cl::init(true));
RegisterPass<SimpleRegisterCoalescing>
- X("simple-register-coalescing",
- "Simple register coalescing to eliminate all possible register copies");
+ X("simple-register-coalescing", "Simple Register Coalescing");
}
const PassInfo *llvm::SimpleRegisterCoalescingID = X.getPassInfo();
// Get the location that B is defined at. Two options: either this value has
// an unknown definition point or it is defined at CopyIdx. If unknown, we
// can't process it.
- unsigned BValNoDefIdx = IntB.getInstForValNum(BValNo);
- if (BValNoDefIdx == ~0U) return false;
+ unsigned BValNoDefIdx = IntB.getDefForValNum(BValNo);
+ if (!IntB.getSrcRegForValNum(BValNo)) return false;
assert(BValNoDefIdx == CopyIdx &&
"Copy doesn't define the value?");
if (rep(SrcReg) != IntB.reg) return false;
// Get the LiveRange in IntB that this value number starts with.
- unsigned AValNoInstIdx = IntA.getInstForValNum(AValNo);
+ unsigned AValNoInstIdx = IntA.getDefForValNum(AValNo);
LiveInterval::iterator ValLR = IntB.FindLiveRangeContaining(AValNoInstIdx-1);
// Make sure that the end of the live range is inside the same block as
DOUT << "\nExtending: "; IntB.print(DOUT, mri_);
+ unsigned FillerStart = ValLR->end, FillerEnd = BLR->start;
// We are about to delete CopyMI, so need to remove it as the 'instruction
- // that defines this value #'.
- IntB.setValueNumberInfo(BValNo, std::make_pair(~0U, 0));
+ // that defines this value #'. Update the the valnum with the new defining
+ // instruction #.
+ IntB.setDefForValNum(BValNo, FillerStart);
+ IntB.setSrcRegForValNum(BValNo, 0);
// Okay, we can merge them. We need to insert a new liverange:
// [ValLR.end, BLR.begin) of either value number, then we merge the
// two value numbers.
- unsigned FillerStart = ValLR->end, FillerEnd = BLR->start;
IntB.addRange(LiveRange(FillerStart, FillerEnd, BValNo));
// If the IntB live range is assigned to a physical register, and if that
for (const unsigned *AS = mri_->getSubRegisters(IntB.reg); *AS; ++AS) {
LiveInterval &AliasLI = li_->getInterval(*AS);
AliasLI.addRange(LiveRange(FillerStart, FillerEnd,
- AliasLI.getNextValue(~0U, 0)));
+ AliasLI.getNextValue(FillerStart, 0)));
}
}
}
if (isShorten || isDead) {
- // Shorten the live interval.
- LiveInterval &LiveInInt = (repSrcReg == DstInt.reg) ? DstInt : SrcInt;
- LiveInInt.removeRange(RemoveStart, RemoveEnd);
+ // Shorten the destination live interval.
+ if (repSrcReg == DstInt.reg)
+ DstInt.removeRange(RemoveStart, RemoveEnd);
}
} else {
// Coalescing failed.
/// contains the value number the copy is from.
///
static unsigned ComputeUltimateVN(unsigned VN,
- SmallVector<std::pair<unsigned,
- unsigned>, 16> &ValueNumberInfo,
+ SmallVector<LiveInterval::VNInfo, 16> &ValueNumberInfo,
SmallVector<int, 16> &ThisFromOther,
SmallVector<int, 16> &OtherFromThis,
SmallVector<int, 16> &ThisValNoAssignments,
// Okay, now that there is a single LHS value number that we're merging the
// RHS into, update the value number info for the LHS to indicate that the
// value number is defined where the RHS value number was.
- LHS.setValueNumberInfo(LHSValNo, RHS.getValNumInfo(0));
+ const LiveInterval::VNInfo VNI = RHS.getValNumInfo(0);
+ LHS.setDefForValNum(LHSValNo, VNI.def);
+ LHS.setSrcRegForValNum(LHSValNo, VNI.reg);
// Okay, the final step is to loop over the RHS live intervals, adding them to
// the LHS.
LHS.MergeRangesInAsValue(RHS, LHSValNo);
+ LHS.addKillsForValNum(LHSValNo, VNI.kills);
LHS.weight += RHS.weight;
if (RHS.preference && !LHS.preference)
LHS.preference = RHS.preference;
// coalesced.
SmallVector<int, 16> LHSValNoAssignments;
SmallVector<int, 16> RHSValNoAssignments;
- SmallVector<std::pair<unsigned,unsigned>, 16> ValueNumberInfo;
+ SmallVector<int, 16> LHSValsDefinedFromRHS;
+ SmallVector<int, 16> RHSValsDefinedFromLHS;
+ SmallVector<LiveInterval::VNInfo, 16> ValueNumberInfo;
// If a live interval is a physical register, conservatively check if any
// of its sub-registers is overlapping the live interval of the virtual
// often RHS is small and LHS is large (e.g. a physreg).
// Find out if the RHS is defined as a copy from some value in the LHS.
+ int RHSVal0DefinedFromLHS = -1;
int RHSValID = -1;
- std::pair<unsigned,unsigned> RHSValNoInfo;
+ LiveInterval::VNInfo RHSValNoInfo;
unsigned RHSSrcReg = RHS.getSrcRegForValNum(0);
if ((RHSSrcReg == 0 || rep(RHSSrcReg) != LHS.reg)) {
// If RHS is not defined as a copy from the LHS, we can use simpler and
}
} else {
// It was defined as a copy from the LHS, find out what value # it is.
- unsigned ValInst = RHS.getInstForValNum(0);
+ unsigned ValInst = RHS.getDefForValNum(0);
RHSValID = LHS.getLiveRangeContaining(ValInst-1)->ValId;
RHSValNoInfo = LHS.getValNumInfo(RHSValID);
+ RHSVal0DefinedFromLHS = RHSValID;
}
LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
// value# for it. Keep the current value number, but remember it.
LHSValNoAssignments[VN] = RHSValID = VN;
ValueNumberInfo[VN] = RHSValNoInfo;
+ RHS.addKills(ValueNumberInfo[VN], LHS.getKillsForValNum(VN));
} else {
// Otherwise, use the specified value #.
LHSValNoAssignments[VN] = RHSValID;
if (VN != (unsigned)RHSValID)
- ValueNumberInfo[VN].first = ~1U;
- else
+ ValueNumberInfo[VN].def = ~1U; // Now this val# is dead.
+ else {
ValueNumberInfo[VN] = RHSValNoInfo;
+ RHS.addKills(ValueNumberInfo[VN], LHS.getKillsForValNum(VN));
+ }
}
} else {
ValueNumberInfo[VN] = LHS.getValNumInfo(VN);
assert(RHSValID != -1 && "Didn't find value #?");
RHSValNoAssignments[0] = RHSValID;
-
+ if (RHSVal0DefinedFromLHS != -1) {
+ int LHSValId = LHSValNoAssignments[RHSVal0DefinedFromLHS];
+ LHS.addKills(ValueNumberInfo[LHSValId], RHS.getKillsForValNum(0));
+ }
} else {
// Loop over the value numbers of the LHS, seeing if any are defined from
// the RHS.
- SmallVector<int, 16> LHSValsDefinedFromRHS;
LHSValsDefinedFromRHS.resize(LHS.getNumValNums(), -1);
for (unsigned VN = 0, e = LHS.getNumValNums(); VN != e; ++VN) {
unsigned ValSrcReg = LHS.getSrcRegForValNum(VN);
continue;
// Figure out the value # from the RHS.
- unsigned ValInst = LHS.getInstForValNum(VN);
+ unsigned ValInst = LHS.getDefForValNum(VN);
LHSValsDefinedFromRHS[VN] = RHS.getLiveRangeContaining(ValInst-1)->ValId;
}
// Loop over the value numbers of the RHS, seeing if any are defined from
// the LHS.
- SmallVector<int, 16> RHSValsDefinedFromLHS;
RHSValsDefinedFromLHS.resize(RHS.getNumValNums(), -1);
for (unsigned VN = 0, e = RHS.getNumValNums(); VN != e; ++VN) {
unsigned ValSrcReg = RHS.getSrcRegForValNum(VN);
continue;
// Figure out the value # from the LHS.
- unsigned ValInst = RHS.getInstForValNum(VN);
+ unsigned ValInst = RHS.getDefForValNum(VN);
RHSValsDefinedFromLHS[VN] = LHS.getLiveRangeContaining(ValInst-1)->ValId;
}
ValueNumberInfo.reserve(LHS.getNumValNums() + RHS.getNumValNums());
for (unsigned VN = 0, e = LHS.getNumValNums(); VN != e; ++VN) {
- if (LHSValNoAssignments[VN] >= 0 || LHS.getInstForValNum(VN) == ~2U)
+ if (LHSValNoAssignments[VN] >= 0 || LHS.getDefForValNum(VN) == ~1U)
continue;
ComputeUltimateVN(VN, ValueNumberInfo,
LHSValsDefinedFromRHS, RHSValsDefinedFromLHS,
LHSValNoAssignments, RHSValNoAssignments, LHS, RHS);
}
for (unsigned VN = 0, e = RHS.getNumValNums(); VN != e; ++VN) {
- if (RHSValNoAssignments[VN] >= 0 || RHS.getInstForValNum(VN) == ~2U)
+ if (RHSValNoAssignments[VN] >= 0 || RHS.getDefForValNum(VN) == ~1U)
continue;
// If this value number isn't a copy from the LHS, it's a new number.
if (RHSValsDefinedFromLHS[VN] == -1) {
}
}
+ // Update kill info. Some live ranges are extended due to copy coalescing.
+ for (unsigned i = 0, e = RHSValsDefinedFromLHS.size(); i != e; ++i) {
+ int LHSValId = RHSValsDefinedFromLHS[i];
+ if (LHSValId == -1)
+ continue;
+ unsigned RHSValId = RHSValNoAssignments[i];
+ LHS.addKills(ValueNumberInfo[RHSValId], RHS.getKillsForValNum(i));
+ }
+ for (unsigned i = 0, e = LHSValsDefinedFromRHS.size(); i != e; ++i) {
+ int RHSValId = LHSValsDefinedFromRHS[i];
+ if (RHSValId == -1)
+ continue;
+ unsigned LHSValId = LHSValNoAssignments[i];
+ RHS.addKills(ValueNumberInfo[LHSValId], LHS.getKillsForValNum(i));
+ }
+
// If we get here, we know that we can coalesce the live ranges. Ask the
// intervals to coalesce themselves now.
LHS.join(RHS, &LHSValNoAssignments[0], &RHSValNoAssignments[0],
continue;
LiveInterval &RegInt = li_->getInterval(reg);
float w = (mop.isUse()+mop.isDef()) * powf(10.0F, (float)loopDepth);
- // If the definition instruction is re-materializable, its spill
- // weight is half of what it would have been normally unless it's
- // a load from fixed stack slot.
- int Dummy;
- if (RegInt.remat && !tii_->isLoadFromStackSlot(RegInt.remat, Dummy))
- w /= 2;
RegInt.weight += w;
UniqueUses.insert(reg);
}
projects / oota-llvm.git / blobdiff