Diego Novillo 95b12c8115 SamplePGO - Fix PR 25482 - Do not rely on llvm.dbg.cu for discriminators
The discriminators pass relied on the presence of llvm.dbg.cu to decide
whether to add discriminators, but this fails in the case where debug
info is only enabled partially when -fprofile-sample-use is active.

The reason llvm.dbg.cu is not present in these cases is to prevent
codegen from emitting debug info (as it is only used for the sample
profile pass).

This changes the discriminators pass to also emit discriminators even
when debug info is not being emitted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252763 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-11 17:54:37 +00:00

67 lines
2.9 KiB
LLVM

; RUN: opt < %s -add-discriminators -S | FileCheck %s
; Basic DWARF discriminator test. All the instructions in block
; 'if.then' should have a different discriminator value than
; the conditional branch at the end of block 'entry'.
;
; Original code:
;
; void foo(int i) {
; int x;
; if (i < 10) x = i;
; }
define void @foo(i32 %i) #0 !dbg !4 {
entry:
%i.addr = alloca i32, align 4
%x = alloca i32, align 4
store i32 %i, i32* %i.addr, align 4
%0 = load i32, i32* %i.addr, align 4, !dbg !10
%cmp = icmp slt i32 %0, 10, !dbg !10
br i1 %cmp, label %if.then, label %if.end, !dbg !10
if.then: ; preds = %entry
%1 = load i32, i32* %i.addr, align 4, !dbg !10
; CHECK: %1 = load i32, i32* %i.addr, align 4, !dbg ![[THEN:[0-9]+]]
store i32 %1, i32* %x, align 4, !dbg !10
; CHECK: store i32 %1, i32* %x, align 4, !dbg ![[THEN]]
br label %if.end, !dbg !10
; CHECK: br label %if.end, !dbg ![[THEN]]
if.end: ; preds = %if.then, %entry
ret void, !dbg !12
; CHECK: ret void, !dbg ![[END:[0-9]+]]
}
attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
; We should be able to add discriminators even in the absence of llvm.dbg.cu.
; When using sample profiles, the front end will generate line tables but it
; does not generate llvm.dbg.cu to prevent codegen from emitting debug info
; to the final binary.
; !llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!7, !8}
!llvm.ident = !{!9}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.5 ", isOptimized: false, emissionKind: 0, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
!1 = !DIFile(filename: "basic.c", directory: ".")
!2 = !{}
!3 = !{!4}
!4 = distinct !DISubprogram(name: "foo", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
!5 = !DIFile(filename: "basic.c", directory: ".")
!6 = !DISubroutineType(types: !2)
!7 = !{i32 2, !"Dwarf Version", i32 4}
!8 = !{i32 1, !"Debug Info Version", i32 3}
!9 = !{!"clang version 3.5 "}
!10 = !DILocation(line: 3, scope: !11)
!11 = distinct !DILexicalBlock(line: 3, column: 0, file: !1, scope: !4)
!12 = !DILocation(line: 4, scope: !4)
; CHECK: ![[FOO:[0-9]+]] = distinct !DISubprogram(name: "foo"
; CHECK: ![[BLOCK:[0-9]+]] = distinct !DILexicalBlock(scope: ![[FOO]],{{.*}} line: 3)
; CHECK: ![[THEN]] = !DILocation(line: 3, scope: ![[BLOCKFILE:[0-9]+]])
; CHECK: ![[BLOCKFILE]] = !DILexicalBlockFile(scope: ![[BLOCK]],{{.*}} discriminator: 1)
; CHECK: ![[END]] = !DILocation(line: 4, scope: ![[FOO]])