# RUN: llc -O1 -start-after register-coalescer -o - %s -experimental-debug-variable-locations=false | FileCheck %s
--- |
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"
define i16 @foo(i8 %zzz) !dbg !4 {
entry:
ret i16 1
}
; Function Attrs: nounwind readnone speculatable
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2)
!1 = !DIFile(filename: "test.c", directory: "")
!2 = !{}
!3 = !{i32 1, !"Debug Info Version", i32 3}
!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)
!5 = !DISubroutineType(types: !6)
!6 = !{null}
!7 = !DILocalVariable(name: "zzz", arg: 1, scope: !4, file: !1, line: 3, type: !8)
!8 = !DIBasicType(name: "char", size: 8, align: 8, encoding: DW_ATE_signed)
!9 = !DILocation(line: 0, scope: !4)
!10 = !DILocation(line: 4, column: 22, scope: !11)
!11 = distinct !DILexicalBlock(scope: !4, file: !1, line: 3, column: 19)
...
---
name: foo
tracksRegLiveness: true
body: |
bb.0:
%0:gr16_abcd = MOV16ri 1
bb.1:
DBG_VALUE %0.sub_8bit_hi, $noreg, !7, !DIExpression(), debug-location !9
%1:gr16 = COPY %0
%2:gr16 = COPY %0
bb.2:
$ax = COPY %1
$dx = COPY %2
RET64 killed $ax, killed $dx
...
# This test case was created as a reproducer for a bug when we got incorrect
# DBG_VALUE instructions after regalloc like this:
#
# movw $1, %cx
# #DEBUG_VALUE: foo:zzz <- $ch
# movl %ecx, %eax
# #DEBUG_VALUE: foo:zzz <- $ax
#
# The above is incorrect since the DBG_VALUE in the input is refering to the
# hi subreg, so after the COPY/movl the value is in $ah and not $ax (nor $al).
#
# We currently only get one DEBUG_VALUE here. In the future we could allow a
# second DEBUG_VALUE, as long as it is mapped to the hi subreg of the movl
# dst.
#
# CHECK-NOT: #DEBUG_VALUE:
# CHECK: #DEBUG_VALUE: foo:zzz <- ${{[abcd]+}}h
# CHECK-NOT: #DEBUG_VALUE:
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