branch.cpp

来自「RISC processor ARM-7 emulator」· C++ 代码 · 共 59 行

/*************************************************************************
    Copyright (C) 2002,2003,2004,2005 Wei Qin
    See file COPYING for more information.

    This program is free software; you can redistribute it and/or modify    
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
*************************************************************************/

#include <cstdio>
#include <armemul.h>
#include "branch.h"

using namespace emulator;

void impl_branch(IMPL_FORMALS)
{
	SInt32 offset;

	offset = (SInt32)(inst<<8)>>6;
	WRITE_REG(PC_REAL_IND, PC + offset);

	EMULATOR_STUB(branch,inst);
}

void impl_branch_link(IMPL_FORMALS)
{
	SInt32 offset;

	offset = (SInt32)(inst<<8)>>6;
	WRITE_REG(LRIND, PC - 4);
	WRITE_REG(PC_REAL_IND, PC + offset);

	EMULATOR_STUB(branch_link,inst);
}


char *disasm_branch(arm_inst_t inst, arm_addr_t pc, char *buf)
{
	SInt32 offset = (SInt32)(inst<<8)>>6;
	buf += sprintf(buf, "b%s 0x%x;\n",
		arm_conditional[COND], pc+8+offset);
	return buf;
}

char *disasm_branch_link(arm_inst_t inst, arm_addr_t pc, char *buf)
{
	SInt32 offset = (SInt32)(inst<<8)>>6;
	buf += sprintf(buf, "bl%s 0x%x;\n",
		arm_conditional[COND], pc+8+offset);
	return buf;
}