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[SystemZ] Build Load And Test from scratch in convertToLoadAndTest. 

This is needed to get CC operand in right place, as expected by the
SchedModel.

Review: Ulrich Weigand
https://reviews.llvm.org/D47820

llvm-svn: 334161
This commit is contained in:
Jonas Paulsson 2018-06-07 05:59:07 +00:00
parent 8153628f6a
commit e80d405760
1 changed files with 16 additions and 10 deletions
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26
llvm/lib/Target/SystemZ/SystemZElimCompare.cpp
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@ -293,9 +293,14 @@ bool SystemZElimCompare::convertToLoadAndTest(
if (!Opcode || !adjustCCMasksForInstr(MI, Compare, CCUsers, Opcode))
return false;
MI.setDesc(TII->get(Opcode));
MachineInstrBuilder(*MI.getParent()->getParent(), MI)
.addReg(SystemZ::CC, RegState::ImplicitDefine);
// Rebuild to get the CC operand in the right place.
MachineInstr *BuiltMI =
BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), TII->get(Opcode));
for (const auto &MO : MI.operands())
BuiltMI->addOperand(MO);
BuiltMI->setMemRefs(MI.memoperands_begin(), MI.memoperands_end());
MI.eraseFromParent();
return true;
}
@ -425,12 +430,12 @@ bool SystemZElimCompare::optimizeCompareZero(
// Search back for CC results that are based on the first operand.
unsigned SrcReg = getCompareSourceReg(Compare);
MachineBasicBlock &MBB = *Compare.getParent();
MachineBasicBlock::iterator MBBI = Compare, MBBE = MBB.begin();
Reference CCRefs;
Reference SrcRefs;
while (MBBI != MBBE) {
--MBBI;
MachineInstr &MI = *MBBI;
for (MachineBasicBlock::reverse_iterator MBBI =
std::next(MachineBasicBlock::reverse_iterator(&Compare)),
MBBE = MBB.rend(); MBBI != MBBE;) {
MachineInstr &MI = *MBBI++;
if (resultTests(MI, SrcReg)) {
// Try to remove both MI and Compare by converting a branch to BRCT(G).
// or a load-and-trap instruction. We don't care in this case whether
@ -463,9 +468,10 @@ bool SystemZElimCompare::optimizeCompareZero(
// Also do a forward search to handle cases where an instruction after the
// compare can be converted, like
// LTEBRCompare %f0s, %f0s; %f2s = LER %f0s => LTEBRCompare %f2s, %f0s
MBBI = Compare, MBBE = MBB.end();
while (++MBBI != MBBE) {
MachineInstr &MI = *MBBI;
for (MachineBasicBlock::iterator MBBI =
std::next(MachineBasicBlock::iterator(&Compare)), MBBE = MBB.end();
MBBI != MBBE;) {
MachineInstr &MI = *MBBI++;
if (preservesValueOf(MI, SrcReg)) {
// Try to eliminate Compare by reusing a CC result from MI.
if (convertToLoadAndTest(MI, Compare, CCUsers)) {