view lwasm/insn_gen.c @ 333:507f442dc71e

Add support for 6800 compatibility instructions. The occasional program uses the 6800 compatibility instructions since they are actually specified by Motorola in at least some documentation. They advertised the 6809 as source compatible with the 6800. This mode is not enabled by default, however. It is my belief that receiving an error when using a non-6809 instruction is more useful since it is unlikely that much 6800 source code is being assembled for the 6809 these days. Nevertheless, the --6809compat option is present for just those purposes so one does not have to resort to using macros (which would work equally well in most cases).
author William Astle <lost@l-w.ca>
date Tue, 15 Apr 2014 10:57:34 -0600
parents 210d261a614d
children 3afb809c7add
line wrap: on
line source

/*
insn_gen.c, Copyright © 2009 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/>.

Contains code for parsing general addressing modes (IMM+DIR+EXT+IND)
*/

#include <ctype.h>
#include <stdlib.h>

#include <lw_expr.h>

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

extern void insn_indexed_parse_aux(asmstate_t *as, line_t *l, char **p);
extern void insn_indexed_resolve_aux(asmstate_t *as, line_t *l, int force, int elen);
extern void insn_indexed_emit_aux(asmstate_t *as, line_t *l);

extern void insn_parse_indexed_aux(asmstate_t *as, line_t *l, char **p);
extern void insn_resolve_indexed_aux(asmstate_t *as, line_t *l, int force, int elen);

// "extra" is required due to the way OIM, EIM, TIM, and AIM work
void insn_parse_gen_aux(asmstate_t *as, line_t *l, char **p, int elen)
{
	const char *optr2;
	int v1, tv;
	lw_expr_t s;

	if (!**p)
	{
		lwasm_register_error(as, l, "Bad operand");
		return;
	}

	optr2 = *p;
	while (*optr2 && !isspace(*optr2) && *optr2 != ',') optr2++
		/* do nothing */ ;

	if (*optr2 == ',' || **p == '[')
	{
		l -> lint = -1;
		l -> lint2 = 1;
		insn_parse_indexed_aux(as, l, p);
		l -> minlen = OPLEN(instab[l -> insn].ops[1]) + 1 + elen;
		l -> maxlen = OPLEN(instab[l -> insn].ops[1]) + 3 + elen;
		goto out;
	}

	if (**p == '<')
	{
		(*p)++;
		l -> lint2 = 0;
	}

	// for compatibility with asxxxx
	// * followed by a digit, alpha, or _, or ., or ?, or another * is "f8"
	else if (**p == '*')
	{
		tv = *(*p + 1);
		if (isdigit(tv) || isalpha(tv) || tv == '_' || tv == '.' || tv == '?' || tv == '@' || tv == '*' || tv == '+' || tv == '-')
		{
			l -> lint2 = 0;
			(*p)++;
		}
	}
	else if (**p == '>')
	{
		(*p)++;
		l -> lint2 = 2;
	}
	else
	{
		l -> lint2 = -1;
	}

	l -> minlen = OPLEN(instab[l -> insn].ops[0]) + 1 + elen;
	l -> maxlen = OPLEN(instab[l -> insn].ops[2]) + 2 + elen;
	s = lwasm_parse_expr(as, p);
	if (!s)
	{
		lwasm_register_error(as, l, "Bad operand");
		return;
	}
	
	lwasm_save_expr(l, 0, s);

	if (as -> output_format == OUTPUT_OBJ && l -> lint2 == -1)
	{
		l -> lint2 = 2;
		goto out;
	}

	if (l -> lint2 != -1)
		goto out;

	// if we have a constant now, figure out dp vs nondp
	if (lw_expr_istype(s, lw_expr_type_int))
	{
		v1 = lw_expr_intval(s);
		if (((v1 >> 8) & 0xff) == (l -> dpval & 0xff))
		{
			l -> lint2 = 0;
			goto out;
		}
		l -> lint2 = 2;
	}
	else
	{
		int min;
		int max;
		
		if (lwasm_calculate_range(as, s, &min, &max) == 0)
		{
//			fprintf(stderr, "range (P) %d...%d for %s\n", min, max, lw_expr_print(s));
			if (min > max)
			{
				// we don't know what to do in this case so don't do anything
				goto out;
			}
			min = (min >> 8) & 0xff;
			max = (max >> 8) & 0xff;
			if ((l -> dpval & 0xff) < min || (l -> dpval & 0xff) > max)
			{
				l -> lint2 = 2;
				goto out;
			}
			if (min == max && (l -> dpval & 0xff) == min)
			{
				l -> lint2 = 0;
				goto out;
			}
			// if here, we don't know if the value is in the DP or not
			{
				l -> lint2 = -1;
				goto out;
			}
		}
	}

out:
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1 + elen;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2 + elen;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1 + elen;
		}
	}
}

void insn_resolve_gen_aux(asmstate_t *as, line_t *l, int force, int elen)
{
	lw_expr_t e;
	
	if (l -> lint2 == 1)
	{
		// indexed
		insn_resolve_indexed_aux(as, l, force, elen);
		goto out;
	}
	
	if (l -> lint2 != -1)
		return;
	
	e = lwasm_fetch_expr(l, 0);
	lwasm_reduce_expr(as, e);
	if (lw_expr_istype(e, lw_expr_type_int))
	{
		int v;
		
		v = lw_expr_intval(e);

		if (((v >> 8) & 0xff) == (l -> dpval & 0xff))
		{
			l -> lint2 = 0;
			goto out;
		}
		l -> lint2 = 2;
		goto out;
	}
	else
	{
		int min;
		int max;
		
		if (lwasm_calculate_range(as, e, &min, &max) == 0)
		{
//			fprintf(stderr, "range (R) %d...%d for %s\n", min, max, lw_expr_print(e));
			if (min > max)
			{
				// we don't know what to do in this case so don't do anything
				goto out;
			}
			min = (min >> 8) & 0xff;
			max = (max >> 8) & 0xff;
			if ((l -> dpval & 0xff) < min || (l -> dpval & 0xff) > max)
			{
				l -> lint2 = 2;
				goto out;
			}
			if (min == max && (l -> dpval & 0xff) == min)
			{
				l -> lint2 = 0;
				goto out;
			}
			// if here, we don't know if the value is in the DP or not
			{
				l -> lint2 = -1;
				goto out;
			}
		}
	}

	if (force)
	{
		l -> lint2 = 2;
	}

out:
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1 + elen;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2 + elen;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1 + elen;
		}
	}
}

void insn_emit_gen_aux(asmstate_t *as, line_t *l, int extra)
{
	lw_expr_t e;
	
	e = lwasm_fetch_expr(l, 0);
	lwasm_emitop(l, instab[l -> insn].ops[l -> lint2]);
	
	if (extra != -1)
		lwasm_emit(l, extra);
	
	if (l -> lint2 == 1)
	{
		lwasm_emit(l, l -> pb);
		if (l -> lint > 0)
		{
			int i;
			i = lw_expr_intval(e);
			if (l -> lint == 1)
			{
				if (i < -128 || i > 127)
					lwasm_register_error(as, l, "Byte overflow");
			}
			lwasm_emitexpr(l, e, l -> lint);
		}
		return;
	}
	
	if (l -> lint2 == 2)
		lwasm_emitexpr(l, e, 2);
	else
		lwasm_emitexpr(l, e, 1);
}

// the various insn_gen? functions have an immediate mode of ? bits
PARSEFUNC(insn_parse_gen0)
{
	if (**p == '#')
	{
		lwasm_register_error(as, l, "Immediate mode not allowed");
		return;
	}
	
	// handle non-immediate
	insn_parse_gen_aux(as, l, p, 0);
}

RESOLVEFUNC(insn_resolve_gen0)
{
	if (l -> len != -1)
		return;

	// handle non-immediate
	insn_resolve_gen_aux(as, l, force, 0);
}

EMITFUNC(insn_emit_gen0)
{
	insn_emit_gen_aux(as, l, -1);
}

PARSEFUNC(insn_parse_gen8)
{
	if (**p == '#')
	{
		lw_expr_t e;
		
		(*p)++;
		e = lwasm_parse_expr(as, p);
		if (!e)
		{
			lwasm_register_error(as, l, "Bad operand");
			return;
		}
		l -> len = OPLEN(instab[l -> insn].ops[3]) + 1;
		l -> lint2 = 3;
		lwasm_save_expr(l, 0, e);
		return;
	}
	
	// handle non-immediate
	insn_parse_gen_aux(as, l, p, 0);
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1;
		}
	}
}

RESOLVEFUNC(insn_resolve_gen8)
{
	if (l -> len != -1)
		return;

	// handle non-immediate
	insn_resolve_gen_aux(as, l, force, 0);
}

EMITFUNC(insn_emit_gen8)
{
	if (l -> lint2 == 3)
	{
		lw_expr_t e;
		e = lwasm_fetch_expr(l, 0);
		lwasm_emitop(l, instab[l -> insn].ops[3]);
		lwasm_emitexpr(l, e, 1);
		return;
	}

	insn_emit_gen_aux(as, l, -1);
}

PARSEFUNC(insn_parse_gen16)
{
	if (**p == '#')
	{
		lw_expr_t e;
		
		(*p)++;
		e = lwasm_parse_expr(as, p);
		if (!e)
		{
			lwasm_register_error(as, l, "Bad operand");
			return;
		}
		l -> len = OPLEN(instab[l -> insn].ops[3]) + 2;
		l -> lint2 = 3;
		lwasm_save_expr(l, 0, e);
		return;
	}
	
	// handle non-immediate
	insn_parse_gen_aux(as, l, p, 0);
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1;
		}
	}
}

RESOLVEFUNC(insn_resolve_gen16)
{
	if (l -> len != -1)
		return;

	// handle non-immediate
	insn_resolve_gen_aux(as, l, force, 0);
}

EMITFUNC(insn_emit_gen16)
{
	if (l -> lint2 == 3)
	{
		lw_expr_t e;
		e = lwasm_fetch_expr(l, 0);
		lwasm_emitop(l, instab[l -> insn].ops[3]);
		lwasm_emitexpr(l, e, 2);
		return;
	}

	insn_emit_gen_aux(as, l, -1);
}

PARSEFUNC(insn_parse_gen32)
{
	if (**p == '#')
	{
		lw_expr_t e;
		
		(*p)++;
		e = lwasm_parse_expr(as, p);
		if (!e)
		{
			lwasm_register_error(as, l, "Bad operand");
			return;
		}
		l -> len = OPLEN(instab[l -> insn].ops[3]) + 4;
		l -> lint2 = 3;
		lwasm_save_expr(l, 0, e);
		return;
	}
	
	// handle non-immediate
	insn_parse_gen_aux(as, l, p, 0);
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1;
		}
	}
}

RESOLVEFUNC(insn_resolve_gen32)
{
	if (l -> len != -1)
		return;

	// handle non-immediate
	insn_resolve_gen_aux(as, l, force, 0);
}

EMITFUNC(insn_emit_gen32)
{
	if (l -> lint2 == 3)
	{
		lw_expr_t e;
		e = lwasm_fetch_expr(l, 0);
		lwasm_emitop(l, instab[l -> insn].ops[3]);
		lwasm_emitexpr(l, e, 4);
		return;
	}

	insn_emit_gen_aux(as, l, -1);
}

PARSEFUNC(insn_parse_imm8)
{
	lw_expr_t e;
	
	if (**p == '#')
	{
		(*p)++;

		e = lwasm_parse_expr(as, p);
		if (!e)
		{
			lwasm_register_error(as, l, "Bad operand");
			return;
		}
		l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
		lwasm_save_expr(l, 0, e);
	}
	else
	{
		lwasm_register_error(as, l, "Bad operand");
	}
}

EMITFUNC(insn_emit_imm8)
{
	lw_expr_t e;
	
	lwasm_emitop(l, instab[l -> insn].ops[0]);
	e = lwasm_fetch_expr(l, 0);
	lwasm_emitexpr(l, e, 1);
}