xref: /llvm-project/llvm/test/DebugInfo/MIR/InstrRef/phi-through-regalloc.mir (revision d53425e2a33a0ff7336c86d3f668b1855c47a6de)
1# RUN: llc %s -o - -mtriple=x86_64-unknown-unknown \
2# RUN:    -experimental-debug-variable-locations \
3# RUN:    -run-pass=phi-node-elimination,livedebugvars,greedy,virtregrewriter \
4# RUN:    | FileCheck %s
5#
6# This test checks that for a very simple PHI, we produce a corresponding
7# DBG_PHI instruction, that a DBG_INSTR_REF refers to. Tests the path through
8# phi-node-elimination, live debug variables, and then placement after register
9# allocation.
10#
11# Original code, compiled with only -mem2reg, then fed to llc -stop-before...
12#
13#    int ext(int);
14#    int foo(int bar, int baz) {
15#      int either = 0;
16#      if (ext(0))
17#        either = bar;
18#      else
19#        either = baz;
20#
21#      return either;
22#    }
23#
24
25--- |
26  ; ModuleID = 'promoted.ll'
27  source_filename = "test.c"
28  target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
29  target triple = "x86_64-unknown-linux-gnu"
30
31  define dso_local i32 @foo(i32 %bar, i32 %baz) !dbg !7 {
32  entry:
33    call void @llvm.dbg.value(metadata i32 %bar, metadata !11, metadata !DIExpression()), !dbg !12
34    call void @llvm.dbg.value(metadata i32 %baz, metadata !13, metadata !DIExpression()), !dbg !12
35    call void @llvm.dbg.value(metadata i32 0, metadata !14, metadata !DIExpression()), !dbg !12
36    %call = call i32 @ext(i32 0), !dbg !15
37    %tobool = icmp ne i32 %call, 0, !dbg !15
38    br i1 %tobool, label %if.end, label %if.else, !dbg !17
39
40  if.else:                                          ; preds = %entry
41    call void @llvm.dbg.value(metadata i32 %baz, metadata !14, metadata !DIExpression()), !dbg !12
42    br label %if.end
43
44  if.end:                                           ; preds = %entry, %if.else
45    %either.0 = phi i32 [ %baz, %if.else ], [ %bar, %entry ], !dbg !18
46    call void @llvm.dbg.value(metadata i32 %either.0, metadata !14, metadata !DIExpression()), !dbg !12
47    ret i32 %either.0, !dbg !19
48  }
49
50  declare dso_local i32 @ext(i32)
51
52  ; Function Attrs: nounwind readnone speculatable willreturn
53  declare void @llvm.dbg.value(metadata, metadata, metadata)
54
55  !llvm.dbg.cu = !{!0}
56  !llvm.module.flags = !{!3, !4, !5}
57  !llvm.ident = !{!6}
58
59  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
60  !1 = !DIFile(filename: "test.c", directory: ".")
61  !2 = !{}
62  !3 = !{i32 7, !"Dwarf Version", i32 4}
63  !4 = !{i32 2, !"Debug Info Version", i32 3}
64  !5 = !{i32 1, !"wchar_size", i32 4}
65  !6 = !{!"."}
66  !7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
67  !8 = !DISubroutineType(types: !9)
68  !9 = !{!10, !10, !10}
69  !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
70  !11 = !DILocalVariable(name: "bar", arg: 1, scope: !7, file: !1, line: 2, type: !10)
71  !12 = !DILocation(line: 0, scope: !7)
72  !13 = !DILocalVariable(name: "baz", arg: 2, scope: !7, file: !1, line: 2, type: !10)
73  !14 = !DILocalVariable(name: "either", scope: !7, file: !1, line: 3, type: !10)
74  !15 = !DILocation(line: 4, column: 7, scope: !16)
75  !16 = distinct !DILexicalBlock(scope: !7, file: !1, line: 4, column: 7)
76  !17 = !DILocation(line: 4, column: 7, scope: !7)
77  !18 = !DILocation(line: 0, scope: !16)
78  !19 = !DILocation(line: 9, column: 3, scope: !7)
79
80...
81---
82name:            foo
83alignment:       16
84tracksRegLiveness: true
85debugInstrRef: true
86registers:
87  - { id: 0, class: gr32 }
88  - { id: 1, class: gr32 }
89  - { id: 2, class: gr32 }
90  - { id: 3, class: gr32 }
91  - { id: 4, class: gr32 }
92liveins:
93  - { reg: '$edi', virtual-reg: '%1' }
94  - { reg: '$esi', virtual-reg: '%2' }
95frameInfo:
96  maxAlignment:    1
97  adjustsStack:    true
98  hasCalls:        true
99machineFunctionInfo: {}
100body:             |
101  bb.0.entry:
102    successors: %bb.2(0x50000000), %bb.1(0x30000000)
103    liveins: $edi, $esi
104
105    DBG_VALUE $edi, $noreg, !11, !DIExpression(), debug-location !12
106    DBG_VALUE $esi, $noreg, !13, !DIExpression(), debug-location !12
107    %2:gr32 = COPY killed $esi
108    %1:gr32 = COPY killed $edi
109    DBG_VALUE 0, $noreg, !14, !DIExpression(), debug-location !12
110    ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp, debug-location !15
111    %3:gr32 = MOV32r0 implicit-def dead $eflags
112    $edi = COPY killed %3, debug-location !15
113    CALL64pcrel32 @ext, csr_64, implicit $rsp, implicit $ssp, implicit killed $edi, implicit-def $rsp, implicit-def $ssp, implicit-def $eax, debug-location !15
114    ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp, debug-location !15
115    %4:gr32 = COPY killed $eax, debug-location !15
116    TEST32rr killed %4, %4, implicit-def $eflags, debug-location !15
117    JCC_1 %bb.2, 5, implicit killed $eflags, debug-location !17
118    JMP_1 %bb.1, debug-location !17
119
120  bb.1.if.else:
121
122    ; CHECK-LABEL: bb.2.if.end:
123  bb.2.if.end:
124    %0:gr32 = PHI %1, %bb.0, %2, %bb.1, debug-instr-number 1, debug-location !18
125    DBG_INSTR_REF !14, !DIExpression(DW_OP_LLVM_arg, 0), dbg-instr-ref(1, 0), debug-location !12
126    ; CHECK:      DBG_PHI $ebp, 1
127    ; CHECK:      DBG_INSTR_REF {{.+}}, dbg-instr-ref(1, 0)
128    $eax = COPY killed %0, debug-location !19
129    ; Confirm that %0 is allocated in $ebp,
130    ; CHECK:      $eax = COPY killed renamable $ebp
131    RET 0, killed $eax, debug-location !19
132
133...
134