diff options
author | Dan Gohman <gohman@apple.com> | 2010-05-13 20:34:42 +0000 |
---|---|---|
committer | Dan Gohman <gohman@apple.com> | 2010-05-13 20:34:42 +0000 |
commit | e6cd757e6800b9b94a6459ec148c0624c4f2e3c1 (patch) | |
tree | d5f6dc0117786538e247416458b5f8fb9bed5367 /lib | |
parent | 1e5a6c46b8f8cca0e4e6d582289bfd13cb462e39 (diff) | |
download | llvm-e6cd757e6800b9b94a6459ec148c0624c4f2e3c1.tar.gz llvm-e6cd757e6800b9b94a6459ec148c0624c4f2e3c1.tar.bz2 llvm-e6cd757e6800b9b94a6459ec148c0624c4f2e3c1.tar.xz |
Teach MachineLICM and MachineSink how to clear kill flags conservatively
when they move instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103737 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/CodeGen/MachineInstr.cpp | 10 | ||||
-rw-r--r-- | lib/CodeGen/MachineLICM.cpp | 13 | ||||
-rw-r--r-- | lib/CodeGen/MachineSink.cpp | 5 |
3 files changed, 27 insertions, 1 deletions
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp index 99b5beb136..d909fb0ef3 100644 --- a/lib/CodeGen/MachineInstr.cpp +++ b/lib/CodeGen/MachineInstr.cpp @@ -938,6 +938,16 @@ isRegTiedToDefOperand(unsigned UseOpIdx, unsigned *DefOpIdx) const { return true; } +/// clearKillInfo - Clears kill flags on all operands. +/// +void MachineInstr::clearKillInfo() { + for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { + MachineOperand &MO = getOperand(i); + if (MO.isReg() && MO.isUse()) + MO.setIsKill(false); + } +} + /// copyKillDeadInfo - Copies kill / dead operand properties from MI. /// void MachineInstr::copyKillDeadInfo(const MachineInstr *MI) { diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp index b2e757d8d6..61206173e6 100644 --- a/lib/CodeGen/MachineLICM.cpp +++ b/lib/CodeGen/MachineLICM.cpp @@ -738,8 +738,10 @@ bool MachineLICM::EliminateCSE(MachineInstr *MI, "Instructions with different phys regs are not identical!"); if (MO.isReg() && MO.isDef() && - !TargetRegisterInfo::isPhysicalRegister(MO.getReg())) + !TargetRegisterInfo::isPhysicalRegister(MO.getReg())) { RegInfo->replaceRegWith(MO.getReg(), Dup->getOperand(i).getReg()); + RegInfo->clearKillFlags(Dup->getOperand(i).getReg()); + } } MI->eraseFromParent(); ++NumCSEed; @@ -784,6 +786,15 @@ void MachineLICM::Hoist(MachineInstr *MI) { // Otherwise, splice the instruction to the preheader. CurPreheader->splice(CurPreheader->getFirstTerminator(),MI->getParent(),MI); + // Clear the kill flags of any register this instruction defines, + // since they may need to be live throughout the entire loop + // rather than just live for part of it. + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + MachineOperand &MO = MI->getOperand(i); + if (MO.isReg() && MO.isDef() && !MO.isDead()) + RegInfo->clearKillFlags(MO.getReg()); + } + // Add to the CSE map. if (CI != CSEMap.end()) CI->second.push_back(MI); diff --git a/lib/CodeGen/MachineSink.cpp b/lib/CodeGen/MachineSink.cpp index ef489dc556..1610e6c961 100644 --- a/lib/CodeGen/MachineSink.cpp +++ b/lib/CodeGen/MachineSink.cpp @@ -314,5 +314,10 @@ bool MachineSinking::SinkInstruction(MachineInstr *MI, bool &SawStore) { // Move the instruction. SuccToSinkTo->splice(InsertPos, ParentBlock, MI, ++MachineBasicBlock::iterator(MI)); + + // Conservatively, clear any kill flags, since it's possible that + // they are no longer correct. + MI->clearKillInfo(); + return true; } |