/**
* lower 64bit subtraction: a 32bit sub for the lower parts, a sub
* with borrow for the higher parts. If the borrow's value is known,
* fold it into the upper sub.
*/
static void ia32_lower_sub64(ir_node *node, ir_mode *mode)
{
dbg_info *dbg = get_irn_dbg_info(node);
ir_node *block = get_nodes_block(node);
ir_node *left = get_Sub_left(node);
ir_node *right = get_Sub_right(node);
ir_node *left_low = get_lowered_low(left);
ir_node *left_high = get_lowered_high(left);
ir_node *right_low = get_lowered_low(right);
ir_node *right_high = get_lowered_high(right);
ir_mode *low_mode = get_irn_mode(left_low);
ir_mode *high_mode = get_irn_mode(left_high);
carry_result cr = lower_sub_borrow(left, right, low_mode);
assert(get_irn_mode(left_low) == get_irn_mode(right_low));
assert(get_irn_mode(left_high) == get_irn_mode(right_high));
if (cr == no_carry) {
ir_node *sub_low = new_rd_Sub(dbg, block, left_low, right_low, low_mode);
ir_node *sub_high = new_rd_Sub(dbg, block, left_high, right_high, high_mode);
ir_set_dw_lowered(node, sub_low, sub_high);
} else if (cr == must_carry && (is_Const(left_high) || is_Const(right_high))) {
ir_node *sub_high;
ir_graph *irg = get_irn_irg(right_high);
ir_node *one = new_rd_Const(dbg, irg, get_mode_one(high_mode));
if (is_Const(right_high)) {
ir_node *new_const = new_rd_Add(dbg, block, right_high, one, high_mode);
sub_high = new_rd_Sub(dbg, block, left_high, new_const, high_mode);
} else if (is_Const(left_high)) {
ir_node *new_const = new_rd_Sub(dbg, block, left_high, one, high_mode);
sub_high = new_rd_Sub(dbg, block, new_const, right_high, high_mode);
} else {
panic("logic error");
}
ir_node *sub_low = new_rd_Sub(dbg, block, left_low, right_low, low_mode);
ir_set_dw_lowered(node, sub_low, sub_high);
} else {
/* l_res = a_l - b_l */
ir_node *sub_low = new_bd_ia32_l_Sub(dbg, block, left_low, right_low);
ir_mode *mode_flags = ia32_reg_classes[CLASS_ia32_flags].mode;
ir_node *res_low = new_r_Proj(sub_low, ia32_mode_gp, pn_ia32_l_Sub_res);
ir_node *flags = new_r_Proj(sub_low, mode_flags, pn_ia32_l_Sub_flags);
/* h_res = a_h - b_h - carry */
ir_node *sub_high
= new_bd_ia32_l_Sbb(dbg, block, left_high, right_high, flags, mode);
ir_set_dw_lowered(node, res_low, sub_high);
}
}
static void lower64_sub(ir_node *node, ir_mode *mode)
{
dbg_info *dbgi = get_irn_dbg_info(node);
ir_node *block = get_nodes_block(node);
ir_node *left = get_Sub_left(node);
ir_node *right = get_Sub_right(node);
ir_node *left_low = get_lowered_low(left);
ir_node *left_high = get_lowered_high(left);
ir_node *right_low = get_lowered_low(right);
ir_node *right_high = get_lowered_high(right);
ir_node *subs = new_bd_arm_SubS_t(dbgi, block, left_low, right_low);
ir_mode *mode_low = get_irn_mode(left_low);
ir_node *res_low = new_r_Proj(subs, mode_low, pn_arm_SubS_t_res);
ir_node *res_flags = new_r_Proj(subs, mode_ANY, pn_arm_SubS_t_flags);
ir_node *sbc = new_bd_arm_SbC_t(dbgi, block, left_high,
right_high, res_flags, mode);
ir_set_dw_lowered(node, res_low, sbc);
}
ir_node *copy_const_value(dbg_info *dbg, ir_node *n, ir_node *block)
{
ir_graph *irg = get_irn_irg(block);
/* @@@ GL I think we should implement this using the routines from irgopt
* for dead node elimination/inlineing. */
ir_mode *m = get_irn_mode(n);
ir_node *nn;
switch (get_irn_opcode(n)) {
case iro_Const:
nn = new_rd_Const(dbg, irg, get_Const_tarval(n));
break;
case iro_SymConst:
nn = new_rd_SymConst(dbg, irg, get_irn_mode(n), get_SymConst_symbol(n), get_SymConst_kind(n));
break;
case iro_Add:
nn = new_rd_Add(dbg, block,
copy_const_value(dbg, get_Add_left(n), block),
copy_const_value(dbg, get_Add_right(n), block), m);
break;
case iro_Sub:
nn = new_rd_Sub(dbg, block,
copy_const_value(dbg, get_Sub_left(n), block),
copy_const_value(dbg, get_Sub_right(n), block), m);
break;
case iro_Mul:
nn = new_rd_Mul(dbg, block,
copy_const_value(dbg, get_Mul_left(n), block),
copy_const_value(dbg, get_Mul_right(n), block), m);
break;
case iro_And:
nn = new_rd_And(dbg, block,
copy_const_value(dbg, get_And_left(n), block),
copy_const_value(dbg, get_And_right(n), block), m);
break;
case iro_Or:
nn = new_rd_Or(dbg, block,
copy_const_value(dbg, get_Or_left(n), block),
copy_const_value(dbg, get_Or_right(n), block), m);
break;
case iro_Eor:
nn = new_rd_Eor(dbg, block,
copy_const_value(dbg, get_Eor_left(n), block),
copy_const_value(dbg, get_Eor_right(n), block), m);
break;
case iro_Conv:
nn = new_rd_Conv(dbg, block,
copy_const_value(dbg, get_Conv_op(n), block), m);
break;
case iro_Minus:
nn = new_rd_Minus(dbg, block,
copy_const_value(dbg, get_Minus_op(n), block), m);
break;
case iro_Not:
nn = new_rd_Not(dbg, block,
copy_const_value(dbg, get_Not_op(n), block), m);
break;
case iro_Unknown:
nn = new_r_Unknown(irg, m);
break;
default:
panic("opcode invalid or not implemented %+F", n);
}
return nn;
}
