diff --git a/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp b/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp --- a/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp +++ b/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp @@ -2533,6 +2533,12 @@ if (*V.second == FirstVal) continue; // No disagreement. + // If both values are not equal but have equal non-empty IDs then they refer + // to the same value from different sources (e.g. one is VPHI and the other + // is Def), which does not cause disagreement. + if (V.second->ID != ValueIDNum::EmptyValue && V.second->ID == FirstVal.ID) + continue; + // Eliminate if a backedge feeds a VPHI back into itself. if (V.second->Kind == DbgValue::VPHI && V.second->BlockNo == MBB.getNumber() && diff --git a/llvm/test/DebugInfo/MIR/X86/instr-ref-join-def-vphi.mir b/llvm/test/DebugInfo/MIR/X86/instr-ref-join-def-vphi.mir new file mode 100644 --- /dev/null +++ b/llvm/test/DebugInfo/MIR/X86/instr-ref-join-def-vphi.mir @@ -0,0 +1,241 @@ +# RUN: llc -run-pass=livedebugvalues %s -o - -experimental-debug-variable-locations | FileCheck %s --check-prefixes=CHECK + +# Test that we do not drop debug values when joining a VPHI and a Def that use +# the same value. +# In this test case, the live out value for "a" from bb.4 is a VPHI with a +# defined value, the value live-in register $esi at bb.3. In bb.5, we also have +# a DBG_INSTR_REF that explicitly defines "a" as holding that same value. When +# joining these values to determine the live-in value of "a" at bb.6, we should +# recognize that these values are identical and produce a valid live-in debug +# value. + +# CHECK: ![[VAR:[0-9]+]] = !DILocalVariable(name: "a" + +# CHECK-LABEL: bb.6 +# CHECK: DBG_VALUE $esi, $noreg, ![[VAR]], !DIExpression() + +--- | + target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" + target triple = "x86_64-unknown-linux-gnu" + + ; Function Attrs: mustprogress uwtable + define dso_local noundef i32 @"?foo@@YAHH@Z"(i32 noundef %0) local_unnamed_addr #0 !dbg !8 { + call void @llvm.dbg.value(metadata i32 %0, metadata !14, metadata !DIExpression()), !dbg !16 + %2 = tail call noundef i32 @"?bar@@YAHXZ"(), !dbg !17 + br label %3, !dbg !18 + + 3: ; preds = %13, %1 + %4 = phi i32 [ %0, %1 ], [ %14, %13 ] + %5 = phi i32 [ %2, %1 ], [ %7, %13 ], !dbg !16 + call void @llvm.dbg.value(metadata i32 %4, metadata !14, metadata !DIExpression()), !dbg !16 + %6 = tail call noundef i32 @"?bar@@YAHXZ"(), !dbg !19 + %7 = sub nsw i32 %5, %6, !dbg !19 + %8 = srem i32 %7, 3, !dbg !21 + %9 = icmp eq i32 %8, 0, !dbg !21 + br i1 %9, label %10, label %13, !dbg !21 + + 10: ; preds = %3 + %11 = tail call noundef i32 @"?bar@@YAHXZ"(), !dbg !22 + %12 = add nsw i32 %11, %4, !dbg !22 + call void @llvm.dbg.value(metadata i32 %12, metadata !14, metadata !DIExpression()), !dbg !16 + br label %13, !dbg !25 + + 13: ; preds = %10, %3 + %14 = phi i32 [ %12, %10 ], [ %4, %3 ] + call void @llvm.dbg.value(metadata i32 %14, metadata !14, metadata !DIExpression()), !dbg !16 + %15 = icmp sgt i32 %7, 0, !dbg !26 + br i1 %15, label %3, label %16, !dbg !26, !llvm.loop !27 + + 16: ; preds = %13 + %17 = and i32 %7, 1, !dbg !30 + %18 = icmp eq i32 %17, 0, !dbg !30 + br i1 %18, label %19, label %22, !dbg !30 + + 19: ; preds = %16 + %20 = tail call noundef i32 @"?bar@@YAHXZ"(), !dbg !31 + %21 = add nsw i32 %20, %14, !dbg !31 + call void @llvm.dbg.value(metadata i32 %21, metadata !14, metadata !DIExpression()), !dbg !16 + br label %22, !dbg !34 + + 22: ; preds = %19, %16 + %23 = phi i32 [ %21, %19 ], [ %14, %16 ], !dbg !16 + call void @llvm.dbg.value(metadata i32 %23, metadata !14, metadata !DIExpression()), !dbg !16 + ret i32 %23, !dbg !35 + } + + declare dso_local noundef i32 @"?bar@@YAHXZ"() local_unnamed_addr #1 + + ; Function Attrs: nocallback nofree nosync nounwind readnone speculatable willreturn + declare void @llvm.dbg.value(metadata, metadata, metadata) #2 + + attributes #0 = { mustprogress uwtable "frame-pointer"="none" "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 #1 = { "frame-pointer"="none" "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 readnone speculatable willreturn } + + !llvm.dbg.cu = !{!0} + !llvm.module.flags = !{!3, !4, !5, !6} + !llvm.ident = !{!7} + + !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 15.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None) + !1 = !DIFile(filename: "test.cpp", directory: "\") + !3 = !{i32 2, !"Debug Info Version", i32 3} + !4 = !{i32 1, !"wchar_size", i32 2} + !5 = !{i32 7, !"PIC Level", i32 2} + !6 = !{i32 7, !"uwtable", i32 2} + !7 = !{!"clang version 15.0.0"} + !8 = distinct !DISubprogram(name: "foo", linkageName: "?foo@@YAHH@Z", scope: !9, file: !9, line: 3, type: !10, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !13) + !9 = !DIFile(filename: ".\\test.cpp", directory: "\") + !10 = !DISubroutineType(types: !11) + !11 = !{!12, !12} + !12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) + !13 = !{!14} + !14 = !DILocalVariable(name: "a", arg: 1, scope: !8, file: !9, line: 3, type: !12) + !16 = !DILocation(line: 0, scope: !8) + !17 = !DILocation(line: 4, scope: !8) + !18 = !DILocation(line: 5, scope: !8) + !19 = !DILocation(line: 6, scope: !20) + !20 = distinct !DILexicalBlock(scope: !8, file: !9, line: 5) + !21 = !DILocation(line: 7, scope: !20) + !22 = !DILocation(line: 8, scope: !23) + !23 = distinct !DILexicalBlock(scope: !24, file: !9, line: 7) + !24 = distinct !DILexicalBlock(scope: !20, file: !9, line: 7) + !25 = !DILocation(line: 9, scope: !23) + !26 = !DILocation(line: 10, scope: !20) + !27 = distinct !{!27, !18, !28, !29} + !28 = !DILocation(line: 10, scope: !8) + !29 = !{!"llvm.loop.mustprogress"} + !30 = !DILocation(line: 11, scope: !8) + !31 = !DILocation(line: 12, scope: !32) + !32 = distinct !DILexicalBlock(scope: !33, file: !9, line: 11) + !33 = distinct !DILexicalBlock(scope: !8, file: !9, line: 11) + !34 = !DILocation(line: 13, scope: !32) + !35 = !DILocation(line: 14, scope: !8) + +... +--- +name: '?foo@@YAHH@Z' +alignment: 16 +exposesReturnsTwice: false +legalized: false +regBankSelected: false +selected: false +failedISel: false +tracksRegLiveness: true +hasWinCFI: true +callsEHReturn: false +callsUnwindInit: false +hasEHCatchret: false +hasEHScopes: false +hasEHFunclets: false +failsVerification: false +tracksDebugUserValues: true +registers: [] +liveins: + - { reg: '$ecx', virtual-reg: '' } +frameInfo: + isFrameAddressTaken: false + isReturnAddressTaken: false + hasStackMap: false + hasPatchPoint: false + stackSize: 56 + offsetAdjustment: -56 + maxAlignment: 8 + adjustsStack: true + hasCalls: true + stackProtector: '' + functionContext: '' + maxCallFrameSize: 32 + cvBytesOfCalleeSavedRegisters: 16 + hasOpaqueSPAdjustment: false + hasVAStart: false + hasMustTailInVarArgFunc: false + hasTailCall: false + localFrameSize: 0 + savePoint: '' + restorePoint: '' +fixedStack: + - { id: 0, type: spill-slot, offset: -24, size: 8, alignment: 8, stack-id: default, + callee-saved-register: '$rdi', callee-saved-restored: true, debug-info-variable: '', + debug-info-expression: '', debug-info-location: '' } + - { id: 1, type: spill-slot, offset: -16, size: 8, alignment: 16, stack-id: default, + callee-saved-register: '$rsi', callee-saved-restored: true, debug-info-variable: '', + debug-info-expression: '', debug-info-location: '' } +stack: [] +callSites: [] +debugValueSubstitutions: [] +constants: [] +machineFunctionInfo: {} +body: | + bb.0 (%ir-block.1): + successors: %bb.1(0x80000000) + liveins: $ecx, $rsi, $rdi + + DBG_VALUE $ecx, $noreg, !14, !DIExpression(), debug-location !16 + frame-setup PUSH64r killed $rsi, implicit-def $rsp, implicit $rsp + frame-setup SEH_PushReg 57 + frame-setup PUSH64r killed $rdi, implicit-def $rsp, implicit $rsp + frame-setup SEH_PushReg 53 + $rsp = frame-setup SUB64ri8 $rsp, 40, implicit-def dead $eflags + frame-setup SEH_StackAlloc 40 + frame-setup SEH_EndPrologue + $esi = MOV32rr $ecx + CALL64pcrel32 @"?bar@@YAHXZ", csr_win64, implicit $rsp, implicit $ssp, implicit-def $rsp, implicit-def $ssp, implicit-def $eax, debug-instr-number 8, debug-location !17 + $edi = MOV32rr $eax, debug-location !17 + JMP_1 %bb.1 + + bb.3 (%ir-block.13, align 16): + successors: %bb.1(0x7c000000), %bb.4(0x04000000) + liveins: $edi, $esi + + DBG_PHI $esi, 5 + TEST32rr renamable $edi, renamable $edi, implicit-def $eflags, debug-location !26 + JCC_1 %bb.4, 14, implicit $eflags, debug-location !26 + + bb.1 (%ir-block.3): + successors: %bb.2(0x30000000), %bb.3(0x50000000) + liveins: $edi, $esi + + DBG_PHI $esi, 3 + DBG_PHI $edi, 2 + DBG_INSTR_REF 3, 0, !14, !DIExpression(), debug-location !16 + CALL64pcrel32 @"?bar@@YAHXZ", csr_win64, implicit $rsp, implicit $ssp, implicit-def $rsp, implicit-def $ssp, implicit-def $eax, debug-location !19 + renamable $edi = nsw SUB32rr killed renamable $edi, killed renamable $eax, implicit-def dead $eflags, debug-instr-number 1, debug-location !19 + renamable $eax = IMUL32rri renamable $edi, -1431655765, implicit-def dead $eflags, debug-location !21 + renamable $eax = ADD32ri killed renamable $eax, 715827882, implicit-def dead $eflags, debug-location !21 + CMP32ri killed renamable $eax, 1431655764, implicit-def $eflags, debug-location !21 + JCC_1 %bb.3, 7, implicit $eflags, debug-location !21 + + bb.2 (%ir-block.10): + successors: %bb.3(0x80000000) + liveins: $edi, $esi + + CALL64pcrel32 @"?bar@@YAHXZ", csr_win64, implicit $rsp, implicit $ssp, implicit-def $rsp, implicit-def $ssp, implicit-def $eax, debug-location !22 + renamable $esi = nsw ADD32rr killed renamable $esi, killed renamable $eax, implicit-def dead $eflags, debug-instr-number 4, debug-location !22 + DBG_INSTR_REF 4, 0, !14, !DIExpression(), debug-location !16 + JMP_1 %bb.3 + + bb.4 (%ir-block.16): + successors: %bb.5(0x40000000), %bb.6(0x40000000) + liveins: $edi, $esi + + TEST8ri renamable $dil, 1, implicit-def $eflags, implicit killed $edi, debug-location !30 + JCC_1 %bb.6, 5, implicit $eflags, debug-location !30 + + bb.5 (%ir-block.19): + successors: %bb.6(0x80000000) + liveins: $esi + + CALL64pcrel32 @"?bar@@YAHXZ", csr_win64, implicit $rsp, implicit $ssp, implicit-def $rsp, implicit-def $ssp, implicit-def $eax, debug-location !31 + DBG_INSTR_REF 5, 0, !14, !DIExpression(), debug-location !16 + + bb.6 (%ir-block.22): + liveins: $esi + + $eax = MOV32rr killed $esi, debug-location !35 + SEH_Epilogue debug-location !35 + $rsp = frame-destroy ADD64ri8 $rsp, 40, implicit-def dead $eflags, debug-location !35 + $rdi = frame-destroy POP64r implicit-def $rsp, implicit $rsp, debug-location !35 + $rsi = frame-destroy POP64r implicit-def $rsp, implicit $rsp, debug-location !35 + RET64 $eax, debug-location !35 + +... diff --git a/llvm/unittests/CodeGen/InstrRefLDVTest.cpp b/llvm/unittests/CodeGen/InstrRefLDVTest.cpp --- a/llvm/unittests/CodeGen/InstrRefLDVTest.cpp +++ b/llvm/unittests/CodeGen/InstrRefLDVTest.cpp @@ -2238,6 +2238,17 @@ EXPECT_EQ(JoinedLoc.Kind, DbgValue::Def); EXPECT_EQ(JoinedLoc.ID, LiveInRsp); + // Try the same PHI elimination but with one incoming value being a VPHI + // referring to the same value. + VLiveOuts[1] = DbgValue(LiveInRsp, EmptyProps, DbgValue::Def); + VLiveOuts[2] = DbgValue(2, EmptyProps, DbgValue::VPHI); + VLiveOuts[2].ID = LiveInRsp; + JoinedLoc = DbgValue(3, EmptyProps, DbgValue::VPHI); + Result = vlocJoin(*MBB3, VLiveOutIdx, AllBlocks, JoinedLoc); + EXPECT_TRUE(Result); + EXPECT_EQ(JoinedLoc.Kind, DbgValue::VPHI); + EXPECT_EQ(JoinedLoc.ID, LiveInRsp); + // If the "current" live-in is a VPHI, but not a VPHI generated in the current // block, then it's the remains of an earlier value propagation. We should // value propagate through this merge. Even if the current incoming values