nsz Git - libfirm/blob - ir/lower/lower_mode_b.c

   1 /*
   2  * Copyright (C) 1995-2007 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  * @author      Matthias Braun, Christoph Mallon
  23  * @version     $Id:$
  24  */
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28
  29 #include <stdlib.h>
  30
  31 #include "irnode_t.h"
  32 #include "ircons_t.h"
  33 #include "irgwalk.h"
  34 #include "irtools.h"
  35 #include "tv.h"
  36 #include "error.h"
  37 #include "lowering.h"
  38 #include "benode_t.h"
  39
  40 static ir_mode *lowered_mode     = NULL;
  41 static int      lower_direct_cmp = 0;
  42
  43 static ir_node *create_not(dbg_info *dbgi, ir_node *node)
  44 {
  45         ir_graph *irg    = current_ir_graph;
  46         ir_node  *block  = get_nodes_block(node);
  47         tarval   *tv_one = get_tarval_one(lowered_mode);
  48         ir_node  *one    = new_d_Const(dbgi, lowered_mode, tv_one);
  49
  50         return new_rd_Eor(dbgi, irg, block, node, one, lowered_mode);
  51 }
  52
  53 static ir_node *create_convb(ir_node *node)
  54 {
  55         ir_graph *irg   = current_ir_graph;
  56         ir_node  *block = get_nodes_block(node);
  57         ir_node  *conv  = new_rd_Conv(NULL, irg, block, node, mode_b);
  58
  59         return conv;
  60 }
  61
  62 static ir_node *create_conv_lowered_mode(ir_node *node)
  63 {
  64         ir_graph *irg   = current_ir_graph;
  65         ir_node  *block = get_nodes_block(node);
  66         ir_node  *conv  = new_rd_Conv(NULL, irg, block, node, lowered_mode);
  67
  68         return conv;
  69 }
  70
  71 static ir_node *lower_node(ir_node *node)
  72 {
  73         ir_graph *irg   = current_ir_graph;
  74         dbg_info *dbgi  = get_irn_dbg_info(node);
  75         ir_op    *op    = get_irn_op(node);
  76         ir_node  *block = get_nodes_block(node);
  77         ir_node  *res;
  78
  79         assert(get_irn_mode(node) == mode_b);
  80
  81         res = get_irn_link(node);
  82         if(res != NULL)
  83                 return res;
  84
  85         /* TODO: be robust against phi-loops... */
  86         if(op == op_Phi) {
  87                 int       i, arity;
  88                 ir_node **in;
  89                 ir_node  *unknown, *new_phi;
  90
  91                 arity = get_irn_arity(node);
  92                 in    = alloca(arity * sizeof(in[0]));
  93                 unknown = new_Unknown(lowered_mode);
  94                 for(i = 0; i < arity; ++i) {
  95                         in[i] = unknown;
  96                 }
  97                 new_phi = new_rd_Phi(dbgi, irg, block, arity, in,
  98                                               lowered_mode);
  99                 set_irn_link(node, new_phi);
 100
 101                 for(i = 0; i < arity; ++i) {
 102                         ir_node *in     = get_irn_n(node, i);
 103                         ir_node *low_in = lower_node(in);
 104
 105                         set_irn_n(new_phi, i, low_in);
 106                 }
 107
 108                 return new_phi;
 109         }
 110
 111         if(op == op_And || op == op_Or || op == op_Eor) {
 112                 int i, arity;
 113                 ir_node *copy = exact_copy(node);
 114
 115                 arity = get_irn_arity(node);
 116                 for(i = 0; i < arity; ++i) {
 117                         ir_node *in     = get_irn_n(node, i);
 118                         ir_node *low_in = lower_node(in);
 119
 120                         set_irn_n(copy, i, low_in);
 121                 }
 122                 set_irn_mode(copy, lowered_mode);
 123
 124                 set_irn_link(node, copy);
 125                 return copy;
 126         }
 127         if(op == op_Not) {
 128                 ir_node *op     = get_Not_op(node);
 129                 ir_node *low_op = lower_node(op);
 130
 131                 res = create_not(dbgi, low_op);
 132                 set_irn_link(node, res);
 133                 return res;
 134         }
 135         if(op == op_Psi) {
 136                 ir_node *cond        = get_Psi_cond(node, 0);
 137                 ir_node *low_cond    = lower_node(cond);
 138                 ir_node *v_true      = get_Psi_val(node, 0);
 139                 ir_node *low_v_true  = lower_node(v_true);
 140                 ir_node *v_false     = get_Psi_default(node);
 141                 ir_node *low_v_false = lower_node(v_false);
 142
 143                 ir_node *and0     = new_rd_And(dbgi, irg, block, low_cond, low_v_true,
 144                                                lowered_mode);
 145
 146                 ir_node *not_cond = create_not(dbgi, low_cond);
 147
 148                 ir_node *and1     = new_rd_And(dbgi, irg, block, not_cond, low_v_false,
 149                                                lowered_mode);
 150
 151                 ir_node *or       = new_rd_Or(dbgi, irg, block, and0, and1,
 152                                               lowered_mode);
 153
 154                 set_irn_link(node, or);
 155                 return or;
 156         }
 157         if(op == op_Conv) {
 158                 tarval  *tv_one   = get_tarval_one(lowered_mode);
 159                 ir_node *one      = new_d_Const(dbgi, lowered_mode, tv_one);
 160                 tarval  *tv_zero  = get_tarval_null(lowered_mode);
 161                 ir_node *zero     = new_d_Const(dbgi, lowered_mode, tv_zero);
 162                 ir_node *pred     = get_Conv_op(node);
 163                 ir_mode *mode     = get_irn_mode(pred);
 164                 tarval  *tv_zeroc = get_tarval_null(mode);
 165                 ir_node *zero_cmp = new_d_Const(dbgi, mode, tv_zeroc);
 166
 167                 ir_node *cmp      = new_rd_Cmp(dbgi, irg, block, pred, zero_cmp);
 168                 ir_node *proj     = new_rd_Proj(dbgi, irg, block, cmp, mode_b,
 169                                                 pn_Cmp_Lg);
 170                 ir_node *vals[2]  = { one, zero };
 171                 ir_node *psi      = new_rd_Psi(dbgi, irg, block, 1, &proj, vals,
 172                                                lowered_mode);
 173
 174                 set_irn_link(node, psi);
 175                 return psi;
 176         }
 177         if(op == op_Proj) {
 178                 ir_node *pred = get_Proj_pred(node);
 179
 180                 if(is_Cmp(pred)) {
 181                         ir_node *left  = get_Cmp_left(pred);
 182                         ir_node *right = get_Cmp_right(pred);
 183                         ir_mode *mode  = get_irn_mode(left);
 184
 185                         if( (mode_is_int(mode) || mode_is_reference(mode)) &&
 186                                 (get_mode_size_bits(mode) < get_mode_size_bits(lowered_mode)
 187                                  || classify_Const(right) == CNST_NULL)) {
 188                                 int      pnc      = get_Proj_proj(node);
 189                                 int      need_not = 0;
 190                                 ir_node *a        = NULL;
 191                                 ir_node *b        = NULL;
 192
 193                                 if(pnc == pn_Cmp_Lt) {
 194                                         /* a < b  ->  (a - b) >> 31 */
 195                                         a = left;
 196                                         b = right;
 197                                 } else if(pnc == pn_Cmp_Le) {
 198                                         /* a <= b  -> ((a - b) >> 31) ^ 1 */
 199                                         a        = right;
 200                                         b        = left;
 201                                         need_not = 1;
 202                                 } else if(pnc == pn_Cmp_Gt) {
 203                                         /* a > b   -> (b - a) >> 31 */
 204                                         a = right;
 205                                         b = left;
 206                                 } else if(pnc == pn_Cmp_Ge) {
 207                                         /* a >= b   -> ((a - b) >> 31) ^ 1 */
 208                                         a        = left;
 209                                         b        = right;
 210                                         need_not = 1;
 211                                 }
 212
 213                                 if(a != NULL) {
 214                                         tarval  *tv        = new_tarval_from_long(31, mode_Iu);
 215                                         ir_node *shift_cnt = new_d_Const(dbgi, mode_Iu, tv);
 216
 217                                         if(mode != lowered_mode) {
 218                                                 a = new_rd_Conv(dbgi, irg, block, a, lowered_mode);
 219                                                 b = new_rd_Conv(dbgi, irg, block, b, lowered_mode);
 220                                         }
 221
 222                                         res = new_rd_Sub(dbgi, irg, block, a, b, lowered_mode);
 223                                         res = new_rd_Shr(dbgi, irg, block, res, shift_cnt,
 224                                                          lowered_mode);
 225
 226                                         if(need_not) {
 227                                                 res = create_not(dbgi, res);
 228                                         }
 229                                         set_irn_link(node, res);
 230                                         return res;
 231                                 }
 232                         }
 233
 234                         {
 235                         /* synthesize the 0/1 value */
 236                         tarval  *tv_one  = get_tarval_one(lowered_mode);
 237                         ir_node *one     = new_d_Const(dbgi, lowered_mode, tv_one);
 238                         tarval  *tv_zero = get_tarval_null(lowered_mode);
 239                         ir_node *zero    = new_d_Const(dbgi, lowered_mode, tv_zero);
 240
 241                         ir_node *vals[2] = { one, zero };
 242                         ir_node *psi     = new_rd_Psi(dbgi, irg, block, 1, &node, vals,
 243                                                       lowered_mode);
 244
 245                         set_irn_link(node, psi);
 246                         return psi;
 247                         }
 248                 } else if(is_Proj(pred) && is_Call(get_Proj_pred(pred))) {
 249                         return create_conv_lowered_mode(node);
 250                 } else if(is_Proj(pred) && is_Start(get_Proj_pred(pred))) {
 251                         return create_conv_lowered_mode(node);
 252                 } else if (be_is_Barrier(pred)) {
 253                         /* nothing to do */
 254                         return node;
 255                 }
 256
 257                 panic("unexpected projb: %+F (pred: %+F)", node, pred);
 258         }
 259         if(op == op_Const) {
 260                 tarval *tv = get_Const_tarval(node);
 261                 if(tv == get_tarval_b_true()) {
 262                         tarval  *tv_one  = get_tarval_one(lowered_mode);
 263                         res              = new_d_Const(dbgi, lowered_mode, tv_one);
 264                 } else if(tv == get_tarval_b_false()) {
 265                         tarval  *tv_zero = get_tarval_null(lowered_mode);
 266                         res              = new_d_Const(dbgi, lowered_mode, tv_zero);
 267                 } else {
 268                         panic("invalid boolean const %+F", node);
 269                 }
 270                 set_irn_link(node, res);
 271                 return res;
 272         }
 273
 274         panic("didn't expect %+F to have mode_b", node);
 275 }
 276
 277 static void lower_mode_b_walker(ir_node *node, void *env)
 278 {
 279         int i, arity;
 280         (void) env;
 281
 282         arity = get_irn_arity(node);
 283         for(i = 0; i < arity; ++i) {
 284                 ir_node *lowered_in;
 285                 ir_node *in = get_irn_n(node, i);
 286                 if(get_irn_mode(in) != mode_b)
 287                         continue;
 288
 289                 if(! lower_direct_cmp) {
 290                         if(is_Cond(node)
 291                                         || (is_Psi(node) && get_irn_mode(node) != mode_b)) {
 292                                 if(is_Proj(in)) {
 293                                         ir_node *pred = get_Proj_pred(in);
 294                                         if(is_Cmp(pred))
 295                                                 continue;
 296                                 }
 297                         }
 298                 }
 299
 300                 lowered_in = lower_node(in);
 301                 lowered_in = create_convb(lowered_in);
 302                 set_irn_n(node, i, lowered_in);
 303         }
 304 }
 305
 306 static void clear_links(ir_node *node, void *env)
 307 {
 308         (void) env;
 309         set_irn_link(node, NULL);
 310 }
 311
 312 void ir_lower_mode_b(ir_graph *irg, ir_mode *mode, int do_lower_direct_cmp)
 313 {
 314         lowered_mode     = mode;
 315         lower_direct_cmp = do_lower_direct_cmp;
 316         set_using_irn_link(irg);
 317         irg_walk_graph(irg, clear_links, NULL, NULL);
 318         irg_walk_graph(irg, lower_mode_b_walker, NULL, NULL);
 319         clear_using_irn_link(irg);
 320 }