xref: /llvm-project/llvm/test/Transforms/ADCE/preserve-memoryssa-if-only-remove-debug.ll (revision d80eb928c78ab3f3a3320014b2b7d513642b1a7e)
1; RUN: opt -passes='require<memoryssa>,adce' -o - -S -debug-pass-manager < %s 2>&1 | FileCheck %s
2
3; ADCE should remove the dbg.declare in test1, but it should preserve
4; MemorySSA since it only removed a debug instruction.
5
6; Invalidating MemorySSA when only removing debug instructions may lead
7; to different code with/without debug info present.
8; In
9;  https://github.com/llvm/llvm-project/issues/58285
10; we saw how ADCE removed a dbg.declare, invalidated all analyses, and later
11; DSE behaved in some way. Without the dbg.declare in the input ADCE kept
12; analysis info, and DSE behaved differently.
13
14; CHECK: Running analysis: MemorySSAAnalysis on test1
15; CHECK: Running pass: ADCEPass on test1 (1 instruction)
16; CHECK-NOT: Invalidating analysis: MemorySSAAnalysis on test1
17
18; In test2 ADCE also removes an instruction, but since we remove a non-debug
19; instruction as well we invalidate several analyses, including MemorySSA.
20
21; CHECK: Running analysis: MemorySSAAnalysis on test2
22; CHECK: Running pass: ADCEPass on test2 (2 instructions)
23; CHECK: Invalidating analysis: MemorySSAAnalysis on test2
24; CHECK: Running pass: PrintModulePass
25
26; CHECK-LABEL: @test1(
27; CHECK-NEXT:  entry:
28; CHECK-NEXT:    ret i16 0
29
30; CHECK-LABEL: @test2(
31; CHECK-NEXT:  entry:
32; CHECK-NEXT:    ret i16 0
33
34define i16 @test1() {
35entry:
36  call void @llvm.dbg.declare(metadata ptr poison, metadata !4, metadata !DIExpression()), !dbg !16
37  ret i16 0
38}
39
40define i16 @test2() {
41entry:
42  %dead = add i16 1, 2
43  ret i16 0
44}
45
46; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
47declare void @llvm.dbg.declare(metadata, metadata, metadata) #0
48
49attributes #0 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
50
51!llvm.dbg.cu = !{}
52!llvm.module.flags = !{!0, !1, !2, !3}
53
54!0 = !{i32 7, !"Dwarf Version", i32 4}
55!1 = !{i32 2, !"Debug Info Version", i32 3}
56!2 = !{i32 1, !"wchar_size", i32 1}
57!3 = !{i32 7, !"frame-pointer", i32 2}
58!4 = !DILocalVariable(name: "w", scope: !5, file: !6, line: 18, type: !11)
59!5 = distinct !DILexicalBlock(scope: !7, file: !6, line: 18, column: 8)
60!6 = !DIFile(filename: "foo2.c", directory: "/llvm")
61!7 = distinct !DISubprogram(name: "test1", scope: !6, file: !6, line: 14, type: !8, scopeLine: 14, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !10)
62!8 = !DISubroutineType(types: !9)
63!9 = !{}
64!10 = distinct !DICompileUnit(language: DW_LANG_C99, file: !6, producer: "clang version 16.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: !9, splitDebugInlining: false, nameTableKind: None)
65!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "uint64_t", file: !12, line: 60, baseType: !13)
66!12 = !DIFile(filename: "/include/sys/_stdint.h", directory: "")
67!13 = !DIDerivedType(tag: DW_TAG_typedef, name: "__uint64_t", file: !14, line: 108, baseType: !15)
68!14 = !DIFile(filename: "/include/machine/_default_types.h", directory: "")
69!15 = !DIBasicType(name: "unsigned long long", size: 64, encoding: DW_ATE_unsigned)
70!16 = !DILocation(line: 18, column: 8, scope: !5)