source: trunk/minix/commands/i386/asmconv/asm86.c@ 20

/*      asm86.c - 80X86 assembly intermediate           Author: Kees J. Bot
 *                                                              24 Dec 1993
 */
#define nil 0
#include <stddef.h>
#include <string.h>
#include <assert.h>
#include "asm86.h"
#include "asmconv.h"
#include "token.h"

expression_t *new_expr(void)
/* Make a new cell to build an expression. */
{
        expression_t *e;

        e= allocate(nil, sizeof(*e));
        e->operator= -1;
        e->left= e->middle= e->right= nil;
        e->name= nil;
        e->magic= 31624;
        return e;
}

void del_expr(expression_t *e)
/* Delete an expression tree. */
{
        if (e != nil) {
                assert(e->magic == 31624);
                e->magic= 0;
                deallocate(e->name);
                del_expr(e->left);
                del_expr(e->middle);
                del_expr(e->right);
                deallocate(e);
        }
}

asm86_t *new_asm86(void)
/* Make a new cell to hold an 80X86 instruction. */
{
        asm86_t *a;

        a= allocate(nil, sizeof(*a));
        a->opcode= -1;
        get_file(&a->file, &a->line);
        a->optype= -1;
        a->oaz= 0;
        a->rep= ONCE;
        a->seg= DEFSEG;
        a->args= nil;
        a->magic= 37937;
        return a;
}

void del_asm86(asm86_t *a)
/* Delete an 80X86 instruction. */
{
        assert(a != nil);
        assert(a->magic == 37937);
        a->magic= 0;
        del_expr(a->args);
        deallocate(a);
}

int isregister(const char *name)
/* True if the string is a register name.  Return its size. */
{
        static char *regs[] = {
                "al", "bl", "cl", "dl", "ah", "bh", "ch", "dh",
                "ax", "bx", "cx", "dx", "si", "di", "bp", "sp",
                "cs", "ds", "es", "fs", "gs", "ss",
                "eax", "ebx", "ecx", "edx", "esi", "edi", "ebp", "esp",
                "cr0", "cr1", "cr2", "cr3",
                "st",
        };
        int reg;

        for (reg= 0; reg < arraysize(regs); reg++) {
                if (strcmp(name, regs[reg]) == 0) {
                        return reg < 8 ? 1 : reg < 22 ? 2 : 4;
                }
        }
        return 0;
}