Add an assertion to catch indirectbr in SplitBlockPredecessors. This

makes several optimization passes abort in cases where they're currently
silently miscompiling code.

Remove the indirectbr assertion from SplitEdge. Indirectbr is only
a problem for critical edges, and SplitEdge defers to SplitCriticalEdge
to handle those, and SplitCriticalEdge has its own assertion for
indirectbr.

llvm-svn: 86147
This commit is contained in:
Dan Gohman 2009-11-05 18:25:44 +00:00
parent 06c26d982e
commit 00c793822e
1 changed files with 6 additions and 2 deletions
llvm/lib/Transforms/Utils

View File

@ -275,8 +275,6 @@ void llvm::RemoveSuccessor(TerminatorInst *TI, unsigned SuccNum) {
/// SplitEdge - Split the edge connecting specified block. Pass P must
/// not be NULL.
BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, Pass *P) {
assert(!isa<IndirectBrInst>(BB->getTerminator()) &&
"Cannot split an edge from an IndirectBrInst");
TerminatorInst *LatchTerm = BB->getTerminator();
unsigned SuccNum = 0;
#ifndef NDEBUG
@ -386,6 +384,12 @@ BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
bool IsLoopEntry = !!L;
bool SplitMakesNewLoopHeader = false;
for (unsigned i = 0; i != NumPreds; ++i) {
// This is slightly more strict than necessary; the minimum requirement
// is that there be no more than one indirectbr branching to BB. And
// all BlockAddress uses would need to be updated.
assert(!isa<IndirectBrInst>(Preds[i]->getTerminator()) &&
"Cannot split an edge from an IndirectBrInst");
Preds[i]->getTerminator()->replaceUsesOfWith(BB, NewBB);
if (LI) {