Skip to content

[DebugInfo][DivRemPairs] Fix missing debug location updates #96045

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jun 23, 2024
Merged

[DebugInfo][DivRemPairs] Fix missing debug location updates #96045

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions llvm/lib/Transforms/Scalar/DivRemPairs.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -215,6 +215,7 @@ static bool optimizeDivRem(Function &F, const TargetTransformInfo &TTI,
RemInst = RealRem;
// And replace the original instruction with the new one.
OrigRemInst->replaceAllUsesWith(RealRem);
RealRem->setDebugLoc(OrigRemInst->getDebugLoc());
OrigRemInst->eraseFromParent();
NumRecomposed++;
// Note that we have left ((X / Y) * Y) around.
Expand Down Expand Up @@ -366,7 +367,9 @@ static bool optimizeDivRem(Function &F, const TargetTransformInfo &TTI,
if (!DivDominates)
DivInst->moveBefore(RemInst);
Mul->insertAfter(RemInst);
Mul->setDebugLoc(RemInst->getDebugLoc());
Sub->insertAfter(Mul);
Sub->setDebugLoc(RemInst->getDebugLoc());

// If DivInst has the exact flag, remove it. Otherwise this optimization
// may replace a well-defined value 'X % Y' with poison.
Expand All @@ -384,6 +387,7 @@ static bool optimizeDivRem(Function &F, const TargetTransformInfo &TTI,
if (!isGuaranteedNotToBeUndef(X, nullptr, DivInst, &DT)) {
auto *FrX =
new FreezeInst(X, X->getName() + ".frozen", DivInst->getIterator());
FrX->setDebugLoc(DivInst->getDebugLoc());
DivInst->setOperand(0, FrX);
Sub->setOperand(0, FrX);
}
Expand All @@ -392,6 +396,7 @@ static bool optimizeDivRem(Function &F, const TargetTransformInfo &TTI,
if (!isGuaranteedNotToBeUndef(Y, nullptr, DivInst, &DT)) {
auto *FrY =
new FreezeInst(Y, Y->getName() + ".frozen", DivInst->getIterator());
FrY->setDebugLoc(DivInst->getDebugLoc());
DivInst->setOperand(1, FrY);
Mul->setOperand(1, FrY);
}
Expand Down
50 changes: 50 additions & 0 deletions llvm/test/Transforms/DivRemPairs/X86/preserving-debugloc-frx-fry-mul-sub.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,50 @@
; RUN: opt -S -passes=div-rem-pairs -mtriple=x86_64-unknown-unknown < %s | FileCheck %s

; Check that DivRemPairs's optimizeDivRem() correctly propagates debug locations
; of `%div` and `%rem` to new freeze, mul and sub instructions.

define i128 @dont_hoist_urem(i128 %a, i128 %b) !dbg !5 {
; CHECK-LABEL: define i128 @dont_hoist_urem(
; CHECK-SAME: i128 [[A:%.*]], i128 [[B:%.*]])
; CHECK: entry:
; CHECK-NEXT: [[A_FROZEN:%.*]] = freeze i128 [[A]], !dbg [[DBG8:![0-9]+]]
; CHECK-NEXT: [[B_FROZEN:%.*]] = freeze i128 [[B]], !dbg [[DBG8]]
; CHECK: if:
; CHECK-NEXT: [[TMP0:%.*]] = mul i128 [[DIV:%.*]], [[B_FROZEN]], !dbg [[DBG11:![0-9]+]]
; CHECK-NEXT: [[REM_DECOMPOSED:%.*]] = sub i128 [[A_FROZEN]], [[TMP0:%.*]], !dbg [[DBG11]]
; CHECK: end:
entry:
%div = udiv i128 %a, %b, !dbg !8
%cmp = icmp eq i128 %div, 42, !dbg !9
br i1 %cmp, label %if, label %end, !dbg !10

if: ; preds = %entry
%rem = urem i128 %a, %b, !dbg !11
br label %end, !dbg !12

end: ; preds = %if, %entry
%ret = phi i128 [ %rem, %if ], [ 3, %entry ], !dbg !13
ret i128 %ret, !dbg !14
}

!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: "frx_fry_.preserve.ll", directory: "/")
!2 = !{i32 7}
!3 = !{i32 0}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = distinct !DISubprogram(name: "dont_hoist_urem", linkageName: "dont_hoist_urem", scope: null, file: !1, line: 1, type: !6, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!6 = !DISubroutineType(types: !7)
!7 = !{}
!8 = !DILocation(line: 1, column: 1, scope: !5)
!9 = !DILocation(line: 2, column: 1, scope: !5)
!10 = !DILocation(line: 3, column: 1, scope: !5)
!11 = !DILocation(line: 4, column: 1, scope: !5)
!12 = !DILocation(line: 5, column: 1, scope: !5)
!13 = !DILocation(line: 6, column: 1, scope: !5)
!14 = !DILocation(line: 7, column: 1, scope: !5)
; CHECK: [[DBG8]] = !DILocation(line: 1,
; CHECK: [[DBG11]] = !DILocation(line: 4,
56 changes: 56 additions & 0 deletions llvm/test/Transforms/DivRemPairs/X86/preserving-debugloc-realrem.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,56 @@
; RUN: opt -S -passes=div-rem-pairs -mtriple=x86_64-unknown-unknown < %s | FileCheck %s

; Check that DivRemPairs's optimizeDivRem() propagates the debug location of
; replaced `%rem` to the new srem or urem instruction.
; @decompose_illegal_srem_same_block tests it when the operands of `%rem` is signed.
; @decompose_illegal_urem_same_block tests it when the operands of `%rem` is unsigned.

define void @decompose_illegal_srem_same_block(i32 %a, i32 %b) !dbg !5 {
; CHECK-LABEL: define void @decompose_illegal_srem_same_block(
; CHECK: %rem.recomposed = srem i32 [[A:%.*]], [[B:%.*]], !dbg [[DBG10:![0-9]+]]
%div = sdiv i32 %a, %b, !dbg !8
%t0 = mul i32 %div, %b, !dbg !9
%rem = sub i32 %a, %t0, !dbg !10
call void @foo(i32 %rem, i32 %div), !dbg !11
ret void, !dbg !12
}

define void @decompose_illegal_urem_same_block(i32 %a, i32 %b) !dbg !13 {
; CHECK-LABEL: define void @decompose_illegal_urem_same_block(
; CHECK: %rem.recomposed = urem i32 [[A:%.*]], [[B:%.*]], !dbg [[DBG16:![0-9]+]]
%div = udiv i32 %a, %b, !dbg !14
%t0 = mul i32 %div, %b, !dbg !15
%rem = sub i32 %a, %t0, !dbg !16
call void @foo(i32 %rem, i32 %div), !dbg !17
ret void, !dbg !18
}

declare void @foo(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: "realrem_preverse.ll", directory: "/")
!2 = !{i32 10}
!3 = !{i32 0}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = distinct !DISubprogram(name: "decompose_illegal_srem_same_block", linkageName: "decompose_illegal_srem_same_block", scope: null, file: !1, line: 1, type: !6, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!6 = !DISubroutineType(types: !7)
!7 = !{}
!8 = !DILocation(line: 1, column: 1, scope: !5)
!9 = !DILocation(line: 2, column: 1, scope: !5)
!10 = !DILocation(line: 3, column: 1, scope: !5)
!11 = !DILocation(line: 4, column: 1, scope: !5)
!12 = !DILocation(line: 5, column: 1, scope: !5)
!13 = distinct !DISubprogram(name: "decompose_illegal_urem_same_block", linkageName: "decompose_illegal_urem_same_block", scope: null, file: !1, line: 6, type: !6, scopeLine: 6, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!14 = !DILocation(line: 6, column: 1, scope: !13)
!15 = !DILocation(line: 7, column: 1, scope: !13)
!16 = !DILocation(line: 8, column: 1, scope: !13)
!17 = !DILocation(line: 9, column: 1, scope: !13)
!18 = !DILocation(line: 10, column: 1, scope: !13)

; CHECK: [[DBG10]] = !DILocation(line: 3,
; CHECK: [[DBG16]] = !DILocation(line: 8,

Loading