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[DebugInfo][NewGVN] Fix debug value loss (#147634)

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Fix #147511
This commit is contained in:
Shan Huang 2025-07-21 10:49:43 +08:00 committed by GitHub
parent 06ed4d2c92
commit 268c44f9ea
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2 changed files with 55 additions and 0 deletions
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10
llvm/lib/Transforms/Scalar/NewGVN.cpp
View File

@ -82,6 +82,7 @@
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstrTypes.h"
@ -4076,6 +4077,15 @@ bool NewGVN::eliminateInstructions(Function &F) {
if (!match(DefI, m_Intrinsic<Intrinsic::ssa_copy>()))
patchReplacementInstruction(DefI, DominatingLeader);
SmallVector<DbgVariableIntrinsic *> DbgUsers;
SmallVector<DbgVariableRecord *> DVRUsers;
findDbgUsers(DbgUsers, DefI, &DVRUsers);
for (auto *DVI : DbgUsers)
DVI->replaceVariableLocationOp(DefI, DominatingLeader);
for (auto *DVR : DVRUsers)
DVR->replaceVariableLocationOp(DefI, DominatingLeader);
markInstructionForDeletion(DefI);
}
}

45
llvm/test/Transforms/NewGVN/salvage-eliminate-instruction.ll Normal file
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@ -0,0 +1,45 @@
; RUN: opt -S -passes=newgvn %s | FileCheck %s
; Check that eliminateInstruction() replaces the debug uses of the instructions
; marked for deletion with the dominating leader.
define void @binop(i32 %x, i32 %y) !dbg !5 {
; CHECK: #dbg_value(i32 %add1, [[META9:![0-9]+]], !DIExpression(), [[META12:![0-9]+]])
; CHECK-NEXT: #dbg_value(i32 %add1, [[META11:![0-9]+]], !DIExpression(), [[META13:![0-9]+]])
;
%add1 = add i32 %x, %y, !dbg !12
#dbg_value(i32 %add1, !9, !DIExpression(), !12)
%add2 = add i32 %y, %x, !dbg !13
#dbg_value(i32 %add2, !11, !DIExpression(), !13)
call void @use(i32 %add1, i32 %add2), !dbg !14
ret void, !dbg !15
}
declare void @use(i32, i32)
!llvm.dbg.cu = !{!0}
!llvm.debugify = !{!2, !3}
!llvm.module.flags = !{!4}
!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
!1 = !DIFile(filename: "/app/example.ll", directory: "/")
!2 = !{i32 4}
!3 = !{i32 2}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = distinct !DISubprogram(name: "binop", linkageName: "binop", scope: null, file: !1, line: 1, type: !6, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !8)
!6 = !DISubroutineType(types: !7)
!7 = !{}
!8 = !{!9, !11}
!9 = !DILocalVariable(name: "1", scope: !5, file: !1, line: 1, type: !10)
!10 = !DIBasicType(name: "ty32", size: 32, encoding: DW_ATE_unsigned)
!11 = !DILocalVariable(name: "2", scope: !5, file: !1, line: 2, type: !10)
!12 = !DILocation(line: 1, column: 1, scope: !5)
!13 = !DILocation(line: 2, column: 1, scope: !5)
!14 = !DILocation(line: 3, column: 1, scope: !5)
!15 = !DILocation(line: 4, column: 1, scope: !5)
;.
; CHECK: [[META9]] = !DILocalVariable(name: "1",
; CHECK: [[META11]] = !DILocalVariable(name: "2",
; CHECK: [[META12]] = !DILocation(line: 1,
; CHECK: [[META13]] = !DILocation(line: 2,
;.