/**
* Adjust the size of a node representing a stack alloc to a certain
* stack_alignment.
*
* @param size the node containing the non-aligned size
* @param block the block where new nodes are allocated on
* @return a node representing the aligned size
*/
static ir_node *adjust_alloc_size(dbg_info *dbgi, ir_node *size, ir_node *block)
{
/* Example: po2_alignment 4 (align to 16 bytes):
* size = (size+15) & 0xfff...f8 */
ir_mode *mode = get_irn_mode(size);
ir_graph *irg = get_irn_irg(block);
ir_tarval *allone = get_mode_all_one(mode);
ir_tarval *shr = tarval_shr_unsigned(allone, po2_stack_alignment);
ir_tarval *mask = tarval_shl_unsigned(shr, po2_stack_alignment);
ir_tarval *invmask = tarval_not(mask);
ir_node *addv = new_r_Const(irg, invmask);
ir_node *add = new_rd_Add(dbgi, block, size, addv);
ir_node *maskc = new_r_Const(irg, mask);
ir_node *and = new_rd_And(dbgi, block, add, maskc);
return and;
}
bool enum_bitfield_big_enough(enum_t *enume, type_t *base_type,
unsigned bitfield_size)
{
ir_mode *mode = get_ir_mode_storage(base_type);
ir_tarval *max = get_mode_max(mode);
ir_tarval *min = get_mode_min(mode);
bool is_signed = is_type_signed(base_type);
unsigned mode_size = get_mode_size_bits(mode);
unsigned shift_amount = mode_size - bitfield_size + is_signed;
ir_tarval *adjusted_max;
ir_tarval *adjusted_min;
/* corner case: signed mode with just sign bit results in shift_amount
* being as big as mode_size triggering "modulo shift" which is not what
* we want here. */
if (shift_amount >= mode_size) {
assert(bitfield_size == 1 && mode_is_signed(mode));
adjusted_max = get_mode_null(mode);
adjusted_min = get_mode_all_one(mode);
} else {
adjusted_max = tarval_shr_unsigned(max, shift_amount);
adjusted_min = tarval_shrs_unsigned(min, shift_amount);
}
for (entity_t *entry = enume->first_value;
entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
entry = entry->base.next) {
ir_tarval *tv = get_enum_value(&entry->enum_value);
if (tv == NULL)
continue;
ir_tarval *tvc = tarval_convert_to(tv, mode);
if (tarval_cmp(tvc, adjusted_min) == ir_relation_less
|| tarval_cmp(tvc, adjusted_max) == ir_relation_greater) {
return false;
}
}
return true;
}
