Revert "Don't treat readnone call in presplit coroutine as not access memory"

This reverts commit 57224ff4a6833dca1f17568cc9cf77f9579030ae. This
commit may trigger crashes on some workloads. Revert

Revert "Don't treat readnone call in presplit coroutine as not access memory"

This reverts commit 57224ff4a6833dca1f17568cc9cf77f9579030ae. This
commit may trigger crashes on some workloads. Revert it for clearness.

show more ...

Don't treat readnone call in presplit coroutine as not access memory

To solve the readnone problems in coroutines. See
https://discourse.llvm.org/t/address-thread-identification-problems-with-corout

Don't treat readnone call in presplit coroutine as not access memory

To solve the readnone problems in coroutines. See
https://discourse.llvm.org/t/address-thread-identification-problems-with-coroutine/62015
for details.

According to the discussion, we decide to fix the problem by inserting
isPresplitCoroutine() checks in different passes instead of
wrapping/unwrapping readnone attributes in CoroEarly/CoroCleanup passes.
In this direction, we might not be able to cover every case at first.
Let's take a "find and fix" strategy.

Reviewed By: nikic, nhaehnle, jyknight

Differential Revision: https://reviews.llvm.org/D127383

show more ...

[Analysis] Qualify auto variables in for loops (NFC)

[AA] Export isEscapeSource() API (NFC)

Export API that was previously private to BasicAliasAnalysis and
will be used in D127202.

[BasicAA] Handle passthru calls in isEscapeSource()

isEscapeSource() currently considers all call return values as
escape sources. However, CaptureTracking can look through certain
calls, so we shou

[BasicAA] Handle passthru calls in isEscapeSource()

isEscapeSource() currently considers all call return values as
escape sources. However, CaptureTracking can look through certain
calls, so we shouldn't consider these as escape sources either.

The corresponding CaptureTracking code is:
https://github.com/llvm/llvm-project/blob/7c9a3825b8420f5d37c5bb8919a9e46684a87089/llvm/lib/Analysis/CaptureTracking.cpp#L332-L333

Differential Revision: https://reviews.llvm.org/D128444

show more ...

[APInt] Remove all uses of zextOrSelf, sextOrSelf and truncOrSelf

Most clients only used these methods because they wanted to be able to
extend or truncate to the same bit width (which is a no-op).

[APInt] Remove all uses of zextOrSelf, sextOrSelf and truncOrSelf

Most clients only used these methods because they wanted to be able to
extend or truncate to the same bit width (which is a no-op). Now that
the standard zext, sext and trunc allow this, there is no reason to use
the OrSelf versions.

The OrSelf versions additionally have the strange behaviour of allowing
extending to a *smaller* width, or truncating to a *larger* width, which
are also treated as no-ops. A small amount of client code relied on this
(ConstantRange::castOp and MicrosoftCXXNameMangler::mangleNumber) and
needed rewriting.

Differential Revision: https://reviews.llvm.org/D125557

show more ...

Revert "[BasicAA] Remove unneeded special case for malloc/calloc"

This reverts commit 9b1e00738c5ddba681e17e5cb7c260d9afc4c3a7.

Nikic reported in commit thread that I had forgotten history here, an

Revert "[BasicAA] Remove unneeded special case for malloc/calloc"

This reverts commit 9b1e00738c5ddba681e17e5cb7c260d9afc4c3a7.

Nikic reported in commit thread that I had forgotten history here, and that a) we'd tried this before, and b) had to revert due to an unexpected codegen impact. Current measurements confirm the same issue still exists.

show more ...

[BasicAA] Remove unneeded special case for malloc/calloc

This code pre-exists the generic handling for inaccessiblememonly. If we remove it and update one test with inaccessiblememonly, nothing els

[BasicAA] Remove unneeded special case for malloc/calloc

This code pre-exists the generic handling for inaccessiblememonly. If we remove it and update one test with inaccessiblememonly, nothing else changes. Note that simply running O1 on that test would annotate malloc with the missing inaccessiblememonly.

show more ...

[BasicAA] Fix order in which we pass MemoryLocations to alias()

D98718 caused the order of Values/MemoryLocations we pass to alias() to
be significant due to storing the offset in the PartialAlias c

[BasicAA] Fix order in which we pass MemoryLocations to alias()

D98718 caused the order of Values/MemoryLocations we pass to alias() to
be significant due to storing the offset in the PartialAlias case. But
some callers weren't audited and were still passing swapped arguments,
causing the returned PartialAlias offset to be negative in some
cases. For example, the newly added unittests would return -1
instead of 1.

Fixes #55343, a miscompile.

Reviewed By: asbirlea, nikic

Differential Revision: https://reviews.llvm.org/D125328

show more ...

[CaptureTracking] Ignore ephemeral values in EarliestEscapeInfo

And thread DSE's ephemeral values to EarliestEscapeInfo.

This allows more precise analysis in DSEState::isReadClobber() via BatchAA.

[CaptureTracking] Ignore ephemeral values in EarliestEscapeInfo

And thread DSE's ephemeral values to EarliestEscapeInfo.

This allows more precise analysis in DSEState::isReadClobber() via BatchAA.

Followup to D123162.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D123342

show more ...

[BasicAA] Account for wrapping when using abs(VarIndex) >= abs(Scale).

The patch adds an extra check to only set MinAbsVarIndex if
abs(V * Scale) won't wrap. In the absence of IsNSW, try to use the

[BasicAA] Account for wrapping when using abs(VarIndex) >= abs(Scale).

The patch adds an extra check to only set MinAbsVarIndex if
abs(V * Scale) won't wrap. In the absence of IsNSW, try to use the
bitwidths of the original V and Scale to rule out wrapping.

Attempt to model https://alive2.llvm.org/ce/z/HE8ZKj

The code in the else if below probably needs the same treatment, but I
need to come up with a test first.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D121695

show more ...

Cleanup includes: LLVMAnalysis

Number of lines output by preprocessor:
before: 1065940348
after: 1065307662

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Diff

Cleanup includes: LLVMAnalysis

Number of lines output by preprocessor:
before: 1065940348
after: 1065307662

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D120659

show more ...

[BasicAA] Add support for memmove intrinsic

Currently, basic AA has special support for llvm.memcpy.* intrinsics. This change extends this support for any memory trancsfer opration and in particular

[BasicAA] Add support for memmove intrinsic

Currently, basic AA has special support for llvm.memcpy.* intrinsics. This change extends this support for any memory trancsfer opration and in particular llvm.memmove.* intrinsic.

Reviewed By: reames, nikic

Differential Revision: https://reviews.llvm.org/D117095

show more ...

[AA] Refine ModRefInfo for llvm.memcpy.* in presence of operand bundles

Presence of operand bundles changes semantics in respect to ModRef. In particular, spec says: "From the compilers perspective,

[AA] Refine ModRefInfo for llvm.memcpy.* in presence of operand bundles

Presence of operand bundles changes semantics in respect to ModRef. In particular, spec says: "From the compilers perspective, deoptimization operand bundles make the call sites theyre attached to at least readonly. They read through all of their pointer typed operands (even if theyre not otherwise escaped) and the entire visible heap. Deoptimization operand bundles do not capture their operands except during deoptimization, in which case control will not be returned to the compiled frame". Fix handling of llvm.memcpy.* according to the spec.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D118033

show more ...

Revert "[BasicAliasAnalysis] Remove isMallocOrCallocLikeFn"

This reverts commit 1f2cfc4fdc1eefb2c5f562c77a5fe7e916bbf670.

[BasicAliasAnalysis] Remove isMallocOrCallocLikeFn

Allocation functions should be marked with onlyAccessesInaccessibleMemory (when that is correct for the given function) which is checked elsewhere

[BasicAliasAnalysis] Remove isMallocOrCallocLikeFn

Allocation functions should be marked with onlyAccessesInaccessibleMemory (when that is correct for the given function) which is checked elsewhere so this check is no longer needed.

Differential Revision: https://reviews.llvm.org/D117180

show more ...

Rename doesNotReadMemory to onlyWritesMemory globally [NFC]

The naming has come up as a source of confusion in several recent reviews. onlyWritesMemory is consist with onlyReadsMemory which we use

Rename doesNotReadMemory to onlyWritesMemory globally [NFC]

The naming has come up as a source of confusion in several recent reviews. onlyWritesMemory is consist with onlyReadsMemory which we use for the corresponding readonly case as well.

show more ...

[Analysis] allow caller to choose signed/unsigned when computing constant range

We should not lose analysis precision if an 'add' has both no-wrap
flags (nsw and nuw) compared to just one or the oth

[Analysis] allow caller to choose signed/unsigned when computing constant range

We should not lose analysis precision if an 'add' has both no-wrap
flags (nsw and nuw) compared to just one or the other.

This patch is modeled on a similar construct that was added with
D59386.

I don't think it is possible to expose a problem with an unsigned
compare because of the way this was coded (nuw is handled first).

InstCombine has an assert that fires with the example from:
https://github.com/llvm/llvm-project/issues/52884
...because it was expecting InstSimplify to handle this kind of
pattern with an smax.

Fixes #52884

Differential Revision: https://reviews.llvm.org/D116322

show more ...

[AA] Correctly maintain the sign of PartiaAlias offset

Preserve the invariant that offset reported in the case of a
`PartialAlias` between `Loc1` and `Loc2`, is such that
`Loc1 + Offset = Loc2`, whe

[AA] Correctly maintain the sign of PartiaAlias offset

Preserve the invariant that offset reported in the case of a
`PartialAlias` between `Loc1` and `Loc2`, is such that
`Loc1 + Offset = Loc2`, where `Loc1` and `Loc2` are the first and
the second argument, respectively, in alias queries.

Differential Revision: https://reviews.llvm.org/D115927

show more ...

[BasicAA] Use index size instead of pointer size

When accumulating the GEP offset in BasicAA, we should use the
pointer index size rather than the pointer size.

Differential Revision: https://revie

[BasicAA] Use index size instead of pointer size

When accumulating the GEP offset in BasicAA, we should use the
pointer index size rather than the pointer size.

Differential Revision: https://reviews.llvm.org/D112370

show more ...

[BasicAA] Check known access sizes earlier (NFC)

All heuristics for variable accesses require both access sizes to
be known, so check this once at the start, rather than for each
particular heuristi

[BasicAA] Check known access sizes earlier (NFC)

All heuristics for variable accesses require both access sizes to
be known, so check this once at the start, rather than for each
particular heuristic.

show more ...

[BasicAA] Use early returns (NFC)

Reduce nesting in aliasGEP() a bit by returning early.

[BasicAA] Use saturating multiply on range if nsw

If we know that the var * scale multiplication is nsw, we can use
a saturating multiplication on the range (as a good approximation
of an nsw multip

[BasicAA] Use saturating multiply on range if nsw

If we know that the var * scale multiplication is nsw, we can use
a saturating multiplication on the range (as a good approximation
of an nsw multiply). This recovers some cases where the fix from
D112611 is unnecessarily strict. (This can be further strengthened
by using a saturating add, but we currently don't track all the
necessary information for that.)

This exposes an issue in our NSW tracking for multiplies. The code
was assuming that (X +nsw Y) *nsw Z results in
(X *nsw Z) +nsw (Y *nsw Z) -- however, it is possible that the
distributed multiplications overflow, even if the non-distributed
one does not. We should discard the nsw flag if the the offset is
non-zero. If we just have (X *nsw Y) *nsw Z then concluding
X *nsw (Y *nsw Z) is fine.

Differential Revision: https://reviews.llvm.org/D112848

show more ...

[BasicAA] Extract linear expression multiplication (NFC)

Extract a common method for multiplying a linear expression by a
factor.

[BasicAA] Don't treat non-inbounds GEP as nsw

The scale multiplication is only guaranteed to be nsw if the GEP
is inbounds (or the multiplication is trivial). Previously we were
only considering exp

[BasicAA] Don't treat non-inbounds GEP as nsw

The scale multiplication is only guaranteed to be nsw if the GEP
is inbounds (or the multiplication is trivial). Previously we were
only considering explicit muls in GEP indices.

show more ...