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- Remove an arbitrary spill weight tweak that should not have been there. 

- Find more reloads from SS.

llvm-svn: 69606
This commit is contained in:
Evan Cheng 2009-04-20 17:23:48 +00:00
parent 0fcc019d36
commit 5dd2e29b67
1 changed files with 26 additions and 5 deletions
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31
llvm/lib/CodeGen/RegAllocLinearScan.cpp
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@ -554,9 +554,6 @@ void RALinScan::updateSpillWeights(std::vector<float> &Weights,
SmallSet<unsigned, 4> Processed;
SmallSet<unsigned, 4> SuperAdded;
SmallVector<unsigned, 4> Supers;
// Unfavor downgraded registers for spilling.
if (DowngradedRegs.count(reg))
weight *= 2.0f;
Weights[reg] += weight;
Processed.insert(reg);
for (const unsigned* as = tri_->getAliasSet(reg); *as; ++as) {
@ -1015,8 +1012,32 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur)
// Merge added with unhandled. Note that we have already sorted
// intervals returned by addIntervalsForSpills by their starting
// point.
for (unsigned i = 0, e = added.size(); i != e; ++i)
unhandled_.push(added[i]);
// This also update the NextReloadMap. That is, it adds mapping from a
// register defined by a reload from SS to the next reload from SS in the
// same basic block.
MachineBasicBlock *LastReloadMBB = 0;
LiveInterval *LastReload = 0;
int LastReloadSS = VirtRegMap::NO_STACK_SLOT;
for (unsigned i = 0, e = added.size(); i != e; ++i) {
LiveInterval *ReloadLi = added[i];
if (ReloadLi->weight == HUGE_VALF &&
li_->getApproximateInstructionCount(*ReloadLi) == 0) {
unsigned ReloadIdx = ReloadLi->beginNumber();
MachineBasicBlock *ReloadMBB = li_->getMBBFromIndex(ReloadIdx);
int ReloadSS = vrm_->getStackSlot(ReloadLi->reg);
if (LastReloadMBB == ReloadMBB && LastReloadSS == ReloadSS) {
// Last reload of same SS is in the same MBB. We want to try to
// allocate both reloads the same register and make sure the reg
// isn't clobbered in between if at all possible.
assert(LastReload->beginNumber() < ReloadIdx);
NextReloadMap.insert(std::make_pair(LastReload->reg, ReloadLi->reg));
}
LastReloadMBB = ReloadMBB;
LastReload = ReloadLi;
LastReloadSS = ReloadSS;
}
unhandled_.push(ReloadLi);
}
return;
}