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
46 static lower_mode_b_config_t config;
47 static ir_type *lowered_type = NULL;
48 static pdeq *lowered_nodes = NULL;
51 * Removes a node if its out-edge count has reached 0.
52 * temporary hack until we have proper automatic dead code elimination.
54 static void maybe_kill_node(ir_node *node)
59 if(get_irn_n_edges(node) != 0)
62 irg = get_irn_irg(node);
64 assert(!is_Bad(node));
66 arity = get_irn_arity(node);
67 for (i = 0; i < arity; ++i) {
68 set_irn_n(node, i, new_Bad());
70 set_nodes_block(node, new_Bad());
72 edges_node_deleted(node, irg);
75 static ir_node *create_not(dbg_info *dbgi, ir_node *node)
77 ir_graph *irg = current_ir_graph;
78 ir_node *block = get_nodes_block(node);
79 ir_mode *mode = config.lowered_mode;
80 tarval *tv_one = get_tarval_one(mode);
81 ir_node *one = new_d_Const(dbgi, mode, tv_one);
83 return new_rd_Eor(dbgi, irg, block, node, one, mode);
86 static ir_node *create_convb(ir_node *node)
88 ir_graph *irg = current_ir_graph;
89 ir_node *block = get_nodes_block(node);
90 ir_node *conv = new_rd_Conv(NULL, irg, block, node, mode_b);
95 static ir_type *create_lowered_type(void)
97 if(lowered_type == NULL) {
98 lowered_type = new_type_primitive(new_id_from_str("__lowered_mode_b"),
105 * creates a "set" node that produces a 0 or 1 based on a Cmp result
107 static ir_node *create_set(ir_node *node)
109 ir_graph *irg = current_ir_graph;
110 dbg_info *dbgi = get_irn_dbg_info(node);
111 ir_mode *mode = config.lowered_set_mode;
112 tarval *tv_one = get_tarval_one(mode);
113 ir_node *one = new_d_Const(dbgi, mode, tv_one);
114 ir_node *block = get_nodes_block(node);
115 tarval *tv_zero = get_tarval_null(mode);
116 ir_node *zero = new_d_Const(dbgi, mode, tv_zero);
118 ir_node *vals[2] = { one, zero };
119 ir_node *set = new_rd_Psi(dbgi, irg, block, 1, &node, vals, mode);
121 if(mode != config.lowered_mode) {
122 set = new_r_Conv(irg, block, set, config.lowered_mode);
128 static void adjust_method_type(ir_type *method_type)
134 n_params = get_method_n_params(method_type);
135 for(i = 0; i < n_params; ++i) {
136 ir_type *param = get_method_param_type(method_type, i);
137 if(get_type_mode(param) == mode_b) {
138 set_method_param_type(method_type, i, create_lowered_type());
142 n_res = get_method_n_ress(method_type);
143 for(i = 0; i < n_res; ++i) {
144 ir_type *res_type = get_method_res_type(method_type, i);
145 if(get_type_mode(res_type) == mode_b) {
146 set_method_res_type(method_type, i, create_lowered_type());
151 static ir_node *lower_node(ir_node *node)
153 ir_graph *irg = current_ir_graph;
154 dbg_info *dbgi = get_irn_dbg_info(node);
155 ir_op *op = get_irn_op(node);
156 ir_node *block = get_nodes_block(node);
157 ir_mode *mode = config.lowered_mode;
160 assert(get_irn_mode(node) == mode_b);
162 res = get_irn_link(node);
166 /* TODO: be robust against phi-loops... */
170 ir_node *unknown, *new_phi;
172 arity = get_irn_arity(node);
173 in = alloca(arity * sizeof(in[0]));
174 unknown = new_Unknown(config.lowered_mode);
175 for(i = 0; i < arity; ++i) {
178 new_phi = new_r_Phi(irg, block, arity, in, config.lowered_mode);
179 set_irn_link(node, new_phi);
180 pdeq_putr(lowered_nodes, node);
182 for(i = 0; i < arity; ++i) {
183 ir_node *in = get_irn_n(node, i);
184 ir_node *low_in = lower_node(in);
186 set_irn_n(new_phi, i, low_in);
192 if(op == op_And || op == op_Or || op == op_Eor) {
194 ir_node *copy = exact_copy(node);
196 arity = get_irn_arity(node);
197 for(i = 0; i < arity; ++i) {
198 ir_node *in = get_irn_n(node, i);
199 ir_node *low_in = lower_node(in);
201 set_irn_n(copy, i, low_in);
203 set_irn_mode(copy, config.lowered_mode);
205 set_irn_link(node, copy);
206 pdeq_putr(lowered_nodes, node);
210 ir_node *op = get_Not_op(node);
211 ir_node *low_op = lower_node(op);
213 res = create_not(dbgi, low_op);
214 set_irn_link(node, res);
215 pdeq_putr(lowered_nodes, node);
219 ir_node *cond = get_Psi_cond(node, 0);
220 ir_node *low_cond = lower_node(cond);
221 ir_node *v_true = get_Psi_val(node, 0);
222 ir_node *low_v_true = lower_node(v_true);
223 ir_node *v_false = get_Psi_default(node);
224 ir_node *low_v_false = lower_node(v_false);
226 ir_node *and0 = new_rd_And(dbgi, irg, block, low_cond, low_v_true,
229 ir_node *not_cond = create_not(dbgi, low_cond);
231 ir_node *and1 = new_rd_And(dbgi, irg, block, not_cond, low_v_false,
234 ir_node *or = new_rd_Or(dbgi, irg, block, and0, and1,
237 set_irn_link(node, or);
238 pdeq_putr(lowered_nodes, node);
242 ir_node *pred = get_Conv_op(node);
243 ir_mode *mode = get_irn_mode(pred);
244 tarval *tv_zeroc = get_tarval_null(mode);
245 ir_node *zero_cmp = new_d_Const(dbgi, mode, tv_zeroc);
248 ir_node *cmp = new_rd_Cmp(dbgi, irg, block, pred, zero_cmp);
249 ir_node *proj = new_rd_Proj(dbgi, irg, block, cmp, mode_b,
251 set = create_set(proj);
253 set_irn_link(node, set);
254 pdeq_putr(lowered_nodes, node);
258 ir_node *pred = get_Proj_pred(node);
261 ir_node *left = get_Cmp_left(pred);
262 ir_node *right = get_Cmp_right(pred);
263 ir_mode *cmp_mode = get_irn_mode(left);
266 if ((mode_is_int(cmp_mode) || mode_is_reference(cmp_mode)) && (
267 get_mode_size_bits(cmp_mode) < get_mode_size_bits(mode) ||
268 (mode_is_signed(cmp_mode) && is_Const(right) && is_Const_null(right))
270 int pnc = get_Proj_proj(node);
275 if(pnc == pn_Cmp_Lt) {
276 /* a < b -> (a - b) >> 31 */
279 } else if(pnc == pn_Cmp_Le) {
280 /* a <= b -> ~(a - b) >> 31 */
284 } else if(pnc == pn_Cmp_Gt) {
285 /* a > b -> (b - a) >> 31 */
288 } else if(pnc == pn_Cmp_Ge) {
289 /* a >= b -> ~(a - b) >> 31 */
296 int bits = get_mode_size_bits(mode);
297 tarval *tv = new_tarval_from_long(bits-1, mode_Iu);
298 ir_node *shift_cnt = new_d_Const(dbgi, mode_Iu, tv);
300 if(cmp_mode != mode) {
301 a = new_rd_Conv(dbgi, irg, block, a, mode);
302 b = new_rd_Conv(dbgi, irg, block, b, mode);
305 res = new_rd_Sub(dbgi, irg, block, a, b, mode);
307 res = new_rd_Not(dbgi, irg, block, res, mode);
309 res = new_rd_Shr(dbgi, irg, block, res, shift_cnt, mode);
311 set_irn_link(node, res);
312 pdeq_putr(lowered_nodes, node);
317 /* synthesize the 0/1 value */
318 set = create_set(node);
319 set_irn_link(node, set);
320 pdeq_putr(lowered_nodes, node);
322 } else if(is_Proj(pred) && is_Call(get_Proj_pred(pred))) {
323 ir_type *type = get_Call_type(get_Proj_pred(pred));
324 adjust_method_type(type);
325 set_irn_mode(node, mode);
327 } else if(is_Proj(pred) && is_Start(get_Proj_pred(pred))) {
328 ir_entity *entity = get_irg_entity(irg);
329 ir_type *type = get_entity_type(entity);
330 adjust_method_type(type);
331 set_irn_mode(node, mode);
335 panic("unexpected projb: %+F (pred: %+F)", node, pred);
338 tarval *tv = get_Const_tarval(node);
339 if(tv == get_tarval_b_true()) {
340 tarval *tv_one = get_tarval_one(mode);
341 res = new_d_Const(dbgi, mode, tv_one);
342 } else if(tv == get_tarval_b_false()) {
343 tarval *tv_zero = get_tarval_null(mode);
344 res = new_d_Const(dbgi, mode, tv_zero);
346 panic("invalid boolean const %+F", node);
348 set_irn_link(node, res);
349 pdeq_putr(lowered_nodes, node);
352 if (op == op_Unknown) {
353 return new_Unknown(config.lowered_mode);
356 panic("didn't expect %+F to have mode_b", node);
359 static void lower_mode_b_walker(ir_node *node, void *env)
365 arity = get_irn_arity(node);
366 for(i = 0; i < arity; ++i) {
368 ir_node *in = get_irn_n(node, i);
369 if(get_irn_mode(in) != mode_b)
372 if(! config.lower_direct_cmp) {
374 || (is_Psi(node) && get_irn_mode(node) != mode_b)) {
376 ir_node *pred = get_Proj_pred(in);
383 lowered_in = lower_node(in);
385 if(is_Return(node)) {
386 ir_entity *entity = get_irg_entity(current_ir_graph);
387 ir_type *type = get_entity_type(entity);
388 adjust_method_type(type);
389 } else if(is_Call(node)) {
390 ir_type *type = get_Call_type(node);
391 adjust_method_type(type);
393 lowered_in = create_convb(lowered_in);
395 set_irn_n(node, i, lowered_in);
399 add_identities(current_ir_graph->value_table, node);
403 static void clear_links(ir_node *node, void *env)
406 set_irn_link(node, NULL);
409 void ir_lower_mode_b(ir_graph *irg, const lower_mode_b_config_t *nconfig)
412 lowered_nodes = new_pdeq();
413 set_using_irn_link(irg);
415 irg_walk_graph(irg, clear_links, NULL, NULL);
416 irg_walk_graph(irg, lower_mode_b_walker, NULL, NULL);
418 while(!pdeq_empty(lowered_nodes)) {
419 ir_node *node = (ir_node*) pdeq_getr(lowered_nodes);
420 maybe_kill_node(node);
422 del_pdeq(lowered_nodes);
424 clear_using_irn_link(irg);