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llvm-mirror/lib/Target/PowerPC/PPC32InstrInfo.cpp
Nate Begeman 76d2a77998 Add ori reg, reg, 0 as a move instruction. This can be generated from
loading a 32bit constant into a register whose low halfword is all zeroes.

We now omit the ori after the lis for the following C code:

int bar(int y) { return y * 0x00F0000; }

_bar:
.LBB_bar_0:     ; entry
        ; IMPLICIT_DEF
        lis r2, 15
        mullw r3, r3, r2
        blr

llvm-svn: 16825
2004-10-07 22:26:12 +00:00

71 lines
2.7 KiB
C++

//===- PPC32InstrInfo.cpp - PowerPC32 Instruction Information ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the PowerPC implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "PPC32InstrInfo.h"
#include "PPC32GenInstrInfo.inc"
#include "PowerPC.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include <iostream>
using namespace llvm;
PPC32InstrInfo::PPC32InstrInfo()
: TargetInstrInfo(PPC32Insts, sizeof(PPC32Insts)/sizeof(PPC32Insts[0])) {}
bool PPC32InstrInfo::isMoveInstr(const MachineInstr& MI,
unsigned& sourceReg,
unsigned& destReg) const {
MachineOpCode oc = MI.getOpcode();
if (oc == PPC::OR) { // or r1, r2, r2
assert(MI.getNumOperands() == 3 &&
MI.getOperand(0).isRegister() &&
MI.getOperand(1).isRegister() &&
MI.getOperand(2).isRegister() &&
"invalid PPC OR instruction!");
if (MI.getOperand(1).getReg() == MI.getOperand(2).getReg()) {
sourceReg = MI.getOperand(1).getReg();
destReg = MI.getOperand(0).getReg();
return true;
}
} else if (oc == PPC::ADDI) { // addi r1, r2, 0
assert(MI.getNumOperands() == 3 &&
MI.getOperand(0).isRegister() &&
MI.getOperand(2).isImmediate() &&
"invalid PPC ADDI instruction!");
if (MI.getOperand(1).isRegister() && MI.getOperand(2).getImmedValue()==0) {
sourceReg = MI.getOperand(1).getReg();
destReg = MI.getOperand(0).getReg();
return true;
}
} else if (oc == PPC::ORI) { // ori r1, r2, 0
assert(MI.getNumOperands() == 3 &&
MI.getOperand(0).isRegister() &&
MI.getOperand(1).isRegister() &&
MI.getOperand(2).isImmediate() &&
"invalid PPC ORI instruction!");
if (MI.getOperand(2).getImmedValue()==0) {
sourceReg = MI.getOperand(1).getReg();
destReg = MI.getOperand(0).getReg();
return true;
}
} else if (oc == PPC::FMR) { // fmr r1, r2
assert(MI.getNumOperands() == 2 &&
MI.getOperand(0).isRegister() &&
MI.getOperand(1).isRegister() &&
"invalid PPC FMR instruction");
sourceReg = MI.getOperand(1).getReg();
destReg = MI.getOperand(0).getReg();
return true;
}
return false;
}