Convert Alpha and Mips to use a MachineFunctionInfo subclass to

carry GlobalBaseReg, and GlobalRetAddr too in Alpha's case. This
eliminates the need for them to search through the
MachineRegisterInfo livein list in order to identify these
virtual registers. EmitLiveInCopies is now the only user of the
virtual register portion of MachineRegisterInfo's livein data.

llvm-svn: 72802

1 files changed, 29 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.cpp b/llvm/lib/Target/Mips/MipsInstrInfo.cpp
index 6225fa9c988..92af973b0d2 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.cpp
@@ -13,8 +13,10 @@
 
 #include "MipsInstrInfo.h"
 #include "MipsTargetMachine.h"
+#include "MipsMachineFunction.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "MipsGenInstrInfo.inc"
 
 using namespace llvm;
@@ -621,3 +623,30 @@ ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const
   Cond[0].setImm(GetOppositeBranchCondition((Mips::CondCode)Cond[0].getImm()));
   return false;
 }
+
+/// getGlobalBaseReg - Return a virtual register initialized with the
+/// the global base register value. Output instructions required to
+/// initialize the register in the function entry block, if necessary.
+///
+unsigned MipsInstrInfo::getGlobalBaseReg(MachineFunction *MF) const {
+  MipsFunctionInfo *MipsFI = MF->getInfo<MipsFunctionInfo>();
+  unsigned GlobalBaseReg = MipsFI->getGlobalBaseReg();
+  if (GlobalBaseReg != 0)
+    return GlobalBaseReg;
+
+  // Insert the set of GlobalBaseReg into the first MBB of the function
+  MachineBasicBlock &FirstMBB = MF->front();
+  MachineBasicBlock::iterator MBBI = FirstMBB.begin();
+  MachineRegisterInfo &RegInfo = MF->getRegInfo();
+  const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
+
+  GlobalBaseReg = RegInfo.createVirtualRegister(Mips::CPURegsRegisterClass);
+  bool Ok = TII->copyRegToReg(FirstMBB, MBBI, GlobalBaseReg, Mips::GP,
+                              Mips::CPURegsRegisterClass,
+                              Mips::CPURegsRegisterClass);
+  assert(Ok && "Couldn't assign to global base register!");
+  RegInfo.addLiveIn(Mips::GP);
+
+  MipsFI->setGlobalBaseReg(GlobalBaseReg);
+  return GlobalBaseReg;
+}