maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Teach PBQPBuilder::build() about regunit interference. 

Filter out physreg candidates with regunit interferrence.
Also compute regmask interference more efficiently.

llvm-svn: 158864
This commit is contained in:
Jakob Stoklund Olesen 2012-06-20 22:32:05 +00:00
parent f9f2fbacb3
commit bfa664eaae
1 changed files with 31 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
llvm/lib/CodeGen/RegAllocPBQP.cpp
View File

@ -196,7 +196,7 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
const RegSet &vregs) {
typedef std::vector<const LiveInterval*> LIVector;
ArrayRef<SlotIndex> regMaskSlots = lis->getRegMaskSlots();
LiveIntervals *LIS = const_cast<LiveIntervals*>(lis);
MachineRegisterInfo *mri = &mf->getRegInfo();
const TargetRegisterInfo *tri = mf->getTarget().getRegisterInfo();
@ -206,7 +206,7 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
// Collect the set of preg intervals, record that they're used in the MF.
for (unsigned Reg = 1, e = tri->getNumRegs(); Reg != e; ++Reg) {
if (!lis->hasInterval(Reg))
if (mri->def_empty(Reg))
continue;
pregs.insert(Reg);
mri->setPhysRegUsed(Reg);
@ -219,7 +219,11 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
vregItr != vregEnd; ++vregItr) {
unsigned vreg = *vregItr;
const TargetRegisterClass *trc = mri->getRegClass(vreg);
const LiveInterval *vregLI = &lis->getInterval(vreg);
LiveInterval *vregLI = &LIS->getInterval(vreg);
// Record any overlaps with regmask operands.
BitVector regMaskOverlaps(tri->getNumRegs());
LIS->checkRegMaskInterference(*vregLI, regMaskOverlaps);
// Compute an initial allowed set for the current vreg.
typedef std::vector<unsigned> VRAllowed;
@ -227,9 +231,28 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
ArrayRef<uint16_t> rawOrder = trc->getRawAllocationOrder(*mf);
for (unsigned i = 0; i != rawOrder.size(); ++i) {
unsigned preg = rawOrder[i];
if (!reservedRegs.test(preg)) {
vrAllowed.push_back(preg);
if (reservedRegs.test(preg))
continue;
// vregLI crosses a regmask operand that clobbers preg.
if (!regMaskOverlaps.empty() && !regMaskOverlaps.test(preg))
continue;
// vregLI overlaps fixed regunit interference.
if (LIS->trackingRegUnits()) {
bool Interference = false;
for (MCRegUnitIterator Units(preg, tri); Units.isValid(); ++Units) {
if (vregLI->overlaps(LIS->getRegUnit(*Units))) {
Interference = true;
break;
}
}
if (Interference)
continue;
}
// preg is usable for this virtual register.
vrAllowed.push_back(preg);
}
RegSet overlappingPRegs;
@ -239,7 +262,9 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
pregEnd = pregs.end();
pregItr != pregEnd; ++pregItr) {
unsigned preg = *pregItr;
const LiveInterval *pregLI = &lis->getInterval(preg);
if (!LIS->hasInterval(preg))
continue;
const LiveInterval *pregLI = &LIS->getInterval(preg);
if (pregLI->empty()) {
continue;
@ -249,33 +274,6 @@ std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
overlappingPRegs.insert(preg);
}
// Record any overlaps with regmask operands.
BitVector regMaskOverlaps(tri->getNumRegs());
for (ArrayRef<SlotIndex>::iterator rmItr = regMaskSlots.begin(),
rmEnd = regMaskSlots.end();
rmItr != rmEnd; ++rmItr) {
SlotIndex rmIdx = *rmItr;
if (vregLI->liveAt(rmIdx)) {
MachineInstr *rmMI = lis->getInstructionFromIndex(rmIdx);
const uint32_t* regMask = 0;
for (MachineInstr::mop_iterator mopItr = rmMI->operands_begin(),
mopEnd = rmMI->operands_end();
mopItr != mopEnd; ++mopItr) {
if (mopItr->isRegMask()) {
regMask = mopItr->getRegMask();
break;
}
}
assert(regMask != 0 && "Couldn't find register mask.");
regMaskOverlaps.setBitsNotInMask(regMask);
}
}
for (unsigned preg = 0; preg < tri->getNumRegs(); ++preg) {
if (regMaskOverlaps.test(preg))
overlappingPRegs.insert(preg);
}
for (RegSet::const_iterator pregItr = overlappingPRegs.begin(),
pregEnd = overlappingPRegs.end();
pregItr != pregEnd; ++pregItr) {