550517bcab
Summary: This is a follow-up to r334830 and r335031. In the valueCoversEntireFragment check we now also handle the situation when there is a variable length array (VLA) involved, and the length of the array has been reduced to a constant. The ConvertDebugDeclareToDebugValue functions that are related to PHI nodes and load instructions now avoid inserting dbg.value intrinsics when the value does not, for certain, cover the variable/fragment that should be described. In r334830 we assumed that the value always covered the entire var/fragment and we had assertions in the code to show that assumption. However, those asserts failed when compiling code with VLAs, so we removed the asserts in r335031. Now when we know that the valueCoversEntireFragment check can fail also for PHI/Load instructions we avoid to insert the faulty dbg.value intrinsic in such situations. Compared to the Store instruction scenario we simply drop the dbg.value here (as the variable does not change its value due to PHI/Load, so an earlier dbg.value describing the variable should still be valid). Reviewers: aprantl, vsk, efriedma Reviewed By: aprantl Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D48547 llvm-svn: 335580
65 lines
2.9 KiB
LLVM
65 lines
2.9 KiB
LLVM
; RUN: opt < %s -mem2reg -S | FileCheck %s
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; Testing conversion from dbg.declare to dbg.value when the variable is a VLA.
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;
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; We can't derive the size of the variable since it is a VLA with an unknown
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; number of element.
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;
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; Verify that we do not get a dbg.value after the phi node (we can't know if
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; the phi nodes result describes the whole array or not). Also verify that we
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; get a dbg.value that says that we do not know the value of the VLA in place
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; of the store (since we do not know which part of the VLA the store is
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; writing to).
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; ModuleID = 'debug-alloca-vla.ll'
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target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-apple-macosx10.12.0"
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; Function Attrs: nounwind ssp uwtable
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define void @scan(i32 %n) #0 !dbg !4 {
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entry:
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%vla1 = alloca i32, i32 %n, align 8
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call void @llvm.dbg.declare(metadata i32* %vla1, metadata !10, metadata !DIExpression()), !dbg !18
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br label %for.cond, !dbg !18
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for.cond: ; preds = %for.cond, %entry
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; CHECK: %[[PHI:.*]] = phi i32 [ undef, %entry ], [ %t0, %for.cond ]
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%entryN = load i32, i32* %vla1, align 8, !dbg !18
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; CHECK-NOT: call void @llvm.dbg.value
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%t0 = add i32 %entryN, 1
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; CHECK: %t0 = add i32 %[[PHI]], 1
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; CHECK: call void @llvm.dbg.value(metadata i32 undef,
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; CHECK-SAME: metadata !DIExpression())
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store i32 %t0, i32* %vla1, align 8, !dbg !18
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br label %for.cond, !dbg !18
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}
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; Function Attrs: nounwind readnone speculatable
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declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
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attributes #0 = { nounwind ssp uwtable }
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attributes #1 = { nounwind readnone speculatable }
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!llvm.dbg.cu = !{!0}
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!llvm.module.flags = !{!2, !3}
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!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "adrian", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
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!1 = !DIFile(filename: "<stdin>", directory: "/")
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!2 = !{i32 2, !"Debug Info Version", i32 3}
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!3 = !{i32 7, !"PIC Level", i32 2}
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!4 = distinct !DISubprogram(name: "scan", scope: !1, file: !1, line: 4, type: !5, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !8)
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!5 = !DISubroutineType(types: !6)
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!6 = !{null, !7, !7}
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!7 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
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!8 = !{!9}
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!9 = !DILocalVariable(name: "entry", scope: !4, file: !1, line: 6, type: !7)
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!10 = !DILocalVariable(name: "ptr32", scope: !4, file: !1, line: 240, type: !11)
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!11 = !DICompositeType(tag: DW_TAG_array_type, baseType: !12, elements: !14)
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!12 = !DIDerivedType(tag: DW_TAG_typedef, name: "__uint32_t", file: !1, line: 41, baseType: !13)
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!13 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
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!14 = !{!15}
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!15 = !DISubrange(count: !16)
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!16 = !DILocalVariable(name: "__vla_expr", scope: !4, type: !17, flags: DIFlagArtificial)
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!17 = !DIBasicType(name: "long unsigned int", size: 64, encoding: DW_ATE_unsigned)
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!18 = !DILocation(line: 6, scope: !4)
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