RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-22 10:42:39 +01:00
Code Issues Projects Releases Wiki Activity

Fix inconsistency with/without debug information (-g)

Browse Source 
This fixes an inconsistency in code generation when compiling with or
without debug information (-g). When debug information is available in
an empty block, the original test would fail, resulting in possibly
different code.

Patch by: Jeroen Dobbelaere

Differential revision: https://reviews.llvm.org/D49467

llvm-svn: 339129
This commit is contained in:
Jonas Devlieghere 2018-08-07 12:14:01 +00:00
parent 179e3b577d
commit 7a74c5eed1
3 changed files with 97 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lib/CodeGen/CodeGenPrepare.cpp
View File

@ -642,7 +642,7 @@ bool CodeGenPrepare::isMergingEmptyBlockProfitable(BasicBlock *BB,
isa<IndirectBrInst>(Pred->getTerminator())))
return true;
if (BB->getTerminator() != BB->getFirstNonPHI())
if (BB->getTerminator() != BB->getFirstNonPHIOrDbg())
return true;
// We use a simple cost heuristic which determine skipping merging is

10
test/Other/2007-04-24-eliminate-mostly-empty-blocks.ll
View File

@ -1,4 +1,12 @@
;RUN: opt < %s -codegenprepare -disable-output
;RUN: opt < %s -codegenprepare -S | FileCheck %s
;CHECK: define void @foo()
;CHECK-NEXT: entry:
;CHECK-NEXT: ret void
;CHECK: cond_next475:
;CHECK-NEXT: br label %cond_next475
define void @foo() {
entry:

87
test/Other/codegenprepare-and-debug.ll Normal file
View File

@ -0,0 +1,87 @@
; RUN: opt -codegenprepare -S < %s | FileCheck %s
; RUN: opt -strip-debug -codegenprepare -S < %s | FileCheck %s
; REQUIRES: x86-registered-target
; In its current state, CodeGenPrepare should not optimize empty blocks after a switch
; (See CodeGenPrepare::isMergingEmptyBlockProfitable)
; This should also be the case when they contain debug information. (sw.bb block)
; Check this by verifying that the switch labels remain the same
; CHECK: while.cond:
; CHECK-NEXT: switch i32 undef, label %sw.default [
; CHECK-NEXT: i32 45, label %sw.bb
; CHECK-NEXT: i32 104, label %while.cond.lbl_crit_edge
; CHECK-NEXT: i32 122, label %while.cond.lbl_crit_edge
; CHECK-NEXT: i32 115, label %while.cond134.preheader
; CHECK-NEXT: i32 100, label %sw.bb29
; CHECK-NEXT: i32 105, label %sw.bb29
; CHECK-NEXT: ]
; ModuleID = 'bugpoint-reduced-instructions.bc'
source_filename = "foobar.c"
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; Function Attrs: nounwind readnone speculatable
declare void @llvm.dbg.declare(metadata, metadata, metadata) #0
; Function Attrs: nounwind readnone speculatable
declare void @llvm.dbg.value(metadata, metadata, metadata) #0
; Function Attrs: noinline nounwind uwtable
define dso_local void @foobar(i32* nocapture %arg0) local_unnamed_addr #0 {
entry:
br label %while.cond
while.cond: ; preds = %entry
switch i32 undef, label %sw.default [
i32 45, label %sw.bb
i32 104, label %while.cond.lbl_crit_edge
i32 122, label %while.cond.lbl_crit_edge
i32 115, label %while.cond134.preheader
i32 100, label %sw.bb29
i32 105, label %sw.bb29
]
while.cond.lbl_crit_edge: ; preds = %while.cond, %while.cond
br label %lbl
while.cond134.preheader: ; preds = %while.cond
unreachable
sw.bb: ; preds = %while.cond
call void @llvm.dbg.value(metadata i32 3, metadata !11, metadata !DIExpression()), !dbg !15
br label %lbl
sw.bb29: ; preds = %while.cond, %while.cond
unreachable
sw.default: ; preds = %while.cond
unreachable
lbl: ; preds = %sw.bb, %while.cond.lbl_crit_edge
%var03.1 = phi i32 [ 0, %while.cond.lbl_crit_edge ], [ 3, %sw.bb ]
unreachable
}
attributes #0 = { nounwind readnone speculatable }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!9, !10}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version XXX ", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, globals: !2)
!1 = !DIFile(filename: "foobar.c", directory: "./")
!2 = !{}
!3 = !{!4, !5}
!4 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!5 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !6, size: 64)
!6 = !DISubroutineType(types: !7)
!7 = !{!4, !4, !8}
!8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
!9 = !{i32 2, !"Debug Info Version", i32 3}
!10 = !{i32 1, !"wchar_size", i32 4}
!11 = !DILocalVariable(name: "var03", scope: !12, file: !1, line: 3, type: !4)
!12 = distinct !DISubprogram(name: "foobar", scope: !1, file: !1, line: 2, type: !13, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
!13 = !DISubroutineType(types: !14)
!14 = !{null, !5, !8}
!15 = !DILocation(line: 4, column: 16, scope: !12)