Stop using LiveIntervals::isReMaterializable().

It is an old function that does a lot more than required by
CalcSpillWeights, which was the only remaining caller.

The isRematerializable() function never actually sets the isLoad
argument, so don't try to compute that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157973 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2012-06-05 01:06:12 +00:00
parent e061053051
commit 3dfd59bdc3
2 changed files with 28 additions and 9 deletions

View File

@ -178,6 +178,10 @@ namespace llvm {
return Indexes;
}
AliasAnalysis *getAliasAnalysis() const {
return AA;
}
/// isNotInMIMap - returns true if the specified machine instr has been
/// removed or was never entered in the map.
bool isNotInMIMap(const MachineInstr* Instr) const {

View File

@ -86,6 +86,27 @@ static unsigned copyHint(const MachineInstr *mi, unsigned reg,
return tri.getMatchingSuperReg(hreg, sub, rc);
}
// 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;
}
void VirtRegAuxInfo::CalculateWeightAndHint(LiveInterval &li) {
MachineRegisterInfo &mri = MF.getRegInfo();
const TargetRegisterInfo &tri = *MF.getTarget().getRegisterInfo();
@ -171,17 +192,11 @@ void VirtRegAuxInfo::CalculateWeightAndHint(LiveInterval &li) {
}
// If all of the definitions of the interval are re-materializable,
// it is a preferred candidate for spilling. If none of the defs are
// loads, then it's potentially very cheap to re-materialize.
// it is a preferred candidate for spilling.
// FIXME: this gets much more complicated once we support non-trivial
// re-materialization.
bool isLoad = false;
if (LIS.isReMaterializable(li, 0, isLoad)) {
if (isLoad)
totalWeight *= 0.9F;
else
totalWeight *= 0.5F;
}
if (isRematerializable(li, LIS, *MF.getTarget().getInstrInfo()))
totalWeight *= 0.5F;
li.weight = normalizeSpillWeight(totalWeight, li.getSize());
}