diff options
Diffstat (limited to 'llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp | 110 |
1 files changed, 0 insertions, 110 deletions
diff --git a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp index 810fabeef7b..ed407eb40cb 100644 --- a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -2622,114 +2622,6 @@ void SimpleRegisterCoalescing::releaseMemory() { ReMatDefs.clear(); } -/// Returns true if the given live interval is zero length. -static bool isZeroLengthInterval(LiveInterval *li, LiveIntervals *li_) { - for (LiveInterval::Ranges::const_iterator - i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i) - if (i->end.getPrevIndex() > i->start) - return false; - return true; -} - - -void SimpleRegisterCoalescing::CalculateSpillWeights() { - SmallSet<unsigned, 4> Processed; - for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end(); - mbbi != mbbe; ++mbbi) { - MachineBasicBlock* MBB = mbbi; - SlotIndex MBBEnd = li_->getMBBEndIdx(MBB); - MachineLoop* loop = loopInfo->getLoopFor(MBB); - unsigned loopDepth = loop ? loop->getLoopDepth() : 0; - bool isExiting = loop ? loop->isLoopExiting(MBB) : false; - - for (MachineBasicBlock::const_iterator mii = MBB->begin(), mie = MBB->end(); - mii != mie; ++mii) { - const MachineInstr *MI = mii; - if (tii_->isIdentityCopy(*MI)) - continue; - - if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) - continue; - - for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { - const MachineOperand &mopi = MI->getOperand(i); - if (!mopi.isReg() || mopi.getReg() == 0) - continue; - unsigned Reg = mopi.getReg(); - if (!TargetRegisterInfo::isVirtualRegister(mopi.getReg())) - continue; - // Multiple uses of reg by the same instruction. It should not - // contribute to spill weight again. - if (!Processed.insert(Reg)) - continue; - - bool HasDef = mopi.isDef(); - bool HasUse = !HasDef; - for (unsigned j = i+1; j != e; ++j) { - const MachineOperand &mopj = MI->getOperand(j); - if (!mopj.isReg() || mopj.getReg() != Reg) - continue; - HasDef |= mopj.isDef(); - HasUse |= mopj.isUse(); - if (HasDef && HasUse) - break; - } - - LiveInterval &RegInt = li_->getInterval(Reg); - float Weight = li_->getSpillWeight(HasDef, HasUse, loopDepth); - if (HasDef && isExiting) { - // Looks like this is a loop count variable update. - SlotIndex DefIdx = li_->getInstructionIndex(MI).getDefIndex(); - const LiveRange *DLR = - li_->getInterval(Reg).getLiveRangeContaining(DefIdx); - if (DLR->end > MBBEnd) - Weight *= 3.0F; - } - RegInt.weight += Weight; - } - Processed.clear(); - } - } - - for (LiveIntervals::iterator I = li_->begin(), E = li_->end(); I != E; ++I) { - LiveInterval &LI = *I->second; - if (TargetRegisterInfo::isVirtualRegister(LI.reg)) { - // If the live interval length is essentially zero, i.e. in every live - // range the use follows def immediately, it doesn't make sense to spill - // it and hope it will be easier to allocate for this li. - if (isZeroLengthInterval(&LI, li_)) { - LI.weight = HUGE_VALF; - continue; - } - - bool isLoad = false; - SmallVector<LiveInterval*, 4> SpillIs; - if (li_->isReMaterializable(LI, SpillIs, isLoad)) { - // If all of the definitions of the interval are re-materializable, - // it is a preferred candidate for spilling. If non of the defs are - // loads, then it's potentially very cheap to re-materialize. - // FIXME: this gets much more complicated once we support non-trivial - // re-materialization. - if (isLoad) - LI.weight *= 0.9F; - else - LI.weight *= 0.5F; - } - - // Slightly prefer live interval that has been assigned a preferred reg. - std::pair<unsigned, unsigned> Hint = mri_->getRegAllocationHint(LI.reg); - if (Hint.first || Hint.second) - LI.weight *= 1.01F; - - // Divide the weight of the interval by its size. This encourages - // spilling of intervals that are large and have few uses, and - // discourages spilling of small intervals with many uses. - LI.weight /= li_->getApproximateInstructionCount(LI) * InstrSlots::NUM; - } - } -} - - bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) { mf_ = &fn; mri_ = &fn.getRegInfo(); @@ -2860,8 +2752,6 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) { } } - CalculateSpillWeights(); - DEBUG(dump()); return true; } |

