llvm-6502/lib/Target/Mips/MipsExpandPseudo.cpp

118 lines
3.6 KiB
C++
Raw Normal View History

//===-- MipsExpandPseudo.cpp - Expand pseudo instructions ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This pass expands pseudo instructions into target instructions after register
// allocation but before post-RA scheduling.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mips-expand-pseudo"
#include "Mips.h"
#include "MipsTargetMachine.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/ADT/Statistic.h"
using namespace llvm;
namespace {
struct MipsExpandPseudo : public MachineFunctionPass {
TargetMachine &TM;
const TargetInstrInfo *TII;
static char ID;
MipsExpandPseudo(TargetMachine &tm)
: MachineFunctionPass(ID), TM(tm), TII(tm.getInstrInfo()) { }
virtual const char *getPassName() const {
return "Mips PseudoInstrs Expansion";
}
bool runOnMachineFunction(MachineFunction &F);
bool runOnMachineBasicBlock(MachineBasicBlock &MBB);
private:
void ExpandBuildPairF64(MachineBasicBlock&, MachineBasicBlock::iterator);
void ExpandExtractElementF64(MachineBasicBlock&,
MachineBasicBlock::iterator);
};
char MipsExpandPseudo::ID = 0;
} // end of anonymous namespace
bool MipsExpandPseudo::runOnMachineFunction(MachineFunction& F) {
bool Changed = false;
for (MachineFunction::iterator I = F.begin(); I != F.end(); ++I)
Changed |= runOnMachineBasicBlock(*I);
return Changed;
}
bool MipsExpandPseudo::runOnMachineBasicBlock(MachineBasicBlock& MBB) {
bool Changed = false;
for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end();) {
const MCInstrDesc& MCid = I->getDesc();
switch(MCid.getOpcode()) {
default:
++I;
continue;
case Mips::BuildPairF64:
ExpandBuildPairF64(MBB, I);
break;
case Mips::ExtractElementF64:
ExpandExtractElementF64(MBB, I);
break;
}
// delete original instr
MBB.erase(I++);
Changed = true;
}
return Changed;
}
void MipsExpandPseudo::ExpandBuildPairF64(MachineBasicBlock& MBB,
MachineBasicBlock::iterator I) {
unsigned DstReg = I->getOperand(0).getReg();
unsigned LoReg = I->getOperand(1).getReg(), HiReg = I->getOperand(2).getReg();
const MCInstrDesc& Mtc1Tdd = TII->get(Mips::MTC1);
DebugLoc dl = I->getDebugLoc();
const unsigned* SubReg =
TM.getRegisterInfo()->getSubRegisters(DstReg);
// mtc1 Lo, $fp
// mtc1 Hi, $fp + 1
BuildMI(MBB, I, dl, Mtc1Tdd, *SubReg).addReg(LoReg);
BuildMI(MBB, I, dl, Mtc1Tdd, *(SubReg + 1)).addReg(HiReg);
}
void MipsExpandPseudo::ExpandExtractElementF64(MachineBasicBlock& MBB,
MachineBasicBlock::iterator I) {
unsigned DstReg = I->getOperand(0).getReg();
unsigned SrcReg = I->getOperand(1).getReg();
unsigned N = I->getOperand(2).getImm();
const MCInstrDesc& Mfc1Tdd = TII->get(Mips::MFC1);
DebugLoc dl = I->getDebugLoc();
const unsigned* SubReg = TM.getRegisterInfo()->getSubRegisters(SrcReg);
BuildMI(MBB, I, dl, Mfc1Tdd, DstReg).addReg(*(SubReg + N));
}
/// createMipsMipsExpandPseudoPass - Returns a pass that expands pseudo
/// instrs into real instrs
FunctionPass *llvm::createMipsExpandPseudoPass(MipsTargetMachine &tm) {
return new MipsExpandPseudo(tm);
}