diff options
| -rw-r--r-- | llvm/include/llvm/Transforms/Utils/SSAUpdater.h | 4 | ||||
| -rw-r--r-- | llvm/include/llvm/Transforms/Utils/SSAUpdaterImpl.h | 7 | ||||
| -rw-r--r-- | llvm/lib/Transforms/Utils/LCSSA.cpp | 16 | ||||
| -rw-r--r-- | llvm/lib/Transforms/Utils/SSAUpdater.cpp | 5 | ||||
| -rw-r--r-- | llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll | 69 |
5 files changed, 97 insertions, 4 deletions
diff --git a/llvm/include/llvm/Transforms/Utils/SSAUpdater.h b/llvm/include/llvm/Transforms/Utils/SSAUpdater.h index 4a791166299..d02607acbbb 100644 --- a/llvm/include/llvm/Transforms/Utils/SSAUpdater.h +++ b/llvm/include/llvm/Transforms/Utils/SSAUpdater.h @@ -76,6 +76,10 @@ public: /// block. bool HasValueForBlock(BasicBlock *BB) const; + /// Return the value for the specified block if the SSAUpdater has one, + /// otherwise return nullptr. + Value *FindValueForBlock(BasicBlock *BB) const; + /// Construct SSA form, materializing a value that is live at the end /// of the specified block. Value *GetValueAtEndOfBlock(BasicBlock *BB); diff --git a/llvm/include/llvm/Transforms/Utils/SSAUpdaterImpl.h b/llvm/include/llvm/Transforms/Utils/SSAUpdaterImpl.h index b7649ba8833..cab0f3e7157 100644 --- a/llvm/include/llvm/Transforms/Utils/SSAUpdaterImpl.h +++ b/llvm/include/llvm/Transforms/Utils/SSAUpdaterImpl.h @@ -357,10 +357,9 @@ public: BBInfo *Info = *I; if (Info->DefBB != Info) { - // Record the available value at join nodes to speed up subsequent - // uses of this SSAUpdater for the same value. - if (Info->NumPreds > 1) - (*AvailableVals)[Info->BB] = Info->DefBB->AvailableVal; + // Record the available value to speed up subsequent uses of this + // SSAUpdater for the same value. + (*AvailableVals)[Info->BB] = Info->DefBB->AvailableVal; continue; } diff --git a/llvm/lib/Transforms/Utils/LCSSA.cpp b/llvm/lib/Transforms/Utils/LCSSA.cpp index a1f8e7484bc..53d444b309d 100644 --- a/llvm/lib/Transforms/Utils/LCSSA.cpp +++ b/llvm/lib/Transforms/Utils/LCSSA.cpp @@ -41,6 +41,7 @@ #include "llvm/IR/Dominators.h" #include "llvm/IR/Function.h" #include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/PredIteratorCache.h" #include "llvm/Pass.h" #include "llvm/Transforms/Utils.h" @@ -201,6 +202,21 @@ bool llvm::formLCSSAForInstructions(SmallVectorImpl<Instruction *> &Worklist, SSAUpdate.RewriteUse(*UseToRewrite); } + SmallVector<DbgValueInst *, 4> DbgValues; + llvm::findDbgValues(DbgValues, I); + + // Update pre-existing debug value uses that reside outside the loop. + auto &Ctx = I->getContext(); + for (auto DVI : DbgValues) { + 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)) + DVI->setOperand(0, MetadataAsValue::get(Ctx, ValueAsMetadata::get(V))); + } + // SSAUpdater might have inserted phi-nodes inside other loops. We'll need // to post-process them to keep LCSSA form. for (PHINode *InsertedPN : InsertedPHIs) { diff --git a/llvm/lib/Transforms/Utils/SSAUpdater.cpp b/llvm/lib/Transforms/Utils/SSAUpdater.cpp index 4a1fd8d571a..9e5fb0e7172 100644 --- a/llvm/lib/Transforms/Utils/SSAUpdater.cpp +++ b/llvm/lib/Transforms/Utils/SSAUpdater.cpp @@ -64,6 +64,11 @@ bool SSAUpdater::HasValueForBlock(BasicBlock *BB) const { return getAvailableVals(AV).count(BB); } +Value *SSAUpdater::FindValueForBlock(BasicBlock *BB) const { + AvailableValsTy::iterator AVI = getAvailableVals(AV).find(BB); + return (AVI != getAvailableVals(AV).end()) ? AVI->second : nullptr; +} + void SSAUpdater::AddAvailableValue(BasicBlock *BB, Value *V) { assert(ProtoType && "Need to initialize SSAUpdater"); assert(ProtoType == V->getType() && diff --git a/llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll b/llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll new file mode 100644 index 00000000000..231e716cb6d --- /dev/null +++ b/llvm/test/Transforms/LCSSA/rewrite-existing-dbg-values.ll @@ -0,0 +1,69 @@ +; 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. + +; 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]]) + +; CHECK-LABEL: for.body: +; CHECK: %add = add nsw i32 0, 2 +; CHECK: call void @llvm.dbg.value(metadata i32 %add, metadata [[VAR]], metadata !DIExpression()) + +; CHECK: [[VAR]] = !DILocalVariable(name: "sum", + +; Function Attrs: nounwind +define void @foo() #0 !dbg !6 { +entry: + br label %for.cond.preheader, !dbg !12 + +for.cond.preheader: ; preds = %for.cond.cleanup1, %entry + br label %for.body, !dbg !12 + +for.cond.cleanup2: ; preds = %for.cond.cleanup1 + 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 + +for.cond.cleanup1: ; preds = %for.body + br i1 false, label %for.cond.preheader, label %for.cond.cleanup2, !dbg !12 + +for.body: ; preds = %for.body, %for.cond.preheader + %add = add nsw i32 0, 2, !dbg !12 + 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 +} + +; Function Attrs: nounwind +declare void @bar(i32) #0 + +; Function Attrs: nounwind readnone speculatable +declare void @llvm.dbg.value(metadata, metadata, metadata) #1 + +attributes #0 = { nounwind } +attributes #1 = { nounwind readnone speculatable } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4} +!llvm.ident = !{!5} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !2) +!1 = !DIFile(filename: "foo.c", directory: "/") +!2 = !{} +!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) +!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) |