Index: llvm/lib/CodeGen/MachineCSE.cpp =================================================================== --- llvm/lib/CodeGen/MachineCSE.cpp +++ llvm/lib/CodeGen/MachineCSE.cpp @@ -831,6 +831,13 @@ continue; MachineInstr &NewMI = TII->duplicate(*CMBB, CMBB->getFirstTerminator(), *MI); + + // When hoisting, make sure we don't carry the debug location of + // the original instruction, as that's not correct and can cause + // unexpected jumps when debugging optimized code. + auto EmptyDL = DebugLoc(); + NewMI.setDebugLoc(EmptyDL); + NewMI.getOperand(0).setReg(NewReg); PREMap[MI] = CMBB; Index: llvm/test/DebugInfo/X86/machinecse-wrongdebug-hoist.ll =================================================================== --- /dev/null +++ llvm/test/DebugInfo/X86/machinecse-wrongdebug-hoist.ll @@ -0,0 +1,80 @@ +; RUN: llc %s -o - -print-after=machine-cse -mtriple=x86_64-- 2>&1 | FileCheck %s --match-full-lines + +; CHECK: %5:gr32 = SUB32ri8 %0:gr32(tied-def 0), 1, implicit-def $eflags, debug-location !24; a.c:3:13 +; CHECK-NEXT: %10:gr32 = MOVSX32rr8 %4:gr8 +; CHECK-NEXT: JCC_1 %bb.2, 15, implicit $eflags, debug-location !25; a.c:3:18 + +target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.15.0" + +@a = local_unnamed_addr global i32 0, align 4, !dbg !0 + +; Function Attrs: norecurse nounwind readonly ssp uwtable +define i32 @b(i8 signext %0) local_unnamed_addr #0 !dbg !12 { + call void @llvm.dbg.value(metadata i8 %0, metadata !17, metadata !DIExpression()), !dbg !18 + %2 = load i32, i32* @a, align 4, !dbg !19, !tbaa !20 + %3 = icmp sgt i32 %2, 1, !dbg !24 + br i1 %3, label %8, label %4, !dbg !25 + +4: ; preds = %1 + %5 = sext i8 %0 to i32, !dbg !26 + %6 = ashr i32 %5, %2, !dbg !27 + %7 = icmp eq i32 %6, 0, !dbg !27 + br i1 %7, label %10, label %8, !dbg !28 + +8: ; preds = %4, %1 + %9 = sext i8 %0 to i32, !dbg !29 + br label %10, !dbg !28 + +10: ; preds = %4, %8 + %11 = phi i32 [ %9, %8 ], [ 0, %4 ], !dbg !28 + ret i32 %11, !dbg !30 +} + +define i32 @main() local_unnamed_addr #0 !dbg !31 { + %1 = call i32 @b(i8 signext 0), !dbg !34 + ret i32 %1, !dbg !35 +} + +declare void @llvm.dbg.value(metadata, metadata, metadata) #1 + +!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 11.0.0 (https://github.com/llvm/llvm-project 75cfd382201978615cca1c91c2d9f14f8b7af56d)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None, sysroot: "/") +!3 = !DIFile(filename: "a.c", directory: "/Users/davide/work/build/bin") +!4 = !{} +!5 = !{!0} +!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!7 = !{i32 7, !"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 11.0.0 (https://github.com/llvm/llvm-project 75cfd382201978615cca1c91c2d9f14f8b7af56d)"} +!12 = distinct !DISubprogram(name: "b", scope: !3, file: !3, line: 2, type: !13, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !16) +!13 = !DISubroutineType(types: !14) +!14 = !{!6, !15} +!15 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char) +!16 = !{!17} +!17 = !DILocalVariable(name: "c", arg: 1, scope: !12, file: !3, line: 2, type: !15) +!18 = !DILocation(line: 0, scope: !12) +!19 = !DILocation(line: 3, column: 11, scope: !12) +!20 = !{!21, !21, i64 0} +!21 = !{!"int", !22, i64 0} +!22 = !{!"omnipotent char", !23, i64 0} +!23 = !{!"Simple C/C++ TBAA"} +!24 = !DILocation(line: 3, column: 13, scope: !12) +!25 = !DILocation(line: 3, column: 18, scope: !12) +!26 = !DILocation(line: 3, column: 21, scope: !12) +!27 = !DILocation(line: 3, column: 23, scope: !12) +!28 = !DILocation(line: 3, column: 10, scope: !12) +!29 = !DILocation(line: 4, column: 16, scope: !12) +!30 = !DILocation(line: 3, column: 3, scope: !12) +!31 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 8, type: !32, scopeLine: 9, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !4) +!32 = !DISubroutineType(types: !33) +!33 = !{!6} +!34 = !DILocation(line: 10, column: 10, scope: !31) +!35 = !DILocation(line: 10, column: 3, scope: !31)