From 1b98ff3e4fb81f83a9c8d04f6b063cbb2114af65 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 31 Oct 2009 21:51:10 +0000 Subject: update the comment above llvm::SplitCriticalEdge, and make it abort on IndirectBrInst as describe in the comment. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85688 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Transforms/Utils/BasicBlockUtils.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'include/llvm/Transforms') diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h index e766d72..1dc5a96 100644 --- a/include/llvm/Transforms/Utils/BasicBlockUtils.h +++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h @@ -116,8 +116,8 @@ bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum, /// SplitCriticalEdge - If this edge is a critical edge, insert a new node to /// split the critical edge. This will update DominatorTree and /// DominatorFrontier information if it is available, thus calling this pass -/// will not invalidate either of them. This returns true if the edge was split, -/// false otherwise. +/// will not invalidate either of them. This returns the new block if the edge +/// was split, null otherwise. /// /// If MergeIdenticalEdges is true (not the default), *all* edges from TI to the /// specified successor will be merged into the same critical edge block. @@ -126,10 +126,16 @@ bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum, /// dest go to one block instead of each going to a different block, but isn't /// the standard definition of a "critical edge". /// +/// It is invalid to call this function on a critical edge that starts at an +/// IndirectBrInst. Splitting these edges will almost always create an invalid +/// program because the addr of the new block won't be the one that is jumped +/// to. +/// BasicBlock *SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P = 0, bool MergeIdenticalEdges = false); -inline BasicBlock *SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, Pass *P = 0) { +inline BasicBlock *SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, + Pass *P = 0) { return SplitCriticalEdge(BB->getTerminator(), SI.getSuccessorIndex(), P); } -- cgit v1.1