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1; RUN: opt -S -passes=instcombine %s | FileCheck %s -check-prefix=RUN-ONCE2 3; This example was reduced from a test case in which InstCombine ran at least4; twice:5; - The first InstCombine run converted dbg.declares to dbg.values using the6; LowerDbgDeclare utility. This produced a dbg.value(ptr %2, DW_OP_deref)7; (this happens when the contents of an alloca are passed by-value), and a8; dbg.value(i32 %0) (due to the store of %0 into the alloca).9; - The second InstCombine run deleted the alloca (%2).10; Check that the DW_OP_deref dbg.value is deleted, just like a dbg.declare would11; be.12;13; RUN-ONCE-LABEL: @t1(14; RUN-ONCE-NEXT: #dbg_value(i32 %0, [[t1_arg0:![0-9]+]], !DIExpression(),15; RUN-ONCE-NEXT: #dbg_value(ptr poison, [[t1_fake_ptr:![0-9]+]], !DIExpression(),16; RUN-ONCE-NEXT: ret void17define void @t1(i32) !dbg !9 {18 %2 = alloca i32, align 419 store i32 %0, ptr %2, align 420 call void @llvm.dbg.value(metadata i32 %0, metadata !14, metadata !DIExpression()), !dbg !1521 call void @llvm.dbg.value(metadata ptr %2, metadata !14, metadata !DIExpression(DW_OP_deref)), !dbg !1522 call void @llvm.dbg.value(metadata ptr %2, metadata !20, metadata !DIExpression()), !dbg !1523 ret void24}25 26; This example is closer to an end-to-end test: the IR looks like it could have27; been produced by a frontend compiling at -O0.28;29; Here's what happens:30; 1) We run InstCombine. This puts a dbg.value(ptr %x.addr, DW_OP_deref)31; before the call to @use, and a dbg.value(i32 %x) after the store.32; 2) We inline @use.33; 3) We run InstCombine again. The alloca %x.addr is erased. We should just get34; dbg.value(i32 %x). There should be no leftover dbg.value(metadata ptr35; undef).36;37;;; define void @use(ptr %addr) alwaysinline { ret void }38;;; define void @t2(i32 %x) !dbg !17 {39;;; %x.addr = alloca i32, align 440;;; store i32 %x, ptr %x.addr, align 441;;; call void @llvm.dbg.declare(metadata ptr %x.addr, metadata !18, metadata !DIExpression()), !dbg !1942;;; call void @use(ptr %x.addr)43;;; ret void44;;; }45 46declare void @llvm.dbg.value(metadata, metadata, metadata)47declare void @llvm.dbg.declare(metadata, metadata, metadata)48 49!llvm.module.flags = !{!0, !1, !2, !3, !4}50!llvm.dbg.cu = !{!5}51!llvm.ident = !{!8}52 53; RUN-ONCE: [[t1_arg0]] = !DILocalVariable(name: "a"54; RUN-ONCE: [[t1_fake_ptr]] = !DILocalVariable(name: "fake_ptr"55 56!0 = !{i32 2, !"SDK Version", [2 x i32] [i32 10, i32 14]}57!1 = !{i32 2, !"Dwarf Version", i32 4}58!2 = !{i32 2, !"Debug Info Version", i32 3}59!3 = !{i32 1, !"wchar_size", i32 4}60!4 = !{i32 7, !"PIC Level", i32 2}61!5 = distinct !DICompileUnit(language: DW_LANG_C99, file: !6, producer: "", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !7, nameTableKind: GNU)62!6 = !DIFile(filename: "-", directory: "/")63!7 = !{}64!8 = !{!""}65!9 = distinct !DISubprogram(name: "t1", scope: !10, file: !10, line: 1, type: !11, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !5, retainedNodes: !7)66!10 = !DIFile(filename: "<stdin>", directory: "/")67!11 = !DISubroutineType(types: !12)68!12 = !{null, !13}69!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)70!14 = !DILocalVariable(name: "a", arg: 1, scope: !9, file: !10, line: 1, type: !13)71!15 = !DILocation(line: 1, column: 13, scope: !9)72!16 = !DILocation(line: 1, column: 17, scope: !9)73!17 = distinct !DISubprogram(name: "t2", scope: !10, file: !10, line: 1, type: !11, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !5, retainedNodes: !7)74!18 = !DILocalVariable(name: "x", arg: 1, scope: !17, file: !10, line: 1, type: !13)75!19 = !DILocation(line: 1, column: 1, scope: !17)76!20 = !DILocalVariable(name: "fake_ptr", scope: !9, file: !10, line: 1, type: !13)77