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Remove an unused option. 

llvm-svn: 99537
This commit is contained in:
Evan Cheng 2010-03-25 18:37:23 +00:00
parent 0ba6a671d4
commit a1d0a02713
1 changed files with 28 additions and 58 deletions
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86
llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp
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@ -59,11 +59,6 @@ DisableCrossClassJoin("disable-cross-class-join",
cl::desc("Avoid coalescing cross register class copies"),
cl::init(false), cl::Hidden);
static cl::opt<bool>
PhysJoinTweak("tweak-phys-join-heuristics",
cl::desc("Tweak heuristics for joining phys reg with vr"),
cl::init(false), cl::Hidden);
static RegisterPass<SimpleRegisterCoalescing>
X("simple-register-coalescing", "Simple Register Coalescing");
@ -1445,7 +1440,6 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
const TargetRegisterClass *SrcRC= SrcIsPhys ? 0 : mri_->getRegClass(SrcReg);
const TargetRegisterClass *DstRC= DstIsPhys ? 0 : mri_->getRegClass(DstReg);
const TargetRegisterClass *NewRC = NULL;
MachineBasicBlock *CopyMBB = CopyMI->getParent();
unsigned RealDstReg = 0;
unsigned RealSrcReg = 0;
if (isExtSubReg || isInsSubReg || isSubRegToReg) {
@ -1656,60 +1650,36 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
// these are not spillable! If the destination interval uses are far away,
// think twice about coalescing them!
if (!isDead && (SrcIsPhys || DstIsPhys)) {
// If the copy is in a loop, take care not to coalesce aggressively if the
// src is coming in from outside the loop (or the dst is out of the loop).
// If it's not in a loop, then determine whether to join them base purely
// by the length of the interval.
if (PhysJoinTweak) {
if (SrcIsPhys) {
if (!isWinToJoinVRWithSrcPhysReg(CopyMI, CopyMBB, DstInt, SrcInt)) {
mri_->setRegAllocationHint(DstInt.reg, 0, SrcReg);
++numAborts;
DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
Again = true; // May be possible to coalesce later.
return false;
}
} else {
if (!isWinToJoinVRWithDstPhysReg(CopyMI, CopyMBB, DstInt, SrcInt)) {
mri_->setRegAllocationHint(SrcInt.reg, 0, DstReg);
++numAborts;
DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
Again = true; // May be possible to coalesce later.
return false;
}
}
} else {
// If the virtual register live interval is long but it has low use
// density, do not join them, instead mark the physical register as its
// allocation preference.
LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
LiveInterval &JoinPInt = SrcIsPhys ? SrcInt : DstInt;
unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
// If the virtual register live interval is long but it has low use
// density, do not join them, instead mark the physical register as its
// allocation preference.
LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
LiveInterval &JoinPInt = SrcIsPhys ? SrcInt : DstInt;
unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
// Don't join with physregs that have a ridiculous number of live
// ranges. The data structure performance is really bad when that
// happens.
if (JoinPInt.ranges.size() > 1000) {
mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
++numAborts;
DEBUG(dbgs() << "\tPhysical register too complicated, abort!\n");
return false;
}
// Don't join with physregs that have a ridiculous number of live
// ranges. The data structure performance is really bad when that
// happens.
if (JoinPInt.ranges.size() > 1000) {
mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
++numAborts;
DEBUG(dbgs() << "\tPhysical register too complicated, abort!\n");
return false;
}
const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
float Ratio = 1.0 / Threshold;
if (Length > Threshold &&
(((float)std::distance(mri_->use_nodbg_begin(JoinVReg),
mri_->use_nodbg_end()) / Length) < Ratio)) {
mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
++numAborts;
DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
Again = true; // May be possible to coalesce later.
return false;
}
const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
float Ratio = 1.0 / Threshold;
if (Length > Threshold &&
(((float)std::distance(mri_->use_nodbg_begin(JoinVReg),
mri_->use_nodbg_end()) / Length) < Ratio)) {
mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
++numAborts;
DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
Again = true; // May be possible to coalesce later.
return false;
}
}
}