[llvm-commits] [llvm] r106548 - in /llvm/trunk: lib/CodeGen/SimpleRegisterCoalescing.cpp lib/CodeGen/SimpleRegisterCoalescing.h test/CodeGen/X86/pr2659.ll
Jakob Stoklund Olesen
stoklund at 2pi.dk
Tue Jun 22 09:13:57 PDT 2010
Author: stoklund
Date: Tue Jun 22 11:13:57 2010
New Revision: 106548
URL: http://llvm.org/viewvc/llvm-project?rev=106548&view=rev
Log:
Remove the SimpleJoin optimization from SimpleRegisterCoalescing.
Measurements show that it does not speed up coalescing, so there is no reason
the keep the added complexity around.
Also clean out some unused methods and static functions.
Modified:
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
llvm/trunk/test/CodeGen/X86/pr2659.ll
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp?rev=106548&r1=106547&r2=106548&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp Tue Jun 22 11:13:57 2010
@@ -1034,119 +1034,6 @@
}
-/// isWinToJoinVRWithSrcPhysReg - Return true if it's worth while to join a
-/// a virtual destination register with physical source register.
-bool
-SimpleRegisterCoalescing::isWinToJoinVRWithSrcPhysReg(MachineInstr *CopyMI,
- MachineBasicBlock *CopyMBB,
- LiveInterval &DstInt,
- LiveInterval &SrcInt) {
- // If the virtual register live interval is long but it has low use desity,
- // do not join them, instead mark the physical register as its allocation
- // preference.
- const TargetRegisterClass *RC = mri_->getRegClass(DstInt.reg);
- unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
- unsigned Length = li_->getApproximateInstructionCount(DstInt);
- if (Length > Threshold &&
- std::distance(mri_->use_nodbg_begin(DstInt.reg),
- mri_->use_nodbg_end()) * Threshold < Length)
- return false;
-
- // If the virtual register live interval extends into a loop, turn down
- // aggressiveness.
- SlotIndex CopyIdx =
- li_->getInstructionIndex(CopyMI).getDefIndex();
- const MachineLoop *L = loopInfo->getLoopFor(CopyMBB);
- if (!L) {
- // Let's see if the virtual register live interval extends into the loop.
- LiveInterval::iterator DLR = DstInt.FindLiveRangeContaining(CopyIdx);
- assert(DLR != DstInt.end() && "Live range not found!");
- DLR = DstInt.FindLiveRangeContaining(DLR->end.getNextSlot());
- if (DLR != DstInt.end()) {
- CopyMBB = li_->getMBBFromIndex(DLR->start);
- L = loopInfo->getLoopFor(CopyMBB);
- }
- }
-
- if (!L || Length <= Threshold)
- return true;
-
- SlotIndex UseIdx = CopyIdx.getUseIndex();
- LiveInterval::iterator SLR = SrcInt.FindLiveRangeContaining(UseIdx);
- MachineBasicBlock *SMBB = li_->getMBBFromIndex(SLR->start);
- if (loopInfo->getLoopFor(SMBB) != L) {
- if (!loopInfo->isLoopHeader(CopyMBB))
- return false;
- // If vr's live interval extends pass the loop header, do not join.
- for (MachineBasicBlock::succ_iterator SI = CopyMBB->succ_begin(),
- SE = CopyMBB->succ_end(); SI != SE; ++SI) {
- MachineBasicBlock *SuccMBB = *SI;
- if (SuccMBB == CopyMBB)
- continue;
- if (DstInt.overlaps(li_->getMBBStartIdx(SuccMBB),
- li_->getMBBEndIdx(SuccMBB)))
- return false;
- }
- }
- return true;
-}
-
-/// isWinToJoinVRWithDstPhysReg - Return true if it's worth while to join a
-/// copy from a virtual source register to a physical destination register.
-bool
-SimpleRegisterCoalescing::isWinToJoinVRWithDstPhysReg(MachineInstr *CopyMI,
- MachineBasicBlock *CopyMBB,
- LiveInterval &DstInt,
- LiveInterval &SrcInt) {
- // 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.
- const TargetRegisterClass *RC = mri_->getRegClass(SrcInt.reg);
- unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
- unsigned Length = li_->getApproximateInstructionCount(SrcInt);
- if (Length > Threshold &&
- std::distance(mri_->use_nodbg_begin(SrcInt.reg),
- mri_->use_nodbg_end()) * Threshold < Length)
- return false;
-
- if (SrcInt.empty())
- // Must be implicit_def.
- return false;
-
- // If the virtual register live interval is defined or cross a loop, turn
- // down aggressiveness.
- SlotIndex CopyIdx =
- li_->getInstructionIndex(CopyMI).getDefIndex();
- SlotIndex UseIdx = CopyIdx.getUseIndex();
- LiveInterval::iterator SLR = SrcInt.FindLiveRangeContaining(UseIdx);
- assert(SLR != SrcInt.end() && "Live range not found!");
- SLR = SrcInt.FindLiveRangeContaining(SLR->start.getPrevSlot());
- if (SLR == SrcInt.end())
- return true;
- MachineBasicBlock *SMBB = li_->getMBBFromIndex(SLR->start);
- const MachineLoop *L = loopInfo->getLoopFor(SMBB);
-
- if (!L || Length <= Threshold)
- return true;
-
- if (loopInfo->getLoopFor(CopyMBB) != L) {
- if (SMBB != L->getLoopLatch())
- return false;
- // If vr's live interval is extended from before the loop latch, do not
- // join.
- for (MachineBasicBlock::pred_iterator PI = SMBB->pred_begin(),
- PE = SMBB->pred_end(); PI != PE; ++PI) {
- MachineBasicBlock *PredMBB = *PI;
- if (PredMBB == SMBB)
- continue;
- if (SrcInt.overlaps(li_->getMBBStartIdx(PredMBB),
- li_->getMBBEndIdx(PredMBB)))
- return false;
- }
- }
- return true;
-}
-
/// isWinToJoinCrossClass - Return true if it's profitable to coalesce
/// two virtual registers from different register classes.
bool
@@ -1921,236 +1808,6 @@
return ThisValNoAssignments[VN] = UltimateVN;
}
-static bool InVector(VNInfo *Val, const SmallVector<VNInfo*, 8> &V) {
- return std::find(V.begin(), V.end(), Val) != V.end();
-}
-
-/// RangeIsDefinedByCopyFromReg - Return true if the specified live range of
-/// the specified live interval is defined by a copy from the specified
-/// register.
-bool SimpleRegisterCoalescing::RangeIsDefinedByCopy(LiveInterval &li,
- LiveRange *LR,
- CoalescerPair &CP) {
- if (CP.isCoalescable(LR->valno->getCopy()))
- return true;
- // FIXME: Do isPHIDef and isDefAccurate both need to be tested?
- if ((LR->valno->isPHIDef() || !LR->valno->isDefAccurate()) &&
- TargetRegisterInfo::isPhysicalRegister(li.reg) &&
- *tri_->getSuperRegisters(li.reg)) {
- // It's a sub-register live interval, we may not have precise information.
- // Re-compute it.
- MachineInstr *DefMI = li_->getInstructionFromIndex(LR->start);
- if (CP.isCoalescable(DefMI)) {
- // Cache computed info.
- LR->valno->def = LR->start;
- LR->valno->setCopy(DefMI);
- return true;
- }
- }
- return false;
-}
-
-
-/// ValueLiveAt - Return true if the LiveRange pointed to by the given
-/// iterator, or any subsequent range with the same value number,
-/// is live at the given point.
-bool SimpleRegisterCoalescing::ValueLiveAt(LiveInterval::iterator LRItr,
- LiveInterval::iterator LREnd,
- SlotIndex defPoint) const {
- for (const VNInfo *valno = LRItr->valno;
- (LRItr != LREnd) && (LRItr->valno == valno); ++LRItr) {
- if (LRItr->contains(defPoint))
- return true;
- }
-
- return false;
-}
-
-
-/// SimpleJoin - Attempt to joint the specified interval into this one. The
-/// caller of this method must guarantee that the RHS only contains a single
-/// value number and that the RHS is not defined by a copy from this
-/// interval. This returns false if the intervals are not joinable, or it
-/// joins them and returns true.
-bool SimpleRegisterCoalescing::SimpleJoin(LiveInterval &LHS, LiveInterval &RHS,
- CoalescerPair &CP) {
- assert(RHS.containsOneValue());
-
- // Some number (potentially more than one) value numbers in the current
- // interval may be defined as copies from the RHS. Scan the overlapping
- // portions of the LHS and RHS, keeping track of this and looking for
- // overlapping live ranges that are NOT defined as copies. If these exist, we
- // cannot coalesce.
-
- LiveInterval::iterator LHSIt = LHS.begin(), LHSEnd = LHS.end();
- LiveInterval::iterator RHSIt = RHS.begin(), RHSEnd = RHS.end();
-
- if (LHSIt->start < RHSIt->start) {
- LHSIt = std::upper_bound(LHSIt, LHSEnd, RHSIt->start);
- if (LHSIt != LHS.begin()) --LHSIt;
- } else if (RHSIt->start < LHSIt->start) {
- RHSIt = std::upper_bound(RHSIt, RHSEnd, LHSIt->start);
- if (RHSIt != RHS.begin()) --RHSIt;
- }
-
- SmallVector<VNInfo*, 8> EliminatedLHSVals;
-
- while (1) {
- // Determine if these live intervals overlap.
- bool Overlaps = false;
- if (LHSIt->start <= RHSIt->start)
- Overlaps = LHSIt->end > RHSIt->start;
- else
- Overlaps = RHSIt->end > LHSIt->start;
-
- // If the live intervals overlap, there are two interesting cases: if the
- // LHS interval is defined by a copy from the RHS, it's ok and we record
- // that the LHS value # is the same as the RHS. If it's not, then we cannot
- // coalesce these live ranges and we bail out.
- if (Overlaps) {
- // If we haven't already recorded that this value # is safe, check it.
- if (!InVector(LHSIt->valno, EliminatedLHSVals)) {
- // If it's re-defined by an early clobber somewhere in the live range,
- // then conservatively abort coalescing.
- if (LHSIt->valno->hasRedefByEC())
- return false;
- // Copy from the RHS?
- if (!RangeIsDefinedByCopy(LHS, LHSIt, CP))
- return false; // Nope, bail out.
-
- if (ValueLiveAt(LHSIt, LHS.end(), RHSIt->valno->def))
- // Here is an interesting situation:
- // BB1:
- // vr1025 = copy vr1024
- // ..
- // BB2:
- // vr1024 = op
- // = vr1025
- // Even though vr1025 is copied from vr1024, it's not safe to
- // coalesce them since the live range of vr1025 intersects the
- // def of vr1024. This happens because vr1025 is assigned the
- // value of the previous iteration of vr1024.
- return false;
- EliminatedLHSVals.push_back(LHSIt->valno);
- }
-
- // We know this entire LHS live range is okay, so skip it now.
- if (++LHSIt == LHSEnd) break;
- continue;
- }
-
- if (LHSIt->end < RHSIt->end) {
- if (++LHSIt == LHSEnd) break;
- } else {
- // One interesting case to check here. It's possible that we have
- // something like "X3 = Y" which defines a new value number in the LHS,
- // and is the last use of this liverange of the RHS. In this case, we
- // want to notice this copy (so that it gets coalesced away) even though
- // the live ranges don't actually overlap.
- if (LHSIt->start == RHSIt->end) {
- if (InVector(LHSIt->valno, EliminatedLHSVals)) {
- // We already know that this value number is going to be merged in
- // if coalescing succeeds. Just skip the liverange.
- if (++LHSIt == LHSEnd) break;
- } else {
- // If it's re-defined by an early clobber somewhere in the live range,
- // then conservatively abort coalescing.
- if (LHSIt->valno->hasRedefByEC())
- return false;
- // Otherwise, if this is a copy from the RHS, mark it as being merged
- // in.
- if (RangeIsDefinedByCopy(LHS, LHSIt, CP)) {
- if (ValueLiveAt(LHSIt, LHS.end(), RHSIt->valno->def))
- // Here is an interesting situation:
- // BB1:
- // vr1025 = copy vr1024
- // ..
- // BB2:
- // vr1024 = op
- // = vr1025
- // Even though vr1025 is copied from vr1024, it's not safe to
- // coalesced them since live range of vr1025 intersects the
- // def of vr1024. This happens because vr1025 is assigned the
- // value of the previous iteration of vr1024.
- return false;
- EliminatedLHSVals.push_back(LHSIt->valno);
-
- // We know this entire LHS live range is okay, so skip it now.
- if (++LHSIt == LHSEnd) break;
- }
- }
- }
-
- if (++RHSIt == RHSEnd) break;
- }
- }
-
- // If we got here, we know that the coalescing will be successful and that
- // the value numbers in EliminatedLHSVals will all be merged together. Since
- // the most common case is that EliminatedLHSVals has a single number, we
- // optimize for it: if there is more than one value, we merge them all into
- // the lowest numbered one, then handle the interval as if we were merging
- // with one value number.
- VNInfo *LHSValNo = NULL;
- if (EliminatedLHSVals.size() > 1) {
- // Loop through all the equal value numbers merging them into the smallest
- // one.
- VNInfo *Smallest = EliminatedLHSVals[0];
- for (unsigned i = 1, e = EliminatedLHSVals.size(); i != e; ++i) {
- if (EliminatedLHSVals[i]->id < Smallest->id) {
- // Merge the current notion of the smallest into the smaller one.
- LHS.MergeValueNumberInto(Smallest, EliminatedLHSVals[i]);
- Smallest = EliminatedLHSVals[i];
- } else {
- // Merge into the smallest.
- LHS.MergeValueNumberInto(EliminatedLHSVals[i], Smallest);
- }
- }
- LHSValNo = Smallest;
- } else if (EliminatedLHSVals.empty()) {
- if (TargetRegisterInfo::isPhysicalRegister(LHS.reg) &&
- *tri_->getSuperRegisters(LHS.reg))
- // Imprecise sub-register information. Can't handle it.
- return false;
- llvm_unreachable("No copies from the RHS?");
- } else {
- LHSValNo = EliminatedLHSVals[0];
- }
-
- // 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.
- const VNInfo *VNI = RHS.getValNumInfo(0);
- LHSValNo->def = VNI->def;
- LHSValNo->setCopy(VNI->getCopy());
-
- // Okay, the final step is to loop over the RHS live intervals, adding them to
- // the LHS.
- if (VNI->hasPHIKill())
- LHSValNo->setHasPHIKill(true);
- LHS.addKills(LHSValNo, VNI->kills);
- LHS.MergeRangesInAsValue(RHS, LHSValNo);
-
- LHS.ComputeJoinedWeight(RHS);
-
- // Update regalloc hint if both are virtual registers.
- if (TargetRegisterInfo::isVirtualRegister(LHS.reg) &&
- TargetRegisterInfo::isVirtualRegister(RHS.reg)) {
- std::pair<unsigned, unsigned> RHSPref = mri_->getRegAllocationHint(RHS.reg);
- std::pair<unsigned, unsigned> LHSPref = mri_->getRegAllocationHint(LHS.reg);
- if (RHSPref != LHSPref)
- mri_->setRegAllocationHint(LHS.reg, RHSPref.first, RHSPref.second);
- }
-
- // Update the liveintervals of sub-registers.
- if (TargetRegisterInfo::isPhysicalRegister(LHS.reg))
- for (const unsigned *AS = tri_->getSubRegisters(LHS.reg); *AS; ++AS)
- li_->getOrCreateInterval(*AS).MergeInClobberRanges(*li_, LHS,
- li_->getVNInfoAllocator());
-
- return true;
-}
-
/// JoinIntervals - Attempt to join these two intervals. On failure, this
/// returns false. Otherwise, if one of the intervals being joined is a
/// physreg, this method always canonicalizes LHS to be it. The output
@@ -2222,150 +1879,84 @@
}
}
- // Compute ultimate value numbers for the LHS and RHS values.
- if (RHS.containsOneValue()) {
- // Copies from a liveinterval with a single value are simple to handle and
- // very common, handle the special case here. This is important, because
- // 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;
- VNInfo *RHSValNoInfo = NULL;
- VNInfo *RHSValNoInfo0 = RHS.getValNumInfo(0);
- unsigned RHSSrcReg = li_->getVNInfoSourceReg(RHSValNoInfo0);
- if (RHSSrcReg == 0 || RHSSrcReg != LHS.reg) {
- // If RHS is not defined as a copy from the LHS, we can use simpler and
- // faster checks to see if the live ranges are coalescable. This joiner
- // can't swap the LHS/RHS intervals though.
- if (!TargetRegisterInfo::isPhysicalRegister(RHS.reg)) {
- return SimpleJoin(LHS, RHS, CP);
- } else {
- RHSValNoInfo = RHSValNoInfo0;
- }
- } else {
- // It was defined as a copy from the LHS, find out what value # it is.
- RHSValNoInfo =
- LHS.getLiveRangeContaining(RHSValNoInfo0->def.getPrevSlot())->valno;
- RHSValID = RHSValNoInfo->id;
- RHSVal0DefinedFromLHS = RHSValID;
- }
-
- LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
- RHSValNoAssignments.resize(RHS.getNumValNums(), -1);
- NewVNInfo.resize(LHS.getNumValNums(), NULL);
-
- // Okay, *all* of the values in LHS that are defined as a copy from RHS
- // should now get updated.
- for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
- i != e; ++i) {
- VNInfo *VNI = *i;
- unsigned VN = VNI->id;
- if (unsigned LHSSrcReg = li_->getVNInfoSourceReg(VNI)) {
- if (LHSSrcReg != RHS.reg) {
- // If this is not a copy from the RHS, its value number will be
- // unmodified by the coalescing.
- NewVNInfo[VN] = VNI;
- LHSValNoAssignments[VN] = VN;
- } else if (RHSValID == -1) {
- // Otherwise, it is a copy from the RHS, and we don't already have a
- // value# for it. Keep the current value number, but remember it.
- LHSValNoAssignments[VN] = RHSValID = VN;
- NewVNInfo[VN] = RHSValNoInfo;
- LHSValsDefinedFromRHS[VNI] = RHSValNoInfo0;
- } else {
- // Otherwise, use the specified value #.
- LHSValNoAssignments[VN] = RHSValID;
- if (VN == (unsigned)RHSValID) { // Else this val# is dead.
- NewVNInfo[VN] = RHSValNoInfo;
- LHSValsDefinedFromRHS[VNI] = RHSValNoInfo0;
- }
- }
- } else {
- NewVNInfo[VN] = VNI;
- LHSValNoAssignments[VN] = VN;
- }
- }
+ // Loop over the value numbers of the LHS, seeing if any are defined from
+ // the RHS.
+ for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
+ i != e; ++i) {
+ VNInfo *VNI = *i;
+ if (VNI->isUnused() || VNI->getCopy() == 0) // Src not defined by a copy?
+ continue;
- assert(RHSValID != -1 && "Didn't find value #?");
- RHSValNoAssignments[0] = RHSValID;
- if (RHSVal0DefinedFromLHS != -1) {
- // This path doesn't go through ComputeUltimateVN so just set
- // it to anything.
- RHSValsDefinedFromLHS[RHSValNoInfo0] = (VNInfo*)1;
- }
- } else {
- // Loop over the value numbers of the LHS, seeing if any are defined from
- // the RHS.
- for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
- i != e; ++i) {
- VNInfo *VNI = *i;
- if (VNI->isUnused() || VNI->getCopy() == 0) // Src not defined by a copy?
- continue;
+ // Never join with a register that has EarlyClobber redefs.
+ if (VNI->hasRedefByEC())
+ return false;
- // DstReg is known to be a register in the LHS interval. If the src is
- // from the RHS interval, we can use its value #.
- if (!CP.isCoalescable(VNI->getCopy()))
- continue;
+ // DstReg is known to be a register in the LHS interval. If the src is
+ // from the RHS interval, we can use its value #.
+ if (!CP.isCoalescable(VNI->getCopy()))
+ continue;
- // Figure out the value # from the RHS.
- LiveRange *lr = RHS.getLiveRangeContaining(VNI->def.getPrevSlot());
- // The copy could be to an aliased physreg.
- if (!lr) continue;
- LHSValsDefinedFromRHS[VNI] = lr->valno;
- }
+ // Figure out the value # from the RHS.
+ LiveRange *lr = RHS.getLiveRangeContaining(VNI->def.getPrevSlot());
+ // The copy could be to an aliased physreg.
+ if (!lr) continue;
+ LHSValsDefinedFromRHS[VNI] = lr->valno;
+ }
- // Loop over the value numbers of the RHS, seeing if any are defined from
- // the LHS.
- for (LiveInterval::vni_iterator i = RHS.vni_begin(), e = RHS.vni_end();
- i != e; ++i) {
- VNInfo *VNI = *i;
- if (VNI->isUnused() || VNI->getCopy() == 0) // Src not defined by a copy?
- continue;
+ // Loop over the value numbers of the RHS, seeing if any are defined from
+ // the LHS.
+ for (LiveInterval::vni_iterator i = RHS.vni_begin(), e = RHS.vni_end();
+ i != e; ++i) {
+ VNInfo *VNI = *i;
+ if (VNI->isUnused() || VNI->getCopy() == 0) // Src not defined by a copy?
+ continue;
- // DstReg is known to be a register in the RHS interval. If the src is
- // from the LHS interval, we can use its value #.
- if (!CP.isCoalescable(VNI->getCopy()))
- continue;
+ // Never join with a register that has EarlyClobber redefs.
+ if (VNI->hasRedefByEC())
+ return false;
- // Figure out the value # from the LHS.
- LiveRange *lr = LHS.getLiveRangeContaining(VNI->def.getPrevSlot());
- // The copy could be to an aliased physreg.
- if (!lr) continue;
- RHSValsDefinedFromLHS[VNI] = lr->valno;
- }
-
- LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
- RHSValNoAssignments.resize(RHS.getNumValNums(), -1);
- NewVNInfo.reserve(LHS.getNumValNums() + RHS.getNumValNums());
-
- for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
- i != e; ++i) {
- VNInfo *VNI = *i;
- unsigned VN = VNI->id;
- if (LHSValNoAssignments[VN] >= 0 || VNI->isUnused())
- continue;
- ComputeUltimateVN(VNI, NewVNInfo,
- LHSValsDefinedFromRHS, RHSValsDefinedFromLHS,
- LHSValNoAssignments, RHSValNoAssignments);
- }
- for (LiveInterval::vni_iterator i = RHS.vni_begin(), e = RHS.vni_end();
- i != e; ++i) {
- VNInfo *VNI = *i;
- unsigned VN = VNI->id;
- if (RHSValNoAssignments[VN] >= 0 || VNI->isUnused())
- continue;
- // If this value number isn't a copy from the LHS, it's a new number.
- if (RHSValsDefinedFromLHS.find(VNI) == RHSValsDefinedFromLHS.end()) {
- NewVNInfo.push_back(VNI);
- RHSValNoAssignments[VN] = NewVNInfo.size()-1;
- continue;
- }
+ // DstReg is known to be a register in the RHS interval. If the src is
+ // from the LHS interval, we can use its value #.
+ if (!CP.isCoalescable(VNI->getCopy()))
+ continue;
- ComputeUltimateVN(VNI, NewVNInfo,
- RHSValsDefinedFromLHS, LHSValsDefinedFromRHS,
- RHSValNoAssignments, LHSValNoAssignments);
+ // Figure out the value # from the LHS.
+ LiveRange *lr = LHS.getLiveRangeContaining(VNI->def.getPrevSlot());
+ // The copy could be to an aliased physreg.
+ if (!lr) continue;
+ RHSValsDefinedFromLHS[VNI] = lr->valno;
+ }
+
+ LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
+ RHSValNoAssignments.resize(RHS.getNumValNums(), -1);
+ NewVNInfo.reserve(LHS.getNumValNums() + RHS.getNumValNums());
+
+ for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
+ i != e; ++i) {
+ VNInfo *VNI = *i;
+ unsigned VN = VNI->id;
+ if (LHSValNoAssignments[VN] >= 0 || VNI->isUnused())
+ continue;
+ ComputeUltimateVN(VNI, NewVNInfo,
+ LHSValsDefinedFromRHS, RHSValsDefinedFromLHS,
+ LHSValNoAssignments, RHSValNoAssignments);
+ }
+ for (LiveInterval::vni_iterator i = RHS.vni_begin(), e = RHS.vni_end();
+ i != e; ++i) {
+ VNInfo *VNI = *i;
+ unsigned VN = VNI->id;
+ if (RHSValNoAssignments[VN] >= 0 || VNI->isUnused())
+ continue;
+ // If this value number isn't a copy from the LHS, it's a new number.
+ if (RHSValsDefinedFromLHS.find(VNI) == RHSValsDefinedFromLHS.end()) {
+ NewVNInfo.push_back(VNI);
+ RHSValNoAssignments[VN] = NewVNInfo.size()-1;
+ continue;
}
+
+ ComputeUltimateVN(VNI, NewVNInfo,
+ RHSValsDefinedFromLHS, LHSValsDefinedFromRHS,
+ RHSValNoAssignments, LHSValNoAssignments);
}
// Armed with the mappings of LHS/RHS values to ultimate values, walk the
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h?rev=106548&r1=106547&r2=106548&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h Tue Jun 22 11:13:57 2010
@@ -113,14 +113,7 @@
/// below to update aliases.
bool JoinIntervals(LiveInterval &LHS, LiveInterval &RHS, bool &Swapped,
CoalescerPair &CP);
-
- /// SimpleJoin - Attempt to join the specified interval into this one. The
- /// caller of this method must guarantee that the RHS only contains a single
- /// value number and that the RHS is not defined by a copy from this
- /// interval. This returns false if the intervals are not joinable, or it
- /// joins them and returns true.
- bool SimpleJoin(LiveInterval &LHS, LiveInterval &RHS, CoalescerPair &CP);
-
+
/// Return true if the two specified registers belong to different register
/// classes. The registers may be either phys or virt regs.
bool differingRegisterClasses(unsigned RegA, unsigned RegB) const;
@@ -161,23 +154,6 @@
bool CanCoalesceWithImpDef(MachineInstr *CopyMI,
LiveInterval &li, LiveInterval &ImpLi) const;
- /// TurnCopiesFromValNoToImpDefs - The specified value# is defined by an
- /// implicit_def and it is being removed. Turn all copies from this value#
- /// into implicit_defs.
- void TurnCopiesFromValNoToImpDefs(LiveInterval &li, VNInfo *VNI);
-
- /// isWinToJoinVRWithSrcPhysReg - Return true if it's worth while to join a
- /// a virtual destination register with physical source register.
- bool isWinToJoinVRWithSrcPhysReg(MachineInstr *CopyMI,
- MachineBasicBlock *CopyMBB,
- LiveInterval &DstInt, LiveInterval &SrcInt);
-
- /// isWinToJoinVRWithDstPhysReg - Return true if it's worth while to join a
- /// copy from a virtual source register to a physical destination register.
- bool isWinToJoinVRWithDstPhysReg(MachineInstr *CopyMI,
- MachineBasicBlock *CopyMBB,
- LiveInterval &DstInt, LiveInterval &SrcInt);
-
/// isWinToJoinCrossClass - Return true if it's profitable to coalesce
/// two virtual registers from different register classes.
bool isWinToJoinCrossClass(unsigned SrcReg,
@@ -205,17 +181,6 @@
bool CanJoinInsertSubRegToPhysReg(unsigned DstReg, unsigned SrcReg,
unsigned SubIdx, unsigned &RealDstReg);
- /// ValueLiveAt - Return true if the LiveRange pointed to by the given
- /// iterator, or any subsequent range with the same value number,
- /// is live at the given point.
- bool ValueLiveAt(LiveInterval::iterator LRItr, LiveInterval::iterator LREnd,
- SlotIndex defPoint) const;
-
- /// RangeIsDefinedByCopy - Return true if the specified live range of the
- /// specified live interval is defined by a coalescable copy.
- bool RangeIsDefinedByCopy(LiveInterval &li, LiveRange *LR,
- CoalescerPair &CP);
-
/// UpdateRegDefsUses - Replace all defs and uses of SrcReg to DstReg and
/// update the subregister number if it is not zero. If DstReg is a
/// physical register and the existing subregister number of the def / use
Modified: llvm/trunk/test/CodeGen/X86/pr2659.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pr2659.ll?rev=106548&r1=106547&r2=106548&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/pr2659.ll (original)
+++ llvm/trunk/test/CodeGen/X86/pr2659.ll Tue Jun 22 11:13:57 2010
@@ -17,7 +17,7 @@
; CHECK: %forcond.preheader.forbody_crit_edge
; CHECK: movl $1
; CHECK-NOT: xorl
-; CHECK-NEXT: movl $1
+; CHECK-NEXT: movl
ifthen: ; preds = %entry
ret i32 0
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