Index: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp =================================================================== --- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -5796,8 +5796,9 @@ if (!SE.isSCEVable(Phi.getType())) continue; auto PhiSCEV = SE.getSCEV(&Phi); - if (Optional Offset = - SE.computeConstantDifference(DbgValueSCEV, PhiSCEV)) + Optional Offset = + SE.computeConstantDifference(DbgValueSCEV, PhiSCEV); + if (Offset && Offset->getMinSignedBits() <= 64) EqSet.emplace_back(std::make_tuple( &Phi, Offset.getValue().getSExtValue(), DVI->getExpression())); } Index: llvm/test/Transforms/LoopStrengthReduce/dbg-preserve-1.ll =================================================================== --- /dev/null +++ llvm/test/Transforms/LoopStrengthReduce/dbg-preserve-1.ll @@ -0,0 +1,73 @@ +; RUN: opt < %s -loop-reduce -S | FileCheck %s +; +; Test that LSR avoids crashing on very large integer inputs. It should +; discard the variable location by creating an undef dbg.value. +; +; CHECK: call void @llvm.dbg.value(metadata i128 undef, + +source_filename = "" +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" + +define dso_local void @qux() local_unnamed_addr !dbg !10 { +entry: + br label %for.body, !dbg !17 + +for.body: ; preds = %for.body.for.body_crit_edge, %entry + %0 = phi i128 [ 0, %entry ], [ %.pre8, %for.body.for.body_crit_edge ], !dbg !19 + %add6.i.i = add i128 %0, 18446744073709551615, !dbg !35 + call void @llvm.dbg.value(metadata i128 %add6.i.i, metadata !25, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 128)), !dbg !36 + br label %for.body.for.body_crit_edge + +for.body.for.body_crit_edge: ; preds = %for.body + %.pre8 = load i128, i128* undef, align 16, !dbg !19, !tbaa !37 + br label %for.body, !dbg !17 +} + +; Function Attrs: nofree nosync nounwind readnone speculatable willreturn +declare void @llvm.dbg.value(metadata, metadata, metadata) + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!7, !8, !9} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, globals: !2, splitDebugInlining: false, nameTableKind: None) +!1 = !DIFile(filename: "/tmp/beans.c", directory: "/tmp") +!2 = !{} +!3 = !{!4} +!4 = !DIDerivedType(tag: DW_TAG_typedef, name: "uint64_t", file: !5, line: 1, baseType: !6) +!5 = !DIFile(filename: "/tmp/beans.c", directory: "") +!6 = !DIBasicType(name: "long unsigned int", size: 64, encoding: DW_ATE_unsigned) +!7 = !{i32 7, !"Dwarf Version", i32 4} +!8 = !{i32 2, !"Debug Info Version", i32 3} +!9 = !{i32 1, !"wchar_size", i32 4} +!10 = distinct !DISubprogram(name: "qux", scope: !5, file: !5, line: 27, type: !11, scopeLine: 27, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2) +!11 = !DISubroutineType(types: !12) +!12 = !{null, !13, !13} +!13 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !14, size: 64) +!14 = !DIDerivedType(tag: DW_TAG_typedef, name: "croix", file: !5, line: 2, baseType: !15) +!15 = !DIDerivedType(tag: DW_TAG_typedef, name: "__uint128_t", file: !1, baseType: !16) +!16 = !DIBasicType(name: "unsigned __int128", size: 128, encoding: DW_ATE_unsigned) +!17 = !DILocation(line: 30, column: 3, scope: !18) +!18 = distinct !DILexicalBlock(scope: !10, file: !5, line: 30, column: 3) +!19 = !DILocation(line: 12, column: 25, scope: !20, inlinedAt: !30) +!20 = distinct !DISubprogram(name: "bar", scope: !5, file: !5, line: 8, type: !21, scopeLine: 8, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !24) +!21 = !DISubroutineType(types: !22) +!22 = !{null, !23, !13} +!23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !4, size: 64) +!24 = !{!25} +!25 = !DILocalVariable(name: "tmp", scope: !20, file: !5, line: 9, type: !26) +!26 = !DIDerivedType(tag: DW_TAG_typedef, name: "xyzzy", file: !5, line: 3, baseType: !27) +!27 = !DICompositeType(tag: DW_TAG_array_type, baseType: !14, size: 512, elements: !28) +!28 = !{!29} +!29 = !DISubrange(count: 4) +!30 = distinct !DILocation(line: 23, column: 3, scope: !31, inlinedAt: !32) +!31 = distinct !DISubprogram(name: "baz", scope: !5, file: !5, line: 21, type: !11, scopeLine: 21, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2) +!32 = distinct !DILocation(line: 31, column: 5, scope: !33) +!33 = distinct !DILexicalBlock(scope: !34, file: !5, line: 30, column: 31) +!34 = distinct !DILexicalBlock(scope: !18, file: !5, line: 30, column: 3) +!35 = !DILocation(line: 12, column: 23, scope: !20, inlinedAt: !30) +!36 = !DILocation(line: 0, scope: !20, inlinedAt: !30) +!37 = !{!38, !38, i64 0} +!38 = !{!"__int128", !39, i64 0} +!39 = !{!"omnipotent char", !40, i64 0} +!40 = !{!"Simple C/C++ TBAA"}