Fixed deadstoreelimination bug where negative indices were incorrectly causing the optimisation to occur

Turns out long long + unsigned long long is unsigned.  Doh!

Fixes http://llvm.org/bugs/show_bug.cgi?id=11455

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145731 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Pete Cooper 2011-12-03 00:04:30 +00:00
parent 24fbf2bf16
commit de2e27cc52
2 changed files with 18 additions and 1 deletions

View File

@ -416,7 +416,7 @@ static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later,
// writes to addresses which will definitely be overwritten later
if (LaterOff > EarlierOff &&
LaterOff < int64_t(EarlierOff + Earlier.Size) &&
LaterOff + Later.Size >= EarlierOff + Earlier.Size)
int64_t(LaterOff + Later.Size) >= int64_t(EarlierOff + Earlier.Size))
return OverwriteEnd;
// Otherwise, they don't completely overlap.

View File

@ -76,3 +76,20 @@ entry:
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
%struct.trapframe = type { i64, i64, i64 }
; bugzilla 11455 - make sure negative GEP's don't break this optimisation
; CHECK: @cpu_lwp_fork
define void @cpu_lwp_fork(%struct.trapframe* %md_regs, i64 %pcb_rsp0) nounwind uwtable noinline ssp {
entry:
%0 = inttoptr i64 %pcb_rsp0 to %struct.trapframe*
%add.ptr = getelementptr inbounds %struct.trapframe* %0, i64 -1
%1 = bitcast %struct.trapframe* %add.ptr to i8*
%2 = bitcast %struct.trapframe* %md_regs to i8*
; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %1, i8* %2, i64 24, i32 1, i1 false)
call void @llvm.memcpy.p0i8.p0i8.i64(i8* %1, i8* %2, i64 24, i32 1, i1 false)
%tf_trapno = getelementptr inbounds %struct.trapframe* %0, i64 -1, i32 1
store i64 3, i64* %tf_trapno, align 8
ret void
}