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
22 * @brief lowers operations with mode_b. The result is a graph which
23 * might still contains some convs from/to mode_b, but no
24 * operations are performed on them anymore, they are just there
25 * so modes match. A backend can safely skip all mode_b convs.
26 * @author Matthias Braun, Christoph Mallon
44 static lower_mode_b_config_t config;
45 static ir_type *lowered_type = NULL;
46 static pdeq *lowered_nodes = NULL;
49 * Removes a node if its out-edge count has reached 0.
50 * temporary hack until we have proper automatic dead code elimination.
52 static void maybe_kill_node(ir_node *node)
57 if(get_irn_n_edges(node) != 0)
60 irg = get_irn_irg(node);
62 assert(!is_Bad(node));
64 arity = get_irn_arity(node);
65 for (i = 0; i < arity; ++i) {
66 set_irn_n(node, i, new_Bad());
68 set_nodes_block(node, new_Bad());
70 edges_node_deleted(node, irg);
73 static ir_node *create_not(dbg_info *dbgi, ir_node *node)
75 ir_graph *irg = current_ir_graph;
76 ir_node *block = get_nodes_block(node);
77 ir_mode *mode = config.lowered_mode;
78 tarval *tv_one = get_tarval_one(mode);
79 ir_node *one = new_d_Const(dbgi, tv_one);
81 return new_rd_Eor(dbgi, irg, block, node, one, mode);
84 static ir_node *create_convb(ir_node *node)
86 ir_graph *irg = current_ir_graph;
87 ir_node *block = get_nodes_block(node);
88 ir_node *conv = new_rd_Conv(NULL, irg, block, node, mode_b, 0);
93 static ir_type *create_lowered_type(void)
95 if(lowered_type == NULL) {
96 lowered_type = new_type_primitive(new_id_from_str("__lowered_mode_b"),
103 * creates a "set" node that produces a 0 or 1 based on a Cmp result
105 static ir_node *create_set(ir_node *node)
107 ir_graph *irg = current_ir_graph;
108 dbg_info *dbgi = get_irn_dbg_info(node);
109 ir_mode *mode = config.lowered_set_mode;
110 tarval *tv_one = get_tarval_one(mode);
111 ir_node *one = new_d_Const(dbgi, tv_one);
112 ir_node *block = get_nodes_block(node);
113 tarval *tv_zero = get_tarval_null(mode);
114 ir_node *zero = new_d_Const(dbgi, tv_zero);
116 ir_node *set = new_rd_Mux(dbgi, irg, block, node, zero, one, mode);
118 if (mode != config.lowered_mode) {
119 set = new_r_Conv(irg, block, set, config.lowered_mode, 0);
125 static void adjust_method_type(ir_type *method_type)
131 n_params = get_method_n_params(method_type);
132 for(i = 0; i < n_params; ++i) {
133 ir_type *param = get_method_param_type(method_type, i);
134 if(get_type_mode(param) == mode_b) {
135 set_method_param_type(method_type, i, create_lowered_type());
139 n_res = get_method_n_ress(method_type);
140 for(i = 0; i < n_res; ++i) {
141 ir_type *res_type = get_method_res_type(method_type, i);
142 if(get_type_mode(res_type) == mode_b) {
143 set_method_res_type(method_type, i, create_lowered_type());
148 static ir_node *lower_node(ir_node *node)
150 ir_graph *irg = current_ir_graph;
151 dbg_info *dbgi = get_irn_dbg_info(node);
152 ir_node *block = get_nodes_block(node);
153 ir_mode *mode = config.lowered_mode;
156 assert(get_irn_mode(node) == mode_b);
158 res = get_irn_link(node);
162 /* TODO: be robust against phi-loops... */
163 switch (get_irn_opcode(node)) {
167 ir_node *unknown, *new_phi;
169 arity = get_irn_arity(node);
170 in = ALLOCAN(ir_node*, arity);
171 unknown = new_Unknown(config.lowered_mode);
172 for(i = 0; i < arity; ++i) {
175 new_phi = new_r_Phi(irg, block, arity, in, config.lowered_mode);
176 set_irn_link(node, new_phi);
177 pdeq_putr(lowered_nodes, node);
179 for(i = 0; i < arity; ++i) {
180 ir_node *in = get_irn_n(node, i);
181 ir_node *low_in = lower_node(in);
183 set_irn_n(new_phi, i, low_in);
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_Mux_sel(node);
219 ir_node *low_cond = lower_node(cond);
220 ir_node *v_true = get_Mux_true(node);
221 ir_node *low_v_true = lower_node(v_true);
222 ir_node *v_false = get_Mux_false(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, mode);
226 ir_node *not_cond = create_not(dbgi, low_cond);
227 ir_node *and1 = new_rd_And(dbgi, irg, block, not_cond, low_v_false, mode);
228 ir_node *or = new_rd_Or(dbgi, irg, block, and0, and1, mode);
230 set_irn_link(node, or);
231 pdeq_putr(lowered_nodes, node);
235 ir_node *pred = get_Conv_op(node);
236 ir_mode *mode = get_irn_mode(pred);
237 tarval *tv_zeroc = get_tarval_null(mode);
238 ir_node *zero_cmp = new_d_Const(dbgi, tv_zeroc);
241 ir_node *cmp = new_rd_Cmp(dbgi, irg, block, pred, zero_cmp);
242 ir_node *proj = new_rd_Proj(dbgi, irg, block, cmp, mode_b,
244 set = create_set(proj);
246 set_irn_link(node, set);
247 pdeq_putr(lowered_nodes, node);
251 ir_node *pred = get_Proj_pred(node);
254 ir_node *left = get_Cmp_left(pred);
255 ir_node *right = get_Cmp_right(pred);
256 ir_mode *cmp_mode = get_irn_mode(left);
259 if ((mode_is_int(cmp_mode) || mode_is_reference(cmp_mode)) && (
260 get_mode_size_bits(cmp_mode) < get_mode_size_bits(mode) ||
261 (mode_is_signed(cmp_mode) && is_Const(right) && is_Const_null(right))
263 int pnc = get_Proj_proj(node);
268 if(pnc == pn_Cmp_Lt) {
269 /* a < b -> (a - b) >> 31 */
272 } else if(pnc == pn_Cmp_Le) {
273 /* a <= b -> ~(a - b) >> 31 */
277 } else if(pnc == pn_Cmp_Gt) {
278 /* a > b -> (b - a) >> 31 */
281 } else if(pnc == pn_Cmp_Ge) {
282 /* a >= b -> ~(a - b) >> 31 */
289 int bits = get_mode_size_bits(mode);
290 tarval *tv = new_tarval_from_long(bits-1, mode_Iu);
291 ir_node *shift_cnt = new_d_Const(dbgi, tv);
293 if(cmp_mode != mode) {
294 a = new_rd_Conv(dbgi, irg, block, a, mode, 0);
295 b = new_rd_Conv(dbgi, irg, block, b, mode, 0);
298 res = new_rd_Sub(dbgi, irg, block, a, b, mode);
300 res = new_rd_Not(dbgi, irg, block, res, mode);
302 res = new_rd_Shr(dbgi, irg, block, res, shift_cnt, mode);
304 set_irn_link(node, res);
305 pdeq_putr(lowered_nodes, node);
310 /* synthesize the 0/1 value */
311 set = create_set(node);
312 set_irn_link(node, set);
313 pdeq_putr(lowered_nodes, node);
315 } else if(is_Proj(pred) && is_Call(get_Proj_pred(pred))) {
316 ir_type *type = get_Call_type(get_Proj_pred(pred));
317 adjust_method_type(type);
318 set_irn_mode(node, mode);
320 } else if(is_Proj(pred) && is_Start(get_Proj_pred(pred))) {
321 ir_entity *entity = get_irg_entity(irg);
322 ir_type *type = get_entity_type(entity);
323 adjust_method_type(type);
324 set_irn_mode(node, mode);
328 panic("unexpected projb: %+F (pred: %+F)", node, pred);
331 tarval *tv = get_Const_tarval(node);
332 if(tv == get_tarval_b_true()) {
333 tarval *tv_one = get_tarval_one(mode);
334 res = new_d_Const(dbgi, tv_one);
335 } else if(tv == get_tarval_b_false()) {
336 tarval *tv_zero = get_tarval_null(mode);
337 res = new_d_Const(dbgi, tv_zero);
339 panic("invalid boolean const %+F", node);
341 set_irn_link(node, res);
342 pdeq_putr(lowered_nodes, node);
346 return new_Unknown(config.lowered_mode);
348 panic("didn't expect %+F to have mode_b", node);
352 static void lower_mode_b_walker(ir_node *node, void *env)
358 arity = get_irn_arity(node);
359 for(i = 0; i < arity; ++i) {
361 ir_node *in = get_irn_n(node, i);
362 if(get_irn_mode(in) != mode_b)
365 if(! config.lower_direct_cmp) {
367 (is_Mux(node) && get_irn_mode(node) != mode_b)) {
369 ir_node *pred = get_Proj_pred(in);
376 lowered_in = lower_node(in);
378 if(is_Return(node)) {
379 ir_entity *entity = get_irg_entity(current_ir_graph);
380 ir_type *type = get_entity_type(entity);
381 adjust_method_type(type);
382 } else if(is_Call(node)) {
383 ir_type *type = get_Call_type(node);
384 adjust_method_type(type);
386 lowered_in = create_convb(lowered_in);
388 set_irn_n(node, i, lowered_in);
392 add_identities(current_ir_graph->value_table, node);
396 static void clear_links(ir_node *node, void *env)
399 set_irn_link(node, NULL);
402 void ir_lower_mode_b(ir_graph *irg, const lower_mode_b_config_t *nconfig)
405 lowered_nodes = new_pdeq();
407 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
409 irg_walk_graph(irg, clear_links, NULL, NULL);
410 irg_walk_graph(irg, lower_mode_b_walker, NULL, NULL);
412 while(!pdeq_empty(lowered_nodes)) {
413 ir_node *node = (ir_node*) pdeq_getr(lowered_nodes);
414 maybe_kill_node(node);
416 del_pdeq(lowered_nodes);
418 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);