2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * @file lowers operations with mode_b. The result is a graph which
22 * might still contains some convs from/to mode_b, but no
23 * operations are performed on them anymore, they are just there
24 * so modes match. A backend can safely skip all mode_b convs.
25 * @author Matthias Braun, Christoph Mallon
45 static lower_mode_b_config_t config;
46 static ir_type *lowered_type = NULL;
47 static pdeq *lowered_nodes = NULL;
50 * Removes a node if its out-edge count has reached 0.
51 * temporary hack until we have proper automatic dead code elimination.
53 static void maybe_kill_node(ir_node *node)
58 if(get_irn_n_edges(node) != 0)
61 irg = get_irn_irg(node);
63 assert(!is_Bad(node));
65 arity = get_irn_arity(node);
66 for (i = 0; i < arity; ++i) {
67 set_irn_n(node, i, new_Bad());
69 set_nodes_block(node, new_Bad());
71 edges_node_deleted(node, irg);
74 static ir_node *create_not(dbg_info *dbgi, ir_node *node)
76 ir_graph *irg = current_ir_graph;
77 ir_node *block = get_nodes_block(node);
78 ir_mode *mode = config.lowered_mode;
79 tarval *tv_one = get_tarval_one(mode);
80 ir_node *one = new_d_Const(dbgi, mode, tv_one);
82 return new_rd_Eor(dbgi, irg, block, node, one, mode);
85 static ir_node *create_convb(ir_node *node)
87 ir_graph *irg = current_ir_graph;
88 ir_node *block = get_nodes_block(node);
89 ir_node *conv = new_rd_Conv(NULL, irg, block, node, mode_b);
94 static ir_type *create_lowered_type(void)
96 if(lowered_type == NULL) {
97 lowered_type = new_type_primitive(new_id_from_str("__lowered_mode_b"),
104 * creates a "set" node that produces a 0 or 1 based on a Cmp result
106 static ir_node *create_set(ir_node *node)
108 ir_graph *irg = current_ir_graph;
109 dbg_info *dbgi = get_irn_dbg_info(node);
110 ir_mode *mode = config.lowered_set_mode;
111 tarval *tv_one = get_tarval_one(mode);
112 ir_node *one = new_d_Const(dbgi, mode, tv_one);
113 ir_node *block = get_nodes_block(node);
114 tarval *tv_zero = get_tarval_null(mode);
115 ir_node *zero = new_d_Const(dbgi, mode, tv_zero);
117 ir_node *vals[2] = { one, zero };
118 ir_node *set = new_rd_Psi(dbgi, irg, block, 1, &node, vals, mode);
120 if(mode != config.lowered_mode) {
121 set = new_r_Conv(irg, block, set, config.lowered_mode);
127 static void adjust_method_type(ir_type *method_type)
133 n_params = get_method_n_params(method_type);
134 for(i = 0; i < n_params; ++i) {
135 ir_type *param = get_method_param_type(method_type, i);
136 if(get_type_mode(param) == mode_b) {
137 set_method_param_type(method_type, i, create_lowered_type());
141 n_res = get_method_n_ress(method_type);
142 for(i = 0; i < n_res; ++i) {
143 ir_type *res_type = get_method_res_type(method_type, i);
144 if(get_type_mode(res_type) == mode_b) {
145 set_method_res_type(method_type, i, create_lowered_type());
150 static ir_node *lower_node(ir_node *node)
152 ir_graph *irg = current_ir_graph;
153 dbg_info *dbgi = get_irn_dbg_info(node);
154 ir_op *op = get_irn_op(node);
155 ir_node *block = get_nodes_block(node);
156 ir_mode *mode = config.lowered_mode;
159 assert(get_irn_mode(node) == mode_b);
161 res = get_irn_link(node);
165 /* TODO: be robust against phi-loops... */
169 ir_node *unknown, *new_phi;
171 arity = get_irn_arity(node);
172 in = alloca(arity * sizeof(in[0]));
173 unknown = new_Unknown(config.lowered_mode);
174 for(i = 0; i < arity; ++i) {
177 new_phi = new_r_Phi(irg, block, arity, in, config.lowered_mode);
178 set_irn_link(node, new_phi);
179 pdeq_putr(lowered_nodes, node);
181 for(i = 0; i < arity; ++i) {
182 ir_node *in = get_irn_n(node, i);
183 ir_node *low_in = lower_node(in);
185 set_irn_n(new_phi, i, low_in);
191 if(op == op_And || op == op_Or || op == op_Eor) {
193 ir_node *copy = exact_copy(node);
195 arity = get_irn_arity(node);
196 for(i = 0; i < arity; ++i) {
197 ir_node *in = get_irn_n(node, i);
198 ir_node *low_in = lower_node(in);
200 set_irn_n(copy, i, low_in);
202 set_irn_mode(copy, config.lowered_mode);
204 set_irn_link(node, copy);
205 pdeq_putr(lowered_nodes, node);
209 ir_node *op = get_Not_op(node);
210 ir_node *low_op = lower_node(op);
212 res = create_not(dbgi, low_op);
213 set_irn_link(node, res);
214 pdeq_putr(lowered_nodes, node);
218 ir_node *cond = get_Psi_cond(node, 0);
219 ir_node *low_cond = lower_node(cond);
220 ir_node *v_true = get_Psi_val(node, 0);
221 ir_node *low_v_true = lower_node(v_true);
222 ir_node *v_false = get_Psi_default(node);
223 ir_node *low_v_false = lower_node(v_false);
225 ir_node *and0 = new_rd_And(dbgi, irg, block, low_cond, low_v_true,
228 ir_node *not_cond = create_not(dbgi, low_cond);
230 ir_node *and1 = new_rd_And(dbgi, irg, block, not_cond, low_v_false,
233 ir_node *or = new_rd_Or(dbgi, irg, block, and0, and1,
236 set_irn_link(node, or);
237 pdeq_putr(lowered_nodes, node);
241 ir_node *pred = get_Conv_op(node);
242 ir_mode *mode = get_irn_mode(pred);
243 tarval *tv_zeroc = get_tarval_null(mode);
244 ir_node *zero_cmp = new_d_Const(dbgi, mode, tv_zeroc);
247 ir_node *cmp = new_rd_Cmp(dbgi, irg, block, pred, zero_cmp);
248 ir_node *proj = new_rd_Proj(dbgi, irg, block, cmp, mode_b,
250 set = create_set(proj);
252 set_irn_link(node, set);
253 pdeq_putr(lowered_nodes, node);
257 ir_node *pred = get_Proj_pred(node);
260 ir_node *left = get_Cmp_left(pred);
261 ir_node *right = get_Cmp_right(pred);
262 ir_mode *cmp_mode = get_irn_mode(left);
265 if ((mode_is_int(cmp_mode) || mode_is_reference(cmp_mode)) && (
266 get_mode_size_bits(cmp_mode) < get_mode_size_bits(mode) ||
267 (mode_is_signed(cmp_mode) && is_Const(right) && is_Const_null(right))
269 int pnc = get_Proj_proj(node);
274 if(pnc == pn_Cmp_Lt) {
275 /* a < b -> (a - b) >> 31 */
278 } else if(pnc == pn_Cmp_Le) {
279 /* a <= b -> ~(a - b) >> 31 */
283 } else if(pnc == pn_Cmp_Gt) {
284 /* a > b -> (b - a) >> 31 */
287 } else if(pnc == pn_Cmp_Ge) {
288 /* a >= b -> ~(a - b) >> 31 */
295 int bits = get_mode_size_bits(mode);
296 tarval *tv = new_tarval_from_long(bits-1, mode_Iu);
297 ir_node *shift_cnt = new_d_Const(dbgi, mode_Iu, tv);
299 if(cmp_mode != mode) {
300 a = new_rd_Conv(dbgi, irg, block, a, mode);
301 b = new_rd_Conv(dbgi, irg, block, b, mode);
304 res = new_rd_Sub(dbgi, irg, block, a, b, mode);
306 res = new_rd_Not(dbgi, irg, block, res, mode);
308 res = new_rd_Shr(dbgi, irg, block, res, shift_cnt, mode);
310 set_irn_link(node, res);
311 pdeq_putr(lowered_nodes, node);
316 /* synthesize the 0/1 value */
317 set = create_set(node);
318 set_irn_link(node, set);
319 pdeq_putr(lowered_nodes, node);
321 } else if(is_Proj(pred) && is_Call(get_Proj_pred(pred))) {
322 ir_type *type = get_Call_type(get_Proj_pred(pred));
323 adjust_method_type(type);
324 set_irn_mode(node, mode);
326 } else if(is_Proj(pred) && is_Start(get_Proj_pred(pred))) {
327 ir_entity *entity = get_irg_entity(irg);
328 ir_type *type = get_entity_type(entity);
329 adjust_method_type(type);
330 set_irn_mode(node, mode);
334 panic("unexpected projb: %+F (pred: %+F)", node, pred);
337 tarval *tv = get_Const_tarval(node);
338 if(tv == get_tarval_b_true()) {
339 tarval *tv_one = get_tarval_one(mode);
340 res = new_d_Const(dbgi, mode, tv_one);
341 } else if(tv == get_tarval_b_false()) {
342 tarval *tv_zero = get_tarval_null(mode);
343 res = new_d_Const(dbgi, mode, tv_zero);
345 panic("invalid boolean const %+F", node);
347 set_irn_link(node, res);
348 pdeq_putr(lowered_nodes, node);
351 if (op == op_Unknown) {
352 return new_Unknown(config.lowered_mode);
355 panic("didn't expect %+F to have mode_b", node);
358 static void lower_mode_b_walker(ir_node *node, void *env)
364 arity = get_irn_arity(node);
365 for(i = 0; i < arity; ++i) {
367 ir_node *in = get_irn_n(node, i);
368 if(get_irn_mode(in) != mode_b)
371 if(! config.lower_direct_cmp) {
373 || (is_Psi(node) && get_irn_mode(node) != mode_b)) {
375 ir_node *pred = get_Proj_pred(in);
382 lowered_in = lower_node(in);
384 if(is_Return(node)) {
385 ir_entity *entity = get_irg_entity(current_ir_graph);
386 ir_type *type = get_entity_type(entity);
387 adjust_method_type(type);
388 } else if(is_Call(node)) {
389 ir_type *type = get_Call_type(node);
390 adjust_method_type(type);
392 lowered_in = create_convb(lowered_in);
394 set_irn_n(node, i, lowered_in);
398 add_identities(current_ir_graph->value_table, node);
402 static void clear_links(ir_node *node, void *env)
405 set_irn_link(node, NULL);
408 void ir_lower_mode_b(ir_graph *irg, const lower_mode_b_config_t *nconfig)
411 lowered_nodes = new_pdeq();
412 set_using_irn_link(irg);
414 irg_walk_graph(irg, clear_links, NULL, NULL);
415 irg_walk_graph(irg, lower_mode_b_walker, NULL, NULL);
417 while(!pdeq_empty(lowered_nodes)) {
418 ir_node *node = (ir_node*) pdeq_getr(lowered_nodes);
419 maybe_kill_node(node);
421 del_pdeq(lowered_nodes);
423 clear_using_irn_link(irg);