Revert r85346 change to control tail merging by CodeGenOpt::Level.

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

diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index e5148e74be820f3660e5da1babf1480da0b8eba1..b31973e04fd9fdeb52ca59011f8d8f7162a2803a 100644 (file)
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -16,6 +16,7 @@ using namespace llvm;
 
 MachineRegisterInfo::MachineRegisterInfo(const TargetRegisterInfo &TRI) {
   VRegInfo.reserve(256);
+  RegAllocHints.reserve(256);
   RegClass2VRegMap.resize(TRI.getNumRegClasses()+1); // RC ID starts at 1.
   UsedPhysRegs.resize(TRI.getNumRegs());
   
@@ -35,6 +36,26 @@ MachineRegisterInfo::~MachineRegisterInfo() {
   delete [] PhysRegUseDefLists;
 }
 
+/// setRegClass - Set the register class of the specified virtual register.
+///
+void
+MachineRegisterInfo::setRegClass(unsigned Reg, const TargetRegisterClass *RC) {
+  unsigned VR = Reg;
+  Reg -= TargetRegisterInfo::FirstVirtualRegister;
+  assert(Reg < VRegInfo.size() && "Invalid vreg!");
+  const TargetRegisterClass *OldRC = VRegInfo[Reg].first;
+  VRegInfo[Reg].first = RC;
+
+  // Remove from old register class's vregs list. This may be slow but
+  // fortunately this operation is rarely needed.
+  std::vector<unsigned> &VRegs = RegClass2VRegMap[OldRC->getID()];
+  std::vector<unsigned>::iterator I=std::find(VRegs.begin(), VRegs.end(), VR);
+  VRegs.erase(I);
+
+  // Add to new register class's vregs list.
+  RegClass2VRegMap[RC->getID()].push_back(VR);
+}
+
 /// createVirtualRegister - Create and return a new virtual register in the
 /// function with the specified register class.
 ///
@@ -44,6 +65,7 @@ MachineRegisterInfo::createVirtualRegister(const TargetRegisterClass *RegClass){
   // Add a reg, but keep track of whether the vector reallocated or not.
   void *ArrayBase = VRegInfo.empty() ? 0 : &VRegInfo[0];
   VRegInfo.push_back(std::make_pair(RegClass, (MachineOperand*)0));
+  RegAllocHints.push_back(std::make_pair(0, 0));
 
   if (!((&VRegInfo[0] == ArrayBase || VRegInfo.size() == 1)))
     // The vector reallocated, handle this now.
@@ -88,11 +110,9 @@ void MachineRegisterInfo::replaceRegWith(unsigned FromReg, unsigned ToReg) {
 MachineInstr *MachineRegisterInfo::getVRegDef(unsigned Reg) const {
   assert(Reg-TargetRegisterInfo::FirstVirtualRegister < VRegInfo.size() &&
          "Invalid vreg!");
-  for (reg_iterator I = reg_begin(Reg), E = reg_end(); I != E; ++I) {
-    // Since we are in SSA form, we can stop at the first definition.
-    if (I.getOperand().isDef())
-      return &*I;
-  }
+  // Since we are in SSA form, we can use the first definition.
+  if (!def_empty(Reg))
+    return &*def_begin(Reg);
   return 0;
 }