-static ir_node *bitfield_extract_to_firm(const unary_expression_t *expression)
-{
- expression_t *select = expression->value;
- assert(select->kind == EXPR_SELECT);
-
- type_t *type = select->base.type;
- assert(type->kind == TYPE_BITFIELD);
- ir_mode *mode = get_ir_mode(type->bitfield.base_type);
- dbg_info *dbgi = get_dbg_info(&expression->base.source_position);
- ir_node *addr = expression_to_addr(select);
- ir_node *mem = get_store();
- ir_node *load = new_d_Load(dbgi, mem, addr, mode);
- ir_node *load_mem = new_d_Proj(dbgi, load, mode_M, pn_Load_M);
- ir_node *load_res = new_d_Proj(dbgi, load, mode, pn_Load_res);
-
- load_res = create_conv(dbgi, load_res, mode_int);
-
- set_store(load_mem);
-
- /* kill upper bits */
- ir_entity *entity = select->select.compound_entry->v.entity;
- int bitoffset = get_entity_offset_bits_remainder(entity);
- ir_type *entity_type = get_entity_type(entity);
- int bitsize = get_mode_size_bits(get_type_mode(entity_type));
- long shift_bitsl = machine_size - bitoffset - bitsize;
- assert(shift_bitsl >= 0);
- tarval *tvl = new_tarval_from_long(shift_bitsl, mode_uint);
- ir_node *countl = new_d_Const(dbgi, mode_uint, tvl);
- ir_node *shiftl = new_d_Shl(dbgi, load_res, countl, mode_int);
-
- long shift_bitsr = bitoffset + shift_bitsl;
- assert(shift_bitsr <= (long) machine_size);
- tarval *tvr = new_tarval_from_long(shift_bitsr, mode_uint);
- ir_node *countr = new_d_Const(dbgi, mode_uint, tvr);
- ir_node *shiftr;
- if(mode_is_signed(mode)) {
- shiftr = new_d_Shrs(dbgi, shiftl, countr, mode_int);
- } else {
- shiftr = new_d_Shr(dbgi, shiftl, countr, mode_int);
- }
-
- return create_conv(dbgi, shiftr, mode);
-}
-