diff --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp index c9b0f2081809..34e204af7132 100644 --- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp +++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp @@ -23,11 +23,13 @@ #include "llvm/IR/BasicBlock.h" #include "llvm/IR/CFG.h" #include "llvm/IR/Constants.h" +#include "llvm/IR/DebugInfoMetadata.h" #include "llvm/IR/Dominators.h" #include "llvm/IR/Function.h" #include "llvm/IR/InstrTypes.h" #include "llvm/IR/Instruction.h" #include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/LLVMContext.h" #include "llvm/IR/Type.h" #include "llvm/IR/User.h" @@ -142,8 +144,16 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, DominatorTree *DT, } // Begin by getting rid of unneeded PHIs. - if (isa(BB->front())) + SmallVector IncomingValues; + if (isa(BB->front())) { + for (auto &I : *BB) + if (PHINode *PN = dyn_cast(&I)) { + if (PN->getIncomingValue(0) != PN) + IncomingValues.push_back(PN->getIncomingValue(0)); + } else + break; FoldSingleEntryPHINodes(BB, MemDep); + } // Delete the unconditional branch from the predecessor... PredBB->getInstList().pop_back(); @@ -155,6 +165,18 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, DominatorTree *DT, // Move all definitions in the successor to the predecessor... PredBB->getInstList().splice(PredBB->end(), BB->getInstList()); + // Eliminate duplicate dbg.values describing the entry PHI node post-splice. + for (auto *Incoming : IncomingValues) { + SmallVector DbgValues; + SmallDenseSet, 2> DbgValueSet; + llvm::findDbgValues(DbgValues, Incoming); + for (auto &DVI : DbgValues) { + auto R = DbgValueSet.insert({DVI->getVariable(), DVI->getExpression()}); + if (!R.second) + DVI->eraseFromParent(); + } + } + // Inherit predecessors name if it exists. if (!PredBB->hasName()) PredBB->takeName(BB); diff --git a/llvm/test/Transforms/LoopRotate/dbg-value-duplicates.ll b/llvm/test/Transforms/LoopRotate/dbg-value-duplicates.ll new file mode 100644 index 000000000000..ad47cbfb55ba --- /dev/null +++ b/llvm/test/Transforms/LoopRotate/dbg-value-duplicates.ll @@ -0,0 +1,86 @@ +; RUN: opt -S -loop-rotate < %s | FileCheck %s +source_filename = "/tmp/loop.c" +target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.13.0" + +; Function Attrs: nounwind ssp uwtable +define void @f(float* %input, i64 %n, i64 %s) local_unnamed_addr #0 !dbg !8 { +entry: + call void @llvm.dbg.value(metadata float* %input, metadata !15, metadata !DIExpression()), !dbg !20 + call void @llvm.dbg.value(metadata i64 %n, metadata !16, metadata !DIExpression()), !dbg !21 + call void @llvm.dbg.value(metadata i64 %s, metadata !17, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i64 0, metadata !18, metadata !DIExpression()), !dbg !23 + br label %for.cond, !dbg !24 + +for.cond: ; preds = %for.body, %entry + ; CHECK: %i.02 = phi i64 [ 0, %for.body.lr.ph ], [ %add, %for.body ] + %i.0 = phi i64 [ 0, %entry ], [ %add, %for.body ] + call void @llvm.dbg.value(metadata i64 %i.0, metadata !18, metadata !DIExpression()), !dbg !23 + %cmp = icmp slt i64 %i.0, %n, !dbg !25 + br i1 %cmp, label %for.body, label %for.cond.cleanup, !dbg !27 + +for.cond.cleanup: ; preds = %for.cond + ret void, !dbg !28 + +for.body: ; preds = %for.cond + %arrayidx = getelementptr inbounds float, float* %input, i64 %i.0, !dbg !29 + %0 = load float, float* %arrayidx, align 4, !dbg !29, !tbaa !30 + call void @bar(float %0), !dbg !34 + %add = add nsw i64 %i.0, %s, !dbg !35 + call void @llvm.dbg.value(metadata i64 %add, metadata !18, metadata !DIExpression()), !dbg !23 + ; CHECK: call void @llvm.dbg.value(metadata i64 %add, metadata !18, metadata !DIExpression()), !dbg !23 + ; CHECK-NOT: call void @llvm.dbg.value(metadata i64 %add, metadata !18, metadata !DIExpression()), !dbg !23 + br label %for.cond, !dbg !36, !llvm.loop !37 +} + +declare void @bar(float) local_unnamed_addr #1 + +; Function Attrs: nounwind readnone speculatable +declare void @llvm.dbg.value(metadata, metadata, metadata) #2 + +attributes #0 = { nounwind ssp uwtable } +attributes #2 = { nounwind readnone speculatable } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4, !5, !6} +!llvm.ident = !{!7} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0 (trunk 316689) (llvm/trunk 316685)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2) +!1 = !DIFile(filename: "/tmp/loop.c", directory: "/Data/llvm") +!2 = !{} +!3 = !{i32 2, !"Dwarf Version", i32 4} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!5 = !{i32 1, !"wchar_size", i32 4} +!6 = !{i32 7, !"PIC Level", i32 2} +!7 = !{!"clang version 6.0.0 (trunk 316689) (llvm/trunk 316685)"} +!8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 2, type: !9, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !14) +!9 = !DISubroutineType(types: !10) +!10 = !{null, !11, !13, !13} +!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64) +!12 = !DIBasicType(name: "float", size: 32, encoding: DW_ATE_float) +!13 = !DIBasicType(name: "long long int", size: 64, encoding: DW_ATE_signed) +!14 = !{!15, !16, !17, !18} +!15 = !DILocalVariable(name: "input", arg: 1, scope: !8, file: !1, line: 2, type: !11) +!16 = !DILocalVariable(name: "n", arg: 2, scope: !8, file: !1, line: 2, type: !13) +!17 = !DILocalVariable(name: "s", arg: 3, scope: !8, file: !1, line: 2, type: !13) +!18 = !DILocalVariable(name: "i", scope: !19, file: !1, line: 3, type: !13) +!19 = distinct !DILexicalBlock(scope: !8, file: !1, line: 3, column: 3) +!20 = !DILocation(line: 2, column: 15, scope: !8) +!21 = !DILocation(line: 2, column: 32, scope: !8) +!22 = !DILocation(line: 2, column: 45, scope: !8) +!23 = !DILocation(line: 3, column: 18, scope: !19) +!24 = !DILocation(line: 3, column: 8, scope: !19) +!25 = !DILocation(line: 3, column: 26, scope: !26) +!26 = distinct !DILexicalBlock(scope: !19, file: !1, line: 3, column: 3) +!27 = !DILocation(line: 3, column: 3, scope: !19) +!28 = !DILocation(line: 5, column: 1, scope: !8) +!29 = !DILocation(line: 4, column: 9, scope: !26) +!30 = !{!31, !31, i64 0} +!31 = !{!"float", !32, i64 0} +!32 = !{!"omnipotent char", !33, i64 0} +!33 = !{!"Simple C/C++ TBAA"} +!34 = !DILocation(line: 4, column: 5, scope: !26) +!35 = !DILocation(line: 3, column: 31, scope: !26) +!36 = !DILocation(line: 3, column: 3, scope: !26) +!37 = distinct !{!37, !27, !38} +!38 = !DILocation(line: 4, column: 17, scope: !19)