diff --git a/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/llvm/lib/CodeGen/PrologEpilogInserter.cpp index 88bd3ec1b823e..cc70ec4776506 100644 --- a/llvm/lib/CodeGen/PrologEpilogInserter.cpp +++ b/llvm/lib/CodeGen/PrologEpilogInserter.cpp @@ -1230,7 +1230,11 @@ void PEI::insertZeroCallUsedRegs(MachineFunction &MF) { BitVector UsedRegs(TRI.getNumRegs()); if (OnlyUsed) for (const MachineBasicBlock &MBB : MF) - for (const MachineInstr &MI : MBB) + for (const MachineInstr &MI : MBB) { + // skip debug instructions + if (MI.isDebugInstr()) + continue; + for (const MachineOperand &MO : MI.operands()) { if (!MO.isReg()) continue; @@ -1240,6 +1244,7 @@ void PEI::insertZeroCallUsedRegs(MachineFunction &MF) { (MO.isDef() || MO.isUse())) UsedRegs.set(Reg); } + } // Get a list of registers that are used. BitVector LiveIns(TRI.getNumRegs()); diff --git a/llvm/test/CodeGen/X86/zero-call-used-regs-debug-info.mir b/llvm/test/CodeGen/X86/zero-call-used-regs-debug-info.mir new file mode 100644 index 0000000000000..68505b6d94528 --- /dev/null +++ b/llvm/test/CodeGen/X86/zero-call-used-regs-debug-info.mir @@ -0,0 +1,142 @@ +# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py +# RUN: llc -run-pass=prologepilog -o - %s | FileCheck %s + +# Test that the presence of debug instructions doesn't trigger arbitrary registers that are unused to be zeroed out. + +--- | + ; ModuleID = 'zero-call-used-regs-debug-info.ll' + source_filename = "zero-call-used-regs-debug-info.c" + target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + target triple = "x86_64-unknown-linux-gnu" + + @b = dso_local local_unnamed_addr global i32 0, align 4, !dbg !0 + @a = dso_local local_unnamed_addr global [1 x i8] zeroinitializer, align 1, !dbg !5 + + ; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(readwrite, argmem: none, inaccessiblemem: none) uwtable + define dso_local signext i8 @c(i32 noundef %d) local_unnamed_addr #0 !dbg !19 { + entry: + call void @llvm.dbg.value(metadata i32 %d, metadata !23, metadata !DIExpression()), !dbg !26 + call void @llvm.dbg.value(metadata i32 %d, metadata !24, metadata !DIExpression()), !dbg !27 + %0 = load i32, ptr @b, align 4, !dbg !28, !tbaa !29 + %conv = trunc i32 %0 to i8, !dbg !33 + store i8 %conv, ptr @a, align 1, !dbg !34, !tbaa !35 + ret i8 undef, !dbg !36 + } + + ; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none) + declare void @llvm.dbg.value(metadata, metadata, metadata) #2 + + attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(readwrite, argmem: none, inaccessiblemem: none) uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" "zero-call-used-regs"="used" } + attributes #1 = { mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" } + attributes #2 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) } + + !llvm.dbg.cu = !{!2} + !llvm.module.flags = !{!12, !13, !14, !15, !16, !17} + !llvm.ident = !{!18} + + !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) + !1 = distinct !DIGlobalVariable(name: "b", scope: !2, file: !3, line: 2, type: !11, isLocal: false, isDefinition: true) + !2 = distinct !DICompileUnit(language: DW_LANG_C11, file: !3, producer: "clang version 16.0.0 (https://github.com/llvm/llvm-project.git ba5acedd979aa94a81be555e0add8e4421499d4f)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, splitDebugInlining: false, nameTableKind: None) + !3 = !DIFile(filename: "zero-call-used-regs-debug-info.c", directory: "/home/xgupta/compiler/llvm-project/build/bin", checksumkind: CSK_MD5, checksum: "fe3a5f45289411a008e07c7debb490ca") + !4 = !{!5, !0} + !5 = !DIGlobalVariableExpression(var: !6, expr: !DIExpression()) + !6 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !7, isLocal: false, isDefinition: true) + !7 = !DICompositeType(tag: DW_TAG_array_type, baseType: !8, size: 8, elements: !9) + !8 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char) + !9 = !{!10} + !10 = !DISubrange(count: 1) + !11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) + !12 = !{i32 7, !"Dwarf Version", i32 5} + !13 = !{i32 2, !"Debug Info Version", i32 3} + !14 = !{i32 1, !"wchar_size", i32 4} + !15 = !{i32 8, !"PIC Level", i32 2} + !16 = !{i32 7, !"PIE Level", i32 2} + !17 = !{i32 7, !"uwtable", i32 2} + !18 = !{!"clang version 16.0.0 (https://github.com/llvm/llvm-project.git ba5acedd979aa94a81be555e0add8e4421499d4f)"} + !19 = distinct !DISubprogram(name: "c", scope: !3, file: !3, line: 3, type: !20, scopeLine: 3, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !22) + !20 = !DISubroutineType(types: !21) + !21 = !{!8, !11} + !22 = !{!23, !24} + !23 = !DILocalVariable(name: "d", arg: 1, scope: !19, file: !3, line: 3, type: !11) + !24 = !DILocalVariable(name: "e", scope: !25, file: !3, line: 5, type: !11) + !25 = distinct !DILexicalBlock(scope: !19, file: !3, line: 4, column: 9) + !26 = !DILocation(line: 0, scope: !19) + !27 = !DILocation(line: 0, scope: !25) + !28 = !DILocation(line: 6, column: 5, scope: !25) + !29 = !{!30, !30, i64 0} + !30 = !{!"int", !31, i64 0} + !31 = !{!"omnipotent char", !32, i64 0} + !32 = !{!"Simple C/C++ TBAA"} + !33 = !DILocation(line: 4, column: 8, scope: !19) + !34 = !DILocation(line: 4, column: 6, scope: !19) + !35 = !{!31, !31, i64 0} + !36 = !DILocation(line: 8, column: 1, scope: !19) + !37 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 9, type: !38, scopeLine: 9, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !40) + !38 = !DISubroutineType(types: !39) + !39 = !{null} + !40 = !{} + !41 = !DILocation(line: 9, column: 14, scope: !37) + +... +--- +name: c +alignment: 16 +exposesReturnsTwice: false +legalized: false +regBankSelected: false +selected: false +failedISel: false +tracksRegLiveness: true +hasWinCFI: false +callsEHReturn: false +callsUnwindInit: false +hasEHCatchret: false +hasEHScopes: false +hasEHFunclets: false +debugInstrRef: true +failsVerification: false +tracksDebugUserValues: true +registers: [] +liveins: [] +frameInfo: + isFrameAddressTaken: false + isReturnAddressTaken: false + hasStackMap: false + hasPatchPoint: false + stackSize: 0 + offsetAdjustment: 0 + maxAlignment: 1 + adjustsStack: false + hasCalls: false + stackProtector: '' + functionContext: '' + maxCallFrameSize: 4294967295 + cvBytesOfCalleeSavedRegisters: 0 + hasOpaqueSPAdjustment: false + hasVAStart: false + hasMustTailInVarArgFunc: false + hasTailCall: false + localFrameSize: 0 + savePoint: '' + restorePoint: '' +fixedStack: [] +stack: [] +callSites: [] +debugValueSubstitutions: [] +constants: [] +machineFunctionInfo: {} +body: | + bb.0.entry: + ; CHECK-LABEL: name: c + ; CHECK: DBG_VALUE $edi, $noreg, !23, !DIExpression(), debug-location !26 + ; CHECK-NEXT: DBG_VALUE $edi, $noreg, !24, !DIExpression(), debug-location !27 + ; CHECK-NEXT: renamable $al = MOV8rm $rip, 1, $noreg, @b, $noreg, debug-location !28 :: (dereferenceable load (s8) from @b, align 4, !tbaa !29) + ; CHECK-NEXT: MOV8mr $rip, 1, $noreg, @a, $noreg, killed renamable $al, debug-location !34 :: (store (s8) into @a, !tbaa !35) + ; CHECK-NEXT: RET 0, undef $al, debug-location !36 + DBG_VALUE $edi, $noreg, !23, !DIExpression(), debug-location !26 + DBG_VALUE $edi, $noreg, !24, !DIExpression(), debug-location !27 + renamable $al = MOV8rm $rip, 1, $noreg, @b, $noreg, debug-location !28 :: (dereferenceable load (s8) from @b, align 4, !tbaa !29) + MOV8mr $rip, 1, $noreg, @a, $noreg, killed renamable $al, debug-location !34 :: (store (s8) into @a, !tbaa !35) + RET 0, undef $al, debug-location !36 + +...