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[AA] Consider extractvalue and extractelement as escape sources #127640

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Merged
merged 1 commit into from
Feb 19, 2025
Merged

[AA] Consider extractvalue and extractelement as escape sources #127640

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6 changes: 6 additions & 0 deletions llvm/lib/Analysis/AliasAnalysis.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -859,6 +859,12 @@ bool llvm::isEscapeSource(const Value *V) {
if (isa<IntToPtrInst>(V))
return true;

// Capture tracking considers insertions into aggregates and vectors as
// captures. As such, extractions from aggregates and vectors are escape
// sources.
if (isa<ExtractValueInst, ExtractElementInst>(V))
return true;

// Same for inttoptr constant expressions.
if (auto *CE = dyn_cast<ConstantExpr>(V))
if (CE->getOpcode() == Instruction::IntToPtr)
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27 changes: 25 additions & 2 deletions llvm/test/Analysis/BasicAA/escape-source-aggregate.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -2,8 +2,9 @@

declare { ptr, i1 } @get_struct()
declare <2 x ptr> @get_vec()
declare void @escape(ptr)

; CHECK: MayAlias: i32* %a, i32* %extract
; CHECK: NoAlias: i32* %a, i32* %extract
define i32 @test_extractvalue() {
%a = alloca i32
%call = call { ptr, i1 } @get_struct()
Expand All @@ -13,7 +14,7 @@ define i32 @test_extractvalue() {
ret i32 %v
}

; CHECK: MayAlias: i32* %a, i32* %extract
; CHECK: NoAlias: i32* %a, i32* %extract
define i32 @test_extractelement() {
%a = alloca i32
%call = call <2 x ptr> @get_vec()
Expand All @@ -22,3 +23,25 @@ define i32 @test_extractelement() {
%v = load i32, ptr %a
ret i32 %v
}

; CHECK: MayAlias: i32* %a, i32* %extract
define i32 @test_extractvalue_escape() {
%a = alloca i32
call void @escape(ptr %a)
%call = call { ptr, i1 } @get_struct()
%extract = extractvalue { ptr, i1 } %call, 0
store i32 0, ptr %extract
%v = load i32, ptr %a
ret i32 %v
}

; CHECK: MayAlias: i32* %a, i32* %extract
define i32 @test_extractelement_escape() {
%a = alloca i32
call void @escape(ptr %a)
%call = call <2 x ptr> @get_vec()
%extract = extractelement <2 x ptr> %call, i32 0
store i32 0, ptr %extract
%v = load i32, ptr %a
ret i32 %v
}