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Differential D73473

[DebugInfo] replaceDbgUsesWithUndef before removing dead alloca
AbandonedPublic

Authored by Orlando on Jan 27 2020, 6:56 AM.

Details

Reviewers
vsk
aprantl
djtodoro
probinson

Diff Detail

Revision Contents

PathSize
llvm/
lib/
Transforms/
Scalar/
1 line
test/
DebugInfo/
X86/
44 lines

Diff 240565

llvm/lib/Transforms/Scalar/SROA.cpp

Show First 20 Lines • Show All 4,430 Lines • ▼ Show 20 Lines
/// the slices of the alloca, and then hands it off to be split and /// the slices of the alloca, and then hands it off to be split and
/// rewritten as needed. /// rewritten as needed.
bool SROA::runOnAlloca(AllocaInst &AI) { bool SROA::runOnAlloca(AllocaInst &AI) {
LLVM_DEBUG(dbgs() << "SROA alloca: " << AI << "\n"); LLVM_DEBUG(dbgs() << "SROA alloca: " << AI << "\n");
++NumAllocasAnalyzed; ++NumAllocasAnalyzed;
// Special case dead allocas, as they're trivial. // Special case dead allocas, as they're trivial.
if (AI.use_empty()) { if (AI.use_empty()) {
replaceDbgUsesWithUndef(&AI);
AI.eraseFromParent(); AI.eraseFromParent();
return true; return true;
} }
const DataLayout &DL = AI.getModule()->getDataLayout(); const DataLayout &DL = AI.getModule()->getDataLayout();
// Skip alloca forms that this analysis can't handle. // Skip alloca forms that this analysis can't handle.
if (AI.isArrayAllocation() || !AI.getAllocatedType()->isSized() || if (AI.isArrayAllocation() || !AI.getAllocatedType()->isSized() ||
DL.getTypeAllocSize(AI.getAllocatedType()) == 0) DL.getTypeAllocSize(AI.getAllocatedType()) == 0)
▲ Show 20 Lines • Show All 210 Lines • Show Last 20 Lines

llvm/test/DebugInfo/X86/sroa-undef-dbg-value.ll

  • This file was added.
; RUN: opt -sroa -S %s | FileCheck %s
; CHECK: call void @llvm.dbg.value(metadata i32* undef, metadata ![[MD_c:[0-9]+]],
; CHECK: [[MD_c]] = !DILocalVariable(name: "c",
; clang reduce.c -O0 -g -w -emit-llvm -S -Xclang -disable-O0-optnone -o reduce.ll
; cat reduce.c
; void a() {
; int b;
; int *c = &b;
; }
define dso_local void @a() !dbg !7 {
entry:
%b = alloca i32, align 4
%c = alloca i32*, align 8
call void @llvm.dbg.declare(metadata i32* %b, metadata !10, metadata !DIExpression()), !dbg !12
call void @llvm.dbg.declare(metadata i32** %c, metadata !13, metadata !DIExpression()), !dbg !15
store i32* %b, i32** %c, align 8, !dbg !15
ret void, !dbg !16
}
; Function Attrs: nounwind readnone speculatable willreturn
declare void @llvm.dbg.declare(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5}
!llvm.ident = !{!6}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "reduce.c", directory: "/")
!2 = !{}
!3 = !{i32 7, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 4}
!6 = !{!"clang version 10.0.0"}
!7 = distinct !DISubprogram(name: "a", scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
!8 = !DISubroutineType(types: !9)
!9 = !{null}
!10 = !DILocalVariable(name: "b", scope: !7, file: !1, line: 2, type: !11)
!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!12 = !DILocation(line: 2, column: 7, scope: !7)
!13 = !DILocalVariable(name: "c", scope: !7, file: !1, line: 3, type: !14)
!14 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 64)
!15 = !DILocation(line: 3, column: 8, scope: !7)
!16 = !DILocation(line: 4, column: 1, scope: !7)