1 /*
   2  * Copyright (c) 2007, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 #include "precompiled.hpp"
  25 #include "memory/allocation.inline.hpp"
  26 #include "opto/connode.hpp"
  27 #include "opto/vectornode.hpp"
  28 
  29 //------------------------------VectorNode--------------------------------------
  30 
  31 // Return the vector operator for the specified scalar operation
  32 // and vector length.
  33 int VectorNode::opcode(int sopc, BasicType bt) {
  34   switch (sopc) {
  35   case Op_AddI:
  36     switch (bt) {
  37     case T_BOOLEAN:
  38     case T_BYTE:      return Op_AddVB;
  39     case T_CHAR:
  40     case T_SHORT:     return Op_AddVS;
  41     case T_INT:       return Op_AddVI;

  42     }
  43     ShouldNotReachHere();
  44   case Op_AddL:
  45     assert(bt == T_LONG, "must be");
  46     return Op_AddVL;
  47   case Op_AddF:
  48     assert(bt == T_FLOAT, "must be");
  49     return Op_AddVF;
  50   case Op_AddD:
  51     assert(bt == T_DOUBLE, "must be");
  52     return Op_AddVD;
  53   case Op_SubI:
  54     switch (bt) {
  55     case T_BOOLEAN:
  56     case T_BYTE:   return Op_SubVB;
  57     case T_CHAR:
  58     case T_SHORT:  return Op_SubVS;
  59     case T_INT:    return Op_SubVI;

  60     }
  61     ShouldNotReachHere();
  62   case Op_SubL:
  63     assert(bt == T_LONG, "must be");
  64     return Op_SubVL;
  65   case Op_SubF:
  66     assert(bt == T_FLOAT, "must be");
  67     return Op_SubVF;
  68   case Op_SubD:
  69     assert(bt == T_DOUBLE, "must be");
  70     return Op_SubVD;
  71   case Op_MulI:
  72     switch (bt) {
  73     case T_BOOLEAN:
  74     case T_BYTE:   return 0;   // Unimplemented
  75     case T_CHAR:
  76     case T_SHORT:  return Op_MulVS;
  77     case T_INT:    return Op_MulVI;

  78     }
  79     ShouldNotReachHere();
  80   case Op_MulL:
  81     assert(bt == T_LONG, "must be");
  82     return Op_MulVL;
  83   case Op_MulF:
  84     assert(bt == T_FLOAT, "must be");
  85     return Op_MulVF;
  86   case Op_MulD:
  87     assert(bt == T_DOUBLE, "must be");
  88     return Op_MulVD;
  89   case Op_FmaD:
  90     assert(bt == T_DOUBLE, "must be");
  91     return Op_FmaVD;
  92   case Op_FmaF:
  93     assert(bt == T_FLOAT, "must be");
  94     return Op_FmaVF;
  95   case Op_CMoveD:
  96     assert(bt == T_DOUBLE, "must be");
  97     return Op_CMoveVD;
  98   case Op_DivF:
  99     assert(bt == T_FLOAT, "must be");
 100     return Op_DivVF;
 101   case Op_DivD:
 102     assert(bt == T_DOUBLE, "must be");
 103     return Op_DivVD;
 104   case Op_AbsF:
 105     assert(bt == T_FLOAT, "must be");
 106     return Op_AbsVF;
 107   case Op_AbsD:
 108     assert(bt == T_DOUBLE, "must be");
 109     return Op_AbsVD;
 110   case Op_NegF:
 111     assert(bt == T_FLOAT, "must be");
 112     return Op_NegVF;
 113   case Op_NegD:
 114     assert(bt == T_DOUBLE, "must be");
 115     return Op_NegVD;
 116   case Op_SqrtD:
 117     assert(bt == T_DOUBLE, "must be");
 118     return Op_SqrtVD;
 119   case Op_LShiftI:
 120     switch (bt) {
 121     case T_BOOLEAN:
 122     case T_BYTE:   return Op_LShiftVB;
 123     case T_CHAR:
 124     case T_SHORT:  return Op_LShiftVS;
 125     case T_INT:    return Op_LShiftVI;

 126     }
 127     ShouldNotReachHere();
 128   case Op_LShiftL:
 129     assert(bt == T_LONG, "must be");
 130     return Op_LShiftVL;
 131   case Op_RShiftI:
 132     switch (bt) {
 133     case T_BOOLEAN:return Op_URShiftVB; // boolean is unsigned value
 134     case T_CHAR:   return Op_URShiftVS; // char is unsigned value
 135     case T_BYTE:   return Op_RShiftVB;
 136     case T_SHORT:  return Op_RShiftVS;
 137     case T_INT:    return Op_RShiftVI;

 138     }
 139     ShouldNotReachHere();
 140   case Op_RShiftL:
 141     assert(bt == T_LONG, "must be");
 142     return Op_RShiftVL;
 143   case Op_URShiftI:
 144     switch (bt) {
 145     case T_BOOLEAN:return Op_URShiftVB;
 146     case T_CHAR:   return Op_URShiftVS;
 147     case T_BYTE:
 148     case T_SHORT:  return 0; // Vector logical right shift for signed short
 149                              // values produces incorrect Java result for
 150                              // negative data because java code should convert
 151                              // a short value into int value with sign
 152                              // extension before a shift.
 153     case T_INT:    return Op_URShiftVI;

 154     }
 155     ShouldNotReachHere();
 156   case Op_URShiftL:
 157     assert(bt == T_LONG, "must be");
 158     return Op_URShiftVL;
 159   case Op_AndI:
 160   case Op_AndL:
 161     return Op_AndV;
 162   case Op_OrI:
 163   case Op_OrL:
 164     return Op_OrV;
 165   case Op_XorI:
 166   case Op_XorL:
 167     return Op_XorV;
 168 
 169   case Op_LoadB:
 170   case Op_LoadUB:
 171   case Op_LoadUS:
 172   case Op_LoadS:
 173   case Op_LoadI:
 174   case Op_LoadL:
 175   case Op_LoadF:
 176   case Op_LoadD:
 177     return Op_LoadVector;
 178 
 179   case Op_StoreB:
 180   case Op_StoreC:
 181   case Op_StoreI:
 182   case Op_StoreL:
 183   case Op_StoreF:
 184   case Op_StoreD:
 185     return Op_StoreVector;
 186   }

 187   return 0; // Unimplemented

 188 }
 189 
 190 // Also used to check if the code generator
 191 // supports the vector operation.
 192 bool VectorNode::implemented(int opc, uint vlen, BasicType bt) {
 193   if (is_java_primitive(bt) &&
 194       (vlen > 1) && is_power_of_2(vlen) &&
 195       Matcher::vector_size_supported(bt, vlen)) {
 196     int vopc = VectorNode::opcode(opc, bt);
 197     return vopc > 0 && Matcher::match_rule_supported_vector(vopc, vlen);
 198   }
 199   return false;
 200 }
 201 
 202 bool VectorNode::is_shift(Node* n) {
 203   switch (n->Opcode()) {
 204   case Op_LShiftI:
 205   case Op_LShiftL:
 206   case Op_RShiftI:
 207   case Op_RShiftL:
 208   case Op_URShiftI:
 209   case Op_URShiftL:
 210     return true;
 211   }
 212   return false;

 213 }
 214 
 215 // Check if input is loop invariant vector.
 216 bool VectorNode::is_invariant_vector(Node* n) {
 217   // Only Replicate vector nodes are loop invariant for now.
 218   switch (n->Opcode()) {
 219   case Op_ReplicateB:
 220   case Op_ReplicateS:
 221   case Op_ReplicateI:
 222   case Op_ReplicateL:
 223   case Op_ReplicateF:
 224   case Op_ReplicateD:
 225     return true;
 226   }
 227   return false;

 228 }
 229 
 230 // [Start, end) half-open range defining which operands are vectors
 231 void VectorNode::vector_operands(Node* n, uint* start, uint* end) {
 232   switch (n->Opcode()) {
 233   case Op_LoadB:   case Op_LoadUB:
 234   case Op_LoadS:   case Op_LoadUS:
 235   case Op_LoadI:   case Op_LoadL:
 236   case Op_LoadF:   case Op_LoadD:
 237   case Op_LoadP:   case Op_LoadN:
 238     *start = 0;
 239     *end   = 0; // no vector operands
 240     break;
 241   case Op_StoreB:  case Op_StoreC:
 242   case Op_StoreI:  case Op_StoreL:
 243   case Op_StoreF:  case Op_StoreD:
 244   case Op_StoreP:  case Op_StoreN:
 245     *start = MemNode::ValueIn;
 246     *end   = MemNode::ValueIn + 1; // 1 vector operand
 247     break;
 248   case Op_LShiftI:  case Op_LShiftL:
 249   case Op_RShiftI:  case Op_RShiftL:
 250   case Op_URShiftI: case Op_URShiftL:
 251     *start = 1;
 252     *end   = 2; // 1 vector operand
 253     break;
 254   case Op_AddI: case Op_AddL: case Op_AddF: case Op_AddD:
 255   case Op_SubI: case Op_SubL: case Op_SubF: case Op_SubD:
 256   case Op_MulI: case Op_MulL: case Op_MulF: case Op_MulD:
 257   case Op_DivF: case Op_DivD:
 258   case Op_AndI: case Op_AndL:
 259   case Op_OrI:  case Op_OrL:
 260   case Op_XorI: case Op_XorL:
 261     *start = 1;
 262     *end   = 3; // 2 vector operands
 263     break;
 264   case Op_CMoveI:  case Op_CMoveL:  case Op_CMoveF:  case Op_CMoveD:
 265     *start = 2;
 266     *end   = n->req();
 267     break;
 268   case Op_FmaD:
 269   case Op_FmaF:
 270     *start = 1;
 271     *end   = 4; // 3 vector operands
 272     break;
 273   default:
 274     *start = 1;
 275     *end   = n->req(); // default is all operands
 276   }
 277 }
 278 
 279 // Return the vector version of a scalar operation node.
 280 VectorNode* VectorNode::make(int opc, Node* n1, Node* n2, uint vlen, BasicType bt) {
 281   const TypeVect* vt = TypeVect::make(bt, vlen);
 282   int vopc = VectorNode::opcode(opc, bt);
 283   // This method should not be called for unimplemented vectors.
 284   guarantee(vopc > 0, "Vector for '%s' is not implemented", NodeClassNames[opc]);
 285   switch (vopc) {
 286   case Op_AddVB: return new AddVBNode(n1, n2, vt);
 287   case Op_AddVS: return new AddVSNode(n1, n2, vt);
 288   case Op_AddVI: return new AddVINode(n1, n2, vt);
 289   case Op_AddVL: return new AddVLNode(n1, n2, vt);
 290   case Op_AddVF: return new AddVFNode(n1, n2, vt);
 291   case Op_AddVD: return new AddVDNode(n1, n2, vt);
 292 
 293   case Op_SubVB: return new SubVBNode(n1, n2, vt);
 294   case Op_SubVS: return new SubVSNode(n1, n2, vt);
 295   case Op_SubVI: return new SubVINode(n1, n2, vt);
 296   case Op_SubVL: return new SubVLNode(n1, n2, vt);
 297   case Op_SubVF: return new SubVFNode(n1, n2, vt);
 298   case Op_SubVD: return new SubVDNode(n1, n2, vt);
 299 
 300   case Op_MulVS: return new MulVSNode(n1, n2, vt);
 301   case Op_MulVI: return new MulVINode(n1, n2, vt);
 302   case Op_MulVL: return new MulVLNode(n1, n2, vt);
 303   case Op_MulVF: return new MulVFNode(n1, n2, vt);
 304   case Op_MulVD: return new MulVDNode(n1, n2, vt);
 305 
 306   case Op_DivVF: return new DivVFNode(n1, n2, vt);
 307   case Op_DivVD: return new DivVDNode(n1, n2, vt);
 308 
 309   case Op_AbsVF: return new AbsVFNode(n1, vt);
 310   case Op_AbsVD: return new AbsVDNode(n1, vt);
 311 
 312   case Op_NegVF: return new NegVFNode(n1, vt);
 313   case Op_NegVD: return new NegVDNode(n1, vt);
 314 
 315   // Currently only supports double precision sqrt
 316   case Op_SqrtVD: return new SqrtVDNode(n1, vt);
 317 
 318   case Op_LShiftVB: return new LShiftVBNode(n1, n2, vt);
 319   case Op_LShiftVS: return new LShiftVSNode(n1, n2, vt);
 320   case Op_LShiftVI: return new LShiftVINode(n1, n2, vt);
 321   case Op_LShiftVL: return new LShiftVLNode(n1, n2, vt);
 322 
 323   case Op_RShiftVB: return new RShiftVBNode(n1, n2, vt);
 324   case Op_RShiftVS: return new RShiftVSNode(n1, n2, vt);
 325   case Op_RShiftVI: return new RShiftVINode(n1, n2, vt);
 326   case Op_RShiftVL: return new RShiftVLNode(n1, n2, vt);
 327 
 328   case Op_URShiftVB: return new URShiftVBNode(n1, n2, vt);
 329   case Op_URShiftVS: return new URShiftVSNode(n1, n2, vt);
 330   case Op_URShiftVI: return new URShiftVINode(n1, n2, vt);
 331   case Op_URShiftVL: return new URShiftVLNode(n1, n2, vt);
 332 
 333   case Op_AndV: return new AndVNode(n1, n2, vt);
 334   case Op_OrV:  return new OrVNode (n1, n2, vt);
 335   case Op_XorV: return new XorVNode(n1, n2, vt);
 336   }
 337   fatal("Missed vector creation for '%s'", NodeClassNames[vopc]);
 338   return NULL;
 339 
 340 }
 341 
 342 VectorNode* VectorNode::make(int opc, Node* n1, Node* n2, Node* n3, uint vlen, BasicType bt) {
 343   const TypeVect* vt = TypeVect::make(bt, vlen);
 344   int vopc = VectorNode::opcode(opc, bt);
 345   // This method should not be called for unimplemented vectors.
 346   guarantee(vopc > 0, "Vector for '%s' is not implemented", NodeClassNames[opc]);
 347   switch (vopc) {
 348   case Op_FmaVD: return new FmaVDNode(n1, n2, n3, vt);
 349   case Op_FmaVF: return new FmaVFNode(n1, n2, n3, vt);
 350   }
 351   fatal("Missed vector creation for '%s'", NodeClassNames[vopc]);
 352   return NULL;

 353 }
 354 
 355 // Scalar promotion
 356 VectorNode* VectorNode::scalar2vector(Node* s, uint vlen, const Type* opd_t) {
 357   BasicType bt = opd_t->array_element_basic_type();
 358   const TypeVect* vt = opd_t->singleton() ? TypeVect::make(opd_t, vlen)
 359                                           : TypeVect::make(bt, vlen);
 360   switch (bt) {
 361   case T_BOOLEAN:
 362   case T_BYTE:
 363     return new ReplicateBNode(s, vt);
 364   case T_CHAR:
 365   case T_SHORT:
 366     return new ReplicateSNode(s, vt);
 367   case T_INT:
 368     return new ReplicateINode(s, vt);
 369   case T_LONG:
 370     return new ReplicateLNode(s, vt);
 371   case T_FLOAT:
 372     return new ReplicateFNode(s, vt);
 373   case T_DOUBLE:
 374     return new ReplicateDNode(s, vt);
 375   }
 376   fatal("Type '%s' is not supported for vectors", type2name(bt));
 377   return NULL;

 378 }
 379 
 380 VectorNode* VectorNode::shift_count(Node* shift, Node* cnt, uint vlen, BasicType bt) {
 381   assert(VectorNode::is_shift(shift) && !cnt->is_Con(), "only variable shift count");
 382   // Match shift count type with shift vector type.
 383   const TypeVect* vt = TypeVect::make(bt, vlen);
 384   switch (shift->Opcode()) {
 385   case Op_LShiftI:
 386   case Op_LShiftL:
 387     return new LShiftCntVNode(cnt, vt);
 388   case Op_RShiftI:
 389   case Op_RShiftL:
 390   case Op_URShiftI:
 391   case Op_URShiftL:
 392     return new RShiftCntVNode(cnt, vt);
 393   }
 394   fatal("Missed vector creation for '%s'", NodeClassNames[shift->Opcode()]);
 395   return NULL;

 396 }
 397 
 398 // Return initial Pack node. Additional operands added with add_opd() calls.
 399 PackNode* PackNode::make(Node* s, uint vlen, BasicType bt) {
 400   const TypeVect* vt = TypeVect::make(bt, vlen);
 401   switch (bt) {
 402   case T_BOOLEAN:
 403   case T_BYTE:
 404     return new PackBNode(s, vt);
 405   case T_CHAR:
 406   case T_SHORT:
 407     return new PackSNode(s, vt);
 408   case T_INT:
 409     return new PackINode(s, vt);
 410   case T_LONG:
 411     return new PackLNode(s, vt);
 412   case T_FLOAT:
 413     return new PackFNode(s, vt);
 414   case T_DOUBLE:
 415     return new PackDNode(s, vt);
 416   }
 417   fatal("Type '%s' is not supported for vectors", type2name(bt));
 418   return NULL;

 419 }
 420 
 421 // Create a binary tree form for Packs. [lo, hi) (half-open) range
 422 PackNode* PackNode::binary_tree_pack(int lo, int hi) {
 423   int ct = hi - lo;
 424   assert(is_power_of_2(ct), "power of 2");
 425   if (ct == 2) {
 426     PackNode* pk = PackNode::make(in(lo), 2, vect_type()->element_basic_type());
 427     pk->add_opd(in(lo+1));
 428     return pk;
 429 
 430   } else {
 431     int mid = lo + ct/2;
 432     PackNode* n1 = binary_tree_pack(lo,  mid);
 433     PackNode* n2 = binary_tree_pack(mid, hi );
 434 
 435     BasicType bt = n1->vect_type()->element_basic_type();
 436     assert(bt == n2->vect_type()->element_basic_type(), "should be the same");
 437     switch (bt) {
 438     case T_BOOLEAN:
 439     case T_BYTE:
 440       return new PackSNode(n1, n2, TypeVect::make(T_SHORT, 2));
 441     case T_CHAR:
 442     case T_SHORT:
 443       return new PackINode(n1, n2, TypeVect::make(T_INT, 2));
 444     case T_INT:
 445       return new PackLNode(n1, n2, TypeVect::make(T_LONG, 2));
 446     case T_LONG:
 447       return new Pack2LNode(n1, n2, TypeVect::make(T_LONG, 2));
 448     case T_FLOAT:
 449       return new PackDNode(n1, n2, TypeVect::make(T_DOUBLE, 2));
 450     case T_DOUBLE:
 451       return new Pack2DNode(n1, n2, TypeVect::make(T_DOUBLE, 2));
 452     }
 453     fatal("Type '%s' is not supported for vectors", type2name(bt));
 454   }
 455   return NULL;


 456 }
 457 
 458 // Return the vector version of a scalar load node.
 459 LoadVectorNode* LoadVectorNode::make(int opc, Node* ctl, Node* mem,
 460                                      Node* adr, const TypePtr* atyp,
 461                                      uint vlen, BasicType bt,
 462                                      ControlDependency control_dependency) {
 463   const TypeVect* vt = TypeVect::make(bt, vlen);
 464   return new LoadVectorNode(ctl, mem, adr, atyp, vt, control_dependency);
 465 }
 466 
 467 // Return the vector version of a scalar store node.
 468 StoreVectorNode* StoreVectorNode::make(int opc, Node* ctl, Node* mem,
 469                                        Node* adr, const TypePtr* atyp, Node* val,
 470                                        uint vlen) {
 471   return new StoreVectorNode(ctl, mem, adr, atyp, val);
 472 }
 473 
 474 // Extract a scalar element of vector.
 475 Node* ExtractNode::make(Node* v, uint position, BasicType bt) {
 476   assert((int)position < Matcher::max_vector_size(bt), "pos in range");
 477   ConINode* pos = ConINode::make((int)position);
 478   switch (bt) {
 479   case T_BOOLEAN:
 480     return new ExtractUBNode(v, pos);
 481   case T_BYTE:
 482     return new ExtractBNode(v, pos);
 483   case T_CHAR:
 484     return new ExtractCNode(v, pos);
 485   case T_SHORT:
 486     return new ExtractSNode(v, pos);
 487   case T_INT:
 488     return new ExtractINode(v, pos);
 489   case T_LONG:
 490     return new ExtractLNode(v, pos);
 491   case T_FLOAT:
 492     return new ExtractFNode(v, pos);
 493   case T_DOUBLE:
 494     return new ExtractDNode(v, pos);
 495   }
 496   fatal("Type '%s' is not supported for vectors", type2name(bt));
 497   return NULL;

 498 }
 499 
 500 int ReductionNode::opcode(int opc, BasicType bt) {
 501   int vopc = opc;
 502   switch (opc) {
 503     case Op_AddI:
 504       assert(bt == T_INT, "must be");
 505       vopc = Op_AddReductionVI;
 506       break;
 507     case Op_AddL:
 508       assert(bt == T_LONG, "must be");
 509       vopc = Op_AddReductionVL;
 510       break;
 511     case Op_AddF:
 512       assert(bt == T_FLOAT, "must be");
 513       vopc = Op_AddReductionVF;
 514       break;
 515     case Op_AddD:
 516       assert(bt == T_DOUBLE, "must be");
 517       vopc = Op_AddReductionVD;
 518       break;
 519     case Op_MulI:
 520       assert(bt == T_INT, "must be");
 521       vopc = Op_MulReductionVI;
 522       break;
 523     case Op_MulL:
 524       assert(bt == T_LONG, "must be");
 525       vopc = Op_MulReductionVL;
 526       break;
 527     case Op_MulF:
 528       assert(bt == T_FLOAT, "must be");
 529       vopc = Op_MulReductionVF;
 530       break;
 531     case Op_MulD:
 532       assert(bt == T_DOUBLE, "must be");
 533       vopc = Op_MulReductionVD;
 534       break;
 535     // TODO: add MulL for targets that support it
 536     default:
 537       break;
 538   }
 539   return vopc;
 540 }
 541 
 542 // Return the appropriate reduction node.
 543 ReductionNode* ReductionNode::make(int opc, Node *ctrl, Node* n1, Node* n2, BasicType bt) {
 544 
 545   int vopc = opcode(opc, bt);
 546 
 547   // This method should not be called for unimplemented vectors.
 548   guarantee(vopc != opc, "Vector for '%s' is not implemented", NodeClassNames[opc]);
 549 
 550   switch (vopc) {
 551   case Op_AddReductionVI: return new AddReductionVINode(ctrl, n1, n2);
 552   case Op_AddReductionVL: return new AddReductionVLNode(ctrl, n1, n2);
 553   case Op_AddReductionVF: return new AddReductionVFNode(ctrl, n1, n2);
 554   case Op_AddReductionVD: return new AddReductionVDNode(ctrl, n1, n2);
 555   case Op_MulReductionVI: return new MulReductionVINode(ctrl, n1, n2);
 556   case Op_MulReductionVL: return new MulReductionVLNode(ctrl, n1, n2);
 557   case Op_MulReductionVF: return new MulReductionVFNode(ctrl, n1, n2);
 558   case Op_MulReductionVD: return new MulReductionVDNode(ctrl, n1, n2);
 559   }
 560   fatal("Missed vector creation for '%s'", NodeClassNames[vopc]);
 561   return NULL;

 562 }
 563 
 564 bool ReductionNode::implemented(int opc, uint vlen, BasicType bt) {
 565   if (is_java_primitive(bt) &&
 566       (vlen > 1) && is_power_of_2(vlen) &&
 567       Matcher::vector_size_supported(bt, vlen)) {
 568     int vopc = ReductionNode::opcode(opc, bt);
 569     return vopc != opc && Matcher::match_rule_supported(vopc);
 570   }
 571   return false;
 572 }
 573 
--- EOF ---