xref: /llvm-project/llvm/test/DebugInfo/MIR/InstrRef/dbg-phis-merging-in-ldv.mir (revision d53425e2a33a0ff7336c86d3f668b1855c47a6de)
1# RUN: llc %s -o - -mtriple=x86_64-unknown-unknown \
2# RUN:    -experimental-debug-variable-locations -run-pass=livedebugvalues \
3# RUN:    | FileCheck %s --check-prefix=CHECK
4#
5# Test that, in a scenario where tail duplication has duplicated DBG_PHI
6# instructions, we can reconstruct the value to refer to. This includes cases
7# where the DBG_PHIs refer to the same value, to values that later merge, and
8# value that become unavailable.
9--- |
10  ; ModuleID = 'before.mir'
11  source_filename = "test.c"
12  target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
13  target triple = "x86_64-unknown-linux-gnu"
14
15  define dso_local i32 @foo(i64 %bar, i64 %baz) !dbg !7 {
16  entry:
17    call void @llvm.dbg.value(metadata i64 %bar, metadata !12, metadata !DIExpression()), !dbg !13
18    call void @llvm.dbg.value(metadata i64 %baz, metadata !14, metadata !DIExpression()), !dbg !13
19    call void @ext(i64 %bar), !dbg !15
20    %add = add nsw i64 %bar, 12, !dbg !16
21    call void @llvm.dbg.value(metadata i64 %add, metadata !12, metadata !DIExpression()), !dbg !13
22    call void @ext(i64 %add), !dbg !17
23    %add1 = add nsw i64 %baz, 1, !dbg !18
24    call void @llvm.dbg.value(metadata i64 %add1, metadata !14, metadata !DIExpression()), !dbg !13
25    %call = call i64 @getlong(), !dbg !19
26    %tobool = icmp ne i64 %call, 0, !dbg !19
27    br i1 %tobool, label %if.then, label %if.else, !dbg !21
28
29  if.then:                                          ; preds = %entry
30    %add2 = add nsw i64 %add, 1, !dbg !22
31    call void @llvm.dbg.value(metadata i64 %add2, metadata !12, metadata !DIExpression()), !dbg !13
32    br label %if.end, !dbg !24
33
34  if.else:                                          ; preds = %entry
35    %add3 = add nsw i64 %add, 2, !dbg !25
36    call void @llvm.dbg.value(metadata i64 %add3, metadata !12, metadata !DIExpression()), !dbg !13
37    br label %if.end
38
39  if.end:                                           ; preds = %if.else, %if.then
40    %bar.addr.0 = phi i64 [ %add2, %if.then ], [ %add3, %if.else ], !dbg !27
41    call void @llvm.dbg.value(metadata i64 %bar.addr.0, metadata !12, metadata !DIExpression()), !dbg !13
42    %add4 = add nsw i64 %bar.addr.0, %add1, !dbg !28
43    call void @llvm.dbg.value(metadata i64 %add4, metadata !12, metadata !DIExpression()), !dbg !13
44    call void @ext(i64 %add4), !dbg !29
45    %conv = trunc i64 %add4 to i32, !dbg !30
46    ret i32 %conv, !dbg !31
47  }
48
49  ; Function Attrs: nounwind readnone speculatable willreturn
50  declare void @llvm.dbg.declare(metadata, metadata, metadata)
51
52  declare dso_local void @ext(i64)
53
54  declare dso_local i64 @getlong()
55
56  ; Function Attrs: nounwind readnone speculatable willreturn
57  declare void @llvm.dbg.value(metadata, metadata, metadata)
58
59  !llvm.dbg.cu = !{!0}
60  !llvm.module.flags = !{!3, !4, !5}
61  !llvm.ident = !{!6}
62
63  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
64  !1 = !DIFile(filename: "test.c", directory: ".")
65  !2 = !{}
66  !3 = !{i32 7, !"Dwarf Version", i32 4}
67  !4 = !{i32 2, !"Debug Info Version", i32 3}
68  !5 = !{i32 1, !"wchar_size", i32 4}
69  !6 = !{!"clang"}
70  !7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 3, type: !8, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
71  !8 = !DISubroutineType(types: !9)
72  !9 = !{!10, !11, !11}
73  !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
74  !11 = !DIBasicType(name: "long int", size: 64, encoding: DW_ATE_signed)
75  !12 = !DILocalVariable(name: "bar", arg: 1, scope: !7, file: !1, line: 3, type: !11)
76  !13 = !DILocation(line: 0, scope: !7)
77  !14 = !DILocalVariable(name: "baz", arg: 2, scope: !7, file: !1, line: 3, type: !11)
78  !15 = !DILocation(line: 4, column: 3, scope: !7)
79  !16 = !DILocation(line: 5, column: 7, scope: !7)
80  !17 = !DILocation(line: 6, column: 3, scope: !7)
81  !18 = !DILocation(line: 7, column: 7, scope: !7)
82  !19 = !DILocation(line: 9, column: 7, scope: !20)
83  !20 = distinct !DILexicalBlock(scope: !7, file: !1, line: 9, column: 7)
84  !21 = !DILocation(line: 9, column: 7, scope: !7)
85  !22 = !DILocation(line: 10, column: 9, scope: !23)
86  !23 = distinct !DILexicalBlock(scope: !20, file: !1, line: 9, column: 18)
87  !24 = !DILocation(line: 11, column: 3, scope: !23)
88  !25 = !DILocation(line: 12, column: 9, scope: !26)
89  !26 = distinct !DILexicalBlock(scope: !20, file: !1, line: 11, column: 10)
90  !27 = !DILocation(line: 0, scope: !20)
91  !28 = !DILocation(line: 15, column: 7, scope: !7)
92  !29 = !DILocation(line: 16, column: 3, scope: !7)
93  !30 = !DILocation(line: 17, column: 10, scope: !7)
94  !31 = !DILocation(line: 17, column: 3, scope: !7)
95
96...
97---
98name:            foo
99alignment:       16
100tracksRegLiveness: true
101debugInstrRef: true
102liveins:
103  - { reg: '$rdi' }
104  - { reg: '$rsi' }
105frameInfo:
106  stackSize:       24
107  offsetAdjustment: -24
108  maxAlignment:    1
109  adjustsStack:    true
110  hasCalls:        true
111  maxCallFrameSize: 0
112  cvBytesOfCalleeSavedRegisters: 16
113fixedStack:
114  - { id: 0, type: spill-slot, offset: -24, size: 8, alignment: 8, callee-saved-register: '$rbx' }
115  - { id: 1, type: spill-slot, offset: -16, size: 8, alignment: 16, callee-saved-register: '$r14' }
116machineFunctionInfo: {}
117body:             |
118  bb.0.entry:
119    successors: %bb.2, %bb.1
120    liveins: $rdi, $rsi, $r14, $rbx
121
122    frame-setup PUSH64r killed $r14, implicit-def $rsp, implicit $rsp
123    CFI_INSTRUCTION def_cfa_offset 16
124    frame-setup PUSH64r killed $rbx, implicit-def $rsp, implicit $rsp
125    CFI_INSTRUCTION def_cfa_offset 24
126    frame-setup PUSH64r undef $rax, implicit-def $rsp, implicit $rsp
127    CFI_INSTRUCTION def_cfa_offset 32
128    CFI_INSTRUCTION offset $rbx, -24
129    CFI_INSTRUCTION offset $r14, -16
130    $r14 = MOV64rr $rsi
131    $rbx = MOV64rr $rdi
132    CALL64pcrel32 @ext, csr_64, implicit $rsp, implicit $ssp, implicit $rdi, debug-location !15
133    renamable $rbx = ADD64ri32 killed renamable $rbx, 12, implicit-def $eflags, debug-location !16
134    $rdi = MOV64rr $rbx, debug-location !17
135    CALL64pcrel32 @ext, csr_64, implicit $rsp, implicit $ssp, implicit $rdi, debug-location !17
136    renamable $r14 = ADD64ri32 killed renamable $r14, 1, implicit-def $eflags, debug-location !18
137    CALL64pcrel32 @getlong, csr_64, implicit $rsp, implicit $ssp, implicit-def $rax, debug-location !19
138    CMP64ri8 killed renamable $rax, 0, implicit-def $eflags, debug-location !19
139    JCC_1 %bb.1, 5, implicit $eflags, debug-location !21
140
141  bb.2.if.else:
142    liveins: $rbx, $r14, $rax
143
144    renamable $rbx = ADD64ri32 killed renamable $rbx, 2, implicit-def $eflags, debug-location !25
145    DBG_PHI $r14, 1
146    DBG_PHI $rbx, 2
147    DBG_PHI $rax, 3
148    $rax = MOV64ri 0
149    JMP_1 %bb.3
150
151  bb.1.if.then:
152    liveins: $rbx, $r14, $rax
153
154    renamable $rbx = ADD64ri32 killed renamable $rbx, 1, implicit-def $eflags, debug-location !22
155    DBG_PHI $r14, 1
156    DBG_PHI $rbx, 2
157    DBG_PHI $rax, 3
158
159  bb.3.if.end:
160    liveins: $rbx, $r14
161
162    DBG_INSTR_REF !14, !DIExpression(DW_OP_LLVM_arg, 0), dbg-instr-ref(1, 0), debug-location !13
163    DBG_INSTR_REF !12, !DIExpression(DW_OP_LLVM_arg, 0), dbg-instr-ref(2, 0), debug-location !13
164    DBG_INSTR_REF !12, !DIExpression(DW_OP_LLVM_arg, 0), dbg-instr-ref(3, 0), debug-location !13
165
166    ; Value number 1 is live-through the above control flow from the two
167    ; DBG_PHIs:
168    ; CHECK:       DBG_INSTR_REF {{.+}}, dbg-instr-ref(1, 0)
169    ; CHECK-NEXT:  DBG_VALUE_LIST {{.+}} $r14
170    ;
171    ; While value number 2 has different defs that merge on entry to bb.3.
172    ; These are both in $rbx though, and we should find its location:
173    ; CHECK:       DBG_INSTR_REF {{.+}}, dbg-instr-ref(2, 0)
174    ; CHECK-NEXT:  DBG_VALUE_LIST {{.+}} $rbx
175    ;
176    ; Value number 3 cannot be resolved because $rax is clobbered in bb.2,
177    ; meaning the merged value in bb.3 is incorrect. It should produce a
178    ; DBG_VALUE $noreg.
179    ; CHECK:       DBG_INSTR_REF {{.+}}, dbg-instr-ref(3, 0)
180    ; CHECK-NEXT:  DBG_VALUE_LIST {{.+}} $noreg
181
182    renamable $rbx = ADD64rr killed renamable $rbx, killed renamable $r14, implicit-def $eflags, debug-location !28
183    DBG_INSTR_REF !12, !DIExpression(DW_OP_LLVM_arg, 0), dbg-instr-ref(2, 0), debug-location !13
184
185    ; After clobbering rbx, the variable location should not be available.
186    ; CHECK:       DBG_INSTR_REF {{.+}}, dbg-instr-ref(2, 0)
187    ; CHECK-NEXT:  DBG_VALUE_LIST {{.+}} $noreg
188
189    $rdi = MOV64rr $rbx, debug-location !29
190    CALL64pcrel32 @ext, csr_64, implicit $rsp, implicit $ssp, implicit $rdi, debug-location !29
191    $eax = MOV32rr $ebx, implicit killed $rbx, debug-location !31
192    $rsp = frame-destroy ADD64ri8 $rsp, 8, implicit-def dead $eflags, debug-location !31
193    CFI_INSTRUCTION def_cfa_offset 24, debug-location !31
194    $rbx = frame-destroy POP64r implicit-def $rsp, implicit $rsp, debug-location !31
195    CFI_INSTRUCTION def_cfa_offset 16, debug-location !31
196    $r14 = frame-destroy POP64r implicit-def $rsp, implicit $rsp, debug-location !31
197    CFI_INSTRUCTION def_cfa_offset 8, debug-location !31
198    RET64 implicit $eax, debug-location !31
199
200...
201