[LLVM] Don't peek through bitcast on pointers and gep with zero indices. NFC. (#102889)

Since we are using opaque pointers now, we don't need to peek through
bitcast on pointers and gep with zero i

[LLVM] Don't peek through bitcast on pointers and gep with zero indices. NFC. (#102889)

Since we are using opaque pointers now, we don't need to peek through
bitcast on pointers and gep with zero indices.

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[LoopUnroll] Add CSE to remove redundant loads after unrolling. (#83860)

This patch adds loadCSE support to simplifyLoopAfterUnroll. It is based
on EarlyCSE's implementation using ScopeHashTable an

[LoopUnroll] Add CSE to remove redundant loads after unrolling. (#83860)

This patch adds loadCSE support to simplifyLoopAfterUnroll. It is based
on EarlyCSE's implementation using ScopeHashTable and is using SCEV for
accessed pointers to check to find redundant loads after unrolling.

This applies to the late unroll pass only, for full unrolling those
redundant loads will be cleaned up by the regular pipeline.

The current approach constructs MSSA on-demand per-loop, but there is
still small but notable compile-time impact:

stage1-O3 +0.04%
stage1-ReleaseThinLTO +0.06%
stage1-ReleaseLTO-g +0.05%
stage1-O0-g +0.02%
stage2-O3 +0.09%
stage2-O0-g +0.04%
stage2-clang +0.02%


https://llvm-compile-time-tracker.com/compare.php?from=c089fa5a729e217d0c0d4647656386dac1a1b135&to=ec7c0f27cb5c12b600d9adfc8543d131765ec7be&stat=instructions:u

This benefits some workloads with runtime-unrolling disabled,
where users use pragmas to force unrolling, as well as with
runtime unrolling enabled.

On SPEC/MultiSource, this removes a number of loads after unrolling
on AArch64 with runtime unrolling enabled.

```
External/S...te/526.blender_r/526.blender_r 96
MultiSourc...rks/mediabench/gsm/toast/toast 39
SingleSource/Benchmarks/Misc/ffbench 4
External/SPEC/CINT2006/403.gcc/403.gcc 18
MultiSourc.../Applications/JM/ldecod/ldecod 4
MultiSourc.../mediabench/jpeg/jpeg-6a/cjpeg 6
MultiSourc...OE-ProxyApps-C/miniGMG/miniGMG 9
MultiSourc...e/Applications/ClamAV/clamscan 4
MultiSourc.../MallocBench/espresso/espresso 3
MultiSourc...dence-flt/LinearDependence-flt 2
MultiSourc...ch/office-ispell/office-ispell 4
MultiSourc...ch/consumer-jpeg/consumer-jpeg 6
MultiSourc...ench/security-sha/security-sha 11
MultiSourc...chmarks/McCat/04-bisect/bisect 3
SingleSour...tTests/2020-01-06-coverage-009 12
MultiSourc...ench/telecomm-gsm/telecomm-gsm 39
MultiSourc...lds-flt/CrossingThresholds-flt 24
MultiSourc...dence-dbl/LinearDependence-dbl 2
External/S...C/CINT2006/445.gobmk/445.gobmk 6
MultiSourc...enchmarks/mafft/pairlocalalign 53
External/S...31.deepsjeng_r/531.deepsjeng_r 3
External/S...rate/510.parest_r/510.parest_r 58
External/S...NT2006/464.h264ref/464.h264ref 29
External/S...NT2017rate/502.gcc_r/502.gcc_r 45
External/S...C/CINT2006/456.hmmer/456.hmmer 6
External/S...te/538.imagick_r/538.imagick_r 18
External/S.../CFP2006/447.dealII/447.dealII 4
MultiSourc...OE-ProxyApps-C++/miniFE/miniFE 12
External/S...2017rate/525.x264_r/525.x264_r 36
MultiSourc...Benchmarks/7zip/7zip-benchmark 33
MultiSourc...hmarks/ASC_Sequoia/AMGmk/AMGmk 2
MultiSourc...chmarks/VersaBench/8b10b/8b10b 1
MultiSourc.../Applications/JM/lencod/lencod 116
MultiSourc...lds-dbl/CrossingThresholds-dbl 24
MultiSource/Benchmarks/McCat/05-eks/eks 15
```

PR: https://github.com/llvm/llvm-project/pull/83860

show more ...

[memoryssa] Exclude llvm.allow.{runtime,ubsan}.check() (#86066)

RFC:
https://discourse.llvm.org/t/rfc-add-llvm-experimental-hot-intrinsic-or-llvm-hot/77641

[Analysis] Use llvm::pred_size (NFC)

[MemorySSA] Handle queries with empty memory location.

[MemorySSA] Always perform MemoryUses liveOnEntry optimization on MSSA construction

Fixes invariant memory regressions in future DSE patches.

Also add a flag to print<memoryssa> to not ensure optim

[MemorySSA] Always perform MemoryUses liveOnEntry optimization on MSSA construction

Fixes invariant memory regressions in future DSE patches.

Also add a flag to print<memoryssa> to not ensure optimized uses to test this.

Noticeable compile time regression [1], but a future DSE change that depends on this more than makes up for it.

[1] https://llvm-compile-time-tracker.com/compare.php?from=9d5466849a770eeab222d5a5890376d3596e8ad6&to=95682dbe11d76a3342870437377216e96b167504&stat=instructions:u

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D152859

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[Passes] Remove some legacy printer passes

MemDepPrinter doesn't have a new PM equivalent, but MemDep is soft deprecated anyway and adding one should be easy if somebody wants to.

[DebugInfo] Remove `dbg.addr` from Analysis

Part of `dbg.addr` removal
Discussed in https://discourse.llvm.org/t/what-is-the-status-of-dbg-addr/62898

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

[DebugInfo] Remove `dbg.addr` from Analysis

Part of `dbg.addr` removal
Discussed in https://discourse.llvm.org/t/what-is-the-status-of-dbg-addr/62898

Differential Revision: https://reviews.llvm.org/D144799

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[MemorySSA] Don't check def set when cloning memoryaccesses

For internal functions, globals-aa returns different ModRefInfo
results if they are inlined and are no longer called by external
functions

[MemorySSA] Don't check def set when cloning memoryaccesses

For internal functions, globals-aa returns different ModRefInfo
results if they are inlined and are no longer called by external
functions. This causes an assertion failure when cloning memoryssa
accesses.

Fixes: https://github.com/llvm/llvm-project/issues/59546

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D141185

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[llvm] Remove redundant initialization of std::optional (NFC)

Don't include Optional.h

These files no longer use llvm::Optional.

[Analysis] llvm::Optional => std::optional

[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://

[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

show more ...

[MemorySSA] Use BatchAA for clobber walker

While MemorySSA use optimization was already using BatchAA, the
publicly exposed MSSA walkers were using plain AAResults. This is
not great, because it is

[MemorySSA] Use BatchAA for clobber walker

While MemorySSA use optimization was already using BatchAA, the
publicly exposed MSSA walkers were using plain AAResults. This is
not great, because it is expected that clobber walking will make
repeated AA queries.

This patch makes the clobber API accept a BatchAAResults instance.
The plain APIs are kept as wrappers and will create a BatchAAResults
instance for the duration of the query. In the future, the explicit
BatchAAResults arguments will be used to share AA results across
queries, not just within one query.

Differential Revision: https://reviews.llvm.org/D136164

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[llvm] Use std::nullopt instead of None in comments (NFC)

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

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalu

[llvm] Use std::nullopt instead of None in comments (NFC)

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

show more ...

[Analysis] Use std::nullopt instead of None (NFC)

This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount o

[Analysis] Use std::nullopt instead of None (NFC)

This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

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

show more ...

[Analysis] Remove unused fields in MemorySSA.cpp (NFC)

The last uses of AR were removed on July 28, 2022 in commit
f96ea53e892e0dfc1ee778868c1ed33616b95a82.

Differential Revision: https://reviews.l

[Analysis] Remove unused fields in MemorySSA.cpp (NFC)

The last uses of AR were removed on July 28, 2022 in commit
f96ea53e892e0dfc1ee778868c1ed33616b95a82.

Differential Revision: https://reviews.llvm.org/D138730

show more ...

[MemorySSA] Relax assert condition in createDefinedAccess

If globals-aa is enabled, because of the deletion of memory instructions, there
may be call instruction that is not in ModOrRefSet but is a

[MemorySSA] Relax assert condition in createDefinedAccess

If globals-aa is enabled, because of the deletion of memory instructions, there
may be call instruction that is not in ModOrRefSet but is a MemoryUseOrDef.
This causes the crash in the process of cloning uses and defs.

Fixes https://github.com/llvm/llvm-project/issues/58719

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D137553

show more ...

[AliasAnalysis] Introduce getModRefInfoMask() as a generalization of pointsToConstantMemory().

The pointsToConstantMemory() method returns true only if the memory pointed to
by the memory location i

[AliasAnalysis] Introduce getModRefInfoMask() as a generalization of pointsToConstantMemory().

The pointsToConstantMemory() method returns true only if the memory pointed to
by the memory location is globally invariant. However, the LLVM memory model
also has the semantic notion of *locally-invariant*: memory that is known to be
invariant for the life of the SSA value representing that pointer. The most
common example of this is a pointer argument that is marked readonly noalias,
which the Rust compiler frequently emits.

It'd be desirable for LLVM to treat locally-invariant memory the same way as
globally-invariant memory when it's safe to do so. This patch implements that,
by introducing the concept of a *ModRefInfo mask*. A ModRefInfo mask is a bound
on the Mod/Ref behavior of an instruction that writes to a memory location,
based on the knowledge that the memory is globally-constant memory (in which
case the mask is NoModRef) or locally-constant memory (in which case the mask
is Ref). ModRefInfo values for an instruction can be combined with the
ModRefInfo mask by simply using the & operator. Where appropriate, this patch
has modified uses of pointsToConstantMemory() to instead examine the mask.

The most notable optimization change I noticed with this patch is that now
redundant loads from readonly noalias pointers can be eliminated across calls,
even when the pointer is captured. Internally, before this patch,
AliasAnalysis was assigning Ref to reads from constant memory; now AA can
assign NoModRef, which is a tighter bound.

Differential Revision: https://reviews.llvm.org/D136659

show more ...

[MemorySSA] Remove PerformedPhiTranslation flag

I believe this is no longer necessary, as the underlying problem
has been fixed in a different way: Nowadays, we will adjust the
location size to befo

[MemorySSA] Remove PerformedPhiTranslation flag

I believe this is no longer necessary, as the underlying problem
has been fixed in a different way: Nowadays, we will adjust the
location size to beforeOrAfterPointer() if the pointer is not loop
invariant. This makes merging results translated across loop
backedges safe.

The two tests in phi-translation.ll show an improvement while still
being correct: The loads in the loop no longer alias with noalias
pointers, but still alias with the store in the entry block (which
they originally did not -- this is the bug that
PerformedPhiTranslation originally fixed).

Differential Revision: https://reviews.llvm.org/D133404

show more ...

[MemorySSA][NFC] Use const whenever possible

Differential Revision: https://reviews.llvm.org/D134162

[MSSA] Fix expensive checks build

[AA] Do not track Must in ModRefInfo

getModRefInfo() queries currently track whether the result is a
MustAlias on a best-effort basis. The only user of this functionality
is the optimized memory acc

[AA] Do not track Must in ModRefInfo

getModRefInfo() queries currently track whether the result is a
MustAlias on a best-effort basis. The only user of this functionality
is the optimized memory access type in MemorySSA -- which in turn
has no users. Given that this functionality has not found a user
since it was introduced five years ago (in D38862), I think we
should drop it again.

The context is that I'm working to separate FunctionModRefBehavior
to track mod/ref for different location kinds (like argmem or
inaccessiblemem) separately, and the fact that ModRefInfo also has
an unrelated Must flag makes this quite awkward, especially as this
means that NoModRef is not a zero value. If we want to retain the
functionality, I would probably split getModRefInfo() results into
a part that just contains the ModRef information, and a separate
part containing a (best-effort) AliasResult.

Differential Revision: https://reviews.llvm.org/D130713

show more ...

[llvm] Use Optional::has_value instead of Optional::hasValue (NFC)

This patch replaces x.hasValue() with x.has_value() where x is not
contextually convertible to bool.

[llvm] Don't use Optional::hasValue (NFC)

This patch replaces Optional::hasValue with the implicit cast to bool
in conditionals only.