1# RUN: llc -O1 -start-after simple-register-coalescing -o - %s | FileCheck %s
2
3--- |
4  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
5  target triple = "x86_64-pc-linux-gnu"
6
7  define i16 @foo(i8 %zzz) !dbg !4 {
8  entry:
9    ret i16 1
10  }
11
12  ; Function Attrs: nounwind readnone speculatable
13  declare void @llvm.dbg.value(metadata, metadata, metadata)
14
15  !llvm.dbg.cu = !{!0}
16  !llvm.module.flags = !{!3}
17
18  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2)
19  !1 = !DIFile(filename: "test.c", directory: "")
20  !2 = !{}
21  !3 = !{i32 1, !"Debug Info Version", i32 3}
22  !4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 3, type: !5, isLocal: false, isDefinition: true, scopeLine: 3, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0)
23  !5 = !DISubroutineType(types: !6)
24  !6 = !{null}
25  !7 = !DILocalVariable(name: "zzz", arg: 1, scope: !4, file: !1, line: 3, type: !8)
26  !8 = !DIBasicType(name: "char", size: 8, align: 8, encoding: DW_ATE_signed)
27  !9 = !DILocation(line: 0, scope: !4)
28  !10 = !DILocation(line: 4, column: 22, scope: !11)
29  !11 = distinct !DILexicalBlock(scope: !4, file: !1, line: 3, column: 19)
30
31...
32---
33name:            foo
34tracksRegLiveness: true
35body:             |
36  bb.0:
37    %0:gr16_abcd = MOV16ri 1
38
39  bb.1:
40    DBG_VALUE %0.sub_8bit_hi, $noreg, !7, !DIExpression(), debug-location !9
41    %1:gr16 = COPY %0
42    %2:gr16 = COPY %0
43
44  bb.2:
45    $ax = COPY %1
46    $dx = COPY %2
47    RETQ killed $ax, killed $dx
48...
49
50# This test case was created as a reproducer for a bug when we got incorrect
51# DBG_VALUE instructions after regalloc like this:
52#
53#        movw    $1, %cx
54#        #DEBUG_VALUE: foo:zzz <- $ch
55#        movl    %ecx, %eax
56#        #DEBUG_VALUE: foo:zzz <- $ax
57#
58# The above is incorrect since the DBG_VALUE in the input is refering to the
59# hi subreg, so after the COPY/movl the value is in $ah and not $ax (nor $al).
60#
61# We currently only get one DEBUG_VALUE here. In the future we could allow a
62# second DEBUG_VALUE, as long as it is mapped to the hi subreg of the movl
63# dst.
64#
65# CHECK-NOT:    #DEBUG_VALUE:
66# CHECK:        #DEBUG_VALUE: foo:zzz <- ${{[abcd]+}}h
67# CHECK-NOT:    #DEBUG_VALUE:
68