From e6cd757e6800b9b94a6459ec148c0624c4f2e3c1 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Thu, 13 May 2010 20:34:42 +0000 Subject: 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 --- lib/CodeGen/MachineLICM.cpp | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'lib/CodeGen/MachineLICM.cpp') diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp index b2e757d8d..6120617 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); -- cgit v1.1