view lwasm/insn_inh.c @ 482:9c24336fa76c

Correct cycle counts for W relative indexing modes Actually handle the 6309 specific W relative indexing modes (,W; n,W; ,W++; ,--W) in the cycle count calculation code. These work differently than the regular indexing modes so it's necessary to handle their bit patterns specially. (The bits that would normally select the base register are used instead to select the operation on W.)
author William Astle <lost@l-w.ca>
date Thu, 24 Jan 2019 18:24:03 -0700
parents 4fd16faa4d93
children
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/*
insn_inh.c
Copyright © 2010 William Astle

This file is part of LWASM.

LWASM 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 3 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.

You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.

*/

#include "lwasm.h"
#include "instab.h"

PARSEFUNC(insn_parse_inh)
{
	l -> len = OPLEN(instab[l -> insn].ops[0]);
	skip_operand(p);
}

EMITFUNC(insn_emit_inh)
{
	lwasm_emitop(l, instab[l -> insn].ops[0]);
}

PARSEFUNC(insn_parse_inh6800)
{
	// there may be two operations here so check for both
	l -> len = OPLEN(instab[l -> insn].ops[0]);
	if (instab[l -> insn].ops[1] >= 0)
		l -> len += OPLEN(instab[l -> insn].ops[1]);
	skip_operand(p);
}

EMITFUNC(insn_emit_inh6800)
{
	// there may be two operations here so check for both
	lwasm_emitop(l, instab[l -> insn].ops[0]);
	if (instab[l -> insn].ops[1] >= 0)
		lwasm_emitop(l, instab[l -> insn].ops[1]);
	l -> cycle_base = instab[l -> insn].ops[3];
}

int negq_ops[] = { 0x10, 0x43, 0x10, 0x53, 0x10, 0x31, 0xc6, 0x10, 0x31, 0xc0 };
#define negq_size (sizeof(negq_ops)/sizeof(int))

PARSEFUNC(insn_parse_conv)
{
	int i;
	l -> len = 0;
	for (i = 0; i <= 2; i++)
	{
		if (instab[l -> insn].ops[i] >= 0)
			l -> len += OPLEN(instab[l -> insn].ops[i]);
	}

	/* negq */
	if (instab[l -> insn].ops[0] == -1)
		l -> len = negq_size;
	skip_operand(p);
}

EMITFUNC(insn_emit_conv)
{
	int i;
	for (i = 0; i <= 2; i++)
	{
		if (instab[l -> insn].ops[i] >= 0)
			lwasm_emitop(l, instab[l -> insn].ops[i]);
	}

	/* special case for negq */
	if (instab[l -> insn].ops[0] == -1)
	{
		// 1043   (2)  comd
		// 1053   (2)  comw
		// 1031C6 (4)  adcr 0,w
		// 1031C0 (4)  adcr 0,d

		for (i = 0; i < negq_size; i++)
			lwasm_emitop(l, negq_ops[i]);
	}

	l->cycle_base = instab[l -> insn].ops[3];
}