1 //===- X86RegisterInfo.cpp - X86 Register Information -----------*- C++ -*-===//
3 // This file contains the X86 implementation of the MRegisterInfo class.
5 //===----------------------------------------------------------------------===//
8 #include "X86RegisterInfo.h"
9 #include "X86InstrBuilder.h"
10 #include "llvm/Constants.h"
11 #include "llvm/Type.h"
12 #include "llvm/CodeGen/MachineInstrBuilder.h"
13 #include "llvm/CodeGen/MachineFunction.h"
15 unsigned getIdx(unsigned dataSize) {
20 // FIXME: longs handled as ints
22 default: assert(0 && "Invalid data size!");
26 MachineBasicBlock::iterator
27 X86RegisterInfo::storeReg2RegOffset(MachineBasicBlock &MBB,
28 MachineBasicBlock::iterator MBBI,
29 unsigned SrcReg, unsigned DestReg,
30 unsigned ImmOffset, unsigned dataSize)
33 static const unsigned Opcode[] = { X86::MOVrm8, X86::MOVrm16, X86::MOVrm32 };
34 MachineInstr *MI = addRegOffset(BuildMI(Opcode[getIdx(dataSize)], 5),
35 DestReg, ImmOffset).addReg(SrcReg);
36 return ++MBB.insert(MBBI, MI);
39 MachineBasicBlock::iterator
40 X86RegisterInfo::loadRegOffset2Reg(MachineBasicBlock &MBB,
41 MachineBasicBlock::iterator MBBI,
42 unsigned DestReg, unsigned SrcReg,
43 unsigned ImmOffset, unsigned dataSize)
46 static const unsigned Opcode[] = { X86::MOVmr8, X86::MOVmr16, X86::MOVmr32 };
47 MachineInstr *MI = addRegOffset(BuildMI(Opcode[getIdx(dataSize)], 4, DestReg),
49 return ++MBB.insert(MBBI, MI);
52 MachineBasicBlock::iterator
53 X86RegisterInfo::moveReg2Reg(MachineBasicBlock &MBB,
54 MachineBasicBlock::iterator MBBI,
55 unsigned DestReg, unsigned SrcReg,
56 unsigned dataSize) const
58 static const unsigned Opcode[] = { X86::MOVrr8, X86::MOVrr16, X86::MOVrr32 };
59 MachineInstr *MI = BuildMI(Opcode[getIdx(dataSize)],1,DestReg).addReg(SrcReg);
60 return ++MBB.insert(MBBI, MI);
63 MachineBasicBlock::iterator
64 X86RegisterInfo::moveImm2Reg(MachineBasicBlock &MBB,
65 MachineBasicBlock::iterator MBBI,
66 unsigned DestReg, unsigned Imm, unsigned dataSize)
69 static const unsigned Opcode[] = { X86::MOVir8, X86::MOVir16, X86::MOVir32 };
70 MachineInstr *MI = BuildMI(Opcode[getIdx(dataSize)], 1, DestReg).addReg(Imm);
71 return ++MBB.insert(MBBI, MI);
75 unsigned X86RegisterInfo::getFramePointer() const {
79 unsigned X86RegisterInfo::getStackPointer() const {
83 const unsigned* X86RegisterInfo::getCalleeSaveRegs() const {
84 static const unsigned CalleeSaveRegs[] = { X86::ESI, X86::EDI, X86::EBX,
85 MRegisterInfo::NoRegister };
86 return CalleeSaveRegs;
90 const unsigned* X86RegisterInfo::getCallerSaveRegs() const {
91 static const unsigned CallerSaveRegs[] = { X86::EAX, X86::ECX, X86::EDX,
92 MRegisterInfo::NoRegister };
93 return CallerSaveRegs;
96 void X86RegisterInfo::emitPrologue(MachineFunction &MF,
97 unsigned NumBytes) const {
98 MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
99 MachineBasicBlock::iterator MBBI = MBB.begin();
101 // Round stack allocation up to a nice alignment to keep the stack aligned
102 NumBytes = (NumBytes + 3) & ~3;
105 MachineInstr *MI = BuildMI(X86::PUSHr32, 1).addReg(X86::EBP);
106 MBBI = ++MBB.insert(MBBI, MI);
109 MI = BuildMI(X86::MOVrr32, 1, X86::EBP).addReg(X86::ESP);
110 MBBI = ++MBB.insert(MBBI, MI);
112 // adjust stack pointer: ESP -= numbytes
113 MI = BuildMI(X86::SUBri32, 2, X86::ESP).addReg(X86::ESP).addZImm(NumBytes);
114 MBBI = ++MBB.insert(MBBI, MI);
117 void X86RegisterInfo::emitEpilogue(MachineBasicBlock &MBB,
118 unsigned numBytes) const {
119 MachineBasicBlock::iterator MBBI = --MBB.end();
120 assert((*MBBI)->getOpcode() == X86::RET &&
121 "Can only insert epilog into returning blocks");
123 // insert LEAVE: mov ESP, EBP; pop EBP
124 MBBI = ++MBB.insert(MBBI, BuildMI(X86::MOVrr32, 1,X86::ESP).addReg(X86::EBP));
125 MBBI = ++MBB.insert(MBBI, BuildMI(X86::POPr32, 1).addReg(X86::EBP));