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Expand the check for a landing pad so that it looks at the basic block's

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containing loop's header to see if that's a landing pad. If it is, then we don't
want to hoist instructions out of the loop and above the header.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141767 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2011-10-12 02:58:01 +00:00
parent 22e8a366ad
commit a2e87912d8
1 changed files with 11 additions and 5 deletions
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16
lib/CodeGen/MachineLICM.cpp
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@ -343,11 +343,6 @@ bool MachineLICM::runOnMachineFunction(MachineFunction &MF) {
continue;
}
// If the header is a landing pad, then we don't want to hoist instructions
// out of it. This can happen with SjLj exception handling which has a
// dispatch table as the landing pad.
if (CurLoop->getHeader()->isLandingPad()) continue;
if (!PreRegAlloc)
HoistRegionPostRA();
else {
@ -472,6 +467,12 @@ void MachineLICM::HoistRegionPostRA() {
const std::vector<MachineBasicBlock*> Blocks = CurLoop->getBlocks();
for (unsigned i = 0, e = Blocks.size(); i != e; ++i) {
MachineBasicBlock *BB = Blocks[i];
// If the header of the loop containing this basic block is a landing pad,
// then don't try to hoist instructions out of this loop.
const MachineLoop *ML = MLI->getLoopFor(BB);
if (ML && ML->getHeader()->isLandingPad()) continue;
// Conservatively treat live-in's as an external def.
// FIXME: That means a reload that're reused in successor block(s) will not
// be LICM'ed.
@ -607,6 +608,11 @@ void MachineLICM::HoistRegion(MachineDomTreeNode *N, bool IsHeader) {
assert(N != 0 && "Null dominator tree node?");
MachineBasicBlock *BB = N->getBlock();
// If the header of the loop containing this basic block is a landing pad,
// then don't try to hoist instructions out of this loop.
const MachineLoop *ML = MLI->getLoopFor(BB);
if (ML && ML->getHeader()->isLandingPad()) return;
// If this subregion is not in the top level loop at all, exit.
if (!CurLoop->contains(BB)) return;