michele Scandale for identifying the bug
Differential Revision: https://reviews.llvm.org/D135625
insertelt DestVec, (fneg (extractelt SrcVec, Index)), Index --> shuffle DestVec, (fneg SrcVec), Mask
This is a specialized form of what could be a more general fold for a binop.
It's also possible that fneg is overlooked by SLP in this kind of
insert/extract pattern since it's a unary op.
This shows up in the motivating example from #issue 58139, but it won't solve
it (that probably requires some x86-specific backend changes). There are also
some small enhancements (see TODO comments) that can be done as follow-up
patches.
Differential Revision: https://reviews.llvm.org/D135278
This reverts commit 4fbe33593c. It causes linking errors, with details provided internally. (Hopefully the author/reviewers will be able to upstream the internal repro).
If the single-thread model is used, or the
-licm-force-thread-model-single flag is specified, skip checks
related to thread-safety. This means that store promotion for
conditionally executed stores only requires proof of
dereferenceability and writability, but not of thread-safety. For
example, this enables promotion of stores to (non-constant) globals,
as well as captured allocas.
Fixes https://github.com/llvm/llvm-project/issues/50537.
Differential Revision: https://reviews.llvm.org/D130466
When determining the initial value of the object, use the constant
folding API to load a given type at a given offset in the global
initializer. This makes it work for cases where the load doesn't
directly correspond to an aggregate member.
Differential Revision: https://reviews.llvm.org/D135435
The current decomposition for GEPs did not correctly handle cases where
GEPs access different source types. Adjust the constraints by including
the indexed type-size as coefficients.
Further generalization to allow GEPs with more than one index is a
needed general follow-up improvement.
If the location ptr to be killed is in no loop and the Function does not
have irreducible loops, then we can regard it as loop invariant.
Differential Revision: https://reviews.llvm.org/D135369
Move common logic shared by callers of getConstraint that use the result
to query the constraint system to a new helper getConstraintForSolving.
This includes common legality checks (i.e. not an equality constraint,
no new variables) and the logic to query the unsigned system if possible
for signed predicates.
See the updated linkonce_resolution_comdat.ll. For a local linkage GV in a
non-prevailing COMDAT, it remains defined while its leader has been made
available_externally. This violates the COMDAT rule that its members must be
retained or discarded as a unit.
To fix this, update the regular LTO change D34803 to track local linkage
GlobalValues, and port the code to ThinLTO (GlobalAliases are not handled.)
Fix https://github.com/llvm/llvm-project/issues/58215:
as a size optimization, we place private `__profd_` in a COMDAT with a
`__profc_` key. When FuncImport.cpp makes `__profc_` available_externally due to
a non-prevailing COMDAT, `__profd_` incorrectly remains private. This change
makes the `__profd_` available_externally.
```
cat > c.h <<'eof'
extern void bar();
inline __attribute__((noinline)) void foo() {}
eof
cat > m1.cc <<'eof'
#include "c.h"
int main() {
bar();
foo();
}
eof
cat > m2.cc <<'eof'
#include "c.h"
__attribute__((noinline)) void bar() {
foo();
}
eof
clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
# one _Z3foov
clang -O2 -fprofile-generate=./t m1.cc m2.cc -flto=thin -fuse-ld=lld -o t_gen
rm -fr t && ./t_gen && llvm-profdata show -function=foo t/default_*.profraw
# one _Z3foov
```
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D135427
The 1st attempt failed to updated the test checks as expected.
Original commit message:
sdiv exact X, (1<<ShAmt) --> ashr exact X, ShAmt (if shl is non-negative)
https://alive2.llvm.org/ce/z/kB6VF7
It would probably be better to use ValueTracking to replace this
and the existing transform above it, but the analysis does not
account for the no-wrap properly, and it's not immediately clear
to me how to fix it.
sdiv exact X, (1<<ShAmt) --> ashr exact X, ShAmt (if shl is non-negative)
https://alive2.llvm.org/ce/z/kB6VF7
It would probably be better to use ValueTracking to replace this
and the existing transform above it, but the analysis does not
account for the no-wrap properly, and it's not immediately clear
to me how to fix it.
The logic added in 3771310eed was placed sub-optimally. Applying the
transform in ::getConstraint meant that it would also impact conditions
that are added to the system by the signed <-> unsigned transfer logic.
This meant we failed to add some signed facts to the signed system. To
make sure we still add as many useful facts to the signed/unsigned
systems, move the logic to the point where we query the system.
Clear all dispositions if there are any dead blocks (which will get
removed later) and also clear dispositions for removed instructions.
Clearing all dispositions in case there are dead blocks happens first,
which should avoid traversing SCEV use-lists for invalidating
dispositions for individual values.
Fixes#58179.
This patch was added way back in the beginning of the work which became the statepoint infrastructure. The idea was that safepoints could be inserted late in the optimization pipeline. This is true if the only concern is garbage collection, but this approach turned out to be incompatible with the requirement to also support deoptimization at safepoints.
In theory, this pass would still be quite useful for an AOT compiled language which wants to support garbage collection, but we have no known users, and haven't for over 5 years. Time to remove unused code. If someone wants to use this, restoring it would not be hard. The immediate motivation for removal is that this is one of the last passes remaining which hasn't been ported to the new pass manager and the (straight forward) work to do so is not justified for unused code.
Differential Revision: https://reviews.llvm.org/D135371
Extend forgetBlockAndLoopDisposition to allow clearing information for a
single value. This can be useful when only a single value is changed,
e.g. because the instruction is moved.
We also need to clear the cached values for all SCEV users, because they
may depend on the starting value's disposition.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D134614
Loop peeling currently requires that a) the latch is exiting
b) a branch and c) other exits are unreachable/deopt. This patch
removes all of these limitations, and adds the necessary branch
weight updating support. It essentially works the same way as
before with latch -> exiting terminator and
loop trip count -> per exit trip count.
It's worth noting that there are still other limitations in
profitability heuristics: This patch enables peeling of loops to
make conditions invariant (which is pretty much always highly
profitable if possible), while peeling to make loads dereferenceable
still checks that non-latch exits are unreachable and PGO-based
peeling has even more conditions. Those checks could be relaxed
later if we consider those cases profitable.
The motivation for this change is that loops using iterator adaptors
in Rust often optimize very badly, and end up with a loop phi of the
form phi(true, false) in the final result. Peeling eliminates that
phi and conditions based on it, which enables a lot of follow-on
simplification.
Differential Revision: https://reviews.llvm.org/D134803
As LoopPredication performs non-equivalent transforms removing some
checks from loops, other passes may not be able to perform transforms
they'd be able to do if the checks were left in loops.
This patch makes LoopPredication insert assumes of the replaced
conditions either after a guard call or in the true block of
widenable condition branch.
Differential Revision: https://reviews.llvm.org/D135354
Relative to the previous attempt, this adjusts simplification to
use the correct context instruction: We need to use the terminator
of the incoming block, not the original instruction.
-----
foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.
This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.
This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.
Differential Revision: https://reviews.llvm.org/D134954
Added analysis for invariant extractelement instructions and improved
detection of the CSE blocks for generated extractelement instructions.
Differential Revision: https://reviews.llvm.org/D135279
The limitation in LibCallSimplifier::optimizeStringLength to only
optimize when the string is an i8 array was changed already in
commit 50ec0b5dce back in 2017.
We still only simplify when 's' points at an array of 'CharSize', so
the comment is still valid in the sense that we do not support
arbitrary array types.
Differential Revision: https://reviews.llvm.org/D135261
Make sure conditions with constant operands come before conditions
without constant operands. This increases the effectiveness of the
current signed <-> unsigned fact transfer logic.
If a call base use will not capture a pointer we can approximate the
effects. This is important especially for readnone/only uses. Even
may-write uses are not too bad with reachability in place. Capturing
is the problem as we loose track of update sides.
If we have a constant aggregate, e.g., as an initializer, we usually
failed to extract the proper value/type from it. This patch provides the
size and offset information necessary to extract the right part of the
constant.
This was already handled correctly below, but not checked for the
original store pointer operand. Encountered when converting tests
to opaque pointers, where the intermediate bitcast goes away.
In the case of non-opaque pointers, when combining consecutive loads,
need to bitcast the pointer source to the combined type size, otherwise
asserts are triggered.
Differential Revision: https://reviews.llvm.org/D135249
The infinite loop seen on buildbots should be fixed by
11897708c0 (assuming there are not
multiple infinite combine loops...)
-----
foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.
This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.
This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.
Differential Revision: https://reviews.llvm.org/D134954
Rather than inserting a ptrtoint + inttoptr pair, directly replace
the inttoptr with the new phi node. This ensures that no other
transform can undo it before the pair gets folded away.
This avoids the infinite loop when combined with D134954.
This is NFCI in the sense that it shouldn't make a difference, but
could due to different worklist order.
SimpleLoopUnswitch may remove blocks from loops. Clear block and loop
dispositions in that case, to clean up invalid entries in the cache.
Fixes#58158.
Fixes#58159.
Loop versioning changes the control-flow, which may impact SCEVs cached
by for other loops in LoopAccessInfoManager. Clear the manager after
making changes.
Fixes#57825.
Depends on D134609.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D134611
isOuterMostDepPositive()
The function isOuterMostDepPositive() is checked after negative dependence
vectors are normalized to be non-negative, so there will not be any negative
dependency ('>' as the outermost non-equal sign) after normalization. And
therefore the check in isOuterMostDepPositive() is irrelevent and redundant.
Reviewed By: congzhe
Differential Revision: https://reviews.llvm.org/D132982
In the canonical form of the shuffle the poison/undef operand is the
second operand, the patch tries to emit canonical form for partial
vectorization of the buildvector sequence.
Also, this patch starts emitting freeze instruction for shuffles with undef indices if the second shuffle operan is undef, not poison. It is an initial step to D93818, where undef mask element are treated as returning poison value.
Differential Revision: https://reviews.llvm.org/D134377
Reapply with a fix for the case where an operand simplified back
to the original phi: We need to map this case to the new phi node.
-----
foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.
This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.
This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.
This currently does not make much of a difference (only one tests is
affected), but it is helpful e.g. for the out-of-tree CHERI target where
Builder.CreateMemCpy() can add attributes other than parameter alignment.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D135075
The helpers in BuildLibCalls normally expect that the Value
arguments already have the correct type (matching the lib call
signature). And exception has been emitFPutC which casted the Char
argument to 'int' using CreateIntCast. This patch moves the cast to
the caller instead of doing it inside emitFPutC.
I think it makes sense to make the BuildLibCall API:s a bit
more consistent this way, despite the need to handle the int cast
in two different places now.
Differential Revision: https://reviews.llvm.org/D135066
Stop assuming that an 'int' is 32 bits in helpers that emit libcalls
to lib functions that had 'int' in the signature. For most targets
this is NFC. For a target with 16 bit 'int' type this could help out
detecting if trying to emit a libcall with incorrect signature.
Similarly we now derive the type mapping to 'size_t' by asking TLI
about the size of 'size_t'. This should be NFC (at least for in-tree
targets) since getSizeTSize(), in TLI, is deriving the size in the
same way as DataLayout::getIntPtrType().
Differential Revision: https://reviews.llvm.org/D135065
Lots of BuildLibCalls helpers are using Builder::getInt32Ty to get
a type matching an 'int', and DataLayout::getIntPtrType to get a
type matching 'size_t'. The former is not true for all targets, since
and 'int' isn't always 32 bits. And the latter is a bit weird as well
as the definition of DataLayout::getIntPtrType isn't clearly mapping
it to 'size_t'.
This patch is not aiming at solving any such problems. It is merely
highlighting when a libcall is expecting to use 'int' and 'size_t'
by naming the types as IntTy and SizeTTy when preparing the type
signatures for the emitted libcalls.
Differential Revision: https://reviews.llvm.org/D135064
Use LoopAccessInfoManager directly instead of various GetLAA lambdas.
Depends on D134608.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D134609
If nonnull is already set, we currently skip setting both nonnull
and dereferenceable. Make these independent, to avoid regressions
when additional nonnull attributes are inferred earlier.
foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.
This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.
This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.
Alex Brachet