diff options
| -rw-r--r-- | llvm/lib/Transforms/Utils/LCSSA.cpp | 20 | ||||
| -rw-r--r-- | llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll | 132 |
2 files changed, 117 insertions, 35 deletions
diff --git a/llvm/lib/Transforms/Utils/LCSSA.cpp b/llvm/lib/Transforms/Utils/LCSSA.cpp index 27067668a8d..73b2e4326c4 100644 --- a/llvm/lib/Transforms/Utils/LCSSA.cpp +++ b/llvm/lib/Transforms/Utils/LCSSA.cpp @@ -197,6 +197,17 @@ bool llvm::formLCSSAForInstructions(SmallVectorImpl<Instruction *> &Worklist, continue; } + // If we added a single PHI, it must dominate all uses and we can directly + // rename it. + if (AddedPHIs.size() == 1) { + // Tell the VHs that the uses changed. This updates SCEV's caches. + // We might call ValueIsRAUWd multiple times for the same value. + if (UseToRewrite->get()->hasValueHandle()) + ValueHandleBase::ValueIsRAUWd(*UseToRewrite, AddedPHIs[0]); + UseToRewrite->set(AddedPHIs[0]); + continue; + } + // Otherwise, do full PHI insertion. SSAUpdate.RewriteUse(*UseToRewrite); } @@ -210,9 +221,12 @@ bool llvm::formLCSSAForInstructions(SmallVectorImpl<Instruction *> &Worklist, BasicBlock *UserBB = DVI->getParent(); if (InstBB == UserBB || L->contains(UserBB)) continue; - // We currently only handle debug values residing in blocks where we have - // inserted a PHI instruction. - if (Value *V = SSAUpdate.FindValueForBlock(UserBB)) + // We currently only handle debug values residing in blocks that were + // traversed while rewriting the uses. If we inserted just a single PHI, + // we will handle all relevant debug values. + Value *V = AddedPHIs.size() == 1 ? AddedPHIs[0] + : SSAUpdate.FindValueForBlock(UserBB); + if (V) DVI->setOperand(0, MetadataAsValue::get(Ctx, ValueAsMetadata::get(V))); } diff --git a/llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll b/llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll index 563a75f407f..bedcc780d31 100644 --- a/llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll +++ b/llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll @@ -1,54 +1,118 @@ ; RUN: opt -S -lcssa < %s | FileCheck %s -target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" -target triple = "x86_64-unknown-linux-gnu" - ; Reproducer for PR39019. ; -; Verify that the llvm.dbg.value in the %for.cond.cleanup2 block is rewritten -; to use the PHI node for %add that is created by LCSSA. +; Verify that the llvm.dbg.values are updated to use the PHI nodes inserted by +; LCSSA. -; CHECK-LABEL: for.cond.cleanup2: -; CHECK-NEXT: [[PN:%[^ ]*]] = phi i32 [ %add.lcssa, %for.cond.cleanup1 ] -; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 [[PN]], metadata [[VAR:![0-9]+]], metadata !DIExpression()) -; CHECK-NEXT: call void @bar(i32 [[PN]]) +; For the test case @single_exit, we can rewrite all llvm.dbg.value calls +; to use the inserted PHI. -; CHECK-LABEL: for.body: +; CHECK-LABEL: @single_exit( + +; CHECK-LABEL: inner.body: ; CHECK: %add = add nsw i32 0, 2 -; CHECK: call void @llvm.dbg.value(metadata i32 %add, metadata [[VAR]], metadata !DIExpression()) +; CHECK: call void @llvm.dbg.value(metadata i32 %add, metadata [[VAR:![0-9]+]], metadata !DIExpression()) -; CHECK: [[VAR]] = !DILocalVariable(name: "sum", -; Function Attrs: nounwind -define void @foo() #0 !dbg !6 { +; CHECK-LABEL: outer.exit: +; CHECK-NEXT: [[PN:%[^ ]*]] = phi i32 [ %add.lcssa, %outer.latch ] +; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 [[PN]], metadata [[VAR]], metadata !DIExpression()) +; CHECK-NEXT: call void @bar(i32 [[PN]]) + +; CHECK-LABEL: exit: +; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 [[PN]], metadata [[VAR]], metadata !DIExpression()) + +define void @single_exit() !dbg !6 { entry: - br label %for.cond.preheader, !dbg !12 + br label %outer.header, !dbg !12 -for.cond.preheader: ; preds = %for.cond.cleanup1, %entry - br label %for.body, !dbg !12 +outer.header: ; preds = %outer.latch, %entry + br label %inner.body, !dbg !12 -for.cond.cleanup2: ; preds = %for.cond.cleanup1 +inner.body: ; preds = %inner.body, %outer.header + %add = add nsw i32 0, 2, !dbg !12 call void @llvm.dbg.value(metadata i32 %add, metadata !9, metadata !DIExpression()), !dbg !12 - tail call void @bar(i32 %add) #0, !dbg !12 - ret void, !dbg !12 + br i1 false, label %inner.body, label %inner.exit, !dbg !12 -for.cond.cleanup1: ; preds = %for.body - br i1 false, label %for.cond.preheader, label %for.cond.cleanup2, !dbg !12 +inner.exit: ; preds = %inner.body + br label %outer.latch -for.body: ; preds = %for.body, %for.cond.preheader - %add = add nsw i32 0, 2, !dbg !12 +outer.latch: ; preds = %inner.exit + br i1 false, label %outer.header, label %outer.exit, !dbg !12 + +outer.exit: ; preds = %outer.latch + call void @llvm.dbg.value(metadata i32 %add, metadata !9, metadata !DIExpression()), !dbg !12 + tail call void @bar(i32 %add), !dbg !12 + br label %exit + +exit: ; preds = %outer.exit call void @llvm.dbg.value(metadata i32 %add, metadata !9, metadata !DIExpression()), !dbg !12 - br i1 false, label %for.body, label %for.cond.cleanup1, !dbg !12 + ret void, !dbg !12 } -; Function Attrs: nounwind -declare void @bar(i32) #0 +; For the test case @multi_exit, we cannot update the llvm.dbg.value call in exit, +; because LCSSA did not insert a PHI node in %exit, as there is no non-debug +; use. + +; CHECK-LABEL: @multi_exit() + +; CHECK-LABEL: for.header: +; CHECK-NEXT: %add = add nsw i32 0, 2 +; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 %add, metadata [[VAR2:![0-9]+]], metadata !DIExpression()) + +; CHECK-LABEL: for.exit1: +; CHECK-NEXT: [[PN1:%[^ ]*]] = phi i32 [ %add, %for.header ] +; CHECK-NEXT: br label %for.exit1.succ + +; CHECK-LABEL: for.exit1.succ: +; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 [[PN1]], metadata [[VAR2]], metadata !DIExpression()) +; CHECK-NEXT: call void @bar(i32 [[PN1]]) + +; CHECK-LABEL: for.exit2: +; CHECK-NEXT: [[PN2:%[^ ]*]] = phi i32 [ %add, %for.latch ] +; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 [[PN2]], metadata [[VAR2]], metadata !DIExpression()) +; CHECK-NEXT: call void @bar(i32 [[PN2]]) + +; CHECK-LABEL: exit: +; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 %add, metadata [[VAR2]], metadata !DIExpression()) + +define void @multi_exit() !dbg !13 { +entry: + br label %for.header, !dbg !14 + +for.header: ; preds = %for.latch, %entry + %add = add nsw i32 0, 2, !dbg !14 + call void @llvm.dbg.value(metadata i32 %add, metadata !16, metadata !DIExpression()), !dbg !14 + br i1 false, label %for.latch, label %for.exit1, !dbg !14 + +for.latch: ; preds = %for.header + br i1 false, label %for.header, label %for.exit2, !dbg !14 + +for.exit1: ; preds = %for.header + br label %for.exit1.succ + +for.exit1.succ: ; preds = %for.exit1 + call void @llvm.dbg.value(metadata i32 %add, metadata !16, metadata !DIExpression()), !dbg !14 + tail call void @bar(i32 %add), !dbg !14 + br label %exit + +for.exit2: ; preds = %for.latch + call void @llvm.dbg.value(metadata i32 %add, metadata !16, metadata !DIExpression()), !dbg !14 + tail call void @bar(i32 %add), !dbg !14 + br label %exit + +exit: ; preds = %for.exit2, %for.exit1.succ + call void @llvm.dbg.value(metadata i32 %add, metadata !16, metadata !DIExpression()), !dbg !14 + ret void, !dbg !14 +} + +; CHECK: [[VAR]] = !DILocalVariable(name: "sum", +; CHECK: [[VAR2]] = !DILocalVariable(name: "sum2", -; Function Attrs: nounwind readnone speculatable -declare void @llvm.dbg.value(metadata, metadata, metadata) #1 +declare void @bar(i32) -attributes #0 = { nounwind } -attributes #1 = { nounwind readnone speculatable } +declare void @llvm.dbg.value(metadata, metadata, metadata) !llvm.dbg.cu = !{!0} !llvm.module.flags = !{!3, !4} @@ -60,10 +124,14 @@ attributes #1 = { nounwind readnone speculatable } !3 = !{i32 2, !"Dwarf Version", i32 4} !4 = !{i32 2, !"Debug Info Version", i32 3} !5 = !{!"clang version 8.0.0"} -!6 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 10, type: !7, isLocal: false, isDefinition: true, scopeLine: 10, isOptimized: true, unit: !0, retainedNodes: !8) +!6 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 10, type: !7, scopeLine: 10, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !8) !7 = !DISubroutineType(types: !2) !8 = !{!9} !9 = !DILocalVariable(name: "sum", scope: !10, file: !1, line: 11, type: !11) !10 = !DILexicalBlockFile(scope: !6, file: !1, discriminator: 0) !11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) !12 = !DILocation(line: 0, scope: !10) +!13 = distinct !DISubprogram(name: "multi_exit", scope: !1, file: !1, line: 10, type: !7, scopeLine: 10, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !8) +!14 = !DILocation(line: 0, scope: !15) +!15 = !DILexicalBlockFile(scope: !13, file: !1, discriminator: 0) +!16 = !DILocalVariable(name: "sum2", scope: !15, file: !1, line: 11, type: !11) |
