RegisterCoalescer: Fix removeCopyByCommutingDef with subreg liveness

The code that eliminated additional coalescable copies in
removeCopyByCommutingDef() used MergeValueNumberInto() which internally
may merge A into B or B into A. In this case A and B had different Def
points, so we have to reset ValNo.Def to the intended one after merging.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225503 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Matthias Braun 2015-01-09 03:01:31 +00:00
parent 4493e98154
commit c41acffe22
2 changed files with 54 additions and 1 deletions

View File

@ -751,7 +751,9 @@ bool RegisterCoalescer::removeCopyByCommutingDef(const CoalescerPair &CP,
if (!SubDVNI)
continue;
VNInfo *SubBValNo = S.getVNInfoAt(CopyIdx);
S.MergeValueNumberInto(SubBValNo, SubDVNI);
assert(SubBValNo->def == CopyIdx);
VNInfo *Merged = S.MergeValueNumberInto(SubBValNo, SubDVNI);
Merged->def = CopyIdx;
}
ErasedInstrs.insert(UseMI);

View File

@ -0,0 +1,51 @@
; RUN: llc -mtriple="x86_64-apple-darwin" -o - -verify-machineinstrs %s
define void @make_wanted() #0 {
entry:
br i1 undef, label %for.end20, label %for.cond1.preheader.lr.ph
for.cond1.preheader.lr.ph:
br label %for.body3
for.body3:
%cmp20.i = icmp eq i32 undef, 0
%.col.057 = select i1 %cmp20.i, i32 0, i32 undef
br i1 undef, label %while.cond.i, label %for.body5.lr.ph.i
for.body5.lr.ph.i:
%0 = sext i32 %.col.057 to i64
%1 = sub i32 0, %.col.057
%2 = zext i32 %1 to i64
%3 = add nuw nsw i64 %2, 1
%n.vec110 = and i64 %3, 8589934588
%end.idx.rnd.down111 = add nsw i64 %n.vec110, %0
br i1 undef, label %middle.block105, label %vector.ph103
vector.ph103:
br i1 undef, label %middle.block105, label %vector.body104
vector.body104:
%4 = icmp eq i64 undef, %end.idx.rnd.down111
br i1 %4, label %middle.block105, label %vector.body104
middle.block105:
%resume.val114 = phi i64 [ %0, %for.body5.lr.ph.i ], [ %end.idx.rnd.down111, %vector.body104 ], [ %end.idx.rnd.down111, %vector.ph103 ]
%cmp.n116 = icmp eq i64 undef, %resume.val114
br i1 %cmp.n116, label %while.cond.i, label %for.body5.i.preheader
for.body5.i.preheader:
%lcmp.or182 = or i1 undef, undef
br i1 %lcmp.or182, label %for.body5.i.prol, label %while.cond.i
for.body5.i.prol:
br i1 undef, label %for.body5.i.prol, label %while.cond.i
while.cond.i:
br i1 undef, label %while.cond.i, label %if.then
if.then:
br label %for.body3
for.end20:
ret void
}