bool LiveRangeEdit::checkRematerializable(VNInfo *VNI,
const MachineInstr *DefMI,
const TargetInstrInfo &tii,
AliasAnalysis *aa) {
assert(DefMI && "Missing instruction");
scannedRemattable_ = true;
if (!tii.isTriviallyReMaterializable(DefMI, aa))
return false;
remattable_.insert(VNI);
return true;
}
// Check if all values in LI are rematerializable
static bool isRematerializable(const LiveInterval &LI,
const LiveIntervals &LIS,
VirtRegMap *VRM,
const TargetInstrInfo &TII) {
unsigned Reg = LI.reg;
unsigned Original = VRM ? VRM->getOriginal(Reg) : 0;
for (LiveInterval::const_vni_iterator I = LI.vni_begin(), E = LI.vni_end();
I != E; ++I) {
const VNInfo *VNI = *I;
if (VNI->isUnused())
continue;
if (VNI->isPHIDef())
return false;
MachineInstr *MI = LIS.getInstructionFromIndex(VNI->def);
assert(MI && "Dead valno in interval");
// Trace copies introduced by live range splitting. The inline
// spiller can rematerialize through these copies, so the spill
// weight must reflect this.
if (VRM) {
while (MI->isFullCopy()) {
// The copy destination must match the interval register.
if (MI->getOperand(0).getReg() != Reg)
return false;
// Get the source register.
Reg = MI->getOperand(1).getReg();
// If the original (pre-splitting) registers match this
// copy came from a split.
if (!TargetRegisterInfo::isVirtualRegister(Reg) ||
VRM->getOriginal(Reg) != Original)
return false;
// Follow the copy live-in value.
const LiveInterval &SrcLI = LIS.getInterval(Reg);
LiveQueryResult SrcQ = SrcLI.Query(VNI->def);
VNI = SrcQ.valueIn();
assert(VNI && "Copy from non-existing value");
if (VNI->isPHIDef())
return false;
MI = LIS.getInstructionFromIndex(VNI->def);
assert(MI && "Dead valno in interval");
}
}
if (!TII.isTriviallyReMaterializable(*MI, LIS.getAliasAnalysis()))
return false;
}
return true;
}
// Check if all values in LI are rematerializable
static bool isRematerializable(const LiveInterval &LI,
const LiveIntervals &LIS,
const TargetInstrInfo &TII) {
for (LiveInterval::const_vni_iterator I = LI.vni_begin(), E = LI.vni_end();
I != E; ++I) {
const VNInfo *VNI = *I;
if (VNI->isUnused())
continue;
if (VNI->isPHIDef())
return false;
MachineInstr *MI = LIS.getInstructionFromIndex(VNI->def);
assert(MI && "Dead valno in interval");
if (!TII.isTriviallyReMaterializable(MI, LIS.getAliasAnalysis()))
return false;
}
return true;
}
