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One more place to skip debug info. 

llvm-svn: 67811
This commit is contained in:
Dale Johannesen 2009-03-27 01:13:37 +00:00
parent db65737b1c
commit 4026b041ce
1 changed files with 14 additions and 7 deletions
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21
llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp
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@ -145,10 +145,11 @@ bool CodeGenPrepare::runOnFunction(Function &F) {
return EverMadeChange;
}
/// EliminateMostlyEmptyBlocks - eliminate blocks that contain only PHI nodes
/// and an unconditional branch. Passes before isel (e.g. LSR/loopsimplify)
/// often split edges in ways that are non-optimal for isel. Start by
/// eliminating these blocks so we can split them the way we want them.
/// EliminateMostlyEmptyBlocks - eliminate blocks that contain only PHI nodes,
/// debug info directives, and an unconditional branch. Passes before isel
/// (e.g. LSR/loopsimplify) often split edges in ways that are non-optimal for
/// isel. Start by eliminating these blocks so we can split them the way we
/// want them.
bool CodeGenPrepare::EliminateMostlyEmptyBlocks(Function &F) {
bool MadeChange = false;
// Note that this intentionally skips the entry block.
@ -160,12 +161,18 @@ bool CodeGenPrepare::EliminateMostlyEmptyBlocks(Function &F) {
if (!BI || !BI->isUnconditional())
continue;
// If the instruction before the branch isn't a phi node, then other stuff
// is happening here.
// If the instruction before the branch (skipping debug info) isn't a phi
// node, then other stuff is happening here.
BasicBlock::iterator BBI = BI;
if (BBI != BB->begin()) {
--BBI;
if (!isa<PHINode>(BBI)) continue;
while (isa<DbgInfoIntrinsic>(BBI)) {
if (BBI == BB->begin())
break;
--BBI;
}
if (!isa<DbgInfoIntrinsic>(BBI) && !isa<PHINode>(BBI))
continue;
}
// Do not break infinite loops.