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Backing out ill-considered 'refactor'. 

llvm-svn: 149146
This commit is contained in:
Lang Hames 2012-01-27 21:43:32 +00:00
parent aefcf999d2
commit 6f108d9229
1 changed files with 53 additions and 39 deletions
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92
llvm/lib/CodeGen/RegisterCoalescer.cpp
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@ -1421,42 +1421,6 @@ static bool RegistersDefinedFromSameValue(LiveIntervals &li,
return true;
}
// Loop over the value numbers of the Dst interval and record the values that
// are defined by a copy from the Src interval.
static void FindValuesCopiedFrom(
LiveIntervals& lis,
const TargetRegisterInfo& tri,
CoalescerPair& CP,
LiveInterval &Dst, LiveInterval &Src,
DenseMap<VNInfo*, VNInfo*>& DstValsDefinedFromSrc,
SmallVector<MachineInstr*, 8>& DupCopies) {
for (LiveInterval::vni_iterator i = Dst.vni_begin(), e = Dst.vni_end();
i != e; ++i) {
VNInfo *VNI = *i;
if (VNI->isUnused() || !VNI->isDefByCopy()) // Src not defined by a copy?
continue;
// Never join with a register that has EarlyClobber redefs.
if (VNI->hasRedefByEC())
return false;
// Figure out the value # from the Src.
LiveRange *lr = Src.getLiveRangeContaining(VNI->def.getPrevSlot());
// The copy could be to an aliased physreg.
if (!lr) continue;
// DstReg is known to be a register in the Dst interval. If the src is
// from the Src interval, we can use its value #.
MachineInstr *MI = VNI->getCopy();
if (!CP.isCoalescable(MI) &&
!RegistersDefinedFromSameValue(lis, tri, CP, VNI, lr, DupCopies))
continue;
DstValsDefinedFromSrc[VNI] = lr->valno;
}
}
/// JoinIntervals - Attempt to join these two intervals. On failure, this
/// returns false.
bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
@ -1542,9 +1506,59 @@ bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
LiveInterval &LHS = LIS->getOrCreateInterval(CP.getDstReg());
DEBUG({ dbgs() << "\t\tLHS = "; LHS.print(dbgs(), TRI); dbgs() << "\n"; });
// Build a map of LHS values defined by copies from RHS and vice-versa.
FindValuesCopiedFrom(*LIS, *TRI, CP, LHS, RHS, LHSValsDefinedFromRHS, DupCopies);
FindValuesCopiedFrom(*LIS, *TRI, CP, RHS, LHS, RHSValsDefinedFromLHS, DupCopies);
// 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->isDefByCopy()) // Src not defined by a copy?
continue;
// Never join with a register that has EarlyClobber redefs.
if (VNI->hasRedefByEC())
return false;
// 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;
// DstReg is known to be a register in the LHS interval. If the src is
// from the RHS interval, we can use its value #.
MachineInstr *MI = VNI->getCopy();
if (!CP.isCoalescable(MI) &&
!RegistersDefinedFromSameValue(*LIS, *TRI, CP, VNI, lr, DupCopies))
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->isDefByCopy()) // Src not defined by a copy?
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;
// DstReg is known to be a register in the RHS interval. If the src is
// from the LHS interval, we can use its value #.
MachineInstr *MI = VNI->getCopy();
if (!CP.isCoalescable(MI) &&
!RegistersDefinedFromSameValue(*LIS, *TRI, CP, VNI, lr, DupCopies))
continue;
RHSValsDefinedFromLHS[VNI] = lr->valno;
}
LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
RHSValNoAssignments.resize(RHS.getNumValNums(), -1);