[PATCH v2 1/1] utils: Fix segfault in flattencfg

[Jan Vesely]

On Fri, 2014-08-08 at 14:18 -0700, Matt Arsenault wrote:
> On Aug 8, 2014, at 1:41 PM, Jan Vesely <jan.vesely at rutgers.edu> wrote:
> 
> > v2: continue iterating through the rest of the bb
> >    use for loop
> > 
> > Signed-off-by: Jan Vesely <jan.vesely at rutgers.edu>
> > ---
> > lib/Transforms/Utils/FlattenCFG.cpp | 9 +++++----
> > 1 file changed, 5 insertions(+), 4 deletions(-)
> > 
> > diff --git a/lib/Transforms/Utils/FlattenCFG.cpp b/lib/Transforms/Utils/FlattenCFG.cpp
> > index 51ead40..4eb3e3d 100644
> > --- a/lib/Transforms/Utils/FlattenCFG.cpp
> > +++ b/lib/Transforms/Utils/FlattenCFG.cpp
> > @@ -238,9 +238,13 @@ bool FlattenCFGOpt::FlattenParallelAndOr(BasicBlock *BB, IRBuilder<> &Builder,
> >     // Do branch inversion.
> >     BasicBlock *CurrBlock = LastCondBlock;
> >     bool EverChanged = false;
> > -    while (1) {
> > +    for (;CurrBlock != FirstCondBlock;
> > +          CurrBlock = CurrBlock->getSinglePredecessor()) {
> >       BranchInst *BI = dyn_cast<BranchInst>(CurrBlock->getTerminator());
> >       CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition());
> > +      if (!CI)
> > +        continue;
> > +
> >       CmpInst::Predicate Predicate = CI->getPredicate();
> >       // Canonicalize icmp_ne -> icmp_eq, fcmp_one -> fcmp_oeq
> >       if ((Predicate == CmpInst::ICMP_NE) || (Predicate == CmpInst::FCMP_ONE)) {
> > @@ -248,9 +252,6 @@ bool FlattenCFGOpt::FlattenParallelAndOr(BasicBlock *BB, IRBuilder<> &Builder,
> >         BI->swapSuccessors();
> >         EverChanged = true;
> >       }
> > -      if (CurrBlock == FirstCondBlock)
> > -        break;
> > -      CurrBlock = CurrBlock->getSinglePredecessor();
> >     }
> >     return EverChanged;
> >   }
> 
> Needs tests

sorry, I misunderstood what you meant by test the first time.

I wanted to add a flattencfg pass specific test but ran into problems

is there an easy way to run only the flattencfg pass?
opt -pass_name works only for analytical passes,
and llc ... -stop-after=flattencfg reports pass not registered.

I guess I'll have to add a codegen test.

I also found the parallel{or,and}ifcollapse tests, that are marked XFAIL
for unrelated reason. Should I try to fix those or add a new test?

jan

-- 
Jan Vesely <jan.vesely at rutgers.edu>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: This is a digitally signed message part
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20140809/ba2a7acc/attachment.sig>