diff --git a/llvm/lib/Transforms/Scalar/GVNHoist.cpp b/llvm/lib/Transforms/Scalar/GVNHoist.cpp --- a/llvm/lib/Transforms/Scalar/GVNHoist.cpp +++ b/llvm/lib/Transforms/Scalar/GVNHoist.cpp @@ -1140,6 +1140,10 @@ // Move the instruction at the end of HoistPt. Instruction *Last = DestBB->getTerminator(); MD->removeInstruction(Repl); + // If there are instructions to hoist, we should conservatively + // drop the debug location: if instructions are hoisted into a + // predecessor block, the source location should not be preserved. + Repl->dropLocation(); Repl->moveBefore(Last); DFSNumber[Repl] = DFSNumber[Last]++; diff --git a/llvm/test/Transforms/GVNHoist/hoist_debugloc.ll b/llvm/test/Transforms/GVNHoist/hoist_debugloc.ll new file mode 100644 --- /dev/null +++ b/llvm/test/Transforms/GVNHoist/hoist_debugloc.ll @@ -0,0 +1,56 @@ +; RUN: opt -gvn-hoist %s -S 2>&1 | FileCheck %s +; COM: Check whether the hoisted store instruction drops the debug location. +; CHECK: store i32 1, i32* @G, align 4{{$}} +source_filename = "abc.ll" + +@G = external global i32, align 4 + +define void @foo(i32 %c1) !dbg !6 { +entry: + call void @llvm.dbg.value(metadata i32 0, metadata !9, metadata !DIExpression()), !dbg !11 + switch i32 %c1, label %exit1 [ + i32 0, label %sw0 + i32 1, label %sw1 + ], !dbg !11 + +sw0: ; preds = %entry + store i32 1, i32* @G, align 4, !dbg !12 + br label %exit, !dbg !13 + +sw1: ; preds = %entry + store i32 1, i32* @G, align 4, !dbg !14 + br label %exit, !dbg !15 + +exit1: ; preds = %entry + store i32 1, i32* @G, align 4, !dbg !16 + ret void, !dbg !17 + +exit: ; preds = %sw1, %sw0 + ret void, !dbg !18 +} + +declare void @llvm.dbg.value(metadata, metadata, metadata) #0 + +!llvm.dbg.cu = !{!0} +!llvm.debugify = !{!3, !4} +!llvm.module.flags = !{!5} + +!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2) +!1 = !DIFile(filename: "abc.ll", directory: "/") +!2 = !{} +!3 = !{i32 8} +!4 = !{i32 1} +!5 = !{i32 2, !"Debug Info Version", i32 3} +!6 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: null, file: !1, line: 1, type: !7, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !8) +!7 = !DISubroutineType(types: !2) +!8 = !{!9} +!9 = !DILocalVariable(name: "1", scope: !6, file: !1, line: 1, type: !10) +!10 = !DIBasicType(name: "ty32", size: 32, encoding: DW_ATE_unsigned) +!11 = !DILocation(line: 1, column: 1, scope: !6) +!12 = !DILocation(line: 2, column: 1, scope: !6) +!13 = !DILocation(line: 3, column: 1, scope: !6) +!14 = !DILocation(line: 4, column: 1, scope: !6) +!15 = !DILocation(line: 5, column: 1, scope: !6) +!16 = !DILocation(line: 6, column: 1, scope: !6) +!17 = !DILocation(line: 7, column: 1, scope: !6) +!18 = !DILocation(line: 8, column: 1, scope: !6)