Simplify interfaces used by regalloc to insert code


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5052 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Target/MRegisterInfo.h b/include/llvm/Target/MRegisterInfo.h
index 2fa4a5a..107adc3 100644
--- a/include/llvm/Target/MRegisterInfo.h
+++ b/include/llvm/Target/MRegisterInfo.h
@@ -13,6 +13,7 @@
 #include <assert.h>
 
 class Type;
+class MachineFunction;
 
 /// MRegisterDesc - This record contains all of the information known about a
 /// particular register.
@@ -112,36 +113,32 @@
 
 
   virtual MachineBasicBlock::iterator
-  storeReg2RegOffset(MachineBasicBlock *MBB,
+  storeReg2RegOffset(MachineBasicBlock &MBB,
                      MachineBasicBlock::iterator MBBI,
                      unsigned SrcReg, unsigned DestReg,
                      unsigned ImmOffset, unsigned dataSize) const = 0;
 
   virtual MachineBasicBlock::iterator
-  loadRegOffset2Reg(MachineBasicBlock *MBB,
+  loadRegOffset2Reg(MachineBasicBlock &MBB,
                     MachineBasicBlock::iterator MBBI,
                     unsigned DestReg, unsigned SrcReg,
                     unsigned ImmOffset, unsigned dataSize) const = 0;
 
   virtual MachineBasicBlock::iterator
-  moveReg2Reg(MachineBasicBlock *MBB,
+  moveReg2Reg(MachineBasicBlock &MBB,
               MachineBasicBlock::iterator MBBI,
               unsigned DestReg, unsigned SrcReg, unsigned dataSize) const = 0;
 
   virtual MachineBasicBlock::iterator
-  moveImm2Reg(MachineBasicBlock *MBB,
+  moveImm2Reg(MachineBasicBlock &MBB,
               MachineBasicBlock::iterator MBBI,
               unsigned DestReg, unsigned Imm, unsigned dataSize) const = 0;
 
-  virtual MachineBasicBlock::iterator
-  emitPrologue(MachineBasicBlock *MBB,
-               MachineBasicBlock::iterator MBBI,
-               unsigned numBytes) const = 0;
+  virtual void
+  emitPrologue(MachineFunction &MF, unsigned numBytes) const = 0;
 
-  virtual MachineBasicBlock::iterator
-  emitEpilogue(MachineBasicBlock *MBB,
-               MachineBasicBlock::iterator MBBI,
-               unsigned numBytes) const = 0;
+  virtual void
+  emitEpilogue(MachineBasicBlock &MBB, unsigned numBytes) const = 0;
 
   virtual const unsigned* getCalleeSaveRegs() const = 0;
   virtual const unsigned* getCallerSaveRegs() const = 0;
diff --git a/lib/CodeGen/RegAllocSimple.cpp b/lib/CodeGen/RegAllocSimple.cpp
index c7348d5..49a205a 100644
--- a/lib/CodeGen/RegAllocSimple.cpp
+++ b/lib/CodeGen/RegAllocSimple.cpp
@@ -199,7 +199,7 @@
   PhysReg = getFreeReg(VirtReg);
 
   // Add move instruction(s)
-  return RegInfo->loadRegOffset2Reg(&MBB, I, PhysReg,
+  return RegInfo->loadRegOffset2Reg(MBB, I, PhysReg,
                                     RegInfo->getFramePointer(),
                                     -stackOffset, regClass->getDataSize());
 }
@@ -215,7 +215,7 @@
   unsigned stackOffset = allocateStackSpaceFor(VirtReg, regClass);
 
   // Add move instruction(s)
-  return RegInfo->storeReg2RegOffset(&MBB, I, PhysReg,
+  return RegInfo->storeReg2RegOffset(MBB, I, PhysReg,
                                      RegInfo->getFramePointer(),
                                      -stackOffset, regClass->getDataSize());
 }
@@ -231,7 +231,7 @@
   unsigned offset = allocateStackSpaceFor(PhysReg, regClass);
 
   // Add move instruction(s)
-  return RegInfo->storeReg2RegOffset(&MBB, I, PhysReg,
+  return RegInfo->storeReg2RegOffset(MBB, I, PhysReg,
                                      RegInfo->getFramePointer(),
                                      offset, regClass->getDataSize());
 }
@@ -293,7 +293,7 @@
       // Retrieve the constant value from this op, move it to target
       // register of the phi
       if (opVal.isImmediate()) {
-        opI = RegInfo->moveImm2Reg(&opBlock, opI, physReg,
+        opI = RegInfo->moveImm2Reg(opBlock, opI, physReg,
                                    (unsigned) opVal.getImmedValue(),
                                    dataSize);
         saveVirtRegToStack(opBlock, opI, virtualReg, physReg);
@@ -384,10 +384,7 @@
     AllocateBasicBlock(*MBB);
 
   // add prologue we should preserve callee-save registers...
-  MachineFunction::iterator Fi = Fn.begin();
-  MachineBasicBlock *MBB = Fi;
-  MachineBasicBlock::iterator MBBi = MBB->begin();
-  RegInfo->emitPrologue(MBB, MBBi, NumBytesAllocated);
+  RegInfo->emitPrologue(Fn, NumBytesAllocated);
 
   const MachineInstrInfo &MII = TM.getInstrInfo();
 
@@ -400,7 +397,7 @@
     MachineInstr *MI = *--I;
     if (MII.isReturn(MI->getOpcode())) {
       // this block has a return instruction, add epilogue
-      RegInfo->emitEpilogue(MBB, I, NumBytesAllocated);
+      RegInfo->emitEpilogue(*MBB, NumBytesAllocated);
     }
   }
 
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 4e5afce..e2c0efd 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -10,6 +10,7 @@
 #include "llvm/Constants.h"
 #include "llvm/Type.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineFunction.h"
 
 // X86Regs - Turn the X86RegisterInfo.def file into a bunch of register
 // descriptors
@@ -35,7 +36,7 @@
 }
 
 MachineBasicBlock::iterator
-X86RegisterInfo::storeReg2RegOffset(MachineBasicBlock *MBB,
+X86RegisterInfo::storeReg2RegOffset(MachineBasicBlock &MBB,
                                     MachineBasicBlock::iterator MBBI,
                                     unsigned SrcReg, unsigned DestReg, 
                                     unsigned ImmOffset, unsigned dataSize)
@@ -44,11 +45,11 @@
   static const unsigned Opcode[] = { X86::MOVrm8, X86::MOVrm16, X86::MOVrm32 };
   MachineInstr *MI = addRegOffset(BuildMI(Opcode[getIdx(dataSize)], 5),
                                   DestReg, ImmOffset).addReg(SrcReg);
-  return ++(MBB->insert(MBBI, MI));
+  return ++MBB.insert(MBBI, MI);
 }
 
 MachineBasicBlock::iterator
-X86RegisterInfo::loadRegOffset2Reg(MachineBasicBlock *MBB,
+X86RegisterInfo::loadRegOffset2Reg(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator MBBI,
                                    unsigned DestReg, unsigned SrcReg,
                                    unsigned ImmOffset, unsigned dataSize)
@@ -57,11 +58,11 @@
   static const unsigned Opcode[] = { X86::MOVmr8, X86::MOVmr16, X86::MOVmr32 };
   MachineInstr *MI = addRegOffset(BuildMI(Opcode[getIdx(dataSize)], 5)
                                   .addReg(DestReg), SrcReg, ImmOffset);
-  return ++(MBB->insert(MBBI, MI));
+  return ++MBB.insert(MBBI, MI);
 }
 
 MachineBasicBlock::iterator
-X86RegisterInfo::moveReg2Reg(MachineBasicBlock *MBB,
+X86RegisterInfo::moveReg2Reg(MachineBasicBlock &MBB,
                              MachineBasicBlock::iterator MBBI,
                              unsigned DestReg, unsigned SrcReg,
                              unsigned dataSize) const
@@ -69,11 +70,11 @@
   static const unsigned Opcode[] = { X86::MOVrr8, X86::MOVrr16, X86::MOVrr32 };
   MachineInstr *MI = 
     BuildMI(Opcode[getIdx(dataSize)], 2).addReg(DestReg).addReg(SrcReg);
-  return ++(MBB->insert(MBBI, MI));
+  return ++MBB.insert(MBBI, MI);
 }
 
 MachineBasicBlock::iterator
-X86RegisterInfo::moveImm2Reg(MachineBasicBlock *MBB,
+X86RegisterInfo::moveImm2Reg(MachineBasicBlock &MBB,
                              MachineBasicBlock::iterator MBBI,
                              unsigned DestReg, unsigned Imm, unsigned dataSize)
   const
@@ -81,7 +82,7 @@
   static const unsigned Opcode[] = { X86::MOVir8, X86::MOVir16, X86::MOVir32 };
   MachineInstr *MI = 
     BuildMI(Opcode[getIdx(dataSize)], 2).addReg(DestReg).addReg(Imm);
-  return ++(MBB->insert(MBBI, MI));
+  return ++MBB.insert(MBBI, MI);
 }
 
 
@@ -106,55 +107,47 @@
   return CallerSaveRegs;
 }
 
-MachineBasicBlock::iterator 
-X86RegisterInfo::emitPrologue(MachineBasicBlock *MBB,
-                              MachineBasicBlock::iterator MBBI,
-                              unsigned numBytes) const
-{
-  MachineInstr *MI;
+void X86RegisterInfo::emitPrologue(MachineFunction &MF,
+                                   unsigned numBytes) const {
+  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
+  MachineBasicBlock::iterator MBBI = MBB.begin();
 
   // PUSH ebp
-  MI = BuildMI (X86::PUSHr32, 1).addReg(X86::EBP);
-  MBBI = ++(MBB->insert(MBBI, MI));
+  MachineInstr *MI = BuildMI (X86::PUSHr32, 1).addReg(X86::EBP);
+  MBBI = ++MBB.insert(MBBI, MI);
 
   // MOV ebp, esp
   MI = BuildMI (X86::MOVrr32, 2).addReg(X86::EBP).addReg(X86::ESP);
-  MBBI = ++(MBB->insert(MBBI, MI));  
+  MBBI = ++MBB.insert(MBBI, MI);
 
   // adjust stack pointer
   MI  = BuildMI(X86::SUBri32, 2).addReg(X86::ESP).addZImm(numBytes);
-  MBBI = ++(MBB->insert(MBBI, MI));
+  MBBI = ++MBB.insert(MBBI, MI);
 
   // PUSH all callee-save registers
   const unsigned* regs = getCalleeSaveRegs();
   while (*regs) {
     MI = BuildMI(X86::PUSHr32, 1).addReg(*regs);
-    MBBI = ++(MBB->insert(MBBI, MI));
+    MBBI = ++MBB.insert(MBBI, MI);
     ++regs;
   }
-
-  return MBBI;
 }
 
-MachineBasicBlock::iterator
-X86RegisterInfo::emitEpilogue(MachineBasicBlock *MBB,
-                              MachineBasicBlock::iterator MBBI,
-                              unsigned numBytes) const
-{
-  MachineInstr *MI;
+void X86RegisterInfo::emitEpilogue(MachineBasicBlock &MBB,
+                                   unsigned numBytes) const {
+  MachineBasicBlock::iterator MBBI = --MBB.end();
+  assert((*MBBI)->getOpcode() == X86::RET &&
+         "Can only insert epilog into returning blocks");
 
   // POP all callee-save registers in REVERSE ORDER
   static const unsigned regs[] = { X86::EBX, X86::EDI, X86::ESI,
                                    MRegisterInfo::NoRegister };
   unsigned idx = 0;
   while (regs[idx]) {
-    MI = BuildMI(X86::POPr32, 1).addReg(regs[idx++]);
-    MBBI = ++(MBB->insert(MBBI, MI));
+    MachineInstr *MI = BuildMI(X86::POPr32, 1).addReg(regs[idx++]);
+    MBBI = ++(MBB.insert(MBBI, MI));
   }
   
   // insert LEAVE
-  MI = BuildMI(X86::LEAVE, 0);
-  MBBI = ++(MBB->insert(MBBI, MI));
-  
-  return MBBI;
+  MBB.insert(MBBI, BuildMI(X86::LEAVE, 0));
 }
diff --git a/lib/Target/X86/X86RegisterInfo.h b/lib/Target/X86/X86RegisterInfo.h
index 5b0c30c..be45f30 100644
--- a/lib/Target/X86/X86RegisterInfo.h
+++ b/lib/Target/X86/X86RegisterInfo.h
@@ -18,24 +18,24 @@
   MRegisterInfo::const_iterator regclass_end() const;
 
   MachineBasicBlock::iterator
-  storeReg2RegOffset(MachineBasicBlock *MBB,
+  storeReg2RegOffset(MachineBasicBlock &MBB,
                      MachineBasicBlock::iterator MBBI,
                      unsigned DestReg, unsigned SrcReg, 
                      unsigned ImmOffset, unsigned dataSize) const;
 
   MachineBasicBlock::iterator
-  loadRegOffset2Reg(MachineBasicBlock *MBB,
+  loadRegOffset2Reg(MachineBasicBlock &MBB,
                     MachineBasicBlock::iterator MBBI,
                     unsigned DestReg, unsigned SrcReg,
                     unsigned ImmOffset, unsigned dataSize) const;
 
   MachineBasicBlock::iterator
-  moveReg2Reg(MachineBasicBlock *MBB,
+  moveReg2Reg(MachineBasicBlock &MBB,
               MachineBasicBlock::iterator MBBI,
               unsigned DestReg, unsigned SrcReg, unsigned dataSize) const;
 
   MachineBasicBlock::iterator
-  moveImm2Reg(MachineBasicBlock *MBB,
+  moveImm2Reg(MachineBasicBlock &MBB,
               MachineBasicBlock::iterator MBBI,
               unsigned DestReg, unsigned Imm, unsigned dataSize) const;
 
@@ -45,13 +45,8 @@
   const unsigned* getCalleeSaveRegs() const;
   const unsigned* getCallerSaveRegs() const;
 
-  MachineBasicBlock::iterator emitPrologue(MachineBasicBlock *MBB,
-                                           MachineBasicBlock::iterator MBBI,
-                                           unsigned numBytes) const;
-
-  MachineBasicBlock::iterator emitEpilogue(MachineBasicBlock *MBB,
-                                           MachineBasicBlock::iterator MBBI,
-                                           unsigned numBytes) const;
+  void emitPrologue(MachineFunction &MF, unsigned numBytes) const;
+  void emitEpilogue(MachineBasicBlock &MBB, unsigned numBytes) const;
 
   /// Returns register class appropriate for input SSA register
   ///