1 /*
   2  * Copyright (c) 1997, 2023, 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 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc/shared/barrierSet.hpp"
  28 #include "gc/shared/c2/barrierSetC2.hpp"
  29 #include "memory/allocation.inline.hpp"
  30 #include "opto/addnode.hpp"
  31 #include "opto/callnode.hpp"
  32 #include "opto/cfgnode.hpp"
  33 #include "opto/inlinetypenode.hpp"
  34 #include "opto/loopnode.hpp"
  35 #include "opto/matcher.hpp"
  36 #include "opto/movenode.hpp"
  37 #include "opto/mulnode.hpp"
  38 #include "opto/opaquenode.hpp"
  39 #include "opto/opcodes.hpp"
  40 #include "opto/phaseX.hpp"
  41 #include "opto/subnode.hpp"
  42 #include "runtime/sharedRuntime.hpp"
  43 #include "utilities/reverse_bits.hpp"
  44 
  45 // Portions of code courtesy of Clifford Click
  46 
  47 // Optimization - Graph Style
  48 
  49 #include "math.h"
  50 
  51 //=============================================================================
  52 //------------------------------Identity---------------------------------------
  53 // If right input is a constant 0, return the left input.
  54 Node* SubNode::Identity(PhaseGVN* phase) {
  55   assert(in(1) != this, "Must already have called Value");
  56   assert(in(2) != this, "Must already have called Value");
  57 
  58   // Remove double negation
  59   const Type *zero = add_id();
  60   if( phase->type( in(1) )->higher_equal( zero ) &&
  61       in(2)->Opcode() == Opcode() &&
  62       phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
  63     return in(2)->in(2);
  64   }
  65 
  66   // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
  67   if (in(1)->Opcode() == Op_AddI || in(1)->Opcode() == Op_AddL) {
  68     if (in(1)->in(2) == in(2)) {
  69       return in(1)->in(1);
  70     }
  71     if (in(1)->in(1) == in(2)) {
  72       return in(1)->in(2);
  73     }
  74   }
  75 
  76   return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
  77 }
  78 
  79 //------------------------------Value------------------------------------------
  80 // A subtract node differences it's two inputs.
  81 const Type* SubNode::Value_common(PhaseValues* phase) const {
  82   const Node* in1 = in(1);
  83   const Node* in2 = in(2);
  84   // Either input is TOP ==> the result is TOP
  85   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
  86   if( t1 == Type::TOP ) return Type::TOP;
  87   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
  88   if( t2 == Type::TOP ) return Type::TOP;
  89 
  90   // Not correct for SubFnode and AddFNode (must check for infinity)
  91   // Equal?  Subtract is zero
  92   if (in1->eqv_uncast(in2))  return add_id();
  93 
  94   // Either input is BOTTOM ==> the result is the local BOTTOM
  95   if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
  96     return bottom_type();
  97 
  98   return nullptr;
  99 }
 100 
 101 const Type* SubNode::Value(PhaseGVN* phase) const {
 102   const Type* t = Value_common(phase);
 103   if (t != nullptr) {
 104     return t;
 105   }
 106   const Type* t1 = phase->type(in(1));
 107   const Type* t2 = phase->type(in(2));
 108   return sub(t1,t2);            // Local flavor of type subtraction
 109 
 110 }
 111 
 112 SubNode* SubNode::make(Node* in1, Node* in2, BasicType bt) {
 113   switch (bt) {
 114     case T_INT:
 115       return new SubINode(in1, in2);
 116     case T_LONG:
 117       return new SubLNode(in1, in2);
 118     default:
 119       fatal("Not implemented for %s", type2name(bt));
 120   }
 121   return nullptr;
 122 }
 123 
 124 //=============================================================================
 125 //------------------------------Helper function--------------------------------
 126 
 127 static bool is_cloop_increment(Node* inc) {
 128   precond(inc->Opcode() == Op_AddI || inc->Opcode() == Op_AddL);
 129 
 130   if (!inc->in(1)->is_Phi()) {
 131     return false;
 132   }
 133   const PhiNode* phi = inc->in(1)->as_Phi();
 134 
 135   if (!phi->region()->is_CountedLoop()) {
 136     return false;
 137   }
 138 
 139   return inc == phi->region()->as_CountedLoop()->incr();
 140 }
 141 
 142 // Given the expression '(x + C) - v', or
 143 //                      'v - (x + C)', we examine nodes '+' and 'v':
 144 //
 145 //  1. Do not convert if '+' is a counted-loop increment, because the '-' is
 146 //     loop invariant and converting extends the live-range of 'x' to overlap
 147 //     with the '+', forcing another register to be used in the loop.
 148 //
 149 //  2. Do not convert if 'v' is a counted-loop induction variable, because
 150 //     'x' might be invariant.
 151 //
 152 static bool ok_to_convert(Node* inc, Node* var) {
 153   return !(is_cloop_increment(inc) || var->is_cloop_ind_var());
 154 }
 155 
 156 //------------------------------Ideal------------------------------------------
 157 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
 158   Node *in1 = in(1);
 159   Node *in2 = in(2);
 160   uint op1 = in1->Opcode();
 161   uint op2 = in2->Opcode();
 162 
 163 #ifdef ASSERT
 164   // Check for dead loop
 165   if ((in1 == this) || (in2 == this) ||
 166       ((op1 == Op_AddI || op1 == Op_SubI) &&
 167        ((in1->in(1) == this) || (in1->in(2) == this) ||
 168         (in1->in(1) == in1)  || (in1->in(2) == in1)))) {
 169     assert(false, "dead loop in SubINode::Ideal");
 170   }
 171 #endif
 172 
 173   const Type *t2 = phase->type( in2 );
 174   if( t2 == Type::TOP ) return nullptr;
 175   // Convert "x-c0" into "x+ -c0".
 176   if( t2->base() == Type::Int ){        // Might be bottom or top...
 177     const TypeInt *i = t2->is_int();
 178     if( i->is_con() )
 179       return new AddINode(in1, phase->intcon(java_negate(i->get_con())));
 180   }
 181 
 182   // Convert "(x+c0) - y" into (x-y) + c0"
 183   // Do not collapse (x+c0)-y if "+" is a loop increment or
 184   // if "y" is a loop induction variable.
 185   if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
 186     const Type *tadd = phase->type( in1->in(2) );
 187     if( tadd->singleton() && tadd != Type::TOP ) {
 188       Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 ));
 189       return new AddINode( sub2, in1->in(2) );
 190     }
 191   }
 192 
 193   // Convert "x - (y+c0)" into "(x-y) - c0" AND
 194   // Convert "c1 - (y+c0)" into "(c1-c0) - y"
 195   // Need the same check as in above optimization but reversed.
 196   if (op2 == Op_AddI
 197       && ok_to_convert(in2, in1)
 198       && in2->in(2)->Opcode() == Op_ConI) {
 199     jint c0 = phase->type(in2->in(2))->isa_int()->get_con();
 200     Node* in21 = in2->in(1);
 201     if (in1->Opcode() == Op_ConI) {
 202       // Match c1
 203       jint c1 = phase->type(in1)->isa_int()->get_con();
 204       Node* sub2 = phase->intcon(java_subtract(c1, c0));
 205       return new SubINode(sub2, in21);
 206     } else {
 207       // Match x
 208       Node* sub2 = phase->transform(new SubINode(in1, in21));
 209       Node* neg_c0 = phase->intcon(java_negate(c0));
 210       return new AddINode(sub2, neg_c0);
 211     }
 212   }
 213 
 214   const Type *t1 = phase->type( in1 );
 215   if( t1 == Type::TOP ) return nullptr;
 216 
 217 #ifdef ASSERT
 218   // Check for dead loop
 219   if ((op2 == Op_AddI || op2 == Op_SubI) &&
 220       ((in2->in(1) == this) || (in2->in(2) == this) ||
 221        (in2->in(1) == in2)  || (in2->in(2) == in2))) {
 222     assert(false, "dead loop in SubINode::Ideal");
 223   }
 224 #endif
 225 
 226   // Convert "x - (x+y)" into "-y"
 227   if (op2 == Op_AddI && in1 == in2->in(1)) {
 228     return new SubINode(phase->intcon(0), in2->in(2));
 229   }
 230   // Convert "(x-y) - x" into "-y"
 231   if (op1 == Op_SubI && in1->in(1) == in2) {
 232     return new SubINode(phase->intcon(0), in1->in(2));
 233   }
 234   // Convert "x - (y+x)" into "-y"
 235   if (op2 == Op_AddI && in1 == in2->in(2)) {
 236     return new SubINode(phase->intcon(0), in2->in(1));
 237   }
 238 
 239   // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity().
 240   if (t1 == TypeInt::ZERO && op2 == Op_SubI && phase->type(in2->in(1)) != TypeInt::ZERO) {
 241     return new SubINode(in2->in(2), in2->in(1));
 242   }
 243 
 244   // Convert "0 - (x+con)" into "-con-x"
 245   jint con;
 246   if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
 247       (con = in2->in(2)->find_int_con(0)) != 0 )
 248     return new SubINode( phase->intcon(-con), in2->in(1) );
 249 
 250   // Convert "(X+A) - (X+B)" into "A - B"
 251   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
 252     return new SubINode( in1->in(2), in2->in(2) );
 253 
 254   // Convert "(A+X) - (B+X)" into "A - B"
 255   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
 256     return new SubINode( in1->in(1), in2->in(1) );
 257 
 258   // Convert "(A+X) - (X+B)" into "A - B"
 259   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
 260     return new SubINode( in1->in(1), in2->in(2) );
 261 
 262   // Convert "(X+A) - (B+X)" into "A - B"
 263   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
 264     return new SubINode( in1->in(2), in2->in(1) );
 265 
 266   // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
 267   // nicer to optimize than subtract.
 268   if( op2 == Op_SubI && in2->outcnt() == 1) {
 269     Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) );
 270     return new SubINode( add1, in2->in(1) );
 271   }
 272 
 273   // Associative
 274   if (op1 == Op_MulI && op2 == Op_MulI) {
 275     Node* sub_in1 = nullptr;
 276     Node* sub_in2 = nullptr;
 277     Node* mul_in = nullptr;
 278 
 279     if (in1->in(1) == in2->in(1)) {
 280       // Convert "a*b-a*c into a*(b-c)
 281       sub_in1 = in1->in(2);
 282       sub_in2 = in2->in(2);
 283       mul_in = in1->in(1);
 284     } else if (in1->in(2) == in2->in(1)) {
 285       // Convert a*b-b*c into b*(a-c)
 286       sub_in1 = in1->in(1);
 287       sub_in2 = in2->in(2);
 288       mul_in = in1->in(2);
 289     } else if (in1->in(2) == in2->in(2)) {
 290       // Convert a*c-b*c into (a-b)*c
 291       sub_in1 = in1->in(1);
 292       sub_in2 = in2->in(1);
 293       mul_in = in1->in(2);
 294     } else if (in1->in(1) == in2->in(2)) {
 295       // Convert a*b-c*a into a*(b-c)
 296       sub_in1 = in1->in(2);
 297       sub_in2 = in2->in(1);
 298       mul_in = in1->in(1);
 299     }
 300 
 301     if (mul_in != nullptr) {
 302       Node* sub = phase->transform(new SubINode(sub_in1, sub_in2));
 303       return new MulINode(mul_in, sub);
 304     }
 305   }
 306 
 307   // Convert "0-(A>>31)" into "(A>>>31)"
 308   if ( op2 == Op_RShiftI ) {
 309     Node *in21 = in2->in(1);
 310     Node *in22 = in2->in(2);
 311     const TypeInt *zero = phase->type(in1)->isa_int();
 312     const TypeInt *t21 = phase->type(in21)->isa_int();
 313     const TypeInt *t22 = phase->type(in22)->isa_int();
 314     if ( t21 && t22 && zero == TypeInt::ZERO && t22->is_con(31) ) {
 315       return new URShiftINode(in21, in22);
 316     }
 317   }
 318 
 319   return nullptr;
 320 }
 321 
 322 //------------------------------sub--------------------------------------------
 323 // A subtract node differences it's two inputs.
 324 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
 325   const TypeInt *r0 = t1->is_int(); // Handy access
 326   const TypeInt *r1 = t2->is_int();
 327   int32_t lo = java_subtract(r0->_lo, r1->_hi);
 328   int32_t hi = java_subtract(r0->_hi, r1->_lo);
 329 
 330   // We next check for 32-bit overflow.
 331   // If that happens, we just assume all integers are possible.
 332   if( (((r0->_lo ^ r1->_hi) >= 0) ||    // lo ends have same signs OR
 333        ((r0->_lo ^      lo) >= 0)) &&   // lo results have same signs AND
 334       (((r0->_hi ^ r1->_lo) >= 0) ||    // hi ends have same signs OR
 335        ((r0->_hi ^      hi) >= 0)) )    // hi results have same signs
 336     return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
 337   else                          // Overflow; assume all integers
 338     return TypeInt::INT;
 339 }
 340 
 341 //=============================================================================
 342 //------------------------------Ideal------------------------------------------
 343 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 344   Node *in1 = in(1);
 345   Node *in2 = in(2);
 346   uint op1 = in1->Opcode();
 347   uint op2 = in2->Opcode();
 348 
 349 #ifdef ASSERT
 350   // Check for dead loop
 351   if ((in1 == this) || (in2 == this) ||
 352       ((op1 == Op_AddL || op1 == Op_SubL) &&
 353        ((in1->in(1) == this) || (in1->in(2) == this) ||
 354         (in1->in(1) == in1)  || (in1->in(2) == in1)))) {
 355     assert(false, "dead loop in SubLNode::Ideal");
 356   }
 357 #endif
 358 
 359   if( phase->type( in2 ) == Type::TOP ) return nullptr;
 360   const TypeLong *i = phase->type( in2 )->isa_long();
 361   // Convert "x-c0" into "x+ -c0".
 362   if( i &&                      // Might be bottom or top...
 363       i->is_con() )
 364     return new AddLNode(in1, phase->longcon(java_negate(i->get_con())));
 365 
 366   // Convert "(x+c0) - y" into (x-y) + c0"
 367   // Do not collapse (x+c0)-y if "+" is a loop increment or
 368   // if "y" is a loop induction variable.
 369   if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
 370     Node *in11 = in1->in(1);
 371     const Type *tadd = phase->type( in1->in(2) );
 372     if( tadd->singleton() && tadd != Type::TOP ) {
 373       Node *sub2 = phase->transform( new SubLNode( in11, in2 ));
 374       return new AddLNode( sub2, in1->in(2) );
 375     }
 376   }
 377 
 378   // Convert "x - (y+c0)" into "(x-y) - c0" AND
 379   // Convert "c1 - (y+c0)" into "(c1-c0) - y"
 380   // Need the same check as in above optimization but reversed.
 381   if (op2 == Op_AddL
 382       && ok_to_convert(in2, in1)
 383       && in2->in(2)->Opcode() == Op_ConL) {
 384     jlong c0 = phase->type(in2->in(2))->isa_long()->get_con();
 385     Node* in21 = in2->in(1);
 386     if (in1->Opcode() == Op_ConL) {
 387       // Match c1
 388       jlong c1 = phase->type(in1)->isa_long()->get_con();
 389       Node* sub2 = phase->longcon(java_subtract(c1, c0));
 390       return new SubLNode(sub2, in21);
 391     } else {
 392       Node* sub2 = phase->transform(new SubLNode(in1, in21));
 393       Node* neg_c0 = phase->longcon(-c0);
 394       return new AddLNode(sub2, neg_c0);
 395     }
 396   }
 397 
 398   const Type *t1 = phase->type( in1 );
 399   if( t1 == Type::TOP ) return nullptr;
 400 
 401 #ifdef ASSERT
 402   // Check for dead loop
 403   if ((op2 == Op_AddL || op2 == Op_SubL) &&
 404       ((in2->in(1) == this) || (in2->in(2) == this) ||
 405        (in2->in(1) == in2)  || (in2->in(2) == in2))) {
 406     assert(false, "dead loop in SubLNode::Ideal");
 407   }
 408 #endif
 409 
 410   // Convert "x - (x+y)" into "-y"
 411   if (op2 == Op_AddL && in1 == in2->in(1)) {
 412     return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(2));
 413   }
 414   // Convert "(x-y) - x" into "-y"
 415   if (op1 == Op_SubL && in1->in(1) == in2) {
 416     return new SubLNode(phase->makecon(TypeLong::ZERO), in1->in(2));
 417   }
 418   // Convert "x - (y+x)" into "-y"
 419   if (op2 == Op_AddL && in1 == in2->in(2)) {
 420     return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(1));
 421   }
 422 
 423   // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity.
 424   if (t1 == TypeLong::ZERO && op2 == Op_SubL && phase->type(in2->in(1)) != TypeLong::ZERO) {
 425     return new SubLNode(in2->in(2), in2->in(1));
 426   }
 427 
 428   // Convert "(X+A) - (X+B)" into "A - B"
 429   if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
 430     return new SubLNode( in1->in(2), in2->in(2) );
 431 
 432   // Convert "(A+X) - (B+X)" into "A - B"
 433   if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
 434     return new SubLNode( in1->in(1), in2->in(1) );
 435 
 436   // Convert "(A+X) - (X+B)" into "A - B"
 437   if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(1) )
 438     return new SubLNode( in1->in(1), in2->in(2) );
 439 
 440   // Convert "(X+A) - (B+X)" into "A - B"
 441   if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(2) )
 442     return new SubLNode( in1->in(2), in2->in(1) );
 443 
 444   // Convert "A-(B-C)" into (A+C)-B"
 445   if( op2 == Op_SubL && in2->outcnt() == 1) {
 446     Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) );
 447     return new SubLNode( add1, in2->in(1) );
 448   }
 449 
 450   // Associative
 451   if (op1 == Op_MulL && op2 == Op_MulL) {
 452     Node* sub_in1 = nullptr;
 453     Node* sub_in2 = nullptr;
 454     Node* mul_in = nullptr;
 455 
 456     if (in1->in(1) == in2->in(1)) {
 457       // Convert "a*b-a*c into a*(b+c)
 458       sub_in1 = in1->in(2);
 459       sub_in2 = in2->in(2);
 460       mul_in = in1->in(1);
 461     } else if (in1->in(2) == in2->in(1)) {
 462       // Convert a*b-b*c into b*(a-c)
 463       sub_in1 = in1->in(1);
 464       sub_in2 = in2->in(2);
 465       mul_in = in1->in(2);
 466     } else if (in1->in(2) == in2->in(2)) {
 467       // Convert a*c-b*c into (a-b)*c
 468       sub_in1 = in1->in(1);
 469       sub_in2 = in2->in(1);
 470       mul_in = in1->in(2);
 471     } else if (in1->in(1) == in2->in(2)) {
 472       // Convert a*b-c*a into a*(b-c)
 473       sub_in1 = in1->in(2);
 474       sub_in2 = in2->in(1);
 475       mul_in = in1->in(1);
 476     }
 477 
 478     if (mul_in != nullptr) {
 479       Node* sub = phase->transform(new SubLNode(sub_in1, sub_in2));
 480       return new MulLNode(mul_in, sub);
 481     }
 482   }
 483 
 484   // Convert "0L-(A>>63)" into "(A>>>63)"
 485   if ( op2 == Op_RShiftL ) {
 486     Node *in21 = in2->in(1);
 487     Node *in22 = in2->in(2);
 488     const TypeLong *zero = phase->type(in1)->isa_long();
 489     const TypeLong *t21 = phase->type(in21)->isa_long();
 490     const TypeInt *t22 = phase->type(in22)->isa_int();
 491     if ( t21 && t22 && zero == TypeLong::ZERO && t22->is_con(63) ) {
 492       return new URShiftLNode(in21, in22);
 493     }
 494   }
 495 
 496   return nullptr;
 497 }
 498 
 499 //------------------------------sub--------------------------------------------
 500 // A subtract node differences it's two inputs.
 501 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
 502   const TypeLong *r0 = t1->is_long(); // Handy access
 503   const TypeLong *r1 = t2->is_long();
 504   jlong lo = java_subtract(r0->_lo, r1->_hi);
 505   jlong hi = java_subtract(r0->_hi, r1->_lo);
 506 
 507   // We next check for 32-bit overflow.
 508   // If that happens, we just assume all integers are possible.
 509   if( (((r0->_lo ^ r1->_hi) >= 0) ||    // lo ends have same signs OR
 510        ((r0->_lo ^      lo) >= 0)) &&   // lo results have same signs AND
 511       (((r0->_hi ^ r1->_lo) >= 0) ||    // hi ends have same signs OR
 512        ((r0->_hi ^      hi) >= 0)) )    // hi results have same signs
 513     return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
 514   else                          // Overflow; assume all integers
 515     return TypeLong::LONG;
 516 }
 517 
 518 //=============================================================================
 519 //------------------------------Value------------------------------------------
 520 // A subtract node differences its two inputs.
 521 const Type* SubFPNode::Value(PhaseGVN* phase) const {
 522   const Node* in1 = in(1);
 523   const Node* in2 = in(2);
 524   // Either input is TOP ==> the result is TOP
 525   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
 526   if( t1 == Type::TOP ) return Type::TOP;
 527   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
 528   if( t2 == Type::TOP ) return Type::TOP;
 529 
 530   // if both operands are infinity of same sign, the result is NaN; do
 531   // not replace with zero
 532   if (t1->is_finite() && t2->is_finite() && in1 == in2) {
 533     return add_id();
 534   }
 535 
 536   // Either input is BOTTOM ==> the result is the local BOTTOM
 537   const Type *bot = bottom_type();
 538   if( (t1 == bot) || (t2 == bot) ||
 539       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
 540     return bot;
 541 
 542   return sub(t1,t2);            // Local flavor of type subtraction
 543 }
 544 
 545 
 546 //=============================================================================
 547 //------------------------------Ideal------------------------------------------
 548 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 549   const Type *t2 = phase->type( in(2) );
 550   // Convert "x-c0" into "x+ -c0".
 551   if( t2->base() == Type::FloatCon ) {  // Might be bottom or top...
 552     // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
 553   }
 554 
 555   // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
 556   // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
 557   //if( phase->type(in(1)) == TypeF::ZERO )
 558   //return new (phase->C, 2) NegFNode(in(2));
 559 
 560   return nullptr;
 561 }
 562 
 563 //------------------------------sub--------------------------------------------
 564 // A subtract node differences its two inputs.
 565 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
 566   // no folding if one of operands is infinity or NaN, do not do constant folding
 567   if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
 568     return TypeF::make( t1->getf() - t2->getf() );
 569   }
 570   else if( g_isnan(t1->getf()) ) {
 571     return t1;
 572   }
 573   else if( g_isnan(t2->getf()) ) {
 574     return t2;
 575   }
 576   else {
 577     return Type::FLOAT;
 578   }
 579 }
 580 
 581 //=============================================================================
 582 //------------------------------Ideal------------------------------------------
 583 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
 584   const Type *t2 = phase->type( in(2) );
 585   // Convert "x-c0" into "x+ -c0".
 586   if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
 587     // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
 588   }
 589 
 590   // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
 591   // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
 592   //if( phase->type(in(1)) == TypeD::ZERO )
 593   //return new (phase->C, 2) NegDNode(in(2));
 594 
 595   return nullptr;
 596 }
 597 
 598 //------------------------------sub--------------------------------------------
 599 // A subtract node differences its two inputs.
 600 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
 601   // no folding if one of operands is infinity or NaN, do not do constant folding
 602   if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
 603     return TypeD::make( t1->getd() - t2->getd() );
 604   }
 605   else if( g_isnan(t1->getd()) ) {
 606     return t1;
 607   }
 608   else if( g_isnan(t2->getd()) ) {
 609     return t2;
 610   }
 611   else {
 612     return Type::DOUBLE;
 613   }
 614 }
 615 
 616 //=============================================================================
 617 //------------------------------Idealize---------------------------------------
 618 // Unlike SubNodes, compare must still flatten return value to the
 619 // range -1, 0, 1.
 620 // And optimizations like those for (X + Y) - X fail if overflow happens.
 621 Node* CmpNode::Identity(PhaseGVN* phase) {
 622   return this;
 623 }
 624 
 625 CmpNode *CmpNode::make(Node *in1, Node *in2, BasicType bt, bool unsigned_comp) {
 626   switch (bt) {
 627     case T_INT:
 628       if (unsigned_comp) {
 629         return new CmpUNode(in1, in2);
 630       }
 631       return new CmpINode(in1, in2);
 632     case T_LONG:
 633       if (unsigned_comp) {
 634         return new CmpULNode(in1, in2);
 635       }
 636       return new CmpLNode(in1, in2);
 637     default:
 638       fatal("Not implemented for %s", type2name(bt));
 639   }
 640   return nullptr;
 641 }
 642 
 643 //=============================================================================
 644 //------------------------------cmp--------------------------------------------
 645 // Simplify a CmpI (compare 2 integers) node, based on local information.
 646 // If both inputs are constants, compare them.
 647 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
 648   const TypeInt *r0 = t1->is_int(); // Handy access
 649   const TypeInt *r1 = t2->is_int();
 650 
 651   if( r0->_hi < r1->_lo )       // Range is always low?
 652     return TypeInt::CC_LT;
 653   else if( r0->_lo > r1->_hi )  // Range is always high?
 654     return TypeInt::CC_GT;
 655 
 656   else if( r0->is_con() && r1->is_con() ) { // comparing constants?
 657     assert(r0->get_con() == r1->get_con(), "must be equal");
 658     return TypeInt::CC_EQ;      // Equal results.
 659   } else if( r0->_hi == r1->_lo ) // Range is never high?
 660     return TypeInt::CC_LE;
 661   else if( r0->_lo == r1->_hi ) // Range is never low?
 662     return TypeInt::CC_GE;
 663   return TypeInt::CC;           // else use worst case results
 664 }
 665 
 666 const Type* CmpINode::Value(PhaseGVN* phase) const {
 667   Node* in1 = in(1);
 668   Node* in2 = in(2);
 669   // If this test is the zero trip guard for a main or post loop, check whether, with the opaque node removed, the test
 670   // would constant fold so the loop is never entered. If so return the type of the test without the opaque node removed:
 671   // make the loop unreachable.
 672   // The reason for this is that the iv phi captures the bounds of the loop and if the loop becomes unreachable, it can
 673   // become top. In that case, the loop must be removed.
 674   // This is safe because:
 675   // - as optimizations proceed, the range of iterations executed by the main loop narrows. If no iterations remain, then
 676   // we're done with optimizations for that loop.
 677   // - the post loop is initially not reachable but as long as there's a main loop, the zero trip guard for the post
 678   // loop takes a phi that merges the pre and main loop's iv and can't constant fold the zero trip guard. Once, the main
 679   // loop is removed, there's no need to preserve the zero trip guard for the post loop anymore.
 680   if (in1 != nullptr && in2 != nullptr) {
 681     uint input = 0;
 682     Node* cmp = nullptr;
 683     BoolTest::mask test;
 684     if (in1->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in1) != Type::TOP) {
 685       cmp = new CmpINode(in1->in(1), in2);
 686       test = ((OpaqueZeroTripGuardNode*)in1)->_loop_entered_mask;
 687     }
 688     if (in2->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in2) != Type::TOP) {
 689       assert(cmp == nullptr, "A cmp with 2 OpaqueZeroTripGuard inputs");
 690       cmp = new CmpINode(in1, in2->in(1));
 691       test = ((OpaqueZeroTripGuardNode*)in2)->_loop_entered_mask;
 692     }
 693     if (cmp != nullptr) {
 694       const Type* cmp_t = cmp->Value(phase);
 695       const Type* t = BoolTest(test).cc2logical(cmp_t);
 696       cmp->destruct(phase);
 697       if (t == TypeInt::ZERO) {
 698         return cmp_t;
 699       }
 700     }
 701   }
 702 
 703   return SubNode::Value(phase);
 704 }
 705 
 706 
 707 // Simplify a CmpU (compare 2 integers) node, based on local information.
 708 // If both inputs are constants, compare them.
 709 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
 710   assert(!t1->isa_ptr(), "obsolete usage of CmpU");
 711 
 712   // comparing two unsigned ints
 713   const TypeInt *r0 = t1->is_int();   // Handy access
 714   const TypeInt *r1 = t2->is_int();
 715 
 716   // Current installed version
 717   // Compare ranges for non-overlap
 718   juint lo0 = r0->_lo;
 719   juint hi0 = r0->_hi;
 720   juint lo1 = r1->_lo;
 721   juint hi1 = r1->_hi;
 722 
 723   // If either one has both negative and positive values,
 724   // it therefore contains both 0 and -1, and since [0..-1] is the
 725   // full unsigned range, the type must act as an unsigned bottom.
 726   bool bot0 = ((jint)(lo0 ^ hi0) < 0);
 727   bool bot1 = ((jint)(lo1 ^ hi1) < 0);
 728 
 729   if (bot0 || bot1) {
 730     // All unsigned values are LE -1 and GE 0.
 731     if (lo0 == 0 && hi0 == 0) {
 732       return TypeInt::CC_LE;            //   0 <= bot
 733     } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
 734       return TypeInt::CC_GE;            // -1 >= bot
 735     } else if (lo1 == 0 && hi1 == 0) {
 736       return TypeInt::CC_GE;            // bot >= 0
 737     } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
 738       return TypeInt::CC_LE;            // bot <= -1
 739     }
 740   } else {
 741     // We can use ranges of the form [lo..hi] if signs are the same.
 742     assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
 743     // results are reversed, '-' > '+' for unsigned compare
 744     if (hi0 < lo1) {
 745       return TypeInt::CC_LT;            // smaller
 746     } else if (lo0 > hi1) {
 747       return TypeInt::CC_GT;            // greater
 748     } else if (hi0 == lo1 && lo0 == hi1) {
 749       return TypeInt::CC_EQ;            // Equal results
 750     } else if (lo0 >= hi1) {
 751       return TypeInt::CC_GE;
 752     } else if (hi0 <= lo1) {
 753       // Check for special case in Hashtable::get.  (See below.)
 754       if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
 755         return TypeInt::CC_LT;
 756       return TypeInt::CC_LE;
 757     }
 758   }
 759   // Check for special case in Hashtable::get - the hash index is
 760   // mod'ed to the table size so the following range check is useless.
 761   // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
 762   // to be positive.
 763   // (This is a gross hack, since the sub method never
 764   // looks at the structure of the node in any other case.)
 765   if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
 766     return TypeInt::CC_LT;
 767   return TypeInt::CC;                   // else use worst case results
 768 }
 769 
 770 const Type* CmpUNode::Value(PhaseGVN* phase) const {
 771   const Type* t = SubNode::Value_common(phase);
 772   if (t != nullptr) {
 773     return t;
 774   }
 775   const Node* in1 = in(1);
 776   const Node* in2 = in(2);
 777   const Type* t1 = phase->type(in1);
 778   const Type* t2 = phase->type(in2);
 779   assert(t1->isa_int(), "CmpU has only Int type inputs");
 780   if (t2 == TypeInt::INT) { // Compare to bottom?
 781     return bottom_type();
 782   }
 783 
 784   const Type* t_sub = sub(t1, t2); // compare based on immediate inputs
 785 
 786   uint in1_op = in1->Opcode();
 787   if (in1_op == Op_AddI || in1_op == Op_SubI) {
 788     // The problem rise when result of AddI(SubI) may overflow
 789     // signed integer value. Let say the input type is
 790     // [256, maxint] then +128 will create 2 ranges due to
 791     // overflow: [minint, minint+127] and [384, maxint].
 792     // But C2 type system keep only 1 type range and as result
 793     // it use general [minint, maxint] for this case which we
 794     // can't optimize.
 795     //
 796     // Make 2 separate type ranges based on types of AddI(SubI) inputs
 797     // and compare results of their compare. If results are the same
 798     // CmpU node can be optimized.
 799     const Node* in11 = in1->in(1);
 800     const Node* in12 = in1->in(2);
 801     const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
 802     const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
 803     // Skip cases when input types are top or bottom.
 804     if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
 805         (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
 806       const TypeInt *r0 = t11->is_int();
 807       const TypeInt *r1 = t12->is_int();
 808       jlong lo_r0 = r0->_lo;
 809       jlong hi_r0 = r0->_hi;
 810       jlong lo_r1 = r1->_lo;
 811       jlong hi_r1 = r1->_hi;
 812       if (in1_op == Op_SubI) {
 813         jlong tmp = hi_r1;
 814         hi_r1 = -lo_r1;
 815         lo_r1 = -tmp;
 816         // Note, for substructing [minint,x] type range
 817         // long arithmetic provides correct overflow answer.
 818         // The confusion come from the fact that in 32-bit
 819         // -minint == minint but in 64-bit -minint == maxint+1.
 820       }
 821       jlong lo_long = lo_r0 + lo_r1;
 822       jlong hi_long = hi_r0 + hi_r1;
 823       int lo_tr1 = min_jint;
 824       int hi_tr1 = (int)hi_long;
 825       int lo_tr2 = (int)lo_long;
 826       int hi_tr2 = max_jint;
 827       bool underflow = lo_long != (jlong)lo_tr2;
 828       bool overflow  = hi_long != (jlong)hi_tr1;
 829       // Use sub(t1, t2) when there is no overflow (one type range)
 830       // or when both overflow and underflow (too complex).
 831       if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
 832         // Overflow only on one boundary, compare 2 separate type ranges.
 833         int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
 834         const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
 835         const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
 836         const TypeInt* cmp1 = sub(tr1, t2)->is_int();
 837         const TypeInt* cmp2 = sub(tr2, t2)->is_int();
 838         // Compute union, so that cmp handles all possible results from the two cases
 839         const Type* t_cmp = cmp1->meet(cmp2);
 840         // Pick narrowest type, based on overflow computation and on immediate inputs
 841         return t_sub->filter(t_cmp);
 842       }
 843     }
 844   }
 845 
 846   return t_sub;
 847 }
 848 
 849 bool CmpUNode::is_index_range_check() const {
 850   // Check for the "(X ModI Y) CmpU Y" shape
 851   return (in(1)->Opcode() == Op_ModI &&
 852           in(1)->in(2)->eqv_uncast(in(2)));
 853 }
 854 
 855 //------------------------------Idealize---------------------------------------
 856 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
 857   if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
 858     switch (in(1)->Opcode()) {
 859     case Op_CmpU3:              // Collapse a CmpU3/CmpI into a CmpU
 860       return new CmpUNode(in(1)->in(1),in(1)->in(2));
 861     case Op_CmpL3:              // Collapse a CmpL3/CmpI into a CmpL
 862       return new CmpLNode(in(1)->in(1),in(1)->in(2));
 863     case Op_CmpUL3:             // Collapse a CmpUL3/CmpI into a CmpUL
 864       return new CmpULNode(in(1)->in(1),in(1)->in(2));
 865     case Op_CmpF3:              // Collapse a CmpF3/CmpI into a CmpF
 866       return new CmpFNode(in(1)->in(1),in(1)->in(2));
 867     case Op_CmpD3:              // Collapse a CmpD3/CmpI into a CmpD
 868       return new CmpDNode(in(1)->in(1),in(1)->in(2));
 869     //case Op_SubI:
 870       // If (x - y) cannot overflow, then ((x - y) <?> 0)
 871       // can be turned into (x <?> y).
 872       // This is handled (with more general cases) by Ideal_sub_algebra.
 873     }
 874   }
 875   return nullptr;                  // No change
 876 }
 877 
 878 //------------------------------Ideal------------------------------------------
 879 Node* CmpLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
 880   Node* a = nullptr;
 881   Node* b = nullptr;
 882   if (is_double_null_check(phase, a, b) && (phase->type(a)->is_zero_type() || phase->type(b)->is_zero_type())) {
 883     // Degraded to a simple null check, use old acmp
 884     return new CmpPNode(a, b);
 885   }
 886   const TypeLong *t2 = phase->type(in(2))->isa_long();
 887   if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) {
 888     const jlong con = t2->get_con();
 889     if (con >= min_jint && con <= max_jint) {
 890       return new CmpINode(in(1)->in(1), phase->intcon((jint)con));
 891     }
 892   }
 893   return nullptr;
 894 }
 895 
 896 // Match double null check emitted by Compile::optimize_acmp()
 897 bool CmpLNode::is_double_null_check(PhaseGVN* phase, Node*& a, Node*& b) const {
 898   if (in(1)->Opcode() == Op_OrL &&
 899       in(1)->in(1)->Opcode() == Op_CastP2X &&
 900       in(1)->in(2)->Opcode() == Op_CastP2X &&
 901       in(2)->bottom_type()->is_zero_type()) {
 902     assert(EnableValhalla, "unexpected double null check");
 903     a = in(1)->in(1)->in(1);
 904     b = in(1)->in(2)->in(1);
 905     return true;
 906   }
 907   return false;
 908 }
 909 
 910 //------------------------------Value------------------------------------------
 911 const Type* CmpLNode::Value(PhaseGVN* phase) const {
 912   Node* a = nullptr;
 913   Node* b = nullptr;
 914   if (is_double_null_check(phase, a, b) && (!phase->type(a)->maybe_null() || !phase->type(b)->maybe_null())) {
 915     // One operand is never nullptr, emit constant false
 916     return TypeInt::CC_GT;
 917   }
 918   return SubNode::Value(phase);
 919 }
 920 
 921 //=============================================================================
 922 // Simplify a CmpL (compare 2 longs ) node, based on local information.
 923 // If both inputs are constants, compare them.
 924 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
 925   const TypeLong *r0 = t1->is_long(); // Handy access
 926   const TypeLong *r1 = t2->is_long();
 927 
 928   if( r0->_hi < r1->_lo )       // Range is always low?
 929     return TypeInt::CC_LT;
 930   else if( r0->_lo > r1->_hi )  // Range is always high?
 931     return TypeInt::CC_GT;
 932 
 933   else if( r0->is_con() && r1->is_con() ) { // comparing constants?
 934     assert(r0->get_con() == r1->get_con(), "must be equal");
 935     return TypeInt::CC_EQ;      // Equal results.
 936   } else if( r0->_hi == r1->_lo ) // Range is never high?
 937     return TypeInt::CC_LE;
 938   else if( r0->_lo == r1->_hi ) // Range is never low?
 939     return TypeInt::CC_GE;
 940   return TypeInt::CC;           // else use worst case results
 941 }
 942 
 943 
 944 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
 945 // If both inputs are constants, compare them.
 946 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
 947   assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
 948 
 949   // comparing two unsigned longs
 950   const TypeLong* r0 = t1->is_long();   // Handy access
 951   const TypeLong* r1 = t2->is_long();
 952 
 953   // Current installed version
 954   // Compare ranges for non-overlap
 955   julong lo0 = r0->_lo;
 956   julong hi0 = r0->_hi;
 957   julong lo1 = r1->_lo;
 958   julong hi1 = r1->_hi;
 959 
 960   // If either one has both negative and positive values,
 961   // it therefore contains both 0 and -1, and since [0..-1] is the
 962   // full unsigned range, the type must act as an unsigned bottom.
 963   bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
 964   bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
 965 
 966   if (bot0 || bot1) {
 967     // All unsigned values are LE -1 and GE 0.
 968     if (lo0 == 0 && hi0 == 0) {
 969       return TypeInt::CC_LE;            //   0 <= bot
 970     } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
 971       return TypeInt::CC_GE;            // -1 >= bot
 972     } else if (lo1 == 0 && hi1 == 0) {
 973       return TypeInt::CC_GE;            // bot >= 0
 974     } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
 975       return TypeInt::CC_LE;            // bot <= -1
 976     }
 977   } else {
 978     // We can use ranges of the form [lo..hi] if signs are the same.
 979     assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
 980     // results are reversed, '-' > '+' for unsigned compare
 981     if (hi0 < lo1) {
 982       return TypeInt::CC_LT;            // smaller
 983     } else if (lo0 > hi1) {
 984       return TypeInt::CC_GT;            // greater
 985     } else if (hi0 == lo1 && lo0 == hi1) {
 986       return TypeInt::CC_EQ;            // Equal results
 987     } else if (lo0 >= hi1) {
 988       return TypeInt::CC_GE;
 989     } else if (hi0 <= lo1) {
 990       return TypeInt::CC_LE;
 991     }
 992   }
 993 
 994   return TypeInt::CC;                   // else use worst case results
 995 }
 996 
 997 //=============================================================================
 998 //------------------------------sub--------------------------------------------
 999 // Simplify an CmpP (compare 2 pointers) node, based on local information.
1000 // If both inputs are constants, compare them.
1001 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
1002   const TypePtr *r0 = t1->is_ptr(); // Handy access
1003   const TypePtr *r1 = t2->is_ptr();
1004 
1005   // Undefined inputs makes for an undefined result
1006   if( TypePtr::above_centerline(r0->_ptr) ||
1007       TypePtr::above_centerline(r1->_ptr) )
1008     return Type::TOP;
1009 
1010   if (r0 == r1 && r0->singleton()) {
1011     // Equal pointer constants (klasses, nulls, etc.)
1012     return TypeInt::CC_EQ;
1013   }
1014 
1015   // See if it is 2 unrelated classes.
1016   const TypeOopPtr* p0 = r0->isa_oopptr();
1017   const TypeOopPtr* p1 = r1->isa_oopptr();
1018   const TypeKlassPtr* k0 = r0->isa_klassptr();
1019   const TypeKlassPtr* k1 = r1->isa_klassptr();
1020   if ((p0 && p1) || (k0 && k1)) {
1021     if (p0 && p1) {
1022       Node* in1 = in(1)->uncast();
1023       Node* in2 = in(2)->uncast();
1024       AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1);
1025       AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2);
1026       if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, nullptr)) {
1027         return TypeInt::CC_GT;  // different pointers
1028       }
1029     }
1030     bool    xklass0 = p0 ? p0->klass_is_exact() : k0->klass_is_exact();
1031     bool    xklass1 = p1 ? p1->klass_is_exact() : k1->klass_is_exact();
1032     bool unrelated_classes = false;
1033 
1034     if ((p0 && p0->is_same_java_type_as(p1)) ||
1035         (k0 && k0->is_same_java_type_as(k1))) {
1036     } else if ((p0 && !p1->maybe_java_subtype_of(p0) && !p0->maybe_java_subtype_of(p1)) ||
1037                (k0 && !k1->maybe_java_subtype_of(k0) && !k0->maybe_java_subtype_of(k1))) {
1038       unrelated_classes = true;
1039     } else if ((p0 && !p1->maybe_java_subtype_of(p0)) ||
1040                (k0 && !k1->maybe_java_subtype_of(k0))) {
1041       unrelated_classes = xklass1;
1042     } else if ((p0 && !p0->maybe_java_subtype_of(p1)) ||
1043                (k0 && !k0->maybe_java_subtype_of(k1))) {
1044       unrelated_classes = xklass0;
1045     }
1046     if (!unrelated_classes) {
1047       // Handle inline type arrays
1048       if ((r0->flat_in_array() && r1->not_flat_in_array()) ||
1049           (r1->flat_in_array() && r0->not_flat_in_array())) {
1050         // One type is in flat arrays but the other type is not. Must be unrelated.
1051         unrelated_classes = true;
1052       } else if ((r0->is_not_flat() && r1->is_flat()) ||
1053                  (r1->is_not_flat() && r0->is_flat())) {
1054         // One type is a non-flat array and the other type is a flat array. Must be unrelated.
1055         unrelated_classes = true;
1056       } else if ((r0->is_not_null_free() && r1->is_null_free()) ||
1057                  (r1->is_not_null_free() && r0->is_null_free())) {
1058         // One type is a nullable array and the other type is a null-free array. Must be unrelated.
1059         unrelated_classes = true;
1060       }
1061     }
1062     if (unrelated_classes) {
1063       // The oops classes are known to be unrelated. If the joined PTRs of
1064       // two oops is not Null and not Bottom, then we are sure that one
1065       // of the two oops is non-null, and the comparison will always fail.
1066       TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1067       if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1068         return TypeInt::CC_GT;
1069       }
1070     }
1071   }
1072 
1073   // Known constants can be compared exactly
1074   // Null can be distinguished from any NotNull pointers
1075   // Unknown inputs makes an unknown result
1076   if( r0->singleton() ) {
1077     intptr_t bits0 = r0->get_con();
1078     if( r1->singleton() )
1079       return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1080     return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1081   } else if( r1->singleton() ) {
1082     intptr_t bits1 = r1->get_con();
1083     return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1084   } else
1085     return TypeInt::CC;
1086 }
1087 
1088 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1089   // Return the klass node for (indirect load from OopHandle)
1090   //   LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1091   //   or null if not matching.
1092   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1093     n = bs->step_over_gc_barrier(n);
1094 
1095   if (n->Opcode() != Op_LoadP) return nullptr;
1096 
1097   const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1098   if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr;
1099 
1100   Node* adr = n->in(MemNode::Address);
1101   // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1102   if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr;
1103   adr = adr->in(MemNode::Address);
1104 
1105   intptr_t off = 0;
1106   Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1107   if (k == nullptr)  return nullptr;
1108   const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1109   if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr;
1110 
1111   // We've found the klass node of a Java mirror load.
1112   return k;
1113 }
1114 
1115 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
1116   // for ConP(Foo.class) return ConP(Foo.klass)
1117   // otherwise return null
1118   if (!n->is_Con()) return nullptr;
1119 
1120   const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1121   if (!tp) return nullptr;
1122 
1123   ciType* mirror_type = tp->java_mirror_type();
1124   // TypeInstPtr::java_mirror_type() returns non-null for compile-
1125   // time Class constants only.
1126   if (!mirror_type) return nullptr;
1127 
1128   // x.getClass() == int.class can never be true (for all primitive types)
1129   // Return a ConP(null) node for this case.
1130   if (mirror_type->is_classless()) {
1131     return phase->makecon(TypePtr::NULL_PTR);
1132   }
1133 
1134   // return the ConP(Foo.klass)
1135   assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
1136   return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass(), Type::trust_interfaces));
1137 }
1138 
1139 //------------------------------Ideal------------------------------------------
1140 // Normalize comparisons between Java mirror loads to compare the klass instead.
1141 //
1142 // Also check for the case of comparing an unknown klass loaded from the primary
1143 // super-type array vs a known klass with no subtypes.  This amounts to
1144 // checking to see an unknown klass subtypes a known klass with no subtypes;
1145 // this only happens on an exact match.  We can shorten this test by 1 load.
1146 Node* CmpPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1147   // TODO 8284443 in(1) could be cast?
1148   if (in(1)->is_InlineType() && phase->type(in(2))->is_zero_type()) {
1149     // Null checking a scalarized but nullable inline type. Check the IsInit
1150     // input instead of the oop input to avoid keeping buffer allocations alive.
1151     return new CmpINode(in(1)->as_InlineType()->get_is_init(), phase->intcon(0));
1152   }
1153 
1154   // Normalize comparisons between Java mirrors into comparisons of the low-
1155   // level klass, where a dependent load could be shortened.
1156   //
1157   // The new pattern has a nice effect of matching the same pattern used in the
1158   // fast path of instanceof/checkcast/Class.isInstance(), which allows
1159   // redundant exact type check be optimized away by GVN.
1160   // For example, in
1161   //   if (x.getClass() == Foo.class) {
1162   //     Foo foo = (Foo) x;
1163   //     // ... use a ...
1164   //   }
1165   // a CmpPNode could be shared between if_acmpne and checkcast
1166   {
1167     Node* k1 = isa_java_mirror_load(phase, in(1));
1168     Node* k2 = isa_java_mirror_load(phase, in(2));
1169     Node* conk2 = isa_const_java_mirror(phase, in(2));
1170 
1171     if (k1 && (k2 || conk2)) {
1172       Node* lhs = k1;
1173       Node* rhs = (k2 != nullptr) ? k2 : conk2;
1174       set_req_X(1, lhs, phase);
1175       set_req_X(2, rhs, phase);
1176       return this;
1177     }
1178   }
1179 
1180   // Constant pointer on right?
1181   const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1182   if (t2 == nullptr || !t2->klass_is_exact())
1183     return nullptr;
1184   // Get the constant klass we are comparing to.
1185   ciKlass* superklass = t2->exact_klass();
1186 
1187   // Now check for LoadKlass on left.
1188   Node* ldk1 = in(1);
1189   if (ldk1->is_DecodeNKlass()) {
1190     ldk1 = ldk1->in(1);
1191     if (ldk1->Opcode() != Op_LoadNKlass )
1192       return nullptr;
1193   } else if (ldk1->Opcode() != Op_LoadKlass )
1194     return nullptr;
1195   // Take apart the address of the LoadKlass:
1196   Node* adr1 = ldk1->in(MemNode::Address);
1197   intptr_t con2 = 0;
1198   Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1199   if (ldk2 == nullptr)
1200     return nullptr;
1201   if (con2 == oopDesc::klass_offset_in_bytes()) {
1202     // We are inspecting an object's concrete class.
1203     // Short-circuit the check if the query is abstract.
1204     if (superklass->is_interface() ||
1205         superklass->is_abstract()) {
1206       // Make it come out always false:
1207       this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1208       return this;
1209     }
1210   }
1211 
1212   // Check for a LoadKlass from primary supertype array.
1213   // Any nested loadklass from loadklass+con must be from the p.s. array.
1214   if (ldk2->is_DecodeNKlass()) {
1215     // Keep ldk2 as DecodeN since it could be used in CmpP below.
1216     if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1217       return nullptr;
1218   } else if (ldk2->Opcode() != Op_LoadKlass)
1219     return nullptr;
1220 
1221   // Verify that we understand the situation
1222   if (con2 != (intptr_t) superklass->super_check_offset())
1223     return nullptr;                // Might be element-klass loading from array klass
1224 
1225   // Do not fold the subtype check to an array klass pointer comparison for [V? arrays.
1226   // [QMyValue is a subtype of [LMyValue but the klass for [QMyValue is not equal to
1227   // the klass for [LMyValue. Do not bypass the klass load from the primary supertype array.
1228   if (superklass->is_obj_array_klass() && !superklass->as_array_klass()->is_elem_null_free() &&
1229       superklass->as_array_klass()->element_klass()->is_inlinetype()) {
1230     return nullptr;
1231   }
1232 
1233   // If 'superklass' has no subklasses and is not an interface, then we are
1234   // assured that the only input which will pass the type check is
1235   // 'superklass' itself.
1236   //
1237   // We could be more liberal here, and allow the optimization on interfaces
1238   // which have a single implementor.  This would require us to increase the
1239   // expressiveness of the add_dependency() mechanism.
1240   // %%% Do this after we fix TypeOopPtr:  Deps are expressive enough now.
1241 
1242   // Object arrays must have their base element have no subtypes
1243   while (superklass->is_obj_array_klass()) {
1244     ciType* elem = superklass->as_obj_array_klass()->element_type();
1245     superklass = elem->as_klass();
1246   }
1247   if (superklass->is_instance_klass()) {
1248     ciInstanceKlass* ik = superklass->as_instance_klass();
1249     if (ik->has_subklass() || ik->is_interface())  return nullptr;
1250     // Add a dependency if there is a chance that a subclass will be added later.
1251     if (!ik->is_final()) {
1252       phase->C->dependencies()->assert_leaf_type(ik);
1253     }
1254   }
1255 
1256   // Bypass the dependent load, and compare directly
1257   this->set_req_X(1, ldk2, phase);
1258 
1259   return this;
1260 }
1261 
1262 //=============================================================================
1263 //------------------------------sub--------------------------------------------
1264 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1265 // If both inputs are constants, compare them.
1266 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1267   ShouldNotReachHere();
1268   return bottom_type();
1269 }
1270 
1271 //------------------------------Ideal------------------------------------------
1272 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1273   return nullptr;
1274 }
1275 
1276 //=============================================================================
1277 //------------------------------Value------------------------------------------
1278 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1279 // If both inputs are constants, compare them.
1280 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1281   const Node* in1 = in(1);
1282   const Node* in2 = in(2);
1283   // Either input is TOP ==> the result is TOP
1284   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1285   if( t1 == Type::TOP ) return Type::TOP;
1286   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1287   if( t2 == Type::TOP ) return Type::TOP;
1288 
1289   // Not constants?  Don't know squat - even if they are the same
1290   // value!  If they are NaN's they compare to LT instead of EQ.
1291   const TypeF *tf1 = t1->isa_float_constant();
1292   const TypeF *tf2 = t2->isa_float_constant();
1293   if( !tf1 || !tf2 ) return TypeInt::CC;
1294 
1295   // This implements the Java bytecode fcmpl, so unordered returns -1.
1296   if( tf1->is_nan() || tf2->is_nan() )
1297     return TypeInt::CC_LT;
1298 
1299   if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1300   if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1301   assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1302   return TypeInt::CC_EQ;
1303 }
1304 
1305 
1306 //=============================================================================
1307 //------------------------------Value------------------------------------------
1308 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1309 // If both inputs are constants, compare them.
1310 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1311   const Node* in1 = in(1);
1312   const Node* in2 = in(2);
1313   // Either input is TOP ==> the result is TOP
1314   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1315   if( t1 == Type::TOP ) return Type::TOP;
1316   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1317   if( t2 == Type::TOP ) return Type::TOP;
1318 
1319   // Not constants?  Don't know squat - even if they are the same
1320   // value!  If they are NaN's they compare to LT instead of EQ.
1321   const TypeD *td1 = t1->isa_double_constant();
1322   const TypeD *td2 = t2->isa_double_constant();
1323   if( !td1 || !td2 ) return TypeInt::CC;
1324 
1325   // This implements the Java bytecode dcmpl, so unordered returns -1.
1326   if( td1->is_nan() || td2->is_nan() )
1327     return TypeInt::CC_LT;
1328 
1329   if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1330   if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1331   assert( td1->_d == td2->_d, "do not understand FP behavior" );
1332   return TypeInt::CC_EQ;
1333 }
1334 
1335 //------------------------------Ideal------------------------------------------
1336 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1337   // Check if we can change this to a CmpF and remove a ConvD2F operation.
1338   // Change  (CMPD (F2D (float)) (ConD value))
1339   // To      (CMPF      (float)  (ConF value))
1340   // Valid when 'value' does not lose precision as a float.
1341   // Benefits: eliminates conversion, does not require 24-bit mode
1342 
1343   // NaNs prevent commuting operands.  This transform works regardless of the
1344   // order of ConD and ConvF2D inputs by preserving the original order.
1345   int idx_f2d = 1;              // ConvF2D on left side?
1346   if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1347     idx_f2d = 2;                // No, swap to check for reversed args
1348   int idx_con = 3-idx_f2d;      // Check for the constant on other input
1349 
1350   if( ConvertCmpD2CmpF &&
1351       in(idx_f2d)->Opcode() == Op_ConvF2D &&
1352       in(idx_con)->Opcode() == Op_ConD ) {
1353     const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1354     double t2_value_as_double = t2->_d;
1355     float  t2_value_as_float  = (float)t2_value_as_double;
1356     if( t2_value_as_double == (double)t2_value_as_float ) {
1357       // Test value can be represented as a float
1358       // Eliminate the conversion to double and create new comparison
1359       Node *new_in1 = in(idx_f2d)->in(1);
1360       Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1361       if( idx_f2d != 1 ) {      // Must flip args to match original order
1362         Node *tmp = new_in1;
1363         new_in1 = new_in2;
1364         new_in2 = tmp;
1365       }
1366       CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1367         ? new CmpF3Node( new_in1, new_in2 )
1368         : new CmpFNode ( new_in1, new_in2 ) ;
1369       return new_cmp;           // Changed to CmpFNode
1370     }
1371     // Testing value required the precision of a double
1372   }
1373   return nullptr;                  // No change
1374 }
1375 
1376 //=============================================================================
1377 //------------------------------Value------------------------------------------
1378 const Type* FlatArrayCheckNode::Value(PhaseGVN* phase) const {
1379   bool all_not_flat = true;
1380   for (uint i = ArrayOrKlass; i < req(); ++i) {
1381     const Type* t = phase->type(in(i));
1382     if (t == Type::TOP) {
1383       return Type::TOP;
1384     }
1385     if (t->is_ptr()->is_flat()) {
1386       // One of the input arrays is flat, check always passes
1387       return TypeInt::CC_EQ;
1388     } else if (!t->is_ptr()->is_not_flat()) {
1389       // One of the input arrays might be flat
1390       all_not_flat = false;
1391     }
1392   }
1393   if (all_not_flat) {
1394     // None of the input arrays can be flat, check always fails
1395     return TypeInt::CC_GT;
1396   }
1397   return TypeInt::CC;
1398 }
1399 
1400 //------------------------------Ideal------------------------------------------
1401 Node* FlatArrayCheckNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1402   bool changed = false;
1403   // Remove inputs that are known to be non-flat
1404   for (uint i = ArrayOrKlass; i < req(); ++i) {
1405     const Type* t = phase->type(in(i));
1406     if (t->isa_ptr() && t->is_ptr()->is_not_flat()) {
1407       del_req(i--);
1408       changed = true;
1409     }
1410   }
1411   return changed ? this : nullptr;
1412 }
1413 
1414 //=============================================================================
1415 //------------------------------cc2logical-------------------------------------
1416 // Convert a condition code type to a logical type
1417 const Type *BoolTest::cc2logical( const Type *CC ) const {
1418   if( CC == Type::TOP ) return Type::TOP;
1419   if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1420   const TypeInt *ti = CC->is_int();
1421   if( ti->is_con() ) {          // Only 1 kind of condition codes set?
1422     // Match low order 2 bits
1423     int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1424     if( _test & 4 ) tmp = 1-tmp;     // Optionally complement result
1425     return TypeInt::make(tmp);       // Boolean result
1426   }
1427 
1428   if( CC == TypeInt::CC_GE ) {
1429     if( _test == ge ) return TypeInt::ONE;
1430     if( _test == lt ) return TypeInt::ZERO;
1431   }
1432   if( CC == TypeInt::CC_LE ) {
1433     if( _test == le ) return TypeInt::ONE;
1434     if( _test == gt ) return TypeInt::ZERO;
1435   }
1436 
1437   return TypeInt::BOOL;
1438 }
1439 
1440 //------------------------------dump_spec-------------------------------------
1441 // Print special per-node info
1442 void BoolTest::dump_on(outputStream *st) const {
1443   const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1444   st->print("%s", msg[_test]);
1445 }
1446 
1447 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1448 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1449 BoolTest::mask BoolTest::merge(BoolTest other) const {
1450   const mask res[illegal+1][illegal+1] = {
1451     // eq,      gt,      of,      lt,      ne,      le,      nof,     ge,      never,   illegal
1452       {eq,      never,   illegal, never,   never,   eq,      illegal, eq,      never,   illegal},  // eq
1453       {never,   gt,      illegal, never,   gt,      never,   illegal, gt,      never,   illegal},  // gt
1454       {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never,   illegal},  // of
1455       {never,   never,   illegal, lt,      lt,      lt,      illegal, never,   never,   illegal},  // lt
1456       {never,   gt,      illegal, lt,      ne,      lt,      illegal, gt,      never,   illegal},  // ne
1457       {eq,      never,   illegal, lt,      lt,      le,      illegal, eq,      never,   illegal},  // le
1458       {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never,   illegal},  // nof
1459       {eq,      gt,      illegal, never,   gt,      eq,      illegal, ge,      never,   illegal},  // ge
1460       {never,   never,   never,   never,   never,   never,   never,   never,   never,   illegal},  // never
1461       {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1462   return res[_test][other._test];
1463 }
1464 
1465 //=============================================================================
1466 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1467 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1468 
1469 //------------------------------operator==-------------------------------------
1470 bool BoolNode::cmp( const Node &n ) const {
1471   const BoolNode *b = (const BoolNode *)&n; // Cast up
1472   return (_test._test == b->_test._test);
1473 }
1474 
1475 //-------------------------------make_predicate--------------------------------
1476 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1477   if (test_value->is_Con())   return test_value;
1478   if (test_value->is_Bool())  return test_value;
1479   if (test_value->is_CMove() &&
1480       test_value->in(CMoveNode::Condition)->is_Bool()) {
1481     BoolNode*   bol   = test_value->in(CMoveNode::Condition)->as_Bool();
1482     const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1483     const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1484     if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1485       return bol;
1486     } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1487       return phase->transform( bol->negate(phase) );
1488     }
1489     // Else fall through.  The CMove gets in the way of the test.
1490     // It should be the case that make_predicate(bol->as_int_value()) == bol.
1491   }
1492   Node* cmp = new CmpINode(test_value, phase->intcon(0));
1493   cmp = phase->transform(cmp);
1494   Node* bol = new BoolNode(cmp, BoolTest::ne);
1495   return phase->transform(bol);
1496 }
1497 
1498 //--------------------------------as_int_value---------------------------------
1499 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1500   // Inverse to make_predicate.  The CMove probably boils down to a Conv2B.
1501   Node* cmov = CMoveNode::make(nullptr, this,
1502                                phase->intcon(0), phase->intcon(1),
1503                                TypeInt::BOOL);
1504   return phase->transform(cmov);
1505 }
1506 
1507 //----------------------------------negate-------------------------------------
1508 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1509   return new BoolNode(in(1), _test.negate());
1510 }
1511 
1512 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1513 // overflows and we can prove that C is not in the two resulting ranges.
1514 // This optimization is similar to the one performed by CmpUNode::Value().
1515 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1516                           int cmp1_op, const TypeInt* cmp2_type) {
1517   // Only optimize eq/ne integer comparison of add/sub
1518   if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1519      (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1520     // Skip cases were inputs of add/sub are not integers or of bottom type
1521     const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1522     const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1523     if ((r0 != nullptr) && (r0 != TypeInt::INT) &&
1524         (r1 != nullptr) && (r1 != TypeInt::INT) &&
1525         (cmp2_type != TypeInt::INT)) {
1526       // Compute exact (long) type range of add/sub result
1527       jlong lo_long = r0->_lo;
1528       jlong hi_long = r0->_hi;
1529       if (cmp1_op == Op_AddI) {
1530         lo_long += r1->_lo;
1531         hi_long += r1->_hi;
1532       } else {
1533         lo_long -= r1->_hi;
1534         hi_long -= r1->_lo;
1535       }
1536       // Check for over-/underflow by casting to integer
1537       int lo_int = (int)lo_long;
1538       int hi_int = (int)hi_long;
1539       bool underflow = lo_long != (jlong)lo_int;
1540       bool overflow  = hi_long != (jlong)hi_int;
1541       if ((underflow != overflow) && (hi_int < lo_int)) {
1542         // Overflow on one boundary, compute resulting type ranges:
1543         // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1544         int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1545         const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1546         const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1547         // Compare second input of cmp to both type ranges
1548         const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1549         const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1550         if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1551           // The result of the add/sub will never equal cmp2. Replace BoolNode
1552           // by false (0) if it tests for equality and by true (1) otherwise.
1553           return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1554         }
1555       }
1556     }
1557   }
1558   return nullptr;
1559 }
1560 
1561 static bool is_counted_loop_cmp(Node *cmp) {
1562   Node *n = cmp->in(1)->in(1);
1563   return n != nullptr &&
1564          n->is_Phi() &&
1565          n->in(0) != nullptr &&
1566          n->in(0)->is_CountedLoop() &&
1567          n->in(0)->as_CountedLoop()->phi() == n;
1568 }
1569 
1570 //------------------------------Ideal------------------------------------------
1571 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1572   // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1573   // This moves the constant to the right.  Helps value-numbering.
1574   Node *cmp = in(1);
1575   if( !cmp->is_Sub() ) return nullptr;
1576   int cop = cmp->Opcode();
1577   if( cop == Op_FastLock || cop == Op_FastUnlock ||
1578       cmp->is_SubTypeCheck() || cop == Op_VectorTest ) {
1579     return nullptr;
1580   }
1581   Node *cmp1 = cmp->in(1);
1582   Node *cmp2 = cmp->in(2);
1583   if( !cmp1 ) return nullptr;
1584 
1585   if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1586     return nullptr;
1587   }
1588 
1589   const int cmp1_op = cmp1->Opcode();
1590   const int cmp2_op = cmp2->Opcode();
1591 
1592   // Constant on left?
1593   Node *con = cmp1;
1594   // Move constants to the right of compare's to canonicalize.
1595   // Do not muck with Opaque1 nodes, as this indicates a loop
1596   // guard that cannot change shape.
1597   if (con->is_Con() && !cmp2->is_Con() && cmp2_op != Op_OpaqueZeroTripGuard &&
1598       // Because of NaN's, CmpD and CmpF are not commutative
1599       cop != Op_CmpD && cop != Op_CmpF &&
1600       // Protect against swapping inputs to a compare when it is used by a
1601       // counted loop exit, which requires maintaining the loop-limit as in(2)
1602       !is_counted_loop_exit_test() ) {
1603     // Ok, commute the constant to the right of the cmp node.
1604     // Clone the Node, getting a new Node of the same class
1605     cmp = cmp->clone();
1606     // Swap inputs to the clone
1607     cmp->swap_edges(1, 2);
1608     cmp = phase->transform( cmp );
1609     return new BoolNode( cmp, _test.commute() );
1610   }
1611 
1612   // Change "bool eq/ne (cmp (cmove (bool tst (cmp2)) 1 0) 0)" into "bool tst/~tst (cmp2)"
1613   if (cop == Op_CmpI &&
1614       (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1615       cmp1_op == Op_CMoveI && cmp2->find_int_con(1) == 0) {
1616     // 0 should be on the true branch
1617     if (cmp1->in(CMoveNode::Condition)->is_Bool() &&
1618         cmp1->in(CMoveNode::IfTrue)->find_int_con(1) == 0 &&
1619         cmp1->in(CMoveNode::IfFalse)->find_int_con(0) != 0) {
1620       BoolNode* target = cmp1->in(CMoveNode::Condition)->as_Bool();
1621       return new BoolNode(target->in(1),
1622                           (_test._test == BoolTest::eq) ? target->_test._test :
1623                                                           target->_test.negate());
1624     }
1625   }
1626 
1627   // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1628   if (cop == Op_CmpI &&
1629       (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1630       cmp1_op == Op_AndI && cmp2_op == Op_ConI &&
1631       cmp1->in(2)->Opcode() == Op_ConI) {
1632     const TypeInt *t12 = phase->type(cmp2)->isa_int();
1633     const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int();
1634     if (t12 && t12->is_con() && t112 && t112->is_con() &&
1635         t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1636       Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1637       return new BoolNode(ncmp, _test.negate());
1638     }
1639   }
1640 
1641   // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1642   if (cop == Op_CmpL &&
1643       (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1644       cmp1_op == Op_AndL && cmp2_op == Op_ConL &&
1645       cmp1->in(2)->Opcode() == Op_ConL) {
1646     const TypeLong *t12 = phase->type(cmp2)->isa_long();
1647     const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long();
1648     if (t12 && t12->is_con() && t112 && t112->is_con() &&
1649         t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1650       Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0)));
1651       return new BoolNode(ncmp, _test.negate());
1652     }
1653   }
1654 
1655   // Change "cmp (add X min_jint) (add Y min_jint)" into "cmpu X Y"
1656   // and    "cmp (add X min_jint) c" into "cmpu X (c + min_jint)"
1657   if (cop == Op_CmpI &&
1658       cmp1_op == Op_AddI &&
1659       !is_cloop_increment(cmp1) &&
1660       phase->type(cmp1->in(2)) == TypeInt::MIN) {
1661     if (cmp2_op == Op_ConI) {
1662       Node* ncmp2 = phase->intcon(java_add(cmp2->get_int(), min_jint));
1663       Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), ncmp2));
1664       return new BoolNode(ncmp, _test._test);
1665     } else if (cmp2_op == Op_AddI &&
1666                !is_cloop_increment(cmp2) &&
1667                phase->type(cmp2->in(2)) == TypeInt::MIN) {
1668       Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), cmp2->in(1)));
1669       return new BoolNode(ncmp, _test._test);
1670     }
1671   }
1672 
1673   // Change "cmp (add X min_jlong) (add Y min_jlong)" into "cmpu X Y"
1674   // and    "cmp (add X min_jlong) c" into "cmpu X (c + min_jlong)"
1675   if (cop == Op_CmpL &&
1676       cmp1_op == Op_AddL &&
1677       !is_cloop_increment(cmp1) &&
1678       phase->type(cmp1->in(2)) == TypeLong::MIN) {
1679     if (cmp2_op == Op_ConL) {
1680       Node* ncmp2 = phase->longcon(java_add(cmp2->get_long(), min_jlong));
1681       Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), ncmp2));
1682       return new BoolNode(ncmp, _test._test);
1683     } else if (cmp2_op == Op_AddL &&
1684                !is_cloop_increment(cmp2) &&
1685                phase->type(cmp2->in(2)) == TypeLong::MIN) {
1686       Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), cmp2->in(1)));
1687       return new BoolNode(ncmp, _test._test);
1688     }
1689   }
1690 
1691   // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1692   // The XOR-1 is an idiom used to flip the sense of a bool.  We flip the
1693   // test instead.
1694   const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1695   if (cmp2_type == nullptr)  return nullptr;
1696   Node* j_xor = cmp1;
1697   if( cmp2_type == TypeInt::ZERO &&
1698       cmp1_op == Op_XorI &&
1699       j_xor->in(1) != j_xor &&          // An xor of itself is dead
1700       phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1701       phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1702       (_test._test == BoolTest::eq ||
1703        _test._test == BoolTest::ne) ) {
1704     Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1705     return new BoolNode( ncmp, _test.negate() );
1706   }
1707 
1708   // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1709   // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1710   if (cop == Op_CmpU &&
1711       cmp1_op == Op_AndI) {
1712     Node* bound = nullptr;
1713     if (_test._test == BoolTest::le) {
1714       bound = cmp2;
1715     } else if (_test._test == BoolTest::lt &&
1716                cmp2->Opcode() == Op_AddI &&
1717                cmp2->in(2)->find_int_con(0) == 1) {
1718       bound = cmp2->in(1);
1719     }
1720     if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1721       return ConINode::make(1);
1722     }
1723   }
1724 
1725   // Change ((x & (m - 1)) u< m) into (m > 0)
1726   // This is the off-by-one variant of the above
1727   if (cop == Op_CmpU &&
1728       _test._test == BoolTest::lt &&
1729       cmp1_op == Op_AndI) {
1730     Node* l = cmp1->in(1);
1731     Node* r = cmp1->in(2);
1732     for (int repeat = 0; repeat < 2; repeat++) {
1733       bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1734                    r->in(1) == cmp2;
1735       if (match) {
1736         // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1737         // but to be compatible with the array range check pattern, use (arraylength u> 0)
1738         Node* ncmp = cmp2->Opcode() == Op_LoadRange
1739                      ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1740                      : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1741         return new BoolNode(ncmp, BoolTest::gt);
1742       } else {
1743         // commute and try again
1744         l = cmp1->in(2);
1745         r = cmp1->in(1);
1746       }
1747     }
1748   }
1749 
1750   // Change x u< 1 or x u<= 0 to x == 0
1751   // and    x u> 0 or u>= 1   to x != 0
1752   if (cop == Op_CmpU &&
1753       cmp1_op != Op_LoadRange &&
1754       (((_test._test == BoolTest::lt || _test._test == BoolTest::ge) &&
1755         cmp2->find_int_con(-1) == 1) ||
1756        ((_test._test == BoolTest::le || _test._test == BoolTest::gt) &&
1757         cmp2->find_int_con(-1) == 0))) {
1758     Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1759     return new BoolNode(ncmp, _test.is_less() ? BoolTest::eq : BoolTest::ne);
1760   }
1761 
1762   // Change (arraylength <= 0) or (arraylength == 0)
1763   //   into (arraylength u<= 0)
1764   // Also change (arraylength != 0) into (arraylength u> 0)
1765   // The latter version matches the code pattern generated for
1766   // array range checks, which will more likely be optimized later.
1767   if (cop == Op_CmpI &&
1768       cmp1_op == Op_LoadRange &&
1769       cmp2->find_int_con(-1) == 0) {
1770     if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1771       Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1772       return new BoolNode(ncmp, BoolTest::le);
1773     } else if (_test._test == BoolTest::ne) {
1774       Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1775       return new BoolNode(ncmp, BoolTest::gt);
1776     }
1777   }
1778 
1779   // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1780   // This is a standard idiom for branching on a boolean value.
1781   Node *c2b = cmp1;
1782   if( cmp2_type == TypeInt::ZERO &&
1783       cmp1_op == Op_Conv2B &&
1784       (_test._test == BoolTest::eq ||
1785        _test._test == BoolTest::ne) ) {
1786     Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1787        ? (Node*)new CmpINode(c2b->in(1),cmp2)
1788        : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1789     );
1790     return new BoolNode( ncmp, _test._test );
1791   }
1792 
1793   // Comparing a SubI against a zero is equal to comparing the SubI
1794   // arguments directly.  This only works for eq and ne comparisons
1795   // due to possible integer overflow.
1796   if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1797         (cop == Op_CmpI) &&
1798         (cmp1_op == Op_SubI) &&
1799         ( cmp2_type == TypeInt::ZERO ) ) {
1800     Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1801     return new BoolNode( ncmp, _test._test );
1802   }
1803 
1804   // Same as above but with and AddI of a constant
1805   if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1806       cop == Op_CmpI &&
1807       cmp1_op == Op_AddI &&
1808       cmp1->in(2) != nullptr &&
1809       phase->type(cmp1->in(2))->isa_int() &&
1810       phase->type(cmp1->in(2))->is_int()->is_con() &&
1811       cmp2_type == TypeInt::ZERO &&
1812       !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1813       ) {
1814     const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1815     Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1816     return new BoolNode( ncmp, _test._test );
1817   }
1818 
1819   // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1820   // since zero check of conditional negation of an integer is equal to
1821   // zero check of the integer directly.
1822   if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1823       (cop == Op_CmpI) &&
1824       (cmp2_type == TypeInt::ZERO) &&
1825       (cmp1_op == Op_Phi)) {
1826     // There should be a diamond phi with true path at index 1 or 2
1827     PhiNode *phi = cmp1->as_Phi();
1828     int idx_true = phi->is_diamond_phi();
1829     if (idx_true != 0) {
1830       // True input is in(idx_true) while false input is in(3 - idx_true)
1831       Node *tin = phi->in(idx_true);
1832       Node *fin = phi->in(3 - idx_true);
1833       if ((tin->Opcode() == Op_SubI) &&
1834           (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1835           (tin->in(2) == fin)) {
1836         // Found conditional negation at true path, create a new CmpINode without that
1837         Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1838         return new BoolNode(ncmp, _test._test);
1839       }
1840       if ((fin->Opcode() == Op_SubI) &&
1841           (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1842           (fin->in(2) == tin)) {
1843         // Found conditional negation at false path, create a new CmpINode without that
1844         Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1845         return new BoolNode(ncmp, _test._test);
1846       }
1847     }
1848   }
1849 
1850   // Change (-A vs 0) into (A vs 0) by commuting the test.  Disallow in the
1851   // most general case because negating 0x80000000 does nothing.  Needed for
1852   // the CmpF3/SubI/CmpI idiom.
1853   if( cop == Op_CmpI &&
1854       cmp1_op == Op_SubI &&
1855       cmp2_type == TypeInt::ZERO &&
1856       phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1857       phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1858     Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1859     return new BoolNode( ncmp, _test.commute() );
1860   }
1861 
1862   // Try to optimize signed integer comparison
1863   return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1864 
1865   //  The transformation below is not valid for either signed or unsigned
1866   //  comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1867   //  This transformation can be resurrected when we are able to
1868   //  make inferences about the range of values being subtracted from
1869   //  (or added to) relative to the wraparound point.
1870   //
1871   //    // Remove +/-1's if possible.
1872   //    // "X <= Y-1" becomes "X <  Y"
1873   //    // "X+1 <= Y" becomes "X <  Y"
1874   //    // "X <  Y+1" becomes "X <= Y"
1875   //    // "X-1 <  Y" becomes "X <= Y"
1876   //    // Do not this to compares off of the counted-loop-end.  These guys are
1877   //    // checking the trip counter and they want to use the post-incremented
1878   //    // counter.  If they use the PRE-incremented counter, then the counter has
1879   //    // to be incremented in a private block on a loop backedge.
1880   //    if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1881   //      return nullptr;
1882   //  #ifndef PRODUCT
1883   //    // Do not do this in a wash GVN pass during verification.
1884   //    // Gets triggered by too many simple optimizations to be bothered with
1885   //    // re-trying it again and again.
1886   //    if( !phase->allow_progress() ) return nullptr;
1887   //  #endif
1888   //    // Not valid for unsigned compare because of corner cases in involving zero.
1889   //    // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1890   //    // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1891   //    // "0 <=u Y" is always true).
1892   //    if( cmp->Opcode() == Op_CmpU ) return nullptr;
1893   //    int cmp2_op = cmp2->Opcode();
1894   //    if( _test._test == BoolTest::le ) {
1895   //      if( cmp1_op == Op_AddI &&
1896   //          phase->type( cmp1->in(2) ) == TypeInt::ONE )
1897   //        return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1898   //      else if( cmp2_op == Op_AddI &&
1899   //         phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1900   //        return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1901   //    } else if( _test._test == BoolTest::lt ) {
1902   //      if( cmp1_op == Op_AddI &&
1903   //          phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1904   //        return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1905   //      else if( cmp2_op == Op_AddI &&
1906   //         phase->type( cmp2->in(2) ) == TypeInt::ONE )
1907   //        return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1908   //    }
1909 }
1910 
1911 //------------------------------Value------------------------------------------
1912 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1913 // based on local information.   If the input is constant, do it.
1914 const Type* BoolNode::Value(PhaseGVN* phase) const {
1915   return _test.cc2logical( phase->type( in(1) ) );
1916 }
1917 
1918 #ifndef PRODUCT
1919 //------------------------------dump_spec--------------------------------------
1920 // Dump special per-node info
1921 void BoolNode::dump_spec(outputStream *st) const {
1922   st->print("[");
1923   _test.dump_on(st);
1924   st->print("]");
1925 }
1926 #endif
1927 
1928 //----------------------is_counted_loop_exit_test------------------------------
1929 // Returns true if node is used by a counted loop node.
1930 bool BoolNode::is_counted_loop_exit_test() {
1931   for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1932     Node* use = fast_out(i);
1933     if (use->is_CountedLoopEnd()) {
1934       return true;
1935     }
1936   }
1937   return false;
1938 }
1939 
1940 //=============================================================================
1941 //------------------------------Value------------------------------------------
1942 const Type* AbsNode::Value(PhaseGVN* phase) const {
1943   const Type* t1 = phase->type(in(1));
1944   if (t1 == Type::TOP) return Type::TOP;
1945 
1946   switch (t1->base()) {
1947   case Type::Int: {
1948     const TypeInt* ti = t1->is_int();
1949     if (ti->is_con()) {
1950       return TypeInt::make(uabs(ti->get_con()));
1951     }
1952     break;
1953   }
1954   case Type::Long: {
1955     const TypeLong* tl = t1->is_long();
1956     if (tl->is_con()) {
1957       return TypeLong::make(uabs(tl->get_con()));
1958     }
1959     break;
1960   }
1961   case Type::FloatCon:
1962     return TypeF::make(abs(t1->getf()));
1963   case Type::DoubleCon:
1964     return TypeD::make(abs(t1->getd()));
1965   default:
1966     break;
1967   }
1968 
1969   return bottom_type();
1970 }
1971 
1972 //------------------------------Identity----------------------------------------
1973 Node* AbsNode::Identity(PhaseGVN* phase) {
1974   Node* in1 = in(1);
1975   // No need to do abs for non-negative values
1976   if (phase->type(in1)->higher_equal(TypeInt::POS) ||
1977       phase->type(in1)->higher_equal(TypeLong::POS)) {
1978     return in1;
1979   }
1980   // Convert "abs(abs(x))" into "abs(x)"
1981   if (in1->Opcode() == Opcode()) {
1982     return in1;
1983   }
1984   return this;
1985 }
1986 
1987 //------------------------------Ideal------------------------------------------
1988 Node* AbsNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1989   Node* in1 = in(1);
1990   // Convert "abs(0-x)" into "abs(x)"
1991   if (in1->is_Sub() && phase->type(in1->in(1))->is_zero_type()) {
1992     set_req_X(1, in1->in(2), phase);
1993     return this;
1994   }
1995   return nullptr;
1996 }
1997 
1998 //=============================================================================
1999 //------------------------------Value------------------------------------------
2000 // Compute sqrt
2001 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
2002   const Type *t1 = phase->type( in(1) );
2003   if( t1 == Type::TOP ) return Type::TOP;
2004   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
2005   double d = t1->getd();
2006   if( d < 0.0 ) return Type::DOUBLE;
2007   return TypeD::make( sqrt( d ) );
2008 }
2009 
2010 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
2011   const Type *t1 = phase->type( in(1) );
2012   if( t1 == Type::TOP ) return Type::TOP;
2013   if( t1->base() != Type::FloatCon ) return Type::FLOAT;
2014   float f = t1->getf();
2015   if( f < 0.0f ) return Type::FLOAT;
2016   return TypeF::make( (float)sqrt( (double)f ) );
2017 }
2018 
2019 const Type* ReverseINode::Value(PhaseGVN* phase) const {
2020   const Type *t1 = phase->type( in(1) );
2021   if (t1 == Type::TOP) {
2022     return Type::TOP;
2023   }
2024   const TypeInt* t1int = t1->isa_int();
2025   if (t1int && t1int->is_con()) {
2026     jint res = reverse_bits(t1int->get_con());
2027     return TypeInt::make(res);
2028   }
2029   return bottom_type();
2030 }
2031 
2032 const Type* ReverseLNode::Value(PhaseGVN* phase) const {
2033   const Type *t1 = phase->type( in(1) );
2034   if (t1 == Type::TOP) {
2035     return Type::TOP;
2036   }
2037   const TypeLong* t1long = t1->isa_long();
2038   if (t1long && t1long->is_con()) {
2039     jlong res = reverse_bits(t1long->get_con());
2040     return TypeLong::make(res);
2041   }
2042   return bottom_type();
2043 }
2044 
2045 Node* ReverseINode::Identity(PhaseGVN* phase) {
2046   if (in(1)->Opcode() == Op_ReverseI) {
2047     return in(1)->in(1);
2048   }
2049   return this;
2050 }
2051 
2052 Node* ReverseLNode::Identity(PhaseGVN* phase) {
2053   if (in(1)->Opcode() == Op_ReverseL) {
2054     return in(1)->in(1);
2055   }
2056   return this;
2057 }