llvm/test/Transforms/SimplifyCFG/remove-debug.ll
Dehao Chen 539e8b4532 Remove debug info when hoisting instruction from then/else branch.
Summary: The hoisted instruction is executed speculatively. It could affect the debugging experience as user would see gdb go into code that may not be expected to execute. It will also affect sample profile accuracy by assigning incorrect frequency to source within then/else branch.

Reviewers: davidxl, dblaikie, chandlerc, kcc, echristo

Subscribers: mehdi_amini, probinson, eric_niebler, andreadb, llvm-commits

Differential Revision: https://reviews.llvm.org/D24164

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280995 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-08 21:53:33 +00:00

84 lines
2.2 KiB
LLVM

; RUN: opt < %s -simplifycfg -S | FileCheck %s
; TODO: Track the acutal DebugLoc of the hoisted instruction when no-line
; DebugLoc is supported (https://reviews.llvm.org/D24180)
; CHECK: line: 6
; CHECK-NOT: line: 7
; CHECK: line: 8
; CHECK: line: 9
; CHECK-NOT: line: 10
; CHECK: line: 11
; Checks if the debug info for hoisted "x = i" is removed
; int x;
; void bar();
; void baz();
;
; void foo(int i) {
; if (i == 0) {
; x = i;
; bar();
; } else {
; x = i;
; baz();
; }
; }
target triple = "x86_64-unknown-linux-gnu"
@x = global i32 0, align 4
; Function Attrs: uwtable
define void @_Z3fooi(i32) #0 !dbg !6 {
%2 = alloca i32, align 4
store i32 %0, i32* %2, align 4, !tbaa !8
%3 = load i32, i32* %2, align 4, !dbg !12, !tbaa !8
%4 = icmp eq i32 %3, 0, !dbg !13
br i1 %4, label %5, label %7, !dbg !12
; <label>:5:
%6 = load i32, i32* %2, align 4, !dbg !14, !tbaa !8
store i32 %6, i32* @x, align 4, !dbg !15, !tbaa !8
call void @_Z3barv(), !dbg !16
br label %9, !dbg !17
; <label>:7:
%8 = load i32, i32* %2, align 4, !dbg !18, !tbaa !8
store i32 %8, i32* @x, align 4, !dbg !19, !tbaa !8
call void @_Z3bazv(), !dbg !20
br label %9
; <label>:9:
ret void, !dbg !21
}
declare void @_Z3barv() #1
declare void @_Z3bazv() #1
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1)
!1 = !DIFile(filename: "a", directory: "b/")
!2 = !{}
!3 = !{i32 2, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{}
!6 = distinct !DISubprogram(unit: !0)
!7 = !DISubroutineType(types: !2)
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !10, i64 0}
!10 = !{!"omnipotent char", !11, i64 0}
!11 = !{!"Simple C++ TBAA"}
!12 = !DILocation(line: 6, column: 7, scope: !6)
!13 = !DILocation(line: 6, column: 9, scope: !6)
!14 = !DILocation(line: 7, column: 9, scope: !6)
!15 = !DILocation(line: 7, column: 7, scope: !6)
!16 = !DILocation(line: 8, column: 5, scope: !6)
!17 = !DILocation(line: 9, column: 3, scope: !6)
!18 = !DILocation(line: 10, column: 9, scope: !6)
!19 = !DILocation(line: 10, column: 7, scope: !6)
!20 = !DILocation(line: 11, column: 5, scope: !6)
!21 = !DILocation(line: 13, column: 1, scope: !6)