[llvm] r187646 - Fix dereferencing end iterator in SimplifyCFG. Patch by Ye Mei.

[Duncan Sands]

Hi Alexey,

On 02/08/13 10:06, Alexey Samsonov wrote:
> Author: samsonov
> Date: Fri Aug  2 03:06:43 2013
> New Revision: 187646
>
> URL: http://llvm.org/viewvc/llvm-project?rev=187646&view=rev
> Log:
> Fix dereferencing end iterator in SimplifyCFG. Patch by Ye Mei.

does this bug fire on some testcases that are already in the regression test
suite (for example if built with expensive checks enabled)?

Ciao, Duncan.

>
> Modified:
>      llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
>
> Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=187646&r1=187645&r2=187646&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
> +++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Fri Aug  2 03:06:43 2013
> @@ -4290,7 +4290,8 @@ bool SimplifyCFGOpt::SimplifyParallelAnd
>     // Do the transformation.
>     BasicBlock *CB;
>     bool Iteration = true;
> -  BasicBlock::iterator ItOld = Builder.GetInsertPoint();
> +  BasicBlock *SaveInsertBB = Builder.GetInsertBlock();
> +  BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint();
>     BranchInst *PBI = dyn_cast<BranchInst>(FirstCondBlock->getTerminator());
>     Value *PC = PBI->getCondition();
>     do {
> @@ -4319,8 +4320,8 @@ bool SimplifyCFGOpt::SimplifyParallelAnd
>       // make CB unreachable and let downstream to delete the block.
>       new UnreachableInst(CB->getContext(), CB);
>     } while (Iteration);
> -
> -  Builder.SetInsertPoint(ItOld);
> +  if (SaveInsertBB)
> +    Builder.SetInsertPoint(SaveInsertBB, SaveInsertPt);
>     DEBUG(dbgs() << "Use parallel and/or in:\n" << *FirstCondBlock);
>     return true;
>   }
> @@ -4454,11 +4455,13 @@ bool SimplifyCFGOpt::MergeIfRegion(Basic
>     FirstEntryBlock->getInstList().splice(FirstEntryBlock->end(), SecondEntryBlock->getInstList());
>     BranchInst *PBI = dyn_cast<BranchInst>(FirstEntryBlock->getTerminator());
>     Value *CC = PBI->getCondition();
> -  BasicBlock::iterator ItOld = Builder.GetInsertPoint();
> +  BasicBlock *SaveInsertBB = Builder.GetInsertBlock();
> +  BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint();
>     Builder.SetInsertPoint(PBI);
>     Value *NC = Builder.CreateOr(CInst1, CC);
>     PBI->replaceUsesOfWith(CC, NC);
> -  Builder.SetInsertPoint(ItOld);
> +  if (SaveInsertBB)
> +    Builder.SetInsertPoint(SaveInsertBB, SaveInsertPt);
>
>     // Remove IfTrue1
>     if (IfTrue1 != FirstEntryBlock) {
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>