diff options
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUtils.cpp | 27 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopDeletion/diundef.ll | 75 |
2 files changed, 102 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp index 388553b1783..a5d88d8269f 100644 --- a/llvm/lib/Transforms/Utils/LoopUtils.cpp +++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp @@ -26,9 +26,11 @@ #include "llvm/Analysis/ScalarEvolutionExpressions.h" #include "llvm/Analysis/TargetTransformInfo.h" #include "llvm/Analysis/ValueTracking.h" +#include "llvm/IR/DIBuilder.h" #include "llvm/IR/DomTreeUpdater.h" #include "llvm/IR/Dominators.h" #include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Module.h" #include "llvm/IR/PatternMatch.h" #include "llvm/IR/ValueHandle.h" @@ -567,6 +569,12 @@ void llvm::deleteDeadLoop(Loop *L, DominatorTree *DT = nullptr, DTU.deleteEdge(Preheader, L->getHeader()); } + // Use a map to unique and a vector to guarantee deterministic ordering. + llvm::SmallDenseMap<std::pair<DIVariable *, DIExpression *>, + DbgVariableIntrinsic *, 4> + DeadDebugMap; + llvm::SmallVector<DbgVariableIntrinsic *, 4> DeadDebugInst; + // Given LCSSA form is satisfied, we should not have users of instructions // within the dead loop outside of the loop. However, LCSSA doesn't take // unreachable uses into account. We handle them here. @@ -591,8 +599,27 @@ void llvm::deleteDeadLoop(Loop *L, DominatorTree *DT = nullptr, "Unexpected user in reachable block"); U.set(Undef); } + auto *DVI = dyn_cast<DbgVariableIntrinsic>(&I); + if (!DVI) + continue; + auto Key = DeadDebugMap.find({DVI->getVariable(), DVI->getExpression()}); + if (Key != DeadDebugMap.end()) + continue; + DeadDebugMap[{DVI->getVariable(), DVI->getExpression()}] = DVI; + DeadDebugInst.push_back(DVI); } + // After the loop has been deleted all the values defined and modified + // inside the loop are going to be unavailable. + // Since debug values in the loop have been deleted, inserting an undef + // dbg.value truncates the range of any dbg.value before the loop where the + // loop used to be. This is particularly important for constant values. + DIBuilder DIB(*ExitBlock->getModule()); + for (auto *DVI : DeadDebugInst) + DIB.insertDbgValueIntrinsic( + UndefValue::get(DVI->getType()), DVI->getVariable(), + DVI->getExpression(), DVI->getDebugLoc(), ExitBlock->getFirstNonPHI()); + // Remove the block from the reference counting scheme, so that we can // delete it freely later. for (auto *Block : L->blocks()) diff --git a/llvm/test/Transforms/LoopDeletion/diundef.ll b/llvm/test/Transforms/LoopDeletion/diundef.ll new file mode 100644 index 00000000000..c9074dea7a6 --- /dev/null +++ b/llvm/test/Transforms/LoopDeletion/diundef.ll @@ -0,0 +1,75 @@ +; RUN: opt %s -loop-deletion -S | FileCheck %s + +target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.14.0" + +@a = common local_unnamed_addr global i32 0, align 4, !dbg !0 + +define i32 @b() local_unnamed_addr !dbg !12 { +entry: + call void @llvm.dbg.value(metadata i32 0, metadata !16, metadata !DIExpression()), !dbg !17 + br label %for.cond, !dbg !18 + +for.cond: ; preds = %for.cond, %entry + %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.cond ], !dbg !20 + call void @llvm.dbg.value(metadata i32 %i.0, metadata !16, metadata !DIExpression()), !dbg !17 + %inc = add nuw nsw i32 %i.0, 1, !dbg !21 + call void @llvm.dbg.value(metadata i32 %inc, metadata !16, metadata !DIExpression()), !dbg !17 + %exitcond = icmp ne i32 %inc, 3, !dbg !23 + br i1 %exitcond, label %for.cond, label %for.end, !dbg !24, !llvm.loop !25 + +; CHECK: call void @llvm.dbg.value(metadata void undef, metadata !16, metadata !DIExpression()), !dbg !17 +; CHECK-NEXT: %call = tail call i32 {{.*}} @patatino() +for.end: ; preds = %for.cond + %call = tail call i32 (...) @patatino() #3, !dbg !27 + %0 = load i32, i32* @a, align 4, !dbg !28 + ret i32 %0, !dbg !33 +} + +declare i32 @patatino(...) local_unnamed_addr + +define i32 @main() local_unnamed_addr !dbg !34 { +entry: + %call = call i32 @b(), !dbg !35 + ret i32 0, !dbg !36 +} + +declare void @llvm.dbg.value(metadata, metadata, metadata) + +!llvm.dbg.cu = !{!2} +!llvm.module.flags = !{!7, !8, !9, !10} +!llvm.ident = !{!11} + +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true) +!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: GNU) +!3 = !DIFile(filename: "a.c", directory: "/Users/davide/work/llvm-project-20170507/build-debug/bin") +!4 = !{} +!5 = !{!0} +!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!7 = !{i32 2, !"Dwarf Version", i32 4} +!8 = !{i32 2, !"Debug Info Version", i32 3} +!9 = !{i32 1, !"wchar_size", i32 4} +!10 = !{i32 7, !"PIC Level", i32 2} +!11 = !{!"clang version 8.0.0 "} +!12 = distinct !DISubprogram(name: "b", scope: !3, file: !3, line: 2, type: !13, scopeLine: 2, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !15) +!13 = !DISubroutineType(types: !14) +!14 = !{!6} +!15 = !{!16} +!16 = !DILocalVariable(name: "i", scope: !12, file: !3, line: 3, type: !6) +!17 = !DILocation(line: 3, column: 7, scope: !12) +!18 = !DILocation(line: 4, column: 8, scope: !19) +!19 = distinct !DILexicalBlock(scope: !12, file: !3, line: 4, column: 3) +!20 = !DILocation(line: 0, scope: !19) +!21 = !DILocation(line: 4, column: 23, scope: !22) +!22 = distinct !DILexicalBlock(scope: !19, file: !3, line: 4, column: 3) +!23 = !DILocation(line: 4, column: 17, scope: !22) +!24 = !DILocation(line: 4, column: 3, scope: !19) +!25 = distinct !{!25, !24, !26} +!26 = !DILocation(line: 5, column: 5, scope: !19) +!27 = !DILocation(line: 6, column: 3, scope: !12) +!28 = !DILocation(line: 7, column: 10, scope: !12) +!33 = !DILocation(line: 7, column: 3, scope: !12) +!34 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 9, type: !13, scopeLine: 9, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !4) +!35 = !DILocation(line: 9, column: 14, scope: !34) +!36 = !DILocation(line: 9, column: 19, scope: !34) |
