|
| 1 | +# RUN: llc -o - %s -mtriple=x86_64-- -run-pass=machine-cp | FileCheck %s |
| 2 | + |
| 3 | +# When MachineCopyPropagation eliminates a dead 'copy', its associated debug |
| 4 | +# information becomes invalid. as the recorded register has been removed. |
| 5 | +# It causes the debugger to display wrong variable value. |
| 6 | +# |
| 7 | +# When in the debugger, on the line "return read1;", the value of "read1" |
| 8 | +# is reported as '4', where it should be '1'. |
| 9 | +# |
| 10 | +# MIR generated with: |
| 11 | +# clang -S -g -O2 -emit-llvm pr38773.cpp -o pr38773.ll -mllvm |
| 12 | +# llc pr38773.ll -stop-after=tailduplication -simplify-mir |
| 13 | +# |
| 14 | +# // pr38773.cpp |
| 15 | +# int main() { |
| 16 | +# volatile int foo = 4; |
| 17 | +# int read1 = foo; |
| 18 | +# int read2 = foo; |
| 19 | +# |
| 20 | +# switch ((read1 == 4) ? 3 : 1) { |
| 21 | +# case 1: |
| 22 | +# read1 *= read2; |
| 23 | +# break; |
| 24 | +# case 3: |
| 25 | +# read1 /= read2; |
| 26 | +# break; |
| 27 | +# } |
| 28 | +# |
| 29 | +# return read1; |
| 30 | +# } |
| 31 | +# |
| 32 | +# Update the register for the '@llvm.dbg.value' associated with 'read1', when |
| 33 | +# the 'copy' is removed, to be the 'source' register. |
| 34 | + |
| 35 | +--- | |
| 36 | + ; ModuleID = 'pr38773.ll' |
| 37 | + source_filename = "pr38773.cpp" |
| 38 | + target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" |
| 39 | + target triple = "x86_64-pc-linux-gnu" |
| 40 | + |
| 41 | + define dso_local i32 @main() local_unnamed_addr !dbg !7 { |
| 42 | + entry: |
| 43 | + %foo = alloca i32, align 4 |
| 44 | + store volatile i32 4, i32* %foo, align 4 |
| 45 | + %foo.0.foo.0. = load volatile i32, i32* %foo, align 4 |
| 46 | + %foo.0.foo.0.6 = load volatile i32, i32* %foo, align 4 |
| 47 | + %cmp = icmp eq i32 %foo.0.foo.0., 4 |
| 48 | + br i1 %cmp, label %sw.bb1, label %sw.bb |
| 49 | + |
| 50 | + sw.bb: ; preds = %entry |
| 51 | + %mul = mul nsw i32 %foo.0.foo.0.6, %foo.0.foo.0. |
| 52 | + br label %sw.epilog |
| 53 | + |
| 54 | + sw.bb1: ; preds = %entry |
| 55 | + %div = sdiv i32 4, %foo.0.foo.0.6 |
| 56 | + call void @llvm.dbg.value(metadata i32 %div, metadata !12, metadata !DIExpression()), !dbg !13 |
| 57 | + br label %sw.epilog |
| 58 | + |
| 59 | + sw.epilog: ; preds = %sw.bb1, %sw.bb |
| 60 | + %read1.0 = phi i32 [ %div, %sw.bb1 ], [ %mul, %sw.bb ] |
| 61 | + call void @llvm.dbg.value(metadata i32 %read1.0, metadata !12, metadata !DIExpression()), !dbg !13 |
| 62 | + ret i32 %read1.0 |
| 63 | + } |
| 64 | + |
| 65 | + declare void @llvm.dbg.value(metadata, metadata, metadata) #0 |
| 66 | + |
| 67 | + !llvm.dbg.cu = !{!0} |
| 68 | + !llvm.module.flags = !{!3, !4, !5} |
| 69 | + !llvm.ident = !{!6} |
| 70 | + |
| 71 | + !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0 (trunk 343183)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None) |
| 72 | + !1 = !DIFile(filename: "pr38773.cpp", directory: ".") |
| 73 | + !2 = !{} |
| 74 | + !3 = !{i32 2, !"Dwarf Version", i32 4} |
| 75 | + !4 = !{i32 2, !"Debug Info Version", i32 3} |
| 76 | + !5 = !{i32 1, !"wchar_size", i32 4} |
| 77 | + !6 = !{!"clang version 8.0.0 (trunk 343183)"} |
| 78 | + !7 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !11) |
| 79 | + !8 = !DISubroutineType(types: !9) |
| 80 | + !9 = !{!10} |
| 81 | + !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) |
| 82 | + !11 = !{!12} |
| 83 | + !12 = !DILocalVariable(name: "read1", scope: !7, file: !1, line: 3, type: !10) |
| 84 | + !13 = !DILocation(line: 3, column: 7, scope: !7) |
| 85 | + |
| 86 | +... |
| 87 | +--- |
| 88 | +name: main |
| 89 | + |
| 90 | +body: | |
| 91 | + |
| 92 | + bb.2.sw.bb1: |
| 93 | + liveins: $ecx |
| 94 | + |
| 95 | + $eax = MOV32ri 4 |
| 96 | + $edx = MOV32r0 implicit-def dead $eflags |
| 97 | + IDIV32r killed renamable $ecx, implicit-def $eax, implicit-def dead $edx, implicit-def dead $eflags, implicit $eax, implicit killed $edx |
| 98 | + renamable $ecx = COPY $eax |
| 99 | + ; CHECK: IDIV32r killed renamable $ecx |
| 100 | + ; CHECK-NEXT: DBG_VALUE debug-use $eax, debug-use $noreg, !12, !DIExpression(), debug-location !13 |
| 101 | + DBG_VALUE debug-use $ecx, debug-use $noreg, !12, !DIExpression(), debug-location !13 |
| 102 | + $eax = COPY killed renamable $ecx |
| 103 | + RET 0, $eax |
| 104 | +
|
| 105 | +... |
0 commit comments