6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-01 00:33:09 +00:00
Code Issues Projects Releases Wiki Activity

This is a fix for PR# 19051. I noticed code gen differences due to code motion when running tests with and without the debug info at O2. The problem is in branch folding. A loop wanted to skip the debug info, but actually it didn't do so.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204865 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Ekaterina Romanova 2014-03-26 22:15:28 +00:00
parent 3d7d0bc71a
commit 899a605fc1
2 changed files with 110 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lib/CodeGen/BranchFolding.cpp
View File

@ -1515,7 +1515,7 @@ MachineBasicBlock::iterator findHoistingInsertPosAndDeps(MachineBasicBlock *MBB,
// branch from condition setting instruction.
MachineBasicBlock::iterator PI = Loc;
--PI;
while (PI != MBB->begin() && Loc->isDebugValue())
while (PI != MBB->begin() && PI->isDebugValue())
--PI;
bool IsDef = false;

109
test/CodeGen/X86/dbg-changes-codegen-branch-folding.ll Normal file
View File

@ -0,0 +1,109 @@
; RUN: llc -march=x86-64 -mtriple=x86_64-linux < %s | FileCheck %s
; RUN: opt -strip-debug < %s | llc -march=x86-64 -mtriple=x86_64-linux | FileCheck %s
; http://llvm.org/PR19051. Minor code-motion difference with -g.
; Presence of debug info shouldn't affect the codegen. Make sure that
; we generated the same code sequence with and without debug info.
;
; CHECK: callq _Z3fooPcjPKc
; CHECK: callq _Z3fooPcjPKc
; CHECK: leaq (%rsp), %rdi
; CHECK: movl $4, %esi
; CHECK: testl {{%[a-z]+}}, {{%[a-z]+}}
; CHECK: je .LBB0_4
; Regenerate test with this command:
; clang -emit-llvm -S -O2 -g
; from this source:
;
; extern void foo(char *dst,unsigned siz,const char *src);
; extern const char * i2str(int);
;
; struct AAA3 {
; AAA3(const char *value) { foo(text,sizeof(text),value);}
; void operator=(const char *value) { foo(text,sizeof(text),value);}
; operator const char*() const { return text;}
; char text[4];
; };
;
; void bar (int param1,int param2) {
; const char * temp(0);
;
; if (param2) {
; temp = i2str(param2);
; }
; AAA3 var1("");
; AAA3 var2("");
;
; if (param1)
; var2 = "+";
; else
; var2 = "-";
; var1 = "";
; }
%struct.AAA3 = type { [4 x i8] }
@.str = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
@.str1 = private unnamed_addr constant [2 x i8] c"+\00", align 1
@.str2 = private unnamed_addr constant [2 x i8] c"-\00", align 1
; Function Attrs: uwtable
define void @_Z3barii(i32 %param1, i32 %param2) #0 {
entry:
%var1 = alloca %struct.AAA3, align 1
%var2 = alloca %struct.AAA3, align 1
%tobool = icmp eq i32 %param2, 0
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
%call = call i8* @_Z5i2stri(i32 %param2)
br label %if.end
if.end: ; preds = %entry, %if.then
call void @llvm.dbg.value(metadata !{%struct.AAA3* %var1}, i64 0, metadata !60)
call void @llvm.dbg.value(metadata !62, i64 0, metadata !63)
%arraydecay.i = getelementptr inbounds %struct.AAA3* %var1, i64 0, i32 0, i64 0
call void @_Z3fooPcjPKc(i8* %arraydecay.i, i32 4, i8* getelementptr inbounds ([1 x i8]* @.str, i64 0, i64 0))
call void @llvm.dbg.declare(metadata !{%struct.AAA3* %var2}, metadata !38)
%arraydecay.i5 = getelementptr inbounds %struct.AAA3* %var2, i64 0, i32 0, i64 0
call void @_Z3fooPcjPKc(i8* %arraydecay.i5, i32 4, i8* getelementptr inbounds ([1 x i8]* @.str, i64 0, i64 0))
%tobool1 = icmp eq i32 %param1, 0
br i1 %tobool1, label %if.else, label %if.then2
if.then2: ; preds = %if.end
call void @_Z3fooPcjPKc(i8* %arraydecay.i5, i32 4, i8* getelementptr inbounds ([2 x i8]* @.str1, i64 0, i64 0))
br label %if.end3
if.else: ; preds = %if.end
call void @_Z3fooPcjPKc(i8* %arraydecay.i5, i32 4, i8* getelementptr inbounds ([2 x i8]* @.str2, i64 0, i64 0))
br label %if.end3
if.end3: ; preds = %if.else, %if.then2
call void @_Z3fooPcjPKc(i8* %arraydecay.i, i32 4, i8* getelementptr inbounds ([1 x i8]* @.str, i64 0, i64 0))
ret void
}
; Function Attrs: nounwind readnone
declare void @llvm.dbg.declare(metadata, metadata) #1
declare i8* @_Z5i2stri(i32) #2
declare void @_Z3fooPcjPKc(i8*, i32, i8*) #2
; Function Attrs: nounwind readnone
declare void @llvm.dbg.value(metadata, i64, metadata) #1
attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { nounwind readnone }
attributes #2 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.module.flags = !{!48, !49}
!llvm.ident = !{!50}
!38 = metadata !{i32 786688, null, metadata !"var2", null, i32 20, null, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [var2] [line 20]
!48 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
!49 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
!50 = metadata !{metadata !"clang version 3.5 (202418)"}
!60 = metadata !{i32 786689, null, metadata !"this", null, i32 16777216, null, i32 1088, null} ; [ DW_TAG_arg_variable ] [this] [line 0]
!62 = metadata !{i8* getelementptr inbounds ([1 x i8]* @.str, i64 0, i64 0)}
!63 = metadata !{i32 786689, null, metadata !"value", null, i32 33554439, null, i32 0, null} ; [ DW_TAG_arg_variable ] [value] [line 7]