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
  39 static ir_mode *lowered_mode     = NULL;
  40 static int      lower_direct_cmp = 0;
  41
  42 static ir_node *create_not(dbg_info *dbgi, ir_node *node)
  43 {
  44         ir_graph *irg    = current_ir_graph;
  45         ir_node  *block  = get_nodes_block(node);
  46         tarval   *tv_one = get_tarval_one(lowered_mode);
  47         ir_node  *one    = new_d_Const(dbgi, lowered_mode, tv_one);
  48
  49         return new_rd_Eor(dbgi, irg, block, node, one, lowered_mode);
  50 }
  51
  52 static ir_node *lower_node(ir_node *node)
  53 {
  54         ir_graph *irg   = current_ir_graph;
  55         dbg_info *dbgi  = get_irn_dbg_info(node);
  56         ir_op    *op    = get_irn_op(node);
  57         ir_node  *block = get_nodes_block(node);
  58
  59         assert(get_irn_mode(node) == mode_b);
  60
  61         /* TODO: be robust against phi-loops... */
  62
  63         if(op == op_And || op == op_Or || op == op_Eor || op == op_Phi) {
  64                 int i, arity;
  65                 ir_node *copy = exact_copy(node);
  66
  67                 arity = get_irn_arity(node);
  68                 for(i = 0; i < arity; ++i) {
  69                         ir_node *in     = get_irn_n(node, i);
  70                         ir_node *low_in = lower_node(in);
  71
  72                         set_irn_n(copy, i, low_in);
  73                 }
  74                 set_irn_mode(copy, lowered_mode);
  75                 return copy;
  76         }
  77         if(op == op_Not) {
  78                 ir_node *op     = get_Not_op(node);
  79                 ir_node *low_op = lower_node(op);
  80
  81                 return create_not(dbgi, low_op);
  82         }
  83         if(op == op_Psi) {
  84                 ir_node *cond        = get_Psi_cond(node, 0);
  85                 ir_node *low_cond    = lower_node(cond);
  86                 ir_node *v_true      = get_Psi_val(node, 0);
  87                 ir_node *low_v_true  = lower_node(v_true);
  88                 ir_node *v_false     = get_Psi_default(node);
  89                 ir_node *low_v_false = lower_node(v_false);
  90
  91                 ir_node *and0     = new_rd_And(dbgi, irg, block, cond, low_v_true,
  92                                                lowered_mode);
  93
  94                 ir_node *not_cond = create_not(dbgi, low_cond);
  95
  96                 ir_node *and1     = new_rd_And(dbgi, irg, block, not_cond, low_v_false,
  97                                                lowered_mode);
  98
  99                 ir_node *or       = new_rd_Or(dbgi, irg, block, and0, and1,
 100                                               lowered_mode);
 101
 102                 return or;
 103         }
 104         if(op == op_Conv) {
 105                 tarval  *tv_one   = get_tarval_one(lowered_mode);
 106                 ir_node *one      = new_d_Const(dbgi, lowered_mode, tv_one);
 107                 tarval  *tv_zero  = get_tarval_null(lowered_mode);
 108                 ir_node *zero     = new_d_Const(dbgi, lowered_mode, tv_zero);
 109                 ir_mode *mode     = get_irn_mode(node);
 110                 tarval  *tv_zeroc = get_tarval_null(mode);
 111                 ir_node *zero_cmp = new_d_Const(dbgi, mode, tv_zeroc);
 112
 113                 ir_node *cmp      = new_rd_Cmp(dbgi, irg, block, node, zero_cmp);
 114                 ir_node *proj     = new_rd_Proj(dbgi, irg, block, cmp, mode_b,
 115                                                 pn_Cmp_Lg);
 116                 ir_node *vals[2]  = { one, zero };
 117                 ir_node *psi      = new_rd_Psi(dbgi, irg, block, 1, &proj, vals,
 118                                                lowered_mode);
 119
 120                 return psi;
 121         }
 122         if(op == op_Proj) {
 123                 ir_node *pred  = get_Proj_pred(node);
 124
 125                 assert(!is_Load(pred));
 126                 if(is_Cmp(pred)) {
 127                         ir_mode *mode  = get_irn_mode(pred);
 128                         ir_node *left  = get_Cmp_left(pred);
 129                         ir_node *right = get_Cmp_right(pred);
 130
 131                         if(get_mode_size_bits(mode) < get_mode_size_bits(lowered_mode)
 132                                  || classify_Const(right) == CNST_NULL) {
 133                                 int      pnc      = get_Proj_proj(node);
 134                                 ir_node *res      = NULL;
 135                                 int      need_not = 0;
 136                                 ir_node *a        = NULL;
 137                                 ir_node *b        = NULL;
 138
 139                                 if(pnc == pn_Cmp_Lt) {
 140                                         /* a < b  ->  (a - b) >> 31 */
 141                                         a = left;
 142                                         b = right;
 143                                 } else if(pnc == pn_Cmp_Le) {
 144                                         /* a <= b  -> ((a - b) >> 31) ^ 1 */
 145                                         a        = right;
 146                                         b        = left;
 147                                         need_not = 1;
 148                                 } else if(pnc == pn_Cmp_Gt) {
 149                                         /* a > b   -> (b - a) >> 31 */
 150                                         a = right;
 151                                         b = left;
 152                                 } else if(pnc == pn_Cmp_Ge) {
 153                                         /* a >= b   -> ((a - b) >> 31) ^ 1 */
 154                                         a        = left;
 155                                         b        = right;
 156                                         need_not = 1;
 157                                 }
 158
 159                                 if(a != NULL) {
 160                                         tarval  *tv        = new_tarval_from_long(31, mode_Iu);
 161                                         ir_node *shift_cnt = new_d_Const(dbgi, mode_Iu, tv);
 162
 163                                         if(mode != lowered_mode) {
 164                                                 a = new_rd_Conv(dbgi, irg, block, a, lowered_mode);
 165                                                 b = new_rd_Conv(dbgi, irg, block, b, lowered_mode);
 166                                         }
 167
 168                                         res = new_rd_Sub(dbgi, irg, block, a, b, lowered_mode);
 169                                         res = new_rd_Shr(dbgi, irg, block, res, shift_cnt,
 170                                                          lowered_mode);
 171
 172                                         if(need_not) {
 173                                                 res = create_not(dbgi, res);
 174                                         }
 175                                         return res;
 176                                 }
 177                         }
 178
 179                         {
 180                         /* synthesize the 0/1 value */
 181                         tarval  *tv_one  = get_tarval_one(lowered_mode);
 182                         ir_node *one     = new_d_Const(dbgi, lowered_mode, tv_one);
 183                         tarval  *tv_zero = get_tarval_null(lowered_mode);
 184                         ir_node *zero    = new_d_Const(dbgi, lowered_mode, tv_zero);
 185
 186                         ir_node *vals[2] = { one, zero };
 187                         ir_node *psi     = new_rd_Psi(dbgi, irg, block, 1, &node, vals,
 188                                                       lowered_mode);
 189
 190                         return psi;
 191                         }
 192                 }
 193
 194                 panic("unexpected projb: %+F (pred: %+F)", node, pred);
 195                 set_irn_mode(node, lowered_mode);
 196                 return node;
 197         }
 198         if(op == op_Const) {
 199                 tarval *tv = get_Const_tarval(node);
 200                 if(tv == get_tarval_b_true()) {
 201                         tarval  *tv_one  = get_tarval_one(lowered_mode);
 202                         ir_node *one     = new_d_Const(dbgi, lowered_mode, tv_one);
 203                         return one;
 204                 } else if(tv == get_tarval_b_false()) {
 205                         tarval  *tv_zero = get_tarval_null(lowered_mode);
 206                         ir_node *zero    = new_d_Const(dbgi, lowered_mode, tv_zero);
 207                         return zero;
 208                 } else {
 209                         panic("invalid boolean const %+F", node);
 210                 }
 211         }
 212
 213         panic("didn't expect %+F to have mode_b", node);
 214 }
 215
 216 static ir_node *create_convb(ir_node *node)
 217 {
 218         ir_graph *irg   = current_ir_graph;
 219         ir_node  *block = get_nodes_block(node);
 220         ir_node  *conv  = new_rd_Conv(NULL, irg, block, node, mode_b);
 221
 222         return conv;
 223 }
 224
 225 static void lower_mode_b_walker(ir_node *node, void *env)
 226 {
 227         int i, arity;
 228         (void) env;
 229
 230         arity = get_irn_arity(node);
 231         for(i = 0; i < arity; ++i) {
 232                 ir_node *lowered_in;
 233                 ir_node *in = get_irn_n(node, i);
 234                 if(get_irn_mode(in) != mode_b)
 235                         continue;
 236
 237                 if(! lower_direct_cmp) {
 238                         if(is_Cond(node)
 239                                         || (is_Psi(node) && get_irn_mode(node) != mode_b)) {
 240                                 if(is_Proj(in)) {
 241                                         ir_node *pred = get_Proj_pred(in);
 242                                         if(is_Cmp(pred))
 243                                                 continue;
 244                                 }
 245                         }
 246                 }
 247
 248                 lowered_in = lower_node(in);
 249                 lowered_in = create_convb(lowered_in);
 250                 set_irn_n(node, i, lowered_in);
 251         }
 252 }
 253
 254 void ir_lower_mode_b(ir_graph *irg, ir_mode *mode, int do_lower_direct_cmp)
 255 {
 256         lowered_mode     = mode;
 257         lower_direct_cmp = do_lower_direct_cmp;
 258         irg_walk_graph(irg, lower_mode_b_walker, NULL, NULL);
 259 }