diff options
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/LiveIntervalAnalysis.cpp | 2 | ||||
| -rw-r--r-- | llvm/lib/CodeGen/RegAllocLinearScan.cpp | 2 | ||||
| -rw-r--r-- | llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp | 16 |
3 files changed, 14 insertions, 6 deletions
diff --git a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp index 68bd0a60c98..07f83ea7cef 100644 --- a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -572,7 +572,7 @@ void LiveIntervals::handleRegisterDef(MachineBasicBlock *MBB, if (TargetRegisterInfo::isVirtualRegister(MO.getReg())) handleVirtualRegisterDef(MBB, MI, MIIdx, MO, MOIdx, getOrCreateInterval(MO.getReg())); - else if (allocatableRegs_[MO.getReg()]) { + else { MachineInstr *CopyMI = NULL; if (MI->isCopyLike()) CopyMI = MI; diff --git a/llvm/lib/CodeGen/RegAllocLinearScan.cpp b/llvm/lib/CodeGen/RegAllocLinearScan.cpp index 966570f3f33..ef78949c54e 100644 --- a/llvm/lib/CodeGen/RegAllocLinearScan.cpp +++ b/llvm/lib/CodeGen/RegAllocLinearScan.cpp @@ -572,7 +572,7 @@ void RALinScan::initIntervalSets() for (LiveIntervals::iterator i = li_->begin(), e = li_->end(); i != e; ++i) { if (TargetRegisterInfo::isPhysicalRegister(i->second->reg)) { - if (!i->second->empty()) { + if (!i->second->empty() && allocatableRegs_.test(i->second->reg)) { mri_->setPhysRegUsed(i->second->reg); fixed_.push_back(std::make_pair(i->second, i->second->begin())); } diff --git a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp index 93aa0a31207..c621726a03f 100644 --- a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -919,13 +919,23 @@ SimpleRegisterCoalescing::ShortenDeadCopySrcLiveRange(LiveInterval &li, /// are not spillable! If the destination interval uses are far away, think /// twice about coalescing them! bool SimpleRegisterCoalescing::shouldJoinPhys(CoalescerPair &CP) { + bool Allocatable = li_->isAllocatable(CP.getDstReg()); + LiveInterval &JoinVInt = li_->getInterval(CP.getSrcReg()); + + /// Always join simple intervals that are defined by a single copy from a + /// reserved register. This doesn't increase register pressure, so it is + /// always beneficial. + if (!Allocatable && CP.isFlipped() && JoinVInt.containsOneValue()) + return true; + if (DisablePhysicalJoin) { DEBUG(dbgs() << "\tPhysreg joins disabled.\n"); return false; } - // Only coalesce to allocatable physreg. - if (!li_->isAllocatable(CP.getDstReg())) { + // Only coalesce to allocatable physreg, we don't want to risk modifying + // reserved registers. + if (!Allocatable) { DEBUG(dbgs() << "\tRegister is an unallocatable physreg.\n"); return false; // Not coalescable. } @@ -944,8 +954,6 @@ bool SimpleRegisterCoalescing::shouldJoinPhys(CoalescerPair &CP) { // FIXME: Why are we skipping this test for partial copies? // CodeGen/X86/phys_subreg_coalesce-3.ll needs it. if (!CP.isPartial()) { - LiveInterval &JoinVInt = li_->getInterval(CP.getSrcReg()); - const TargetRegisterClass *RC = mri_->getRegClass(CP.getSrcReg()); unsigned Threshold = allocatableRCRegs_[RC].count() * 2; unsigned Length = li_->getApproximateInstructionCount(JoinVInt); |
