6636 Commits

Author SHA1 Message Date
Roman Lebedev
428f36401b
Reland "[SimplifyCFG] FoldBranchToCommonDest(): deal with mismatched IV's in PHI's in common successor block"
This reverts commit 37b8f09a4b61bf9bf9d0b9017d790c8b82be2e17,
and returns commit 1bd0b82e508d049efdb07f4f8a342f35818df341.
The miscompile was in InstCombine, and it has been addressed.

This tries to approach the problem noted by @arsenm:
terrible codegen for `__builtin_fpclassify()`:
https://godbolt.org/z/388zqdE37

Just because the PHI in the common successor happens to have different
incoming values for these two blocks, doesn't mean we have to give up.
It's quite easy to deal with this, we just need to produce a select:
https://alive2.llvm.org/ce/z/000srb

Now, the cost model for this transform is rather overly strict,
so this will basically never fire. We tally all (over all preds)
the selects needed to the NumBonusInsts

Differential Revision: https://reviews.llvm.org/D139275
2022-12-17 05:18:54 +03:00
Fangrui Song
fb8eb84e5f [Transforms,InstCombine] std::optional::value => operator*/operator->
value() has undesired exception checking semantics and calls
__throw_bad_optional_access in libc++. Moreover, the API is unavailable without
_LIBCPP_NO_EXCEPTIONS on older Mach-O platforms (see
_LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS).
2022-12-16 22:57:56 +00:00
Alexander Kornienko
37b8f09a4b Revert "[SimplifyCFG] FoldBranchToCommonDest(): deal with mismatched IV's in PHI's in common successor block"
This reverts commit 1bd0b82e508d049efdb07f4f8a342f35818df341, since it leads to
miscompiles. See https://reviews.llvm.org/D139275#3993229 and
https://reviews.llvm.org/D139275#4001580.
2022-12-16 17:23:35 +01:00
HanSheng Zhang
6c5f3f62bd [reg2mem] Add special handling to CatchSwitchInst
When promoting a phi in a catchswitch block to memory, we cannot
insert load/store instruction in that block, and need to insert
them inside all successors instead.

Fixes https://github.com/llvm/llvm-project/issues/59185.

Differential Revision: https://reviews.llvm.org/D138641
2022-12-16 16:04:35 +01:00
Nikita Popov
04d652994d [SCEV] Return ArrayRef for SCEV operands() (NFC)
Use a consistent type for the operands() methods of different SCEV
types. Also make the API consistent by only providing operands(),
rather than also providin op_begin() and op_end() for some of them.
2022-12-16 15:36:19 +01:00
Florian Hahn
d459be4527
[LoopRotate] Clear block and loop dispo cache when merging blocks.
Merging blocks in LoopRotate may remove blocks reference in the block
disposition cache. Clear the cache.

Fixes #59534.
2022-12-15 22:22:22 +00:00
Vasileios Porpodas
32b38d248f [NFC] Rename Instruction::insertAt() to Instruction::insertInto(), to be consistent with BasicBlock::insertInto()
Differential Revision: https://reviews.llvm.org/D140085
2022-12-15 12:27:45 -08:00
Vasileios Porpodas
80f2f1eabc [NFC] Rename Function::insertBasicBlockAt() to Function::insert().
I think this is a better name because it is what STL uses.

Differential Revision: https://reviews.llvm.org/D140068
2022-12-15 10:03:37 -08:00
Kazu Hirata
6eb0b0a045 Don't include Optional.h
These files no longer use llvm::Optional.
2022-12-14 21:16:22 -08:00
Vasileios Porpodas
dc891846b8 [NFC] Cleanup: Replace Function::getBasicBlockList().splice() with Function::splice()
This is part of a series of patches that aim at making Function::getBasicBlockList() private.

Differential Revision: https://reviews.llvm.org/D139984
2022-12-14 15:34:19 -08:00
Matt Arsenault
aa9bdd50c2 llvm-reduce: Fix invalid reductions with llvm.used
Fixes issue 59413.
2022-12-14 15:06:22 -05:00
Fangrui Song
d4b6fcb32e [Analysis] llvm::Optional => std::optional 2022-12-14 07:32:24 +00:00
Vasileios Porpodas
adfb23c607 [NFC] Cleanup: Remove Function::getBasicBlockList() when not required.
This is part of a series of patches that aim at making Function::getBasicBlockList() private.

Differential Revision: https://reviews.llvm.org/D139910
2022-12-13 11:46:29 -08:00
Nikita Popov
5810927dcb [SCEVExpander] Produce canonical constant GEP
Go through IRBuilder to enable DL-based folding, so that we produce
a canonical constant GEP. Noticed while converting tests to opaque
pointers.
2022-12-13 15:08:28 +01:00
Vasileios Porpodas
a19ae77d2a [IR][NFC] Adds Function::insertBasicBlockAt() to replace things like F->getBasicBlockList().insert()
This is part of a series of patches that aim at making Function::getBasicBlockList() private.

Differential Revision: https://reviews.llvm.org/D139906
2022-12-12 20:22:55 -08:00
Vasileios Porpodas
da49083dbf [NFC] Remove the instruction list from the arguments of llvm::ReplaceInstWithValue().
This is part of a series of cleanup patches towards making BasicBlock::getInstList() private.

Differential Revision: https://reviews.llvm.org/D139153
2022-12-12 17:47:24 -08:00
Vasileios Porpodas
06911ba6ea [NFC] Cleanup: Replaces BB->getInstList().insert() with I->insertAt().
This is part of a series of cleanup patches towards making BasicBlock::getInstList() private.

Differential Revision: https://reviews.llvm.org/D138877
2022-12-12 13:33:05 -08:00
Felipe de Azevedo Piovezan
cde2cc9a8f [CodeExtractor] Use scope reparenting helper to update loop dbg loc
Apply the same strategy from D139217 to loop debug locations.

Differential Revision: https://reviews.llvm.org/D139851
2022-12-12 15:50:52 -05:00
Felipe de Azevedo Piovezan
b432dd2d4b [CodeExtractor] Preserve entire scope of labels when moving them
When a dbg.label is moved into a new function, its corresponding scope
should be preserved, with the exception of the subprogram at the end of
the scope chain, which should now be the subprogram of the destination
function. See D139671.

Differential Revision: https://reviews.llvm.org/D139849
2022-12-12 15:48:55 -05:00
Felipe de Azevedo Piovezan
79d59c3f3e [CodeExtractor] Only rewrite scope of labels that were not inlined
dbg.labels that were inlined from other functions should have their
scope preserved upon outlining for the same reasons described in
D139669.
2022-12-12 15:44:16 -05:00
Felipe de Azevedo Piovezan
d23b7f5f9f [CodeExtractor] Preserve entire scope of !DIVariables when moving them
When a dbg.value is moved into a new function, the corresponding
variable should have its entire scope chain reparented with the new
function. The current implementation drops the scope chain and replaces
it with a subprogram for the new function.

Differential Revision: https://reviews.llvm.org/D139671
2022-12-12 10:20:36 -05:00
Roman Lebedev
1bd0b82e50
[SimplifyCFG] FoldBranchToCommonDest(): deal with mismatched IV's in PHI's in common successor block
This tries to approach the problem noted by @arsenm:
terrible codegen for `__builtin_fpclassify()`:
https://godbolt.org/z/388zqdE37

Just because the PHI in the common successor happens to have different
incoming values for these two blocks, doesn't mean we have to give up.
It's quite easy to deal with this, we just need to produce a select:
https://alive2.llvm.org/ce/z/000srb

Now, the cost model for this transform is rather overly strict,
so this will basically never fire. We tally all (over all preds)
the selects needed to the NumBonusInsts

Differential Revision: https://reviews.llvm.org/D139275
2022-12-12 18:20:03 +03:00
Fangrui Song
c178ed33bd Transforms/Utils: llvm::Optional => std::optional 2022-12-12 08:29:05 +00:00
Felipe de Azevedo Piovezan
60f406c4db [CodeExtractor] Only rewrite scope of non-inlined variables
When a dbg.value instruction for a variable V is extracted into a new
function, the scope of the underlying variable should be set to the new
function iff V was in the scope of the old function (i.e. it hadn't been
inlined). Prior to this patch, the code extractor would always update
the scope of V.

Differential Revision: https://reviews.llvm.org/D139669
2022-12-10 14:38:09 -05:00
Kazu Hirata
f7dffc28b3 Don't include None.h (NFC)
I've converted all known uses of None to std::nullopt, so we no longer
need to include None.h.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-10 11:24:26 -08:00
Alexandros Lamprineas
8136a0172b [FuncSpec] Make the Function Specializer part of the IPSCCP pass.
Reland 877a9f9abec61f06e39f1cd872e37b828139c2d1 since D138654 (parent)
has been fixed with 9ebaf4fef4aac89d4eff08e48185d61bc893f14e and with
8f1e11c5a7d70f96943a72649daa69f152d73e90.

Differential Revision: https://reviews.llvm.org/D126455
2022-12-10 14:39:49 +00:00
Alexandros Lamprineas
9ebaf4fef4 [IPSCCP] Move the IPSCCP run function under the IPO directory.
Reland 42c2dc401742266da3e0251b6c1ca491f4779963 which was reverted
in cb03b1bd99313a728d47060b909a73e7f5991231. The fix for the link
errors was to reintroduce one of the two occurences of 'Scalar'
under the LINK_COMPONENTS.

Differential Revision: https://reviews.llvm.org/D138654
2022-12-09 15:05:11 +00:00
Nikita Popov
b3df1ce389 [MemoryBuiltins] Remove unused TLI parameters (NFC) 2022-12-09 12:57:40 +01:00
Dmitry Makogon
b134119137 [SimplifyCFG] Prohibit hoisting of llvm.deoptimize calls
This prohibits hoisiting identical llvm.deoptimize calls
from 'then' and 'else' blocks of a conditional branch.
This fixes a crash that happened because we didn't hoist
the return instructions together with the llvm.deoptimize calls,
so the verifier would crash.

Differential Revision: https://reviews.llvm.org/D139437
2022-12-09 17:44:32 +07:00
Nikita Popov
ce51cae794 [PtrAuth] Use default attributes for some ptrauth intrinsics
This uses the default intrinsic attributes (nofree, nosync,
nocallback, willreturn) for a subset of the ptrauth intrinsics.
Notably, this does not use them for auth and resign, because these
intrinsics are specified to trap and as such are not willreturn.
As far as I understood, the remaining intrinsics may not trap
(or can only trap in cases where behavior is undefined).

Differential Revision: https://reviews.llvm.org/D137557
2022-12-09 10:41:28 +01:00
Sami Tolvanen
3b14862f0a [ModuleUtils][KCFI] Set !kcfi_type metadata for sanitizer constructors
Set KCFI type metadata for the sanitizer constructors to prevent
runtime failures when these functions are indirectly called in
instrumented code. This fixes a compatibility issue with KASAN and
-fsanitize=kcfi in the Linux kernel.

Link: https://github.com/ClangBuiltLinux/linux/issues/1742

Reviewed By: nickdesaulniers, MaskRay

Differential Revision: https://reviews.llvm.org/D138945
2022-12-09 00:26:08 +00:00
Roman Lebedev
4f7e5d2206
[SROA] For non-speculatable loads of selects -- split block, insert then/else blocks, form two-entry PHI node, take 2
Currently, SROA is CFG-preserving.
Not doing so does not affect any pipeline test. (???)
Internally, SROA requires Dominator Tree, and uses it solely for the final `-mem2reg` call.

By design, we can't really SROA alloca if their address escapes somehow,
but we have logic to deal with `load` of `select`/`PHI`,
where at least one of the possible addresses prevents promotion,
by speculating the `load`s and `select`ing between loaded values.

As one would expect, that requires ensuring that the speculation is actually legal.
Even ignoring complexity bailouts, that logic does not deal with everything,
e.g. `isSafeToLoadUnconditionally()` does not recurse into hands of `select`.
There can also be cases where the load is genuinely non-speculate.

So if we can't prove that the load can be speculated,
unfold the select, produce two-entry phi node, and perform predicated load.

Now, that transformation must obviously update Dominator Tree,
since we require it later on. Doing so is trivial.
Additionally, we don't want to do this for the final SROA invocation (D136806).

In the end, this ends up having negative (!) compile-time cost:
https://llvm-compile-time-tracker.com/compare.php?from=c6d7e80ec4c17a415673b1cfd25924f98ac83608&to=ddf9600365093ea50d7e278696cbfa01641c959d&stat=instructions:u

Though indeed, this only deals with `select`s, `PHI`s are still using speculation.

Should we update some more analysis?

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D138238

This reverts commit 739611870d3b06605afe25cc07833f6a62de9545,
and recommits 03e6d9d9d1d48e43f3efc35eb75369b90d4510d5
with a fixed assertion - we should check that DTU is there,
not just assert false...
2022-12-08 20:19:55 +03:00
Roman Lebedev
739611870d
Revert "[SROA] For non-speculatable loads of selects -- split block, insert then/else blocks, form two-entry PHI node"
The assertion about not modifying the CFG seems to not hold,
will recommit in a bit.

https://lab.llvm.org/buildbot#builders/139/builds/32412

This reverts commit 03e6d9d9d1d48e43f3efc35eb75369b90d4510d5.
This reverts commit 4f90f4ada33718f9025d0870a4fe3fe88276b3da.
2022-12-08 19:51:15 +03:00
Roman Lebedev
03e6d9d9d1
[SROA] For non-speculatable loads of selects -- split block, insert then/else blocks, form two-entry PHI node
Currently, SROA is CFG-preserving.
Not doing so does not affect any pipeline test. (???)
Internally, SROA requires Dominator Tree, and uses it solely for the final `-mem2reg` call.

By design, we can't really SROA alloca if their address escapes somehow,
but we have logic to deal with `load` of `select`/`PHI`,
where at least one of the possible addresses prevents promotion,
by speculating the `load`s and `select`ing between loaded values.

As one would expect, that requires ensuring that the speculation is actually legal.
Even ignoring complexity bailouts, that logic does not deal with everything,
e.g. `isSafeToLoadUnconditionally()` does not recurse into hands of `select`.
There can also be cases where the load is genuinely non-speculate.

So if we can't prove that the load can be speculated,
unfold the select, produce two-entry phi node, and perform predicated load.

Now, that transformation must obviously update Dominator Tree,
since we require it later on. Doing so is trivial.
Additionally, we don't want to do this for the final SROA invocation (D136806).

In the end, this ends up having negative (!) compile-time cost:
https://llvm-compile-time-tracker.com/compare.php?from=c6d7e80ec4c17a415673b1cfd25924f98ac83608&to=ddf9600365093ea50d7e278696cbfa01641c959d&stat=instructions:u

Though indeed, this only deals with `select`s, `PHI`s are still using speculation.

Should we update some more analysis?

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D138238
2022-12-08 16:51:32 +03:00
Alexandros Lamprineas
cb03b1bd99 Revert "[IPSCCP] Move the IPSCCP run function under the IPO directory."
This reverts commit 42c2dc401742266da3e0251b6c1ca491f4779963.

This broke some buildbots:

 undefined reference to `llvm::createBitTrackingDCEPass()'
 undefined reference to `llvm::createAlignmentFromAssumptionsPass()'
 undefined reference to `llvm::createLoopUnrollPass(int, bool, bool, int, int, int, int, int, int)'
 undefined reference to `llvm::createLICMPass(unsigned int, unsigned int, bool)'
 undefined reference to `llvm::createWarnMissedTransformationsPass()'
 undefined reference to `llvm::createAlignmentFromAssumptionsPass()'
 undefined reference to `llvm::createCallSiteSplittingPass()'
 undefined reference to `llvm::createCFGSimplificationPass(llvm::SimplifyCFGOptions, std::function<bool (llvm::Function const&)>)'
 undefined reference to `llvm::createFloat2IntPass()'
 undefined reference to `llvm::createLowerConstantIntrinsicsPass()'
 undefined reference to `llvm::createLoopRotatePass(int, bool)'
 undefined reference to `llvm::createLoopDistributePass()'
 undefined reference to `llvm::createLoopSinkPass()'
 undefined reference to `llvm::createInstSimplifyLegacyPass()'
 undefined reference to `llvm::createDivRemPairsPass()'
 undefined reference to `llvm::createCFGSimplificationPass(llvm::SimplifyCFGOptions, std::function<bool (llvm::Function const&)>)'
 undefined reference to `llvm::SetLicmMssaOptCap'
 undefined reference to `llvm::SetLicmMssaNoAccForPromotionCap'
 undefined reference to `llvm::ForgetSCEVInLoopUnroll'
2022-12-08 12:42:34 +00:00
Alexandros Lamprineas
0f0cb92cb2 Revert "[FuncSpec] Make the Function Specializer part of the IPSCCP pass."
This reverts commit 877a9f9abec61f06e39f1cd872e37b828139c2d1.

It depends on the parent revision 42c2dc401742266da3e0251b6c1ca491f4779963
which needs to be reverted as it broke some buildbots, so reverting both.
2022-12-08 12:41:43 +00:00
Alexandros Lamprineas
877a9f9abe [FuncSpec] Make the Function Specializer part of the IPSCCP pass.
The aim of this patch is to minimize the compilation time overhead of
running Function Specialization. It is about 40% slower to run as a
standalone pass (IPSCCP + FuncSpec vs IPSCCP with FuncSpec) according
to my measurements. I compiled the llvm testsuite with NewPM-O3 + LTO
and measured single threaded [user + system] time of IPSCCP and FuncSpec
by passing the '-time-passes' option to lld. Then I compared the two
configurations in terms of Instruction Count of the total compilation
(not of the individual passes) as in https://llvm-compile-time-tracker.com.
Geomean for non-LTO builds is -0.25% and LTO is -0.5% approximately.

You can find more info below:

https://discourse.llvm.org/t/rfc-should-we-enable-function-specialization/61518

Differential Revision: https://reviews.llvm.org/D126455
2022-12-08 12:14:27 +00:00
Alexandros Lamprineas
42c2dc4017 [IPSCCP] Move the IPSCCP run function under the IPO directory.
The LLVMipo library no longer depends on the Scalar component.
The shared functions between IPSCCP and SCCP have been moved
under Utils, in the SCCPSolver.

This is preliminary work for D126455, in order to break a cyclic
dependency between LLVM libraries.

Differential Revision: https://reviews.llvm.org/D138654
2022-12-08 12:14:27 +00:00
Sebastian Neubauer
19158eb7f0 Revert "[llvm] Replace llvm::Any with std::any"
msvc fails to link when using any_cast. This seems to be fixed recently
only.

https://developercommunity.visualstudio.com/t/stdany-doesnt-link-when-exceptions-are-disabled/376072

This reverts commit aeac2e4884a3ce62c920cd51806a9396da64d9f7.
2022-12-08 12:07:30 +01:00
Sebastian Neubauer
aeac2e4884 [llvm] Replace llvm::Any with std::any
llvm::Any had several bugs in the past, due to being sensitive to symbol
visibility. (See D101972 and D108943)

Even with these fixes applied, I still encounter the same issue on
Windows.

Similar to llvm::Optional going away in favor of std::optional, we can
use std::any from C++17.

Using std::any fixes the problem and puts the burden to do it correctly
on the standard library.

Differential Revision: https://reviews.llvm.org/D139532
2022-12-08 11:48:00 +01:00
Kazu Hirata
934942c033 [llvm] Don't include Optional.h (NFC)
These source files no longer use Optional<T>, so they do not need to
include Optional.h.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-06 22:34:50 -08:00
Kazu Hirata
405fc404bf [ADT] Don't including None.h (NFC)
These source files no longer use None, so they do not need to include
None.h.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-06 20:14:51 -08:00
Felipe de Azevedo Piovezan
62b27f893e [CodeExtractor] Correctly propagate scope information post extraction
When a new function "NewF" is created with instructions extracted from
another function "OldF", the CodeExtractor only preserves debug
line/column of the extracted instructions. However:

1. Any inlinedAt nodes are dropped.
2. The scope chain is replaced with a single node, the Subprogram of NewF.

Both of these are incorrect: most of the debug metadata from the
original instructions should be preserved. We only need to update the
Subprogram found at the scope of the last node of the inline chain; this
Subprogram used to be OldF but now should be NewF.

Differential Revision: https://reviews.llvm.org/D139217
2022-12-06 14:26:06 -05:00
Nikita Popov
0b20c3034c [IR] Don't assume readnone/readonly intrinsics are willreturn
This removes our "temporary" hack to assume that readnone/readonly
intrinsics are also willreturn. An explicit willreturn annotation,
usually via default intrinsic attributes, is now required.

Differential Revision: https://reviews.llvm.org/D137630
2022-12-06 11:48:50 +01:00
Max Kazantsev
6dac170140 [SCEVExpander] Support cost evaluation of several SCEVs with same budget
This is a follow-up from discussion in D138412. Sometimes we want to evaluate
the cost of expansion of several SCEVs together with same budget. For example,
if one of them is a bit above cheap limit, and the second one is free, then
we still want to expand. Checking each of them with "cheap" limit is a bit more
pessimistic.

Differential Revision: https://reviews.llvm.org/D138475
Reviewed By: lebedev.ri
2022-12-06 17:02:26 +07:00
Jamie Schmeiser
2b6683fd5f Expand loop peeling phi computation to handle binary ops and casts
Summary:
Expand the capabilities of the code for computing how many peels are
needed to make phis determined.  A cast gets the peel count for the
value being casted while a binary op gets the maximum of the operands.

Respond to review comments: remove redundant asserts.

Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By:mkazantsev (Max Kazantsev),syzaara (Zaara Syeda)
Differential Revision: https://reviews.llvm.org/D138719
2022-12-05 12:10:53 -05:00
luxufan
b0f7876917 [SCCP] Propagate equality of a not-constant
The equality state of a not-constant can be used to do constant
propagation. For example,
```
define i32 @equal_not_constant(ptr noundef %p, ptr noundef %q) {
entry:
  %cmp = icmp ne ptr %p, null
  br i1 %cmp, label %if.then, label %if.end

if.then:                                          ; preds = %entry
  %cmp.then = icmp eq ptr %p, %q
  br i1 %cmp.then, label %if.then1, label %if.end

if.then1:                                         ; preds = %if.then
  %cmp.then1 = icmp ne ptr %q, null
  call void @use(i1 %cmp.then1)
  br label %if.end

if.end:
  ret i32 0
}

```
In this case, we can fold `%cmp.then1` as `true`.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D139289
2022-12-05 19:54:13 +08:00
Nikita Popov
f101196d69 [SCCP] Add support for with.overflow intrinsics
This adds SCCP support for extractvalues of with.overflow.
We compute both the range of the result value and determine when
the overflow value is always false.

Differential Revision: https://reviews.llvm.org/D137713
2022-12-05 12:00:22 +01:00
Fangrui Song
a996cc217c Remove unused #include "llvm/ADT/Optional.h" 2022-12-05 06:31:11 +00:00
Fangrui Song
89fae41ef1 [IR] llvm::Optional => std::optional
Many llvm/IR/* files have been migrated by other contributors.
This migrates most remaining files.
2022-12-05 04:13:11 +00:00