diff options
| -rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 8 | ||||
| -rw-r--r-- | llvm/test/Transforms/SimplifyCFG/fold-branch-debuginvariant.ll | 49 |
2 files changed, 54 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 833e13f890d..c38164e6bd1 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -2498,7 +2498,7 @@ static bool SimplifyCondBranchToTwoReturns(BranchInst *BI, /// Return true if the given instruction is available /// in its predecessor block. If yes, the instruction will be removed. -static bool checkCSEInPredecessor(Instruction *Inst, BasicBlock *PB) { +static bool tryCSEWithPredecessor(Instruction *Inst, BasicBlock *PB) { if (!isa<BinaryOperator>(Inst) && !isa<CmpInst>(Inst)) return false; for (Instruction &I : *PB) { @@ -2555,14 +2555,16 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, unsigned BonusInstThreshold) { if (PBI->isConditional() && (BI->getSuccessor(0) == PBI->getSuccessor(0) || BI->getSuccessor(0) == PBI->getSuccessor(1))) { - for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;) { + for (auto I = BB->instructionsWithoutDebug().begin(), + E = BB->instructionsWithoutDebug().end(); + I != E;) { Instruction *Curr = &*I++; if (isa<CmpInst>(Curr)) { Cond = Curr; break; } // Quit if we can't remove this instruction. - if (!checkCSEInPredecessor(Curr, PB)) + if (!tryCSEWithPredecessor(Curr, PB)) return false; } } diff --git a/llvm/test/Transforms/SimplifyCFG/fold-branch-debuginvariant.ll b/llvm/test/Transforms/SimplifyCFG/fold-branch-debuginvariant.ll new file mode 100644 index 00000000000..7b26b6f95de --- /dev/null +++ b/llvm/test/Transforms/SimplifyCFG/fold-branch-debuginvariant.ll @@ -0,0 +1,49 @@ +; RUN: opt < %s -simplifycfg -S | FileCheck %s +; RUN: opt < %s -strip-debug -simplifycfg -S | FileCheck %s + +; Verify that the and.2 instruction is eliminated even in the presence of a +; preceding debug intrinsic. + +; CHECK-LABEL: bb1: +; CHECK: and i1 false, false +; CHECK-LABEL: bb2: +; CHECK-NOT: and i1 false, false + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +; Function Attrs: norecurse nounwind +define void @foo() local_unnamed_addr #0 !dbg !4 { +bb1: + %and.1 = and i1 false, false + %cmp = icmp eq i16 0, 0 + br i1 %cmp, label %bb2, label %bb3 + +bb2: ; preds = %bb1 + call void @llvm.dbg.value(metadata i16 0, metadata !8, metadata !DIExpression()), !dbg !9 + %and.2 = and i1 false, false + br label %bb3 + +bb3: ; preds = %bb2, %bb1 + ret void +} + +; Function Attrs: nounwind readnone speculatable +declare void @llvm.dbg.value(metadata, metadata, metadata) #1 + +attributes #0 = { norecurse nounwind } +attributes #1 = { nounwind readnone speculatable } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3} + +!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "Foo", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2) +!1 = !DIFile(filename: "foo.c", directory: "/") +!2 = !{} +!3 = !{i32 2, !"Debug Info Version", i32 3} +!4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 10, type: !5, isLocal: false, isDefinition: true, scopeLine: 10, isOptimized: false, unit: !0, retainedNodes: !2) +!5 = !DISubroutineType(types: !6) +!6 = !{null, !7} +!7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!8 = !DILocalVariable(name: "p_1", arg: 1, scope: !4, line: 4, type: !7) +!9 = distinct !DILocation(line: 11, column: 3, scope: !4) |
