[LLVMdev] CodeExtractor.cpp potential bug?

[Vu Le]

Thank you, Cameron.
I also think Dominator::splitBasicBlock() is kind of OK, except the
assertion at line 232 (Dominator.h)
That assertion fails when we split the entry basic block (obviously, it does
not have any dominator).

What I asked for was the use of splitBasicBlock in CodeExtractor.cpp, line
145.
Vu

On Mon, Jan 3, 2011 at 3:25 PM, Cameron Zwarich <zwarich at apple.com> wrote:

> On Dec 31, 2010, at 11:20 AM, Vu Le wrote:
>
> > There might be a misuse of DominatorTree::splitBasicBlock in
> CodeExtractor.cpp, line 145.
> > Header is splited into two (OldPred->NewBB).
> >
> > Line 145 updates the dominator tree by calling
> DT->splitBasicBlock(NewBB).
> > I think it should be DT->splitBasicBlock(OldPred).
> >
> > When I tried to extract a code region whose header has 2 successors, my
> pass crashed.
> > It was because header (or OldPred) is the block that was splited, not
> NewBB.
> > DominatorTree::splitBasicBlock(BB) requires BB to have one successor.
>
>
> The code in Dominator::splitBasicBlock() looks correct, but I think the
> comment and assert may not be. I was writing a patch where I hit the same
> issue.
>
> Cameron
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20110104/13e6e6e6/attachment.html>