int
yasm_bc_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span,
void *add_span_data)
{
int retval = 0;
bc->len = 0;
if (!bc->callback)
yasm_internal_error(N_("got empty bytecode in yasm_bc_calc_len"));
else
retval = bc->callback->calc_len(bc, add_span, add_span_data);
/* Check for multiples */
bc->mult_int = 1;
if (bc->multiple) {
/*@dependent@*/ /*@null@*/ const yasm_intnum *num;
num = yasm_expr_get_intnum(&bc->multiple, 0);
if (num) {
if (yasm_intnum_sign(num) < 0) {
yasm_error_set(YASM_ERROR_VALUE, N_("multiple is negative"));
retval = -1;
} else
bc->mult_int = yasm_intnum_get_int(num);
} else {
if (yasm_expr__contains(bc->multiple, YASM_EXPR_FLOAT)) {
yasm_error_set(YASM_ERROR_VALUE,
N_("expression must not contain floating point value"));
retval = -1;
} else {
yasm_value value;
yasm_value_initialize(&value, bc->multiple, 0);
add_span(add_span_data, bc, 0, &value, 0, 0);
bc->mult_int = 0; /* assume 0 to start */
}
}
}
/* If we got an error somewhere along the line, clear out any calc len */
if (retval < 0)
bc->len = 0;
return retval;
}
/* Check for and simplify identities. Returns new number of expr terms.
* Sets e->op = EXPR_IDENT if numterms ends up being 1.
* Uses numterms parameter instead of e->numterms for basis of "new" number
* of terms.
* Assumes int_term is *only* integer term in e.
* NOTE: Really designed to only be used by expr_level_op().
*/
static int
expr_simplify_identity(yasm_expr *e, int numterms, int *int_term,
int simplify_reg_mul)
{
int i;
int save_numterms;
/* Don't do this step if it's 1*REG. Save and restore numterms so
* yasm_expr__contains() works correctly.
*/
save_numterms = e->numterms;
e->numterms = numterms;
if (simplify_reg_mul || e->op != YASM_EXPR_MUL
|| !yasm_intnum_is_pos1(e->terms[*int_term].data.intn)
|| !yasm_expr__contains(e, YASM_EXPR_REG)) {
/* Check for simple identities that delete the intnum.
* Don't delete if the intnum is the only thing in the expn.
*/
if ((*int_term == 0 && numterms > 1 &&
expr_can_destroy_int_left(e->op, e->terms[0].data.intn)) ||
(*int_term > 0 &&
expr_can_destroy_int_right(e->op,
e->terms[*int_term].data.intn))) {
/* Delete the intnum */
yasm_intnum_destroy(e->terms[*int_term].data.intn);
/* Slide everything to its right over by 1 */
if (*int_term != numterms-1) /* if it wasn't last.. */
memmove(&e->terms[*int_term], &e->terms[*int_term+1],
(numterms-1-*int_term)*sizeof(yasm_expr__item));
/* Update numterms */
numterms--;
*int_term = -1; /* no longer an int term */
}
}
e->numterms = save_numterms;
/* Check for simple identites that delete everything BUT the intnum.
* Don't bother if the intnum is the only thing in the expn.
*/
if (numterms > 1 && *int_term != -1 &&
expr_is_constant(e->op, e->terms[*int_term].data.intn)) {
/* Loop through, deleting everything but the integer term */
for (i=0; i<e->numterms; i++)
if (i != *int_term)
expr_delete_term(&e->terms[i], 1);
/* Move integer term to the first term (if not already there) */
if (*int_term != 0)
e->terms[0] = e->terms[*int_term]; /* structure copy */
/* Set numterms to 1 */
numterms = 1;
}
/* Compute NOT, NEG, and LNOT on single intnum. */
if (numterms == 1 && *int_term == 0 &&
(e->op == YASM_EXPR_NOT || e->op == YASM_EXPR_NEG ||
e->op == YASM_EXPR_LNOT))
yasm_intnum_calc(e->terms[0].data.intn, e->op, NULL);
/* Change expression to IDENT if possible. */
if (numterms == 1)
e->op = YASM_EXPR_IDENT;
/* Return the updated numterms */
return numterms;
}
int
yasm_value_output_basic(yasm_value *value, /*@out@*/ unsigned char *buf,
size_t destsize, yasm_bytecode *bc, int warn,
yasm_arch *arch)
{
/*@dependent@*/ /*@null@*/ yasm_intnum *intn = NULL;
/*@only@*/ yasm_intnum *outval;
int sym_local;
int retval = 1;
unsigned int valsize = value->size;
if (value->no_warn)
warn = 0;
if (value->abs) {
/* Handle floating point expressions */
if (!value->rel && value->abs->op == YASM_EXPR_IDENT
&& value->abs->terms[0].type == YASM_EXPR_FLOAT) {
if (yasm_arch_floatnum_tobytes(arch, value->abs->terms[0].data.flt,
buf, destsize, valsize, 0, warn))
return -1;
else
return 1;
}
/* Check for complex float expressions */
if (yasm_expr__contains(value->abs, YASM_EXPR_FLOAT)) {
yasm_error_set(YASM_ERROR_FLOATING_POINT,
N_("floating point expression too complex"));
return -1;
}
/* Handle normal integer expressions */
intn = yasm_expr_get_intnum(&value->abs, 1);
if (!intn) {
/* Second try before erroring: yasm_expr_get_intnum doesn't handle
* SEG:OFF, so try simplifying out any to just the OFF portion,
* then getting the intnum again.
*/
yasm_expr *seg = yasm_expr_extract_deep_segoff(&value->abs);
if (seg)
yasm_expr_destroy(seg);
intn = yasm_expr_get_intnum(&value->abs, 1);
}
if (!intn) {
/* Still don't have an integer! */
yasm_error_set(YASM_ERROR_TOO_COMPLEX,
N_("expression too complex"));
return -1;
}
}
/* Adjust warn for signed/unsigned integer warnings */
if (warn != 0)
warn = value->sign ? -1 : 1;
if (value->rel) {
/* If relative portion is not in bc section, don't try to handle it
* here. Otherwise get the relative portion's offset.
*/
/*@dependent@*/ yasm_bytecode *rel_prevbc;
unsigned long dist;
sym_local = yasm_symrec_get_label(value->rel, &rel_prevbc);
if (value->wrt || value->seg_of || value->section_rel || !sym_local)
return 0; /* we can't handle SEG, WRT, or external symbols */
if (rel_prevbc->section != bc->section)
return 0; /* not in this section */
if (!value->curpos_rel)
return 0; /* not PC-relative */
/* Calculate value relative to current assembly position */
dist = yasm_bc_next_offset(rel_prevbc);
if (dist < bc->offset) {
outval = yasm_intnum_create_uint(bc->offset - dist);
yasm_intnum_calc(outval, YASM_EXPR_NEG, NULL);
} else {
dist -= bc->offset;
outval = yasm_intnum_create_uint(dist);
}
if (value->rshift > 0) {
/*@only@*/ yasm_intnum *shamt =
yasm_intnum_create_uint((unsigned long)value->rshift);
yasm_intnum_calc(outval, YASM_EXPR_SHR, shamt);
yasm_intnum_destroy(shamt);
}
/* Add in absolute portion */
if (intn)
yasm_intnum_calc(outval, YASM_EXPR_ADD, intn);
/* Output! */
if (yasm_arch_intnum_tobytes(arch, outval, buf, destsize, valsize, 0,
bc, warn))
retval = -1;
yasm_intnum_destroy(outval);
return retval;
}
if (value->seg_of || value->rshift || value->curpos_rel || value->ip_rel
|| value->section_rel)
return 0; /* We can't handle this with just an absolute */
if (intn) {
/* Output just absolute portion */
if (yasm_arch_intnum_tobytes(arch, intn, buf, destsize, valsize, 0, bc,
warn))
retval = -1;
} else {
/* No absolute or relative portions: output 0 */
outval = yasm_intnum_create_uint(0);
if (yasm_arch_intnum_tobytes(arch, outval, buf, destsize, valsize, 0,
bc, warn))
retval = -1;
yasm_intnum_destroy(outval);
}
return retval;
}
/* Negates e by multiplying by -1, with distribution over lower-precedence
* operators (eg ADD) and special handling to simplify result w/ADD, NEG, and
* others.
*
* Returns a possibly reallocated e.
*/
static /*@only@*/ yasm_expr *
expr_xform_neg_helper(/*@returned@*/ /*@only@*/ yasm_expr *e)
{
yasm_expr *ne;
int i;
switch (e->op) {
case YASM_EXPR_ADD:
/* distribute (recursively if expr) over terms */
for (i=0; i<e->numterms; i++) {
if (e->terms[i].type == YASM_EXPR_EXPR)
e->terms[i].data.expn =
expr_xform_neg_helper(e->terms[i].data.expn);
else
expr_xform_neg_item(e, &e->terms[i]);
}
break;
case YASM_EXPR_SUB:
/* change op to ADD, and recursively negate left side (if expr) */
e->op = YASM_EXPR_ADD;
if (e->terms[0].type == YASM_EXPR_EXPR)
e->terms[0].data.expn =
expr_xform_neg_helper(e->terms[0].data.expn);
else
expr_xform_neg_item(e, &e->terms[0]);
break;
case YASM_EXPR_NEG:
/* Negating a negated value? Make it an IDENT. */
e->op = YASM_EXPR_IDENT;
break;
case YASM_EXPR_IDENT:
/* Negating an ident? Change it into a MUL w/ -1 if there's no
* floatnums present below; if there ARE floatnums, recurse.
*/
if (e->terms[0].type == YASM_EXPR_FLOAT)
yasm_floatnum_calc(e->terms[0].data.flt, YASM_EXPR_NEG, NULL);
else if (e->terms[0].type == YASM_EXPR_INT)
yasm_intnum_calc(e->terms[0].data.intn, YASM_EXPR_NEG, NULL);
else if (e->terms[0].type == YASM_EXPR_EXPR &&
yasm_expr__contains(e->terms[0].data.expn, YASM_EXPR_FLOAT))
expr_xform_neg_helper(e->terms[0].data.expn);
else {
e->op = YASM_EXPR_MUL;
e->numterms = 2;
e->terms[1].type = YASM_EXPR_INT;
e->terms[1].data.intn = yasm_intnum_create_int(-1);
}
break;
default:
/* Everything else. MUL will be combined when it's leveled.
* Make a new expr (to replace e) with -1*e.
*/
ne = yasm_xmalloc(sizeof(yasm_expr));
ne->op = YASM_EXPR_MUL;
ne->line = e->line;
ne->numterms = 2;
ne->terms[0].type = YASM_EXPR_INT;
ne->terms[0].data.intn = yasm_intnum_create_int(-1);
ne->terms[1].type = YASM_EXPR_EXPR;
ne->terms[1].data.expn = e;
return ne;
}
return e;
}
