[llvm] [MemCpyOpt] Drop dead `memmove` calls on `memset`'d source data (PR #101930)
Antonio Frighetto via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 28 12:21:52 PDT 2024
https://github.com/antoniofrighetto updated https://github.com/llvm/llvm-project/pull/101930
>From 2573b26d9dc2dcb53fe0492eccecd2f6f8486295 Mon Sep 17 00:00:00 2001
From: Antonio Frighetto <me at antoniofrighetto.com>
Date: Mon, 5 Aug 2024 09:35:37 +0200
Subject: [PATCH 1/5] [MemCpyOpt] Introduce test for PR101930 (NFC)
---
.../memset-memmove-redundant-memmove.ll | 64 +++++++++++++++++++
1 file changed, 64 insertions(+)
create mode 100644 llvm/test/Transforms/MemCpyOpt/memset-memmove-redundant-memmove.ll
diff --git a/llvm/test/Transforms/MemCpyOpt/memset-memmove-redundant-memmove.ll b/llvm/test/Transforms/MemCpyOpt/memset-memmove-redundant-memmove.ll
new file mode 100644
index 00000000000000..832b951e6220fe
--- /dev/null
+++ b/llvm/test/Transforms/MemCpyOpt/memset-memmove-redundant-memmove.ll
@@ -0,0 +1,64 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=memcpyopt -S %s -verify-memoryssa | FileCheck %s
+
+; Redundant memmove.
+define i32 @test() {
+; CHECK-LABEL: @test(
+; CHECK-NEXT: [[ARRAY:%.*]] = alloca [26 x i32], align 16
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 [[ARRAY]], i8 0, i64 104, i1 false)
+; CHECK-NEXT: [[ARRAY_IDX:%.*]] = getelementptr inbounds i8, ptr [[ARRAY]], i64 4
+; CHECK-NEXT: call void @llvm.memmove.p0.p0.i64(ptr noundef nonnull align 16 [[ARRAY]], ptr noundef nonnull align 4 [[ARRAY_IDX]], i64 100, i1 false)
+; CHECK-NEXT: [[VAL:%.*]] = load i32, ptr [[ARRAY]], align 16
+; CHECK-NEXT: ret i32 [[VAL]]
+;
+ %array = alloca [26 x i32], align 16
+ call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 %array, i8 0, i64 104, i1 false)
+ %array.idx = getelementptr inbounds i8, ptr %array, i64 4
+ call void @llvm.memmove.p0.p0.i64(ptr noundef nonnull align 16 %array, ptr noundef nonnull align 4 %array.idx, i64 100, i1 false)
+ %val = load i32, ptr %array, align 16
+ ret i32 %val
+}
+
+; Used memmmove, buffer is reset to zero.
+define i32 @test1() {
+; CHECK-LABEL: @test1(
+; CHECK-NEXT: [[ARRAY:%.*]] = alloca [26 x i32], align 16
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 [[ARRAY]], i8 0, i64 104, i1 false)
+; CHECK-NEXT: [[ARRAY_IDX:%.*]] = getelementptr inbounds i8, ptr [[ARRAY]], i64 4
+; CHECK-NEXT: store i32 1, ptr [[ARRAY_IDX]], align 4
+; CHECK-NEXT: call void @llvm.memmove.p0.p0.i64(ptr noundef nonnull align 16 [[ARRAY]], ptr noundef nonnull align 4 [[ARRAY_IDX]], i64 100, i1 false)
+; CHECK-NEXT: [[VAL:%.*]] = load i32, ptr [[ARRAY_IDX]], align 4
+; CHECK-NEXT: ret i32 [[VAL]]
+;
+ %array = alloca [26 x i32], align 16
+ call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 %array, i8 0, i64 104, i1 false)
+ %array.idx = getelementptr inbounds i8, ptr %array, i64 4
+ store i32 1, ptr %array.idx
+ call void @llvm.memmove.p0.p0.i64(ptr noundef nonnull align 16 %array, ptr noundef nonnull align 4 %array.idx, i64 100, i1 false)
+ %val = load i32, ptr %array.idx, align 4
+ ret i32 %val
+}
+
+; Used memmove, buffer clobbered by opaque.
+define i32 @test2() {
+; CHECK-LABEL: @test2(
+; CHECK-NEXT: [[ARRAY:%.*]] = alloca [25 x i32], align 16
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(100) [[ARRAY]], i8 0, i64 100, i1 false)
+; CHECK-NEXT: call void @opaque(ptr noundef nonnull [[ARRAY]])
+; CHECK-NEXT: [[ARRAY_IDX:%.*]] = getelementptr inbounds i8, ptr [[ARRAY]], i64 4
+; CHECK-NEXT: call void @llvm.memmove.p0.p0.i64(ptr noundef nonnull align 16 dereferenceable(96) [[ARRAY]], ptr noundef nonnull align 4 dereferenceable(96) [[ARRAY_IDX]], i64 96, i1 false)
+; CHECK-NEXT: [[VAL:%.*]] = load i32, ptr [[ARRAY]], align 16
+; CHECK-NEXT: ret i32 [[VAL]]
+;
+ %array = alloca [25 x i32], align 16
+ call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(100) %array, i8 0, i64 100, i1 false)
+ call void @opaque(ptr noundef nonnull %array)
+ %array.idx = getelementptr inbounds i8, ptr %array, i64 4
+ call void @llvm.memmove.p0.p0.i64(ptr noundef nonnull align 16 dereferenceable(96) %array, ptr noundef nonnull align 4 dereferenceable(96) %array.idx, i64 96, i1 false)
+ %val = load i32, ptr %array, align 16
+ ret i32 %val
+}
+
+declare void @opaque(ptr)
+declare void @llvm.memset.p0.i64(ptr nocapture, i8, i64, i1)
+declare void @llvm.memmove.p0.p0.i64(ptr nocapture, ptr nocapture, i64, i1) nounwind
>From fd47d7f80291f5384c2ace760463cd39791f81ff Mon Sep 17 00:00:00 2001
From: Antonio Frighetto <me at antoniofrighetto.com>
Date: Mon, 5 Aug 2024 09:36:22 +0200
Subject: [PATCH 2/5] [MemCpyOpt] Drop dead `memmove` calls on `memset`'d
source data
When a memmove happens to clobber source data, and such data have
been previously memset'd, the memmove may be redundant.
---
.../llvm/Transforms/Scalar/MemCpyOptimizer.h | 3 +-
.../lib/Transforms/Scalar/MemCpyOptimizer.cpp | 49 +++++++++++++++++--
.../memset-memmove-redundant-memmove.ll | 1 -
3 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h b/llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h
index 8ed03d7f3ddbff..1fbd29ea8b32a6 100644
--- a/llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h
+++ b/llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h
@@ -66,7 +66,7 @@ class MemCpyOptPass : public PassInfoMixin<MemCpyOptPass> {
BasicBlock::iterator &BBI);
bool processMemSet(MemSetInst *SI, BasicBlock::iterator &BBI);
bool processMemCpy(MemCpyInst *M, BasicBlock::iterator &BBI);
- bool processMemMove(MemMoveInst *M);
+ bool processMemMove(MemMoveInst *M, BasicBlock::iterator &BBI);
bool performCallSlotOptzn(Instruction *cpyLoad, Instruction *cpyStore,
Value *cpyDst, Value *cpySrc, TypeSize cpyLen,
Align cpyAlign, BatchAAResults &BAA,
@@ -85,6 +85,7 @@ class MemCpyOptPass : public PassInfoMixin<MemCpyOptPass> {
bool performStackMoveOptzn(Instruction *Load, Instruction *Store,
AllocaInst *DestAlloca, AllocaInst *SrcAlloca,
TypeSize Size, BatchAAResults &BAA);
+ bool mayBeMemMoveMemSetDependency(MemMoveInst *M);
void eraseInstruction(Instruction *I);
bool iterateOnFunction(Function &F);
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index cee34f0a6da1f3..30d16ca3f2f038 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -69,6 +69,7 @@ static cl::opt<bool> EnableMemCpyOptWithoutLibcalls(
cl::desc("Enable memcpyopt even when libcalls are disabled"));
STATISTIC(NumMemCpyInstr, "Number of memcpy instructions deleted");
+STATISTIC(NumMemMoveInstr, "Number of memmove instructions deleted");
STATISTIC(NumMemSetInfer, "Number of memsets inferred");
STATISTIC(NumMoveToCpy, "Number of memmoves converted to memcpy");
STATISTIC(NumCpyToSet, "Number of memcpys converted to memset");
@@ -1854,12 +1855,54 @@ bool MemCpyOptPass::processMemCpy(MemCpyInst *M, BasicBlock::iterator &BBI) {
return false;
}
+/// Memmove calls with overlapping src/dest buffers that come after a memset may
+/// be removed.
+bool MemCpyOptPass::mayBeMemMoveMemSetDependency(MemMoveInst *M) {
+ MemoryUseOrDef *MemMoveAccess = MSSA->getMemoryAccess(M);
+ if (!MemMoveAccess)
+ return false;
+
+ BatchAAResults BAA(*AA);
+ MemoryAccess *FirstDef = MemMoveAccess->getDefiningAccess();
+ MemoryLocation SourceLoc = MemoryLocation::getForSource(M);
+ MemoryAccess *SourceClobber =
+ MSSA->getWalker()->getClobberingMemoryAccess(FirstDef, SourceLoc, BAA);
+
+ MemSetInst *MS = nullptr;
+ if (auto *Def = dyn_cast<MemoryDef>(SourceClobber))
+ if (auto *I = dyn_cast<Instruction>(Def->getMemoryInst()))
+ MS = dyn_cast_or_null<MemSetInst>(I);
+
+ if (!MS || MS->getParent() != M->getParent())
+ return false;
+
+ // The destination buffer must have been memset'd.
+ if (!BAA.isMustAlias(MS->getDest(), M->getDest()))
+ return false;
+
+ // No clobbering writes in between.
+ if (writtenBetween(MSSA, BAA, SourceLoc, MSSA->getMemoryAccess(MS),
+ MemMoveAccess))
+ return false;
+ return true;
+}
+
/// Transforms memmove calls to memcpy calls when the src/dst are guaranteed
/// not to alias.
-bool MemCpyOptPass::processMemMove(MemMoveInst *M) {
+bool MemCpyOptPass::processMemMove(MemMoveInst *M, BasicBlock::iterator &BBI) {
// See if the source could be modified by this memmove potentially.
- if (isModSet(AA->getModRefInfo(M, MemoryLocation::getForSource(M))))
+ if (isModSet(AA->getModRefInfo(M, MemoryLocation::getForSource(M)))) {
+ // On the off-chance the memmove clobbers src with previously memset'd
+ // bytes, the memmove may be redundant.
+ if (mayBeMemMoveMemSetDependency(M)) {
+ LLVM_DEBUG(dbgs() << "Removed redundant memmove.\n");
+ ++BBI;
+ eraseInstruction(M);
+ ++NumMemMoveInstr;
+ return true;
+ }
return false;
+ }
LLVM_DEBUG(dbgs() << "MemCpyOptPass: Optimizing memmove -> memcpy: " << *M
<< "\n");
@@ -2068,7 +2111,7 @@ bool MemCpyOptPass::iterateOnFunction(Function &F) {
else if (auto *M = dyn_cast<MemCpyInst>(I))
RepeatInstruction = processMemCpy(M, BI);
else if (auto *M = dyn_cast<MemMoveInst>(I))
- RepeatInstruction = processMemMove(M);
+ RepeatInstruction = processMemMove(M, BI);
else if (auto *CB = dyn_cast<CallBase>(I)) {
for (unsigned i = 0, e = CB->arg_size(); i != e; ++i) {
if (CB->isByValArgument(i))
diff --git a/llvm/test/Transforms/MemCpyOpt/memset-memmove-redundant-memmove.ll b/llvm/test/Transforms/MemCpyOpt/memset-memmove-redundant-memmove.ll
index 832b951e6220fe..6017f39a90c86b 100644
--- a/llvm/test/Transforms/MemCpyOpt/memset-memmove-redundant-memmove.ll
+++ b/llvm/test/Transforms/MemCpyOpt/memset-memmove-redundant-memmove.ll
@@ -7,7 +7,6 @@ define i32 @test() {
; CHECK-NEXT: [[ARRAY:%.*]] = alloca [26 x i32], align 16
; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 [[ARRAY]], i8 0, i64 104, i1 false)
; CHECK-NEXT: [[ARRAY_IDX:%.*]] = getelementptr inbounds i8, ptr [[ARRAY]], i64 4
-; CHECK-NEXT: call void @llvm.memmove.p0.p0.i64(ptr noundef nonnull align 16 [[ARRAY]], ptr noundef nonnull align 4 [[ARRAY_IDX]], i64 100, i1 false)
; CHECK-NEXT: [[VAL:%.*]] = load i32, ptr [[ARRAY]], align 16
; CHECK-NEXT: ret i32 [[VAL]]
;
>From f2d8fe5ed66a914999b555f782b3b29734dd2435 Mon Sep 17 00:00:00 2001
From: Antonio Frighetto <me at antoniofrighetto.com>
Date: Mon, 5 Aug 2024 10:44:20 +0200
Subject: [PATCH 3/5] !fixup fix check / regenerate test
---
llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp | 3 +--
llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll | 18 +++++++++---------
2 files changed, 10 insertions(+), 11 deletions(-)
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 30d16ca3f2f038..1372ecf7196438 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -1870,8 +1870,7 @@ bool MemCpyOptPass::mayBeMemMoveMemSetDependency(MemMoveInst *M) {
MemSetInst *MS = nullptr;
if (auto *Def = dyn_cast<MemoryDef>(SourceClobber))
- if (auto *I = dyn_cast<Instruction>(Def->getMemoryInst()))
- MS = dyn_cast_or_null<MemSetInst>(I);
+ MS = dyn_cast_or_null<MemSetInst>(Def->getMemoryInst());
if (!MS || MS->getParent() != M->getParent())
return false;
diff --git a/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll b/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll
index 51fad820509393..abb8a43616bd08 100644
--- a/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll
+++ b/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll
@@ -51,8 +51,8 @@ define void @destroysrc(ptr %src, ptr %dst) {
define void @destroynoaliassrc(ptr noalias %src, ptr %dst) {
; CHECK-LABEL: @destroynoaliassrc(
-; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 8 [[DST:%.*]], ptr align 8 [[SRC]], i64 16, i1 false)
-; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC:%.*]], i8 0, i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 8 [[DST:%.*]], ptr align 8 [[SRC:%.*]], i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC]], i8 0, i64 16, i1 false)
; CHECK-NEXT: ret void
;
%1 = load %S, ptr %src
@@ -79,9 +79,9 @@ define void @copyalias(ptr %src, ptr %dst) {
; sure we lift the computation as well if needed and possible.
define void @addrproducer(ptr %src, ptr %dst) {
; CHECK-LABEL: @addrproducer(
-; CHECK-NEXT: [[DST2:%.*]] = getelementptr [[S:%.*]], ptr [[DST]], i64 1
+; CHECK-NEXT: [[DST2:%.*]] = getelementptr [[S:%.*]], ptr [[DST:%.*]], i64 1
; CHECK-NEXT: call void @llvm.memmove.p0.p0.i64(ptr align 8 [[DST2]], ptr align 8 [[SRC:%.*]], i64 16, i1 false)
-; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[DST:%.*]], i8 undef, i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[DST]], i8 undef, i64 16, i1 false)
; CHECK-NEXT: ret void
;
%1 = load %S, ptr %src
@@ -110,11 +110,11 @@ define void @aliasaddrproducer(ptr %src, ptr %dst, ptr %dstidptr) {
define void @noaliasaddrproducer(ptr %src, ptr noalias %dst, ptr noalias %dstidptr) {
; CHECK-LABEL: @noaliasaddrproducer(
-; CHECK-NEXT: [[TMP2:%.*]] = load i32, ptr [[DSTIDPTR:%.*]], align 4
-; CHECK-NEXT: [[DSTINDEX:%.*]] = or i32 [[TMP2]], 1
+; CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[DSTIDPTR:%.*]], align 4
+; CHECK-NEXT: [[DSTINDEX:%.*]] = or i32 [[TMP1]], 1
; CHECK-NEXT: [[DST2:%.*]] = getelementptr [[S:%.*]], ptr [[DST:%.*]], i32 [[DSTINDEX]]
-; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 8 [[DST2]], ptr align 8 [[SRC]], i64 16, i1 false)
-; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC:%.*]], i8 undef, i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 8 [[DST2]], ptr align 8 [[SRC:%.*]], i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC]], i8 undef, i64 16, i1 false)
; CHECK-NEXT: ret void
;
%1 = load %S, ptr %src
@@ -130,7 +130,7 @@ define void @throwing_call(ptr noalias %src, ptr %dst) {
; CHECK-LABEL: @throwing_call(
; CHECK-NEXT: [[TMP1:%.*]] = load [[S:%.*]], ptr [[SRC:%.*]], align 8
; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC]], i8 0, i64 16, i1 false)
-; CHECK-NEXT: call void @call() [[ATTR2:#.*]]
+; CHECK-NEXT: call void @call() #[[ATTR2:[0-9]+]]
; CHECK-NEXT: store [[S]] [[TMP1]], ptr [[DST:%.*]], align 8
; CHECK-NEXT: ret void
;
>From 61105151beac42dde55f8632e946584bb0dd3e44 Mon Sep 17 00:00:00 2001
From: Antonio Frighetto <me at antoniofrighetto.com>
Date: Thu, 8 Aug 2024 19:02:44 +0200
Subject: [PATCH 4/5] !fixup drop separate test nfc change
---
llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll b/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll
index abb8a43616bd08..51fad820509393 100644
--- a/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll
+++ b/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll
@@ -51,8 +51,8 @@ define void @destroysrc(ptr %src, ptr %dst) {
define void @destroynoaliassrc(ptr noalias %src, ptr %dst) {
; CHECK-LABEL: @destroynoaliassrc(
-; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 8 [[DST:%.*]], ptr align 8 [[SRC:%.*]], i64 16, i1 false)
-; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC]], i8 0, i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 8 [[DST:%.*]], ptr align 8 [[SRC]], i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC:%.*]], i8 0, i64 16, i1 false)
; CHECK-NEXT: ret void
;
%1 = load %S, ptr %src
@@ -79,9 +79,9 @@ define void @copyalias(ptr %src, ptr %dst) {
; sure we lift the computation as well if needed and possible.
define void @addrproducer(ptr %src, ptr %dst) {
; CHECK-LABEL: @addrproducer(
-; CHECK-NEXT: [[DST2:%.*]] = getelementptr [[S:%.*]], ptr [[DST:%.*]], i64 1
+; CHECK-NEXT: [[DST2:%.*]] = getelementptr [[S:%.*]], ptr [[DST]], i64 1
; CHECK-NEXT: call void @llvm.memmove.p0.p0.i64(ptr align 8 [[DST2]], ptr align 8 [[SRC:%.*]], i64 16, i1 false)
-; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[DST]], i8 undef, i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[DST:%.*]], i8 undef, i64 16, i1 false)
; CHECK-NEXT: ret void
;
%1 = load %S, ptr %src
@@ -110,11 +110,11 @@ define void @aliasaddrproducer(ptr %src, ptr %dst, ptr %dstidptr) {
define void @noaliasaddrproducer(ptr %src, ptr noalias %dst, ptr noalias %dstidptr) {
; CHECK-LABEL: @noaliasaddrproducer(
-; CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[DSTIDPTR:%.*]], align 4
-; CHECK-NEXT: [[DSTINDEX:%.*]] = or i32 [[TMP1]], 1
+; CHECK-NEXT: [[TMP2:%.*]] = load i32, ptr [[DSTIDPTR:%.*]], align 4
+; CHECK-NEXT: [[DSTINDEX:%.*]] = or i32 [[TMP2]], 1
; CHECK-NEXT: [[DST2:%.*]] = getelementptr [[S:%.*]], ptr [[DST:%.*]], i32 [[DSTINDEX]]
-; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 8 [[DST2]], ptr align 8 [[SRC:%.*]], i64 16, i1 false)
-; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC]], i8 undef, i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 8 [[DST2]], ptr align 8 [[SRC]], i64 16, i1 false)
+; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC:%.*]], i8 undef, i64 16, i1 false)
; CHECK-NEXT: ret void
;
%1 = load %S, ptr %src
@@ -130,7 +130,7 @@ define void @throwing_call(ptr noalias %src, ptr %dst) {
; CHECK-LABEL: @throwing_call(
; CHECK-NEXT: [[TMP1:%.*]] = load [[S:%.*]], ptr [[SRC:%.*]], align 8
; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 8 [[SRC]], i8 0, i64 16, i1 false)
-; CHECK-NEXT: call void @call() #[[ATTR2:[0-9]+]]
+; CHECK-NEXT: call void @call() [[ATTR2:#.*]]
; CHECK-NEXT: store [[S]] [[TMP1]], ptr [[DST:%.*]], align 8
; CHECK-NEXT: ret void
;
>From b2dd2b9543b08f70b3fb719e88659a0155a818a9 Mon Sep 17 00:00:00 2001
From: Antonio Frighetto <me at antoniofrighetto.com>
Date: Wed, 28 Aug 2024 21:21:16 +0200
Subject: [PATCH 5/5] !fixup rename to isMemMoveMemSetDependency
---
llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h | 2 +-
llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h b/llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h
index 1fbd29ea8b32a6..63e6fa8e805eca 100644
--- a/llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h
+++ b/llvm/include/llvm/Transforms/Scalar/MemCpyOptimizer.h
@@ -85,7 +85,7 @@ class MemCpyOptPass : public PassInfoMixin<MemCpyOptPass> {
bool performStackMoveOptzn(Instruction *Load, Instruction *Store,
AllocaInst *DestAlloca, AllocaInst *SrcAlloca,
TypeSize Size, BatchAAResults &BAA);
- bool mayBeMemMoveMemSetDependency(MemMoveInst *M);
+ bool isMemMoveMemSetDependency(MemMoveInst *M);
void eraseInstruction(Instruction *I);
bool iterateOnFunction(Function &F);
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 1372ecf7196438..ed8c3856782f47 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -1857,7 +1857,7 @@ bool MemCpyOptPass::processMemCpy(MemCpyInst *M, BasicBlock::iterator &BBI) {
/// Memmove calls with overlapping src/dest buffers that come after a memset may
/// be removed.
-bool MemCpyOptPass::mayBeMemMoveMemSetDependency(MemMoveInst *M) {
+bool MemCpyOptPass::isMemMoveMemSetDependency(MemMoveInst *M) {
MemoryUseOrDef *MemMoveAccess = MSSA->getMemoryAccess(M);
if (!MemMoveAccess)
return false;
@@ -1893,7 +1893,7 @@ bool MemCpyOptPass::processMemMove(MemMoveInst *M, BasicBlock::iterator &BBI) {
if (isModSet(AA->getModRefInfo(M, MemoryLocation::getForSource(M)))) {
// On the off-chance the memmove clobbers src with previously memset'd
// bytes, the memmove may be redundant.
- if (mayBeMemMoveMemSetDependency(M)) {
+ if (isMemMoveMemSetDependency(M)) {
LLVM_DEBUG(dbgs() << "Removed redundant memmove.\n");
++BBI;
eraseInstruction(M);
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