[EarlyCSE,TTI] Clean up temporary insts created by getOrCreateResult. #134534
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getOrCreateResultFromMemIntrinsic can modify the current function by inserting new instructions without EarlyCSE keeping track of the changes. Currently, EarlyCSE will treat the IR as unchanged, even if new instructions are inserted. This leads to missed invalidation on the newly added test case. To solve this, the patch updates getOrCreateResultFromMemIntrinsic and the only user (EarlyCSE) to keep track of newly created instructions and cleans them up at the end of EarlyCSE. Alternatively getOrCreateResultFromMemIntrinsic could indicate that new instructions have been added and update Changed in EarlyCSE accordingly.
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@llvm/pr-subscribers-llvm-transforms @llvm/pr-subscribers-backend-aarch64 Author: Florian Hahn (fhahn) ChangesgetOrCreateResultFromMemIntrinsic can modify the current function by inserting new instructions without EarlyCSE keeping track of the changes. Currently, EarlyCSE will treat the IR as unchanged, even if new instructions are inserted. This leads to missed invalidation on the newly added test case. To solve this, the patch updates getOrCreateResultFromMemIntrinsic and the only user (EarlyCSE) to keep track of newly created instructions and cleans them up at the end of EarlyCSE. Alternatively getOrCreateResultFromMemIntrinsic could indicate that new instructions have been added and update Changed in EarlyCSE accordingly. Full diff: https://github.com/llvm/llvm-project/pull/134534.diff 7 Files Affected:
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfo.h b/llvm/include/llvm/Analysis/TargetTransformInfo.h
index 4835c66a7a3bc..6d355dee74bfb 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfo.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfo.h
@@ -1673,9 +1673,10 @@ class TargetTransformInfo {
/// \returns A value which is the result of the given memory intrinsic. New
/// instructions may be created to extract the result from the given intrinsic
/// memory operation. Returns nullptr if the target cannot create a result
- /// from the given intrinsic.
- Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
- Type *ExpectedType) const;
+ /// from the given intrinsic. Adds newly created instructions to \p NewInsts.
+ Value *getOrCreateResultFromMemIntrinsic(
+ IntrinsicInst *Inst, Type *ExpectedType,
+ SmallVectorImpl<Instruction *> &NewInsts) const;
/// \returns The type to use in a loop expansion of a memcpy call.
Type *getMemcpyLoopLoweringType(
@@ -2290,8 +2291,9 @@ class TargetTransformInfo::Concept {
virtual bool getTgtMemIntrinsic(IntrinsicInst *Inst,
MemIntrinsicInfo &Info) = 0;
virtual unsigned getAtomicMemIntrinsicMaxElementSize() const = 0;
- virtual Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
- Type *ExpectedType) = 0;
+ virtual Value *getOrCreateResultFromMemIntrinsic(
+ IntrinsicInst *Inst, Type *ExpectedType,
+ SmallVectorImpl<Instruction *> &NewInsts) = 0;
virtual Type *getMemcpyLoopLoweringType(
LLVMContext &Context, Value *Length, unsigned SrcAddrSpace,
unsigned DestAddrSpace, Align SrcAlign, Align DestAlign,
@@ -3065,9 +3067,10 @@ class TargetTransformInfo::Model final : public TargetTransformInfo::Concept {
unsigned getAtomicMemIntrinsicMaxElementSize() const override {
return Impl.getAtomicMemIntrinsicMaxElementSize();
}
- Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
- Type *ExpectedType) override {
- return Impl.getOrCreateResultFromMemIntrinsic(Inst, ExpectedType);
+ Value *getOrCreateResultFromMemIntrinsic(
+ IntrinsicInst *Inst, Type *ExpectedType,
+ SmallVectorImpl<Instruction *> &NewInsts) override {
+ return Impl.getOrCreateResultFromMemIntrinsic(Inst, ExpectedType, NewInsts);
}
Type *getMemcpyLoopLoweringType(
LLVMContext &Context, Value *Length, unsigned SrcAddrSpace,
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
index 261d5eacc91b0..a111d6903b6eb 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -917,8 +917,9 @@ class TargetTransformInfoImplBase {
return 0;
}
- Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
- Type *ExpectedType) const {
+ Value *getOrCreateResultFromMemIntrinsic(
+ IntrinsicInst *Inst, Type *ExpectedType,
+ SmallVectorImpl<Instruction *> &NewInsts) const {
return nullptr;
}
diff --git a/llvm/lib/Analysis/TargetTransformInfo.cpp b/llvm/lib/Analysis/TargetTransformInfo.cpp
index e3212135e9b19..6e75b6831cd9a 100644
--- a/llvm/lib/Analysis/TargetTransformInfo.cpp
+++ b/llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -1278,8 +1278,10 @@ unsigned TargetTransformInfo::getAtomicMemIntrinsicMaxElementSize() const {
}
Value *TargetTransformInfo::getOrCreateResultFromMemIntrinsic(
- IntrinsicInst *Inst, Type *ExpectedType) const {
- return TTIImpl->getOrCreateResultFromMemIntrinsic(Inst, ExpectedType);
+ IntrinsicInst *Inst, Type *ExpectedType,
+ SmallVectorImpl<Instruction *> &NewInsts) const {
+ return TTIImpl->getOrCreateResultFromMemIntrinsic(Inst, ExpectedType,
+ NewInsts);
}
Type *TargetTransformInfo::getMemcpyLoopLoweringType(
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 77be41b78bc7f..d55aa9ba24718 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -4743,8 +4743,9 @@ void AArch64TTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
BaseT::getPeelingPreferences(L, SE, PP);
}
-Value *AArch64TTIImpl::getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
- Type *ExpectedType) {
+Value *AArch64TTIImpl::getOrCreateResultFromMemIntrinsic(
+ IntrinsicInst *Inst, Type *ExpectedType,
+ SmallVectorImpl<Instruction *> &NewInsts) {
switch (Inst->getIntrinsicID()) {
default:
return nullptr;
@@ -4763,7 +4764,11 @@ Value *AArch64TTIImpl::getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
return nullptr;
}
Value *Res = PoisonValue::get(ExpectedType);
- IRBuilder<> Builder(Inst);
+ IRBuilder<ConstantFolder, IRBuilderCallbackInserter> Builder(
+ Inst->getContext(), ConstantFolder(),
+ IRBuilderCallbackInserter(
+ [&NewInsts](Instruction *I) { NewInsts.push_back(I); }));
+ Builder.SetInsertPoint(Inst);
for (unsigned i = 0, e = NumElts; i != e; ++i) {
Value *L = Inst->getArgOperand(i);
Res = Builder.CreateInsertValue(Res, L, i);
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
index ae0df6b895ec8..85e0e6dbddbe5 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
@@ -256,8 +256,9 @@ class AArch64TTIImpl : public BasicTTIImplBase<AArch64TTIImpl> {
void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
TTI::PeelingPreferences &PP);
- Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
- Type *ExpectedType);
+ Value *
+ getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst, Type *ExpectedType,
+ SmallVectorImpl<Instruction *> &NewInsts);
bool getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info);
diff --git a/llvm/lib/Transforms/Scalar/EarlyCSE.cpp b/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
index 3a0ae6b01a114..7d8b3a7073da5 100644
--- a/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
+++ b/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
@@ -729,6 +729,8 @@ class EarlyCSE {
/// This is the current generation of the memory value.
unsigned CurrentGeneration = 0;
+ SmallVector<Instruction *> TmpInstructions;
+
/// Set up the EarlyCSE runner for a particular function.
EarlyCSE(const DataLayout &DL, const TargetLibraryInfo &TLI,
const TargetTransformInfo &TTI, DominatorTree &DT,
@@ -965,7 +967,8 @@ class EarlyCSE {
bool overridingStores(const ParseMemoryInst &Earlier,
const ParseMemoryInst &Later);
- Value *getOrCreateResult(Instruction *Inst, Type *ExpectedType) const {
+ Value *getOrCreateResult(Instruction *Inst, Type *ExpectedType,
+ SmallVectorImpl<Instruction *> &TmpInsts) const {
// TODO: We could insert relevant casts on type mismatch.
// The load or the store's first operand.
Value *V;
@@ -978,7 +981,8 @@ class EarlyCSE {
V = II->getOperand(0);
break;
default:
- return TTI.getOrCreateResultFromMemIntrinsic(II, ExpectedType);
+ return TTI.getOrCreateResultFromMemIntrinsic(II, ExpectedType,
+ TmpInsts);
}
} else {
V = isa<LoadInst>(Inst) ? Inst : cast<StoreInst>(Inst)->getValueOperand();
@@ -1262,9 +1266,10 @@ Value *EarlyCSE::getMatchingValue(LoadValue &InVal, ParseMemoryInst &MemInst,
// For stores check the result values before checking memory generation
// (otherwise isSameMemGeneration may crash).
- Value *Result = MemInst.isStore()
- ? getOrCreateResult(Matching, Other->getType())
- : nullptr;
+ Value *Result =
+ MemInst.isStore()
+ ? getOrCreateResult(Matching, Other->getType(), TmpInstructions)
+ : nullptr;
if (MemInst.isStore() && InVal.DefInst != Result)
return nullptr;
@@ -1285,7 +1290,7 @@ Value *EarlyCSE::getMatchingValue(LoadValue &InVal, ParseMemoryInst &MemInst,
return nullptr;
if (!Result)
- Result = getOrCreateResult(Matching, Other->getType());
+ Result = getOrCreateResult(Matching, Other->getType(), TmpInstructions);
return Result;
}
@@ -1833,6 +1838,11 @@ bool EarlyCSE::run() {
}
} // while (!nodes...)
+ // Clean up temporary instructions.
+ for (Instruction *I : reverse(TmpInstructions))
+ if (I->use_empty())
+ I->eraseFromParent();
+
return Changed;
}
diff --git a/llvm/test/Transforms/EarlyCSE/AArch64/intrinsics.ll b/llvm/test/Transforms/EarlyCSE/AArch64/intrinsics.ll
index 94b17510bb95d..4744e3761fa6b 100644
--- a/llvm/test/Transforms/EarlyCSE/AArch64/intrinsics.ll
+++ b/llvm/test/Transforms/EarlyCSE/AArch64/intrinsics.ll
@@ -1,6 +1,6 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt < %s -S -mtriple=aarch64-none-linux-gnu -mattr=+neon -passes=early-cse -earlycse-debug-hash | FileCheck %s
-; RUN: opt < %s -S -mtriple=aarch64-none-linux-gnu -mattr=+neon -aa-pipeline=basic-aa -passes='early-cse<memssa>' | FileCheck %s
+; RUN: opt < %s -S -mtriple=aarch64-none-linux-gnu -mattr=+neon -aa-pipeline=basic-aa -passes='early-cse<memssa>' -verify-analysis-invalidation | FileCheck %s
define <4 x i32> @test_cse(ptr %a, [2 x <4 x i32>] %s.coerce, i32 %n) {
; CHECK-LABEL: define <4 x i32> @test_cse(
@@ -17,8 +17,6 @@ define <4 x i32> @test_cse(ptr %a, [2 x <4 x i32>] %s.coerce, i32 %n) {
; CHECK: [[FOR_BODY]]:
; CHECK-NEXT: [[TMP0:%.*]] = bitcast <4 x i32> [[S_COERCE_FCA_0_EXTRACT]] to <16 x i8>
; CHECK-NEXT: [[TMP1:%.*]] = bitcast <4 x i32> [[S_COERCE_FCA_1_EXTRACT]] to <16 x i8>
-; CHECK-NEXT: [[TMP2:%.*]] = insertvalue { <4 x i32>, <4 x i32> } poison, <4 x i32> [[S_COERCE_FCA_0_EXTRACT]], 0
-; CHECK-NEXT: [[TMP3:%.*]] = insertvalue { <4 x i32>, <4 x i32> } [[TMP2]], <4 x i32> [[S_COERCE_FCA_1_EXTRACT]], 1
; CHECK-NEXT: call void @llvm.aarch64.neon.st2.v4i32.p0(<4 x i32> [[S_COERCE_FCA_0_EXTRACT]], <4 x i32> [[S_COERCE_FCA_1_EXTRACT]], ptr [[A]])
; CHECK-NEXT: [[CALL]] = call <4 x i32> @vaddq_s32(<4 x i32> [[S_COERCE_FCA_0_EXTRACT]], <4 x i32> [[S_COERCE_FCA_0_EXTRACT]])
; CHECK-NEXT: [[INC]] = add nsw i32 [[I_0]], 1
@@ -71,8 +69,6 @@ define <4 x i32> @test_cse2(ptr %a, [2 x <4 x i32>] %s.coerce, i32 %n) {
; CHECK-NEXT: [[TMP0:%.*]] = bitcast <4 x i32> [[S_COERCE_FCA_0_EXTRACT]] to <16 x i8>
; CHECK-NEXT: [[TMP1:%.*]] = bitcast <4 x i32> [[S_COERCE_FCA_1_EXTRACT]] to <16 x i8>
; CHECK-NEXT: call void @llvm.aarch64.neon.st2.v4i32.p0(<4 x i32> [[S_COERCE_FCA_0_EXTRACT]], <4 x i32> [[S_COERCE_FCA_0_EXTRACT]], ptr [[A]])
-; CHECK-NEXT: [[TMP2:%.*]] = insertvalue { <4 x i32>, <4 x i32> } poison, <4 x i32> [[S_COERCE_FCA_0_EXTRACT]], 0
-; CHECK-NEXT: [[TMP3:%.*]] = insertvalue { <4 x i32>, <4 x i32> } [[TMP2]], <4 x i32> [[S_COERCE_FCA_1_EXTRACT]], 1
; CHECK-NEXT: call void @llvm.aarch64.neon.st2.v4i32.p0(<4 x i32> [[S_COERCE_FCA_0_EXTRACT]], <4 x i32> [[S_COERCE_FCA_1_EXTRACT]], ptr [[A]])
; CHECK-NEXT: [[CALL]] = call <4 x i32> @vaddq_s32(<4 x i32> [[S_COERCE_FCA_0_EXTRACT]], <4 x i32> [[S_COERCE_FCA_0_EXTRACT]])
; CHECK-NEXT: [[INC]] = add nsw i32 [[I_0]], 1
@@ -324,6 +320,22 @@ for.end: ; preds = %for.cond
ret <4 x i32> %res.0
}
+define void @test_ld4_st4_no_cse(ptr %p, <16 x i8> %A, <16 x i8> %B) {
+; CHECK-LABEL: define void @test_ld4_st4_no_cse(
+; CHECK-SAME: ptr [[P:%.*]], <16 x i8> [[A:%.*]], <16 x i8> [[B:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[LD:%.*]] = tail call { <16 x i8>, <16 x i8>, <16 x i8>, <16 x i8> } @llvm.aarch64.neon.ld4.v16i8.p0(ptr [[P]])
+; CHECK-NEXT: [[EXT:%.*]] = extractvalue { <16 x i8>, <16 x i8>, <16 x i8>, <16 x i8> } [[LD]], 0
+; CHECK-NEXT: tail call void @llvm.aarch64.neon.st4.v16i8.p0(<16 x i8> [[EXT]], <16 x i8> [[A]], <16 x i8> [[B]], <16 x i8> zeroinitializer, ptr [[P]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %ld = tail call { <16 x i8>, <16 x i8>, <16 x i8>, <16 x i8> } @llvm.aarch64.neon.ld4.v16i8.p0(ptr %p)
+ %ext = extractvalue { <16 x i8>, <16 x i8>, <16 x i8>, <16 x i8> } %ld, 0
+ tail call void @llvm.aarch64.neon.st4.v16i8.p0(<16 x i8> %ext, <16 x i8> %A, <16 x i8> %B, <16 x i8> zeroinitializer, ptr %p)
+ ret void
+}
+
; Function Attrs: nounwind
declare void @llvm.aarch64.neon.st2.v4i32.p0(<4 x i32>, <4 x i32>, ptr nocapture)
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dtcxzyw
approved these changes
Apr 6, 2025
| @@ -978,7 +981,8 @@ class EarlyCSE { | |||
| V = II->getOperand(0); | |||
| break; | |||
| default: | |||
| return TTI.getOrCreateResultFromMemIntrinsic(II, ExpectedType); | |||
| return TTI.getOrCreateResultFromMemIntrinsic(II, ExpectedType, | |||
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Can we use TmpInstructions directly?
There was a problem hiding this comment.
Yes, if we make the function non-const, but that would expose much more to be potentially modified, which is why I went with passing in the SmallVectorImpl. can change if preferred
nikic
reviewed
Apr 6, 2025
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getOrCreateResultFromMemIntrinsic can modify the current function by inserting new instructions without EarlyCSE keeping track of the changes.
Currently, EarlyCSE will treat the IR as unchanged, even if new instructions are inserted. This leads to missed invalidation on the newly added test case.
To solve this, the patch updates getOrCreateResultFromMemIntrinsic and the only user (EarlyCSE) to keep track of newly created instructions and cleans them up at the end of EarlyCSE.
Alternatively getOrCreateResultFromMemIntrinsic could indicate that new instructions have been added and update Changed in EarlyCSE accordingly.