nsz Git - libfirm/blob - ir/be/bepeephole.c

   1 /*
   2  * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   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.
  10  *
  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.
  14  *
  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
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief       Peephole optimisation framework keeps track of which registers contain which values
  23  * @author      Matthias Braun
  24  * @version     $Id$
  25  */
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include "bepeephole.h"
  31
  32 #include "iredges_t.h"
  33 #include "irgwalk.h"
  34 #include "irprintf.h"
  35 #include "error.h"
  36
  37 #include "beirg_t.h"
  38 #include "belive_t.h"
  39 #include "bearch_t.h"
  40 #include "besched_t.h"
  41 #include "bemodule.h"
  42
  43 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
  44
  45 static const arch_env_t *arch_env;
  46 static be_lv_t          *lv;
  47 static ir_node          *current_node;
  48 ir_node               ***register_values;
  49
  50 static void clear_reg_value(ir_node *node)
  51 {
  52         const arch_register_t       *reg;
  53         const arch_register_class_t *cls;
  54         unsigned                     reg_idx;
  55         unsigned                     cls_idx;
  56
  57         if(!mode_is_data(get_irn_mode(node)))
  58                 return;
  59
  60         reg     = arch_get_irn_register(arch_env, node);
  61         if(reg == NULL) {
  62                 panic("No register assigned at %+F\n", node);
  63         }
  64         if(arch_register_type_is(reg, virtual))
  65                 return;
  66         cls     = arch_register_get_class(reg);
  67         reg_idx = arch_register_get_index(reg);
  68         cls_idx = arch_register_class_index(cls);
  69
  70         //assert(register_values[cls_idx][reg_idx] != NULL);
  71         DBG((dbg, LEVEL_1, "Clear Register %s\n", reg->name));
  72         register_values[cls_idx][reg_idx] = NULL;
  73 }
  74
  75 static void set_reg_value(ir_node *node)
  76 {
  77         const arch_register_t       *reg;
  78         const arch_register_class_t *cls;
  79         unsigned                     reg_idx;
  80         unsigned                     cls_idx;
  81
  82         if(!mode_is_data(get_irn_mode(node)))
  83                 return;
  84
  85         reg = arch_get_irn_register(arch_env, node);
  86         if(reg == NULL) {
  87                 panic("No register assigned at %+F\n", node);
  88         }
  89         if(arch_register_type_is(reg, virtual))
  90                 return;
  91         cls     = arch_register_get_class(reg);
  92         reg_idx = arch_register_get_index(reg);
  93         cls_idx = arch_register_class_index(cls);
  94
  95         DBG((dbg, LEVEL_1, "Set Register %s: %+F\n", reg->name, node));
  96         register_values[cls_idx][reg_idx] = node;
  97 }
  98
  99 static void clear_defs(ir_node *node)
 100 {
 101         /* clear values defined */
 102         if(get_irn_mode(node) == mode_T) {
 103                 const ir_edge_t *edge;
 104                 foreach_out_edge(node, edge) {
 105                         ir_node *proj = get_edge_src_irn(edge);
 106                         clear_reg_value(proj);
 107                 }
 108         } else {
 109                 clear_reg_value(node);
 110         }
 111 }
 112
 113 static void set_uses(ir_node *node)
 114 {
 115         int i, arity;
 116
 117         /* set values used */
 118         arity = get_irn_arity(node);
 119         for(i = 0; i < arity; ++i) {
 120                 ir_node *in = get_irn_n(node, i);
 121                 set_reg_value(in);
 122         }
 123 }
 124
 125 void be_peephole_before_exchange(const ir_node *old_node, ir_node *new_node)
 126 {
 127         const arch_register_t       *reg;
 128         const arch_register_class_t *cls;
 129         unsigned                     reg_idx;
 130         unsigned                     cls_idx;
 131
 132         DBG((dbg, LEVEL_1, "About to exchange %+F with %+F\n", old_node, new_node));
 133
 134         if(old_node == current_node) {
 135                 if(is_Proj(new_node)) {
 136                         current_node = get_Proj_pred(new_node);
 137                 } else {
 138                         current_node = new_node;
 139                 }
 140         }
 141
 142         if(!mode_is_data(get_irn_mode(old_node)))
 143                 return;
 144
 145         reg = arch_get_irn_register(arch_env, old_node);
 146         if(reg == NULL) {
 147                 panic("No register assigned at %+F\n", old_node);
 148         }
 149         cls     = arch_register_get_class(reg);
 150         reg_idx = arch_register_get_index(reg);
 151         cls_idx = arch_register_class_index(cls);
 152
 153         if(register_values[cls_idx][reg_idx] == old_node) {
 154                 register_values[cls_idx][reg_idx] = new_node;
 155         }
 156
 157         be_liveness_remove(lv, old_node);
 158 }
 159
 160 void be_peephole_after_exchange(ir_node *new_node)
 161 {
 162         be_liveness_introduce(lv, new_node);
 163 }
 164
 165 static void process_block(ir_node *block, void *data)
 166 {
 167         unsigned n_classes;
 168         unsigned i;
 169         int l;
 170         (void) data;
 171
 172         /* construct initial register assignment */
 173         n_classes = arch_env_get_n_reg_class(arch_env);
 174         for(i = 0; i < n_classes; ++i) {
 175                 const arch_register_class_t *cls    = arch_env_get_reg_class(arch_env, i);
 176                 unsigned                     n_regs = arch_register_class_n_regs(cls);
 177                 memset(register_values[i], 0, sizeof(ir_node*) * n_regs);
 178         }
 179
 180         assert(lv->nodes && "live sets must be computed");
 181         DBG((dbg, LEVEL_1, "\nProcessing block %+F (from end)\n", block));
 182         be_lv_foreach(lv, block, be_lv_state_end, l) {
 183                 ir_node *node = be_lv_get_irn(lv, block, l);
 184                 set_reg_value(node);
 185         }
 186         DBG((dbg, LEVEL_1, "\nstart processing\n"));
 187
 188         /* walk the block from last insn to the first */
 189         current_node = sched_last(block);
 190         for( ; !sched_is_begin(current_node);
 191                         current_node = sched_prev(current_node)) {
 192                 ir_op             *op;
 193                 ir_node           *last;
 194                 peephole_opt_func  func;
 195
 196                 if(is_Phi(current_node))
 197                         break;
 198
 199                 clear_defs(current_node);
 200                 set_uses(current_node);
 201
 202                 op   = get_irn_op(current_node);
 203                 func = (peephole_opt_func) op->ops.generic;
 204                 if(func == NULL)
 205                         continue;
 206
 207                 last = current_node;
 208                 func(current_node);
 209                 /* was the current node replaced? */
 210                 if(current_node != last) {
 211                         set_uses(current_node);
 212                 }
 213         }
 214 }
 215
 216 void be_peephole_opt(be_irg_t *birg)
 217 {
 218         ir_graph   *irg = be_get_birg_irg(birg);
 219         unsigned n_classes;
 220         unsigned i;
 221
 222         /* we sometimes find BadE nodes in float apps like optest_float.c or
 223          * kahansum.c for example... */
 224         be_liveness_invalidate(birg->lv);
 225         be_liveness_assure_sets(be_assure_liveness(birg));
 226
 227         arch_env = be_get_birg_arch_env(birg);
 228         lv       = be_get_birg_liveness(birg);
 229
 230         n_classes = arch_env_get_n_reg_class(arch_env);
 231         register_values = alloca(sizeof(register_values[0]) * n_classes);
 232         for(i = 0; i < n_classes; ++i) {
 233                 const arch_register_class_t *cls    = arch_env_get_reg_class(arch_env, i);
 234                 unsigned                     n_regs = arch_register_class_n_regs(cls);
 235                 register_values[i] = alloca(sizeof(ir_node*) * n_regs);
 236         }
 237
 238         irg_block_walk_graph(irg, process_block, NULL, NULL);
 239 }
 240
 241 void be_peephole_init(void)
 242 {
 243         clear_irp_opcodes_generic_func();
 244 }
 245
 246 void be_init_peephole(void)
 247 {
 248         FIRM_DBG_REGISTER(dbg, "firm.be.peephole");
 249 }
 250
 251 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);