Don't store COPY pointers in VNInfo.

If a value is defined by a COPY, that instuction can easily and cheaply
be found by getInstructionFromIndex(VNI->def).

This reduces the size of VNInfo from 24 to 16 bytes, and improves
llc compile time by 3%.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149763 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 21 insertions, 48 deletions

diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index 698c2cff37..3cd42c466f 100644
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -169,10 +169,6 @@ namespace {
     /// it as well.
     bool RemoveDeadDef(LiveInterval &li, MachineInstr *DefMI);
 
-    /// RemoveCopyFlag - If DstReg is no longer defined by CopyMI, clear the
-    /// VNInfo copy flag for DstReg and all aliases.
-    void RemoveCopyFlag(unsigned DstReg, const MachineInstr *CopyMI);
-
     /// markAsJoined - Remember that CopyMI has already been joined.
     void markAsJoined(MachineInstr *CopyMI);
 
@@ -434,8 +430,7 @@ bool RegisterCoalescer::AdjustCopiesBackFrom(const CoalescerPair &CP,
   // 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.
-  if (!BValNo->isDefByCopy()) return false;
-  assert(BValNo->def == CopyIdx && "Copy doesn't define the value?");
+  if (BValNo->def != CopyIdx) return false;
 
   // AValNo is the value number in A that defines the copy, A3 in the example.
   SlotIndex CopyUseIdx = CopyIdx.getRegSlot(true);
@@ -467,7 +462,8 @@ bool RegisterCoalescer::AdjustCopiesBackFrom(const CoalescerPair &CP,
 
   // If AValNo is defined as a copy from IntB, we can potentially process this.
   // Get the instruction that defines this value number.
-  if (!CP.isCoalescable(AValNo->getCopy()))
+  MachineInstr *ACopyMI = LIS->getInstructionFromIndex(AValNo->def);
+  if (!CP.isCoalescable(ACopyMI))
     return false;
 
   // Get the LiveRange in IntB that this value number starts with.
@@ -511,8 +507,7 @@ bool RegisterCoalescer::AdjustCopiesBackFrom(const CoalescerPair &CP,
   // We are about to delete CopyMI, so need to remove it as the 'instruction
   // that defines this value #'. Update the valnum with the new defining
   // instruction #.
-  BValNo->def  = FillerStart;
-  BValNo->setCopy(0);
+  BValNo->def = FillerStart;
 
   // Okay, we can merge them.  We need to insert a new liverange:
   // [ValLR.end, BLR.begin) of either value number, then we merge the
@@ -527,7 +522,7 @@ bool RegisterCoalescer::AdjustCopiesBackFrom(const CoalescerPair &CP,
         continue;
       LiveInterval &SRLI = LIS->getInterval(*SR);
       SRLI.addRange(LiveRange(FillerStart, FillerEnd,
-                              SRLI.getNextValue(FillerStart, 0,
+                              SRLI.getNextValue(FillerStart,
                                                 LIS->getVNInfoAllocator())));
     }
   }
@@ -637,7 +632,7 @@ bool RegisterCoalescer::RemoveCopyByCommutingDef(const CoalescerPair &CP,
   // BValNo is a value number in B that is defined by a copy from A. 'B3' in
   // the example above.
   VNInfo *BValNo = IntB.getVNInfoAt(CopyIdx);
-  if (!BValNo || !BValNo->isDefByCopy())
+  if (!BValNo || BValNo->def != CopyIdx)
     return false;
 
   assert(BValNo->def == CopyIdx && "Copy doesn't define the value?");
@@ -781,7 +776,6 @@ bool RegisterCoalescer::RemoveCopyByCommutingDef(const CoalescerPair &CP,
   // is updated.
   VNInfo *ValNo = BValNo;
   ValNo->def = AValNo->def;
-  ValNo->setCopy(0);
   for (LiveInterval::iterator AI = IntA.begin(), AE = IntA.end();
        AI != AE; ++AI) {
     if (AI->valno != AValNo) continue;
@@ -833,8 +827,6 @@ bool RegisterCoalescer::ReMaterializeTrivialDef(LiveInterval &SrcInt,
       return false;
   }
 
-  RemoveCopyFlag(DstReg, CopyMI);
-
   MachineBasicBlock *MBB = CopyMI->getParent();
   MachineBasicBlock::iterator MII =
     llvm::next(MachineBasicBlock::iterator(CopyMI));
@@ -861,8 +853,6 @@ bool RegisterCoalescer::ReMaterializeTrivialDef(LiveInterval &SrcInt,
     MachineOperand &MO = CopyMI->getOperand(i);
     if (MO.isReg() && MO.isImplicit())
       NewMI->addOperand(MO);
-    if (MO.isDef())
-      RemoveCopyFlag(MO.getReg(), CopyMI);
   }
 
   LIS->ReplaceMachineInstrInMaps(CopyMI, NewMI);
@@ -871,7 +861,7 @@ bool RegisterCoalescer::ReMaterializeTrivialDef(LiveInterval &SrcInt,
   for (unsigned i = 0, e = NewMIImplDefs.size(); i != e; ++i) {
     unsigned reg = NewMIImplDefs[i];
     LiveInterval &li = LIS->getInterval(reg);
-    VNInfo *DeadDefVN = li.getNextValue(NewMIIdx.getRegSlot(), 0,
+    VNInfo *DeadDefVN = li.getNextValue(NewMIIdx.getRegSlot(),
                                         LIS->getVNInfoAllocator());
     LiveRange lr(NewMIIdx.getRegSlot(), NewMIIdx.getDeadSlot(), DeadDefVN);
     li.addRange(lr);
@@ -1047,27 +1037,6 @@ bool RegisterCoalescer::RemoveDeadDef(LiveInterval &li,
   return removeIntervalIfEmpty(li, LIS, TRI);
 }
 
-void RegisterCoalescer::RemoveCopyFlag(unsigned DstReg,
-                                              const MachineInstr *CopyMI) {
-  SlotIndex DefIdx = LIS->getInstructionIndex(CopyMI).getRegSlot();
-  if (LIS->hasInterval(DstReg)) {
-    LiveInterval &LI = LIS->getInterval(DstReg);
-    if (const LiveRange *LR = LI.getLiveRangeContaining(DefIdx))
-      if (LR->valno->def == DefIdx)
-        LR->valno->setCopy(0);
-  }
-  if (!TargetRegisterInfo::isPhysicalRegister(DstReg))
-    return;
-  for (const unsigned* AS = TRI->getAliasSet(DstReg); *AS; ++AS) {
-    if (!LIS->hasInterval(*AS))
-      continue;
-    LiveInterval &LI = LIS->getInterval(*AS);
-    if (const LiveRange *LR = LI.getLiveRangeContaining(DefIdx))
-      if (LR->valno->def == DefIdx)
-        LR->valno->setCopy(0);
-  }
-}
-
 /// shouldJoinPhys - Return true if a copy involving a physreg should be joined.
 /// We need to be careful about coalescing a source physical register with a
 /// virtual register. Once the coalescing is done, it cannot be broken and these
@@ -1394,9 +1363,9 @@ static bool RegistersDefinedFromSameValue(LiveIntervals &li,
   // FIXME: This is very conservative. For example, we don't handle
   // physical registers.
 
-  MachineInstr *MI = VNI->getCopy();
+  MachineInstr *MI = li.getInstructionFromIndex(VNI->def);
 
-  if (!MI->isFullCopy() || CP.isPartial() || CP.isPhys())
+  if (!MI || !MI->isFullCopy() || CP.isPartial() || CP.isPhys())
     return false;
 
   unsigned Dst = MI->getOperand(0).getReg();
@@ -1414,11 +1383,9 @@ static bool RegistersDefinedFromSameValue(LiveIntervals &li,
   assert(Dst == A);
 
   VNInfo *Other = LR->valno;
-  if (!Other->isDefByCopy())
-    return false;
-  const MachineInstr *OtherMI = Other->getCopy();
+  const MachineInstr *OtherMI = li.getInstructionFromIndex(Other->def);
 
-  if (!OtherMI->isFullCopy())
+  if (!OtherMI || !OtherMI->isFullCopy())
     return false;
 
   unsigned OtherDst = OtherMI->getOperand(0).getReg();
@@ -1536,7 +1503,11 @@ bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
   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?
+    if (VNI->isUnused() || VNI->isPHIDef())
+      continue;
+    MachineInstr *MI = LIS->getInstructionFromIndex(VNI->def);
+    assert(MI && "Missing def");
+    if (!MI->isCopyLike())  // Src not defined by a copy?
       continue;
 
     // Never join with a register that has EarlyClobber redefs.
@@ -1550,7 +1521,6 @@ bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
 
     // 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;
@@ -1563,7 +1533,11 @@ bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
   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?
+    if (VNI->isUnused() || VNI->isPHIDef())
+      continue;
+    MachineInstr *MI = LIS->getInstructionFromIndex(VNI->def);
+    assert(MI && "Missing def");
+    if (!MI->isCopyLike())  // Src not defined by a copy?
       continue;
 
     // Never join with a register that has EarlyClobber redefs.
@@ -1577,7 +1551,6 @@ bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
 
     // 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;