| Jeremy Morse | b33a5c7 | 2019-02-12 10:54:30 +0000 | [diff] [blame] | 1 | ; RUN: opt -early-cse -S %s -o - | FileCheck %s |
| 2 | |
| 3 | ; PR40628: The first load below is determined to be redundant by EarlyCSE. |
| 4 | ; During salvaging, the corresponding dbg.value could have a DW_OP_deref used |
| 5 | ; in its DIExpression to represent the redundant operation -- however LLVM |
| 6 | ; cannot currently determine that the subsequent store should terminate the |
| 7 | ; variables location range. A debugger would display zero for the "redundant" |
| 8 | ; variable after stepping onto the return instruction. |
| 9 | |
| 10 | ; Test that the load being removed results in the corresponding dbg.value |
| 11 | ; being assigned the 'undef' value. |
| 12 | |
| 13 | ; CHECK: @foo |
| 14 | ; CHECK-NEXT: dbg.value(metadata i32 undef, metadata ![[DEADVAR:[0-9]+]], |
| 15 | ; CHECK-NEXT: load |
| 16 | ; CHECK-NEXT: dbg.value(metadata i32 %{{[0-9]+}}, metadata ![[LIVEVAR:[0-9]+]], |
| 17 | ; CHECK-NEXT: store |
| 18 | ; CHECK-NEXT: ret |
| 19 | |
| 20 | ; CHECK: ![[DEADVAR]] = !DILocalVariable(name: "redundant", |
| 21 | ; CHECK: ![[LIVEVAR]] = !DILocalVariable(name: "loaded", |
| 22 | |
| 23 | target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" |
| 24 | target triple = "x86_64-unknown-linux-gnu" |
| 25 | |
| 26 | define dso_local i32 @foo(i32*) !dbg !7 { |
| 27 | %2 = load i32, i32* %0, align 4, !dbg !23 |
| 28 | call void @llvm.dbg.value(metadata i32 %2, metadata !16, metadata !DIExpression()), !dbg !23 |
| 29 | %3 = load i32, i32* %0, align 4, !dbg !23 |
| 30 | call void @llvm.dbg.value(metadata i32 %3, metadata !17, metadata !DIExpression()), !dbg !23 |
| 31 | store i32 0, i32* %0, align 4, !dbg !23 |
| 32 | ret i32 %3, !dbg !23 |
| 33 | } |
| 34 | |
| 35 | declare void @llvm.dbg.value(metadata, metadata, metadata) |
| 36 | |
| 37 | !llvm.dbg.cu = !{!0} |
| 38 | !llvm.module.flags = !{!3, !4, !5} |
| 39 | !llvm.ident = !{!6} |
| 40 | |
| 41 | !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None) |
| 42 | !1 = !DIFile(filename: "pr40628.c", directory: ".") |
| 43 | !2 = !{} |
| 44 | !3 = !{i32 2, !"Dwarf Version", i32 4} |
| 45 | !4 = !{i32 2, !"Debug Info Version", i32 3} |
| 46 | !5 = !{i32 1, !"wchar_size", i32 4} |
| 47 | !6 = !{!"clang"} |
| 48 | !7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !8, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !12) |
| 49 | !8 = !DISubroutineType(types: !9) |
| 50 | !9 = !{!10, !11} |
| 51 | !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) |
| 52 | !11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size: 64) |
| 53 | !12 = !{!16, !17} |
| 54 | !16 = !DILocalVariable(name: "redundant", scope: !7, file: !1, line: 4, type: !10) |
| 55 | !17 = !DILocalVariable(name: "loaded", scope: !7, file: !1, line: 5, type: !10) |
| 56 | !23 = !DILocation(line: 4, column: 7, scope: !7) |