give MCCodeEmitters access to the current MCContext.

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

diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp
index 6a09bd981665f0172242705421cdbfe2be82a898..4d2e3a318b4f3126d846bb569dfe30b23a65e235 100644 (file)
--- a/lib/CodeGen/RegAllocLocal.cpp
+++ b/lib/CodeGen/RegAllocLocal.cpp
@@ -531,7 +531,7 @@ MachineInstr *RALocal::reloadVirtReg(MachineBasicBlock &MBB, MachineInstr *MI,
     std::string msg;
     raw_string_ostream Msg(msg);
     Msg << "Ran out of registers during register allocation!";
-    if (MI->getOpcode() == TargetInstrInfo::INLINEASM) {
+    if (MI->isInlineAsm()) {
       Msg << "\nPlease check your inline asm statement for invalid "
            << "constraints:\n";
       MI->print(Msg, TM);
@@ -544,7 +544,7 @@ MachineInstr *RALocal::reloadVirtReg(MachineBasicBlock &MBB, MachineInstr *MI,
       std::string msg;
       raw_string_ostream Msg(msg);
       Msg << "Ran out of registers during register allocation!";
-      if (MI->getOpcode() == TargetInstrInfo::INLINEASM) {
+      if (MI->isInlineAsm()) {
         Msg << "\nPlease check your inline asm statement for invalid "
              << "constraints:\n";
         MI->print(Msg, TM);
@@ -764,8 +764,11 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
     // Determine whether this is a copy instruction.  The cases where the
     // source or destination are phys regs are handled specially.
     unsigned SrcCopyReg, DstCopyReg, SrcCopySubReg, DstCopySubReg;
+    unsigned SrcCopyPhysReg = 0U;
     bool isCopy = TII->isMoveInstr(*MI, SrcCopyReg, DstCopyReg, 
                                    SrcCopySubReg, DstCopySubReg);
+    if (isCopy && TargetRegisterInfo::isVirtualRegister(SrcCopyReg))
+      SrcCopyPhysReg = getVirt2PhysRegMapSlot(SrcCopyReg);
 
     // Loop over the implicit uses, making sure that they are at the head of the
     // use order list, so they don't get reallocated.
@@ -793,7 +796,7 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
     // have in them, then mark them unallocatable.
     // If any virtual regs are earlyclobber, allocate them now (before
     // freeing inputs that are killed).
-    if (MI->getOpcode()==TargetInstrInfo::INLINEASM) {
+    if (MI->isInlineAsm()) {
       for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
         MachineOperand& MO = MI->getOperand(i);
         if (MO.isReg() && MO.isDef() && MO.isEarlyClobber() &&
@@ -838,11 +841,11 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
       }
     }
 
-    // If a DEBUG_VALUE says something is located in a spilled register,
-    // change the DEBUG_VALUE to be undef, which prevents the register
+    // If a DBG_VALUE says something is located in a spilled register,
+    // change the DBG_VALUE to be undef, which prevents the register
     // from being reloaded here.  Doing that would change the generated
     // code, unless another use immediately follows this instruction.
-    if (MI->getOpcode()==TargetInstrInfo::DEBUG_VALUE &&
+    if (MI->isDebugValue() &&
         MI->getNumOperands()==3 && MI->getOperand(0).isReg()) {
       unsigned VirtReg = MI->getOperand(0).getReg();
       if (VirtReg && TargetRegisterInfo::isVirtualRegister(VirtReg) &&
@@ -977,13 +980,26 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
 
         // If DestVirtReg already has a value, use it.
         if (!(DestPhysReg = getVirt2PhysRegMapSlot(DestVirtReg))) {
+          // If this is a copy try to reuse the input as the output;
+          // that will make the copy go away.
           // If this is a copy, the source reg is a phys reg, and
           // that reg is available, use that phys reg for DestPhysReg.
+          // If this is a copy, the source reg is a virtual reg, and
+          // the phys reg that was assigned to that virtual reg is now
+          // available, use that phys reg for DestPhysReg.  (If it's now
+          // available that means this was the last use of the source.)
           if (isCopy &&
               TargetRegisterInfo::isPhysicalRegister(SrcCopyReg) &&
               isPhysRegAvailable(SrcCopyReg)) {
             DestPhysReg = SrcCopyReg;
             assignVirtToPhysReg(DestVirtReg, DestPhysReg);
+          } else if (isCopy &&
+              TargetRegisterInfo::isVirtualRegister(SrcCopyReg) &&
+              SrcCopyPhysReg && isPhysRegAvailable(SrcCopyPhysReg) &&
+              MF->getRegInfo().getRegClass(DestVirtReg)->
+                               contains(SrcCopyPhysReg)) {
+            DestPhysReg = SrcCopyPhysReg;
+            assignVirtToPhysReg(DestVirtReg, DestPhysReg);
           } else
             DestPhysReg = getReg(MBB, MI, DestVirtReg);
         }