Mercurial > hg-old > index.cgi
diff src/insn_rel.c @ 29:37aec845aef3
Added relative addressing handler
author | lost |
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date | Fri, 02 Jan 2009 03:27:33 +0000 |
parents | |
children | 9bd0fbfe7405 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/insn_rel.c Fri Jan 02 03:27:33 2009 +0000 @@ -0,0 +1,80 @@ +/* +insn_rel.c +Copyright © 2008 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/>. +*/ + +/* +for handling relative mode instructions +*/ + +#define __insn_inh_c_seen__ + +#include <stdlib.h> + +#include "expr.h" +#include "lwasm.h" +#include "instab.h" + +OPFUNC(insn_rel8) +{ + lwasm_expr_stack_t *s; + int v; + + lwasm_emitop(as, l, instab[opnum].ops[0]); + + s = lwasm_expr_eval(*p, NULL); + if (!s) + { + register_error(as, l, 1, "Bad operand"); + lwasm_emitop(as, l, 0); + return; + } + if (lwasm_expr_is_constant(s)) + register_error(as, l, 2, "Incomplete reference"); + v = lwasm_expr_get_value(s); + v -= as -> addr + 1; + if (v < -128 || v > 127) + register_error(as, l, 2, "Byte overflow"); + lwasm_emit(as, l, v & 0xff); + + lwasm_expr_stack_free(s); +} + +OPFUNC(insn_rel16) +{ + lwasm_expr_stack_t *s; + int v; + + lwasm_emitop(as, l, instab[opnum].ops[0]); + + s = lwasm_expr_eval(*p, NULL); + if (!s) + { + register_error(as, l, 1, "Bad operand"); + lwasm_emitop(as, l, 0); + return; + } + if (lwasm_expr_is_constant(s)) + register_error(as, l, 2, "Incomplete reference"); + v = lwasm_expr_get_value(s); + v -= as -> addr + 2; + lwasm_emit(as, l, (v >> 8) & 0xff); + lwasm_emit(as, l, v & 0xff); + + lwasm_expr_stack_free(s); +}