Add a LiveRangeEdit delegate callback before shrinking a live range.

[oota-llvm.git] / lib / CodeGen / RegAllocFast.cpp

diff --git a/lib/CodeGen/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp
index 109da42e9c3d92538ab79f68f18a4a109a2d87ce..15036e38b89376a8ffef6c1440955080abd3a330 100644 (file)
--- a/lib/CodeGen/RegAllocFast.cpp
+++ b/lib/CodeGen/RegAllocFast.cpp
@@ -656,7 +656,8 @@ void RAFast::handleThroughOperands(MachineInstr *MI,
     MachineOperand &MO = MI->getOperand(i);
     if (!MO.isReg()) continue;
     unsigned Reg = MO.getReg();
-    if (!Reg || TargetRegisterInfo::isPhysicalRegister(Reg)) continue;
+    if (!TargetRegisterInfo::isVirtualRegister(Reg))
+      continue;
     if (MO.isEarlyClobber() || MI->isRegTiedToDefOperand(i) ||
         (MO.getSubReg() && MI->readsVirtualRegister(Reg))) {
       if (ThroughRegs.insert(Reg))
@@ -688,7 +689,7 @@ void RAFast::handleThroughOperands(MachineInstr *MI,
     MachineOperand &MO = MI->getOperand(i);
     if (!MO.isReg()) continue;
     unsigned Reg = MO.getReg();
-    if (!Reg || TargetRegisterInfo::isPhysicalRegister(Reg)) continue;
+    if (!TargetRegisterInfo::isVirtualRegister(Reg)) continue;
     if (MO.isUse()) {
       unsigned DefIdx = 0;
       if (!MI->isRegTiedToDefOperand(i, &DefIdx)) continue;
@@ -734,6 +735,27 @@ void RAFast::handleThroughOperands(MachineInstr *MI,
 void RAFast::AllocateBasicBlock() {
   DEBUG(dbgs() << "\nAllocating " << *MBB);
 
+  // FIXME: This should probably be added by instruction selection instead?
+  // If the last instruction in the block is a return, make sure to mark it as
+  // using all of the live-out values in the function.  Things marked both call
+  // and return are tail calls; do not do this for them.  The tail callee need
+  // not take the same registers as input that it produces as output, and there
+  // are dependencies for its input registers elsewhere.
+  if (!MBB->empty() && MBB->back().getDesc().isReturn() &&
+      !MBB->back().getDesc().isCall()) {
+    MachineInstr *Ret = &MBB->back();
+
+    for (MachineRegisterInfo::liveout_iterator
+         I = MF->getRegInfo().liveout_begin(),
+         E = MF->getRegInfo().liveout_end(); I != E; ++I) {
+      assert(TargetRegisterInfo::isPhysicalRegister(*I) &&
+             "Cannot have a live-out virtual register.");
+
+      // Add live-out registers as implicit uses.
+      Ret->addRegisterKilled(*I, TRI, true);
+    }
+  }
+
   PhysRegState.assign(TRI->getNumRegs(), regDisabled);
   assert(LiveVirtRegs.empty() && "Mapping not cleared form last block?");
 
@@ -794,7 +816,7 @@ void RAFast::AllocateBasicBlock() {
           MachineOperand &MO = MI->getOperand(i);
           if (!MO.isReg()) continue;
           unsigned Reg = MO.getReg();
-          if (!Reg || TargetRegisterInfo::isPhysicalRegister(Reg)) continue;
+          if (!TargetRegisterInfo::isVirtualRegister(Reg)) continue;
           LiveDbgValueMap[Reg] = MI;
           LiveRegMap::iterator LRI = LiveVirtRegs.find(Reg);
           if (LRI != LiveVirtRegs.end())
@@ -909,7 +931,7 @@ void RAFast::AllocateBasicBlock() {
       MachineOperand &MO = MI->getOperand(i);
       if (!MO.isReg()) continue;
       unsigned Reg = MO.getReg();
-      if (!Reg || TargetRegisterInfo::isPhysicalRegister(Reg)) continue;
+      if (!TargetRegisterInfo::isVirtualRegister(Reg)) continue;
       if (MO.isUse()) {
         LiveRegMap::iterator LRI = reloadVirtReg(MI, i, Reg, CopyDst);
         unsigned PhysReg = LRI->second.PhysReg;
@@ -1024,8 +1046,7 @@ bool RAFast::runOnMachineFunction(MachineFunction &Fn) {
 
   // initialize the virtual->physical register map to have a 'null'
   // mapping for all virtual registers
-  unsigned LastVirtReg = MRI->getLastVirtReg();
-  StackSlotForVirtReg.grow(LastVirtReg);
+  StackSlotForVirtReg.resize(MRI->getNumVirtRegs());
 
   // Loop over all of the basic blocks, eliminating virtual register references
   for (MachineFunction::iterator MBBi = Fn.begin(), MBBe = Fn.end();