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Simplify. 

llvm-svn: 72970
This commit is contained in:
Devang Patel 2009-06-05 23:08:56 +00:00
parent d185a7a629
commit afa8a1592f
1 changed files with 6 additions and 15 deletions
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21
llvm/lib/Analysis/ScalarEvolution.cpp
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@ -2462,24 +2462,15 @@ void ScalarEvolution::forgetLoopPHIs(const Loop *L) {
ScalarEvolution::BackedgeTakenInfo
ScalarEvolution::ComputeBackedgeTakenCount(const Loop *L) {
// If the loop has a non-one exit block count, we can't analyze it.
SmallVector<BasicBlock*, 8> ExitBlocks;
L->getExitBlocks(ExitBlocks);
if (ExitBlocks.size() != 1) return UnknownValue;
BasicBlock *ExitBlock = L->getExitBlock();
if (!ExitBlock)
return UnknownValue;
// Okay, there is one exit block. Try to find the condition that causes the
// loop to be exited.
BasicBlock *ExitBlock = ExitBlocks[0];
BasicBlock *ExitingBlock = 0;
for (pred_iterator PI = pred_begin(ExitBlock), E = pred_end(ExitBlock);
PI != E; ++PI)
if (L->contains(*PI)) {
if (ExitingBlock == 0)
ExitingBlock = *PI;
else
return UnknownValue; // More than one block exiting!
}
assert(ExitingBlock && "No exits from loop, something is broken!");
BasicBlock *ExitingBlock = L->getExitingBlock();
if (!ExitingBlock)
return UnknownValue; // More than one block exiting!
// Okay, we've computed the exiting block. See what condition causes us to
// exit.