[LLVMdev] CodeExtractor.cpp potential bug?

[Cameron Zwarich]

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