1 /*
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   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.
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   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).
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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  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
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  24 
  25 #include "memory/allocation.inline.hpp"
  26 #include "opto/addnode.hpp"
  27 #include "opto/connode.hpp"
  28 #include "opto/convertnode.hpp"
  29 #include "opto/memnode.hpp"
  30 #include "opto/mulnode.hpp"
  31 #include "opto/phaseX.hpp"
  32 #include "opto/subnode.hpp"
  33 #include "utilities/powerOfTwo.hpp"
  34 
  35 // Portions of code courtesy of Clifford Click
  36 
  37 
  38 //=============================================================================
  39 //------------------------------hash-------------------------------------------
  40 // Hash function over MulNodes.  Needs to be commutative; i.e., I swap
  41 // (commute) inputs to MulNodes willy-nilly so the hash function must return
  42 // the same value in the presence of edge swapping.
  43 uint MulNode::hash() const {
  44   return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
  45 }
  46 
  47 //------------------------------Identity---------------------------------------
  48 // Multiplying a one preserves the other argument
  49 Node* MulNode::Identity(PhaseGVN* phase) {
  50   const Type *one = mul_id();  // The multiplicative identity
  51   if( phase->type( in(1) )->higher_equal( one ) ) return in(2);
  52   if( phase->type( in(2) )->higher_equal( one ) ) return in(1);
  53 
  54   return this;
  55 }
  56 
  57 //------------------------------Ideal------------------------------------------
  58 // We also canonicalize the Node, moving constants to the right input,
  59 // and flatten expressions (so that 1+x+2 becomes x+3).
  60 Node *MulNode::Ideal(PhaseGVN *phase, bool can_reshape) {
  61   Node* in1 = in(1);
  62   Node* in2 = in(2);
  63   Node* progress = nullptr;        // Progress flag
  64 
  65   // This code is used by And nodes too, but some conversions are
  66   // only valid for the actual Mul nodes.
  67   uint op = Opcode();
  68   bool real_mul = (op == Op_MulI) || (op == Op_MulL) ||
  69                   (op == Op_MulF) || (op == Op_MulD) ||
  70                   (op == Op_MulHF);
  71 
  72   // Convert "(-a)*(-b)" into "a*b".
  73   if (real_mul && in1->is_Sub() && in2->is_Sub()) {
  74     if (phase->type(in1->in(1))->is_zero_type() &&
  75         phase->type(in2->in(1))->is_zero_type()) {
  76       set_req_X(1, in1->in(2), phase);
  77       set_req_X(2, in2->in(2), phase);
  78       in1 = in(1);
  79       in2 = in(2);
  80       progress = this;
  81     }
  82   }
  83 
  84   // convert "max(a,b) * min(a,b)" into "a*b".
  85   if ((in(1)->Opcode() == max_opcode() && in(2)->Opcode() == min_opcode())
  86       || (in(1)->Opcode() == min_opcode() && in(2)->Opcode() == max_opcode())) {
  87     Node *in11 = in(1)->in(1);
  88     Node *in12 = in(1)->in(2);
  89 
  90     Node *in21 = in(2)->in(1);
  91     Node *in22 = in(2)->in(2);
  92 
  93     if ((in11 == in21 && in12 == in22) ||
  94         (in11 == in22 && in12 == in21)) {
  95       set_req_X(1, in11, phase);
  96       set_req_X(2, in12, phase);
  97       in1 = in(1);
  98       in2 = in(2);
  99       progress = this;
 100     }
 101   }
 102 
 103   const Type* t1 = phase->type(in1);
 104   const Type* t2 = phase->type(in2);
 105 
 106   // We are OK if right is a constant, or right is a load and
 107   // left is a non-constant.
 108   if( !(t2->singleton() ||
 109         (in(2)->is_Load() && !(t1->singleton() || in(1)->is_Load())) ) ) {
 110     if( t1->singleton() ||       // Left input is a constant?
 111         // Otherwise, sort inputs (commutativity) to help value numbering.
 112         (in(1)->_idx > in(2)->_idx) ) {
 113       swap_edges(1, 2);
 114       const Type *t = t1;
 115       t1 = t2;
 116       t2 = t;
 117       progress = this;            // Made progress
 118     }
 119   }
 120 
 121   // If the right input is a constant, and the left input is a product of a
 122   // constant, flatten the expression tree.
 123   if( t2->singleton() &&        // Right input is a constant?
 124       op != Op_MulF &&          // Float & double cannot reassociate
 125       op != Op_MulD &&
 126       op != Op_MulHF) {
 127     if( t2 == Type::TOP ) return nullptr;
 128     Node *mul1 = in(1);
 129 #ifdef ASSERT
 130     // Check for dead loop
 131     int op1 = mul1->Opcode();
 132     if ((mul1 == this) || (in(2) == this) ||
 133         ((op1 == mul_opcode() || op1 == add_opcode()) &&
 134          ((mul1->in(1) == this) || (mul1->in(2) == this) ||
 135           (mul1->in(1) == mul1) || (mul1->in(2) == mul1)))) {
 136       assert(false, "dead loop in MulNode::Ideal");
 137     }
 138 #endif
 139 
 140     if( mul1->Opcode() == mul_opcode() ) {  // Left input is a multiply?
 141       // Mul of a constant?
 142       const Type *t12 = phase->type( mul1->in(2) );
 143       if( t12->singleton() && t12 != Type::TOP) { // Left input is an add of a constant?
 144         // Compute new constant; check for overflow
 145         const Type *tcon01 = ((MulNode*)mul1)->mul_ring(t2,t12);
 146         if( tcon01->singleton() ) {
 147           // The Mul of the flattened expression
 148           set_req_X(1, mul1->in(1), phase);
 149           set_req_X(2, phase->makecon(tcon01), phase);
 150           t2 = tcon01;
 151           progress = this;      // Made progress
 152         }
 153       }
 154     }
 155     // If the right input is a constant, and the left input is an add of a
 156     // constant, flatten the tree: (X+con1)*con0 ==> X*con0 + con1*con0
 157     const Node *add1 = in(1);
 158     if( add1->Opcode() == add_opcode() ) {      // Left input is an add?
 159       // Add of a constant?
 160       const Type *t12 = phase->type( add1->in(2) );
 161       if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
 162         assert( add1->in(1) != add1, "dead loop in MulNode::Ideal" );
 163         // Compute new constant; check for overflow
 164         const Type *tcon01 = mul_ring(t2,t12);
 165         if( tcon01->singleton() ) {
 166 
 167         // Convert (X+con1)*con0 into X*con0
 168           Node *mul = clone();    // mul = ()*con0
 169           mul->set_req(1,add1->in(1));  // mul = X*con0
 170           mul = phase->transform(mul);
 171 
 172           Node *add2 = add1->clone();
 173           add2->set_req(1, mul);        // X*con0 + con0*con1
 174           add2->set_req(2, phase->makecon(tcon01) );
 175           progress = add2;
 176         }
 177       }
 178     } // End of is left input an add
 179   } // End of is right input a Mul
 180 
 181   return progress;
 182 }
 183 
 184 //------------------------------Value-----------------------------------------
 185 const Type* MulNode::Value(PhaseGVN* phase) const {
 186   const Type *t1 = phase->type( in(1) );
 187   const Type *t2 = phase->type( in(2) );
 188   // Either input is TOP ==> the result is TOP
 189   if( t1 == Type::TOP ) return Type::TOP;
 190   if( t2 == Type::TOP ) return Type::TOP;
 191 
 192   // Either input is ZERO ==> the result is ZERO.
 193   // Not valid for floats or doubles since +0.0 * -0.0 --> +0.0
 194   int op = Opcode();
 195   if( op == Op_MulI || op == Op_AndI || op == Op_MulL || op == Op_AndL ) {
 196     const Type *zero = add_id();        // The multiplicative zero
 197     if( t1->higher_equal( zero ) ) return zero;
 198     if( t2->higher_equal( zero ) ) return zero;
 199   }
 200 
 201   // Either input is BOTTOM ==> the result is the local BOTTOM
 202   if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
 203     return bottom_type();
 204 
 205 #if defined(IA32)
 206   // Can't trust native compilers to properly fold strict double
 207   // multiplication with round-to-zero on this platform.
 208   if (op == Op_MulD) {
 209     return TypeD::DOUBLE;
 210   }
 211 #endif
 212 
 213   return mul_ring(t1,t2);            // Local flavor of type multiplication
 214 }
 215 
 216 MulNode* MulNode::make(Node* in1, Node* in2, BasicType bt) {
 217   switch (bt) {
 218     case T_INT:
 219       return new MulINode(in1, in2);
 220     case T_LONG:
 221       return new MulLNode(in1, in2);
 222     default:
 223       fatal("Not implemented for %s", type2name(bt));
 224   }
 225   return nullptr;
 226 }
 227 
 228 MulNode* MulNode::make_and(Node* in1, Node* in2, BasicType bt) {
 229   switch (bt) {
 230     case T_INT:
 231       return new AndINode(in1, in2);
 232     case T_LONG:
 233       return new AndLNode(in1, in2);
 234     default:
 235       fatal("Not implemented for %s", type2name(bt));
 236   }
 237   return nullptr;
 238 }
 239 
 240 
 241 //=============================================================================
 242 //------------------------------Ideal------------------------------------------
 243 // Check for power-of-2 multiply, then try the regular MulNode::Ideal
 244 Node *MulINode::Ideal(PhaseGVN *phase, bool can_reshape) {
 245   const jint con = in(2)->find_int_con(0);
 246   if (con == 0) {
 247     // If in(2) is not a constant, call Ideal() of the parent class to
 248     // try to move constant to the right side.
 249     return MulNode::Ideal(phase, can_reshape);
 250   }
 251 
 252   // Now we have a constant Node on the right and the constant in con.
 253   if (con == 1) {
 254     // By one is handled by Identity call
 255     return nullptr;
 256   }
 257 
 258   // Check for negative constant; if so negate the final result
 259   bool sign_flip = false;
 260 
 261   unsigned int abs_con = uabs(con);
 262   if (abs_con != (unsigned int)con) {
 263     sign_flip = true;
 264   }
 265 
 266   // Get low bit; check for being the only bit
 267   Node *res = nullptr;
 268   unsigned int bit1 = submultiple_power_of_2(abs_con);
 269   if (bit1 == abs_con) {           // Found a power of 2?
 270     res = new LShiftINode(in(1), phase->intcon(log2i_exact(bit1)));
 271   } else {
 272     // Check for constant with 2 bits set
 273     unsigned int bit2 = abs_con - bit1;
 274     bit2 = bit2 & (0 - bit2);          // Extract 2nd bit
 275     if (bit2 + bit1 == abs_con) {    // Found all bits in con?
 276       Node *n1 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(bit1))));
 277       Node *n2 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(bit2))));
 278       res = new AddINode(n2, n1);
 279     } else if (is_power_of_2(abs_con + 1)) {
 280       // Sleezy: power-of-2 - 1.  Next time be generic.
 281       unsigned int temp = abs_con + 1;
 282       Node *n1 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(temp))));
 283       res = new SubINode(n1, in(1));
 284     } else {
 285       return MulNode::Ideal(phase, can_reshape);
 286     }
 287   }
 288 
 289   if (sign_flip) {             // Need to negate result?
 290     res = phase->transform(res);// Transform, before making the zero con
 291     res = new SubINode(phase->intcon(0),res);
 292   }
 293 
 294   return res;                   // Return final result
 295 }
 296 
 297 // This template class performs type multiplication for MulI/MulLNode. NativeType is either jint or jlong.
 298 // In this class, the inputs of the MulNodes are named left and right with types [left_lo,left_hi] and [right_lo,right_hi].
 299 //
 300 // In general, the multiplication of two x-bit values could produce a result that consumes up to 2x bits if there is
 301 // enough space to hold them all. We can therefore distinguish the following two cases for the product:
 302 // - no overflow (i.e. product fits into x bits)
 303 // - overflow (i.e. product does not fit into x bits)
 304 //
 305 // When multiplying the two x-bit inputs 'left' and 'right' with their x-bit types [left_lo,left_hi] and [right_lo,right_hi]
 306 // we need to find the minimum and maximum of all possible products to define a new type. To do that, we compute the
 307 // cross product of [left_lo,left_hi] and [right_lo,right_hi] in 2x-bit space where no over- or underflow can happen.
 308 // The cross product consists of the following four multiplications with 2x-bit results:
 309 // (1) left_lo * right_lo
 310 // (2) left_lo * right_hi
 311 // (3) left_hi * right_lo
 312 // (4) left_hi * right_hi
 313 //
 314 // Let's define the following two functions:
 315 // - Lx(i): Returns the lower x bits of the 2x-bit number i.
 316 // - Ux(i): Returns the upper x bits of the 2x-bit number i.
 317 //
 318 // Let's first assume all products are positive where only overflows are possible but no underflows. If there is no
 319 // overflow for a product p, then the upper x bits of the 2x-bit result p are all zero:
 320 //     Ux(p) = 0
 321 //     Lx(p) = p
 322 //
 323 // If none of the multiplications (1)-(4) overflow, we can truncate the upper x bits and use the following result type
 324 // with x bits:
 325 //      [result_lo,result_hi] = [MIN(Lx(1),Lx(2),Lx(3),Lx(4)),MAX(Lx(1),Lx(2),Lx(3),Lx(4))]
 326 //
 327 // If any of these multiplications overflows, we could pessimistically take the bottom type for the x bit result
 328 // (i.e. all values in the x-bit space could be possible):
 329 //      [result_lo,result_hi] = [NativeType_min,NativeType_max]
 330 //
 331 // However, in case of any overflow, we can do better by analyzing the upper x bits of all multiplications (1)-(4) with
 332 // 2x-bit results. The upper x bits tell us something about how many times a multiplication has overflown the lower
 333 // x bits. If the upper x bits of (1)-(4) are all equal, then we know that all of these multiplications overflowed
 334 // the lower x bits the same number of times:
 335 //     Ux((1)) = Ux((2)) = Ux((3)) = Ux((4))
 336 //
 337 // If all upper x bits are equal, we can conclude:
 338 //     Lx(MIN((1),(2),(3),(4))) = MIN(Lx(1),Lx(2),Lx(3),Lx(4)))
 339 //     Lx(MAX((1),(2),(3),(4))) = MAX(Lx(1),Lx(2),Lx(3),Lx(4)))
 340 //
 341 // Therefore, we can use the same precise x-bit result type as for the no-overflow case:
 342 //     [result_lo,result_hi] = [(MIN(Lx(1),Lx(2),Lx(3),Lx(4))),MAX(Lx(1),Lx(2),Lx(3),Lx(4)))]
 343 //
 344 //
 345 // Now let's assume that (1)-(4) are signed multiplications where over- and underflow could occur:
 346 // Negative numbers are all sign extend with ones. Therefore, if a negative product does not underflow, then the
 347 // upper x bits of the 2x-bit result are all set to ones which is minus one in two's complement. If there is an underflow,
 348 // the upper x bits are decremented by the number of times an underflow occurred. The smallest possible negative product
 349 // is NativeType_min*NativeType_max, where the upper x bits are set to NativeType_min / 2 (b11...0). It is therefore
 350 // impossible to underflow the upper x bits. Thus, when having all ones (i.e. minus one) in the upper x bits, we know
 351 // that there is no underflow.
 352 //
 353 // To be able to compare the number of over-/underflows of positive and negative products, respectively, we normalize
 354 // the upper x bits of negative 2x-bit products by adding one. This way a product has no over- or underflow if the
 355 // normalized upper x bits are zero. Now we can use the same improved type as for strictly positive products because we
 356 // can compare the upper x bits in a unified way with N() being the normalization function:
 357 //     N(Ux((1))) = N(Ux((2))) = N(Ux((3)) = N(Ux((4)))
 358 template<typename NativeType>
 359 class IntegerTypeMultiplication {
 360 
 361   NativeType _lo_left;
 362   NativeType _lo_right;
 363   NativeType _hi_left;
 364   NativeType _hi_right;
 365   short _widen_left;
 366   short _widen_right;
 367 
 368   static const Type* overflow_type();
 369   static NativeType multiply_high(NativeType x, NativeType y);
 370   const Type* create_type(NativeType lo, NativeType hi) const;
 371 
 372   static NativeType multiply_high_signed_overflow_value(NativeType x, NativeType y) {
 373     return normalize_overflow_value(x, y, multiply_high(x, y));
 374   }
 375 
 376   bool cross_product_not_same_overflow_value() const {
 377     const NativeType lo_lo_high_product = multiply_high_signed_overflow_value(_lo_left, _lo_right);
 378     const NativeType lo_hi_high_product = multiply_high_signed_overflow_value(_lo_left, _hi_right);
 379     const NativeType hi_lo_high_product = multiply_high_signed_overflow_value(_hi_left, _lo_right);
 380     const NativeType hi_hi_high_product = multiply_high_signed_overflow_value(_hi_left, _hi_right);
 381     return lo_lo_high_product != lo_hi_high_product ||
 382            lo_hi_high_product != hi_lo_high_product ||
 383            hi_lo_high_product != hi_hi_high_product;
 384   }
 385 
 386   bool does_product_overflow(NativeType x, NativeType y) const {
 387     return multiply_high_signed_overflow_value(x, y) != 0;
 388   }
 389 
 390   static NativeType normalize_overflow_value(const NativeType x, const NativeType y, NativeType result) {
 391     return java_multiply(x, y) < 0 ? result + 1 : result;
 392   }
 393 
 394  public:
 395   template<class IntegerType>
 396   IntegerTypeMultiplication(const IntegerType* left, const IntegerType* right)
 397       : _lo_left(left->_lo), _lo_right(right->_lo),
 398         _hi_left(left->_hi), _hi_right(right->_hi),
 399         _widen_left(left->_widen), _widen_right(right->_widen)  {}
 400 
 401   // Compute the product type by multiplying the two input type ranges. We take the minimum and maximum of all possible
 402   // values (requires 4 multiplications of all possible combinations of the two range boundary values). If any of these
 403   // multiplications overflows/underflows, we need to make sure that they all have the same number of overflows/underflows
 404   // If that is not the case, we return the bottom type to cover all values due to the inconsistent overflows/underflows).
 405   const Type* compute() const {
 406     if (cross_product_not_same_overflow_value()) {
 407       return overflow_type();
 408     }
 409 
 410     NativeType lo_lo_product = java_multiply(_lo_left, _lo_right);
 411     NativeType lo_hi_product = java_multiply(_lo_left, _hi_right);
 412     NativeType hi_lo_product = java_multiply(_hi_left, _lo_right);
 413     NativeType hi_hi_product = java_multiply(_hi_left, _hi_right);
 414     const NativeType min = MIN4(lo_lo_product, lo_hi_product, hi_lo_product, hi_hi_product);
 415     const NativeType max = MAX4(lo_lo_product, lo_hi_product, hi_lo_product, hi_hi_product);
 416     return create_type(min, max);
 417   }
 418 
 419   bool does_overflow() const {
 420     return does_product_overflow(_lo_left, _lo_right) ||
 421            does_product_overflow(_lo_left, _hi_right) ||
 422            does_product_overflow(_hi_left, _lo_right) ||
 423            does_product_overflow(_hi_left, _hi_right);
 424   }
 425 };
 426 
 427 template <>
 428 const Type* IntegerTypeMultiplication<jint>::overflow_type() {
 429   return TypeInt::INT;
 430 }
 431 
 432 template <>
 433 jint IntegerTypeMultiplication<jint>::multiply_high(const jint x, const jint y) {
 434   const jlong x_64 = x;
 435   const jlong y_64 = y;
 436   const jlong product = x_64 * y_64;
 437   return (jint)((uint64_t)product >> 32u);
 438 }
 439 
 440 template <>
 441 const Type* IntegerTypeMultiplication<jint>::create_type(jint lo, jint hi) const {
 442   return TypeInt::make(lo, hi, MAX2(_widen_left, _widen_right));
 443 }
 444 
 445 template <>
 446 const Type* IntegerTypeMultiplication<jlong>::overflow_type() {
 447   return TypeLong::LONG;
 448 }
 449 
 450 template <>
 451 jlong IntegerTypeMultiplication<jlong>::multiply_high(const jlong x, const jlong y) {
 452   return multiply_high_signed(x, y);
 453 }
 454 
 455 template <>
 456 const Type* IntegerTypeMultiplication<jlong>::create_type(jlong lo, jlong hi) const {
 457   return TypeLong::make(lo, hi, MAX2(_widen_left, _widen_right));
 458 }
 459 
 460 // Compute the product type of two integer ranges into this node.
 461 const Type* MulINode::mul_ring(const Type* type_left, const Type* type_right) const {
 462   const IntegerTypeMultiplication<jint> integer_multiplication(type_left->is_int(), type_right->is_int());
 463   return integer_multiplication.compute();
 464 }
 465 
 466 bool MulINode::does_overflow(const TypeInt* type_left, const TypeInt* type_right) {
 467   const IntegerTypeMultiplication<jint> integer_multiplication(type_left, type_right);
 468   return integer_multiplication.does_overflow();
 469 }
 470 
 471 // Compute the product type of two long ranges into this node.
 472 const Type* MulLNode::mul_ring(const Type* type_left, const Type* type_right) const {
 473   const IntegerTypeMultiplication<jlong> integer_multiplication(type_left->is_long(), type_right->is_long());
 474   return integer_multiplication.compute();
 475 }
 476 
 477 //=============================================================================
 478 //------------------------------Ideal------------------------------------------
 479 // Check for power-of-2 multiply, then try the regular MulNode::Ideal
 480 Node *MulLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 481   const jlong con = in(2)->find_long_con(0);
 482   if (con == 0) {
 483     // If in(2) is not a constant, call Ideal() of the parent class to
 484     // try to move constant to the right side.
 485     return MulNode::Ideal(phase, can_reshape);
 486   }
 487 
 488   // Now we have a constant Node on the right and the constant in con.
 489   if (con == 1) {
 490     // By one is handled by Identity call
 491     return nullptr;
 492   }
 493 
 494   // Check for negative constant; if so negate the final result
 495   bool sign_flip = false;
 496   julong abs_con = uabs(con);
 497   if (abs_con != (julong)con) {
 498     sign_flip = true;
 499   }
 500 
 501   // Get low bit; check for being the only bit
 502   Node *res = nullptr;
 503   julong bit1 = submultiple_power_of_2(abs_con);
 504   if (bit1 == abs_con) {           // Found a power of 2?
 505     res = new LShiftLNode(in(1), phase->intcon(log2i_exact(bit1)));
 506   } else {
 507 
 508     // Check for constant with 2 bits set
 509     julong bit2 = abs_con-bit1;
 510     bit2 = bit2 & (0-bit2);          // Extract 2nd bit
 511     if (bit2 + bit1 == abs_con) {    // Found all bits in con?
 512       Node *n1 = phase->transform(new LShiftLNode(in(1), phase->intcon(log2i_exact(bit1))));
 513       Node *n2 = phase->transform(new LShiftLNode(in(1), phase->intcon(log2i_exact(bit2))));
 514       res = new AddLNode(n2, n1);
 515 
 516     } else if (is_power_of_2(abs_con+1)) {
 517       // Sleezy: power-of-2 -1.  Next time be generic.
 518       julong temp = abs_con + 1;
 519       Node *n1 = phase->transform( new LShiftLNode(in(1), phase->intcon(log2i_exact(temp))));
 520       res = new SubLNode(n1, in(1));
 521     } else {
 522       return MulNode::Ideal(phase, can_reshape);
 523     }
 524   }
 525 
 526   if (sign_flip) {             // Need to negate result?
 527     res = phase->transform(res);// Transform, before making the zero con
 528     res = new SubLNode(phase->longcon(0),res);
 529   }
 530 
 531   return res;                   // Return final result
 532 }
 533 
 534 //=============================================================================
 535 //------------------------------mul_ring---------------------------------------
 536 // Compute the product type of two double ranges into this node.
 537 const Type *MulFNode::mul_ring(const Type *t0, const Type *t1) const {
 538   if( t0 == Type::FLOAT || t1 == Type::FLOAT ) return Type::FLOAT;
 539   return TypeF::make( t0->getf() * t1->getf() );
 540 }
 541 
 542 //------------------------------Ideal---------------------------------------
 543 // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal
 544 Node* MulFNode::Ideal(PhaseGVN* phase, bool can_reshape) {
 545   const TypeF *t2 = phase->type(in(2))->isa_float_constant();
 546 
 547   // x * 2 -> x + x
 548   if (t2 != nullptr && t2->getf() == 2) {
 549     Node* base = in(1);
 550     return new AddFNode(base, base);
 551   }
 552   return MulNode::Ideal(phase, can_reshape);
 553 }
 554 
 555 //=============================================================================
 556 //------------------------------Ideal------------------------------------------
 557 // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal
 558 Node* MulHFNode::Ideal(PhaseGVN* phase, bool can_reshape) {
 559   const TypeH* t2 = phase->type(in(2))->isa_half_float_constant();
 560 
 561   // x * 2 -> x + x
 562   if (t2 != nullptr && t2->getf() == 2) {
 563     Node* base = in(1);
 564     return new AddHFNode(base, base);
 565   }
 566   return MulNode::Ideal(phase, can_reshape);
 567 }
 568 
 569 // Compute the product type of two half float ranges into this node.
 570 const Type* MulHFNode::mul_ring(const Type* t0, const Type* t1) const {
 571   if (t0 == Type::HALF_FLOAT || t1 == Type::HALF_FLOAT) {
 572     return Type::HALF_FLOAT;
 573   }
 574   return TypeH::make(t0->getf() * t1->getf());
 575 }
 576 
 577 //=============================================================================
 578 //------------------------------mul_ring---------------------------------------
 579 // Compute the product type of two double ranges into this node.
 580 const Type *MulDNode::mul_ring(const Type *t0, const Type *t1) const {
 581   if( t0 == Type::DOUBLE || t1 == Type::DOUBLE ) return Type::DOUBLE;
 582   // We must be multiplying 2 double constants.
 583   return TypeD::make( t0->getd() * t1->getd() );
 584 }
 585 
 586 //------------------------------Ideal---------------------------------------
 587 // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal
 588 Node* MulDNode::Ideal(PhaseGVN* phase, bool can_reshape) {
 589   const TypeD *t2 = phase->type(in(2))->isa_double_constant();
 590 
 591   // x * 2 -> x + x
 592   if (t2 != nullptr && t2->getd() == 2) {
 593     Node* base = in(1);
 594     return new AddDNode(base, base);
 595   }
 596 
 597   return MulNode::Ideal(phase, can_reshape);
 598 }
 599 
 600 //=============================================================================
 601 //------------------------------Value------------------------------------------
 602 const Type* MulHiLNode::Value(PhaseGVN* phase) const {
 603   const Type *t1 = phase->type( in(1) );
 604   const Type *t2 = phase->type( in(2) );
 605   const Type *bot = bottom_type();
 606   return MulHiValue(t1, t2, bot);
 607 }
 608 
 609 const Type* UMulHiLNode::Value(PhaseGVN* phase) const {
 610   const Type *t1 = phase->type( in(1) );
 611   const Type *t2 = phase->type( in(2) );
 612   const Type *bot = bottom_type();
 613   return MulHiValue(t1, t2, bot);
 614 }
 615 
 616 // A common routine used by UMulHiLNode and MulHiLNode
 617 const Type* MulHiValue(const Type *t1, const Type *t2, const Type *bot) {
 618   // Either input is TOP ==> the result is TOP
 619   if( t1 == Type::TOP ) return Type::TOP;
 620   if( t2 == Type::TOP ) return Type::TOP;
 621 
 622   // Either input is BOTTOM ==> the result is the local BOTTOM
 623   if( (t1 == bot) || (t2 == bot) ||
 624       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
 625     return bot;
 626 
 627   // It is not worth trying to constant fold this stuff!
 628   return TypeLong::LONG;
 629 }
 630 
 631 template<typename IntegerType>
 632 static const IntegerType* and_value(const IntegerType* r0, const IntegerType* r1) {
 633   typedef typename IntegerType::NativeType NativeType;
 634   static_assert(std::is_signed<NativeType>::value, "Native type of IntegerType must be signed!");
 635 
 636   int widen = MAX2(r0->_widen, r1->_widen);
 637 
 638   // If both types are constants, we can calculate a constant result.
 639   if (r0->is_con() && r1->is_con()) {
 640     return IntegerType::make(r0->get_con() & r1->get_con());
 641   }
 642 
 643   // If both ranges are positive, the result will range from 0 up to the hi value of the smaller range. The minimum
 644   // of the two constrains the upper bound because any higher value in the other range will see all zeroes, so it will be masked out.
 645   if (r0->_lo >= 0 && r1->_lo >= 0) {
 646     return IntegerType::make(0, MIN2(r0->_hi, r1->_hi), widen);
 647   }
 648 
 649   // If only one range is positive, the result will range from 0 up to that range's maximum value.
 650   // For the operation 'x & C' where C is a positive constant, the result will be in the range [0..C]. With that observation,
 651   // we can say that for any integer c such that 0 <= c <= C will also be in the range [0..C]. Therefore, 'x & [c..C]'
 652   // where c >= 0 will be in the range [0..C].
 653   if (r0->_lo >= 0) {
 654     return IntegerType::make(0, r0->_hi, widen);
 655   }
 656 
 657   if (r1->_lo >= 0) {
 658     return IntegerType::make(0, r1->_hi, widen);
 659   }
 660 
 661   // At this point, all positive ranges will have already been handled, so the only remaining cases will be negative ranges
 662   // and constants.
 663 
 664   assert(r0->_lo < 0 && r1->_lo < 0, "positive ranges should already be handled!");
 665 
 666   // As two's complement means that both numbers will start with leading 1s, the lower bound of both ranges will contain
 667   // the common leading 1s of both minimum values. In order to count them with count_leading_zeros, the bits are inverted.
 668   NativeType sel_val = ~MIN2(r0->_lo, r1->_lo);
 669 
 670   NativeType min;
 671   if (sel_val == 0) {
 672     // Since count_leading_zeros is undefined at 0, we short-circuit the condition where both ranges have a minimum of -1.
 673     min = -1;
 674   } else {
 675     // To get the number of bits to shift, we count the leading 0-bits and then subtract one, as the sign bit is already set.
 676     int shift_bits = count_leading_zeros(sel_val) - 1;
 677     min = std::numeric_limits<NativeType>::min() >> shift_bits;
 678   }
 679 
 680   NativeType max;
 681   if (r0->_hi < 0 && r1->_hi < 0) {
 682     // If both ranges are negative, then the same optimization as both positive ranges will apply, and the smaller hi
 683     // value will mask off any bits set by higher values.
 684     max = MIN2(r0->_hi, r1->_hi);
 685   } else {
 686     // In the case of ranges that cross zero, negative values can cause the higher order bits to be set, so the maximum
 687     // positive value can be as high as the larger hi value.
 688     max = MAX2(r0->_hi, r1->_hi);
 689   }
 690 
 691   return IntegerType::make(min, max, widen);
 692 }
 693 
 694 //=============================================================================
 695 //------------------------------mul_ring---------------------------------------
 696 // Supplied function returns the product of the inputs IN THE CURRENT RING.
 697 // For the logical operations the ring's MUL is really a logical AND function.
 698 // This also type-checks the inputs for sanity.  Guaranteed never to
 699 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 700 const Type *AndINode::mul_ring( const Type *t0, const Type *t1 ) const {
 701   const TypeInt* r0 = t0->is_int();
 702   const TypeInt* r1 = t1->is_int();
 703 
 704   return and_value<TypeInt>(r0, r1);
 705 }
 706 
 707 static bool AndIL_is_zero_element_under_mask(const PhaseGVN* phase, const Node* expr, const Node* mask, BasicType bt);
 708 
 709 const Type* AndINode::Value(PhaseGVN* phase) const {
 710   if (AndIL_is_zero_element_under_mask(phase, in(1), in(2), T_INT) ||
 711       AndIL_is_zero_element_under_mask(phase, in(2), in(1), T_INT)) {
 712     return TypeInt::ZERO;
 713   }
 714 
 715   return MulNode::Value(phase);
 716 }
 717 
 718 //------------------------------Identity---------------------------------------
 719 // Masking off the high bits of an unsigned load is not required
 720 Node* AndINode::Identity(PhaseGVN* phase) {
 721 
 722   // x & x => x
 723   if (in(1) == in(2)) {
 724     return in(1);
 725   }
 726 
 727   Node* in1 = in(1);
 728   uint op = in1->Opcode();
 729   const TypeInt* t2 = phase->type(in(2))->isa_int();
 730   if (t2 && t2->is_con()) {
 731     int con = t2->get_con();
 732     // Masking off high bits which are always zero is useless.
 733     const TypeInt* t1 = phase->type(in(1))->isa_int();
 734     if (t1 != nullptr && t1->_lo >= 0) {
 735       jint t1_support = right_n_bits(1 + log2i_graceful(t1->_hi));
 736       if ((t1_support & con) == t1_support)
 737         return in1;
 738     }
 739     // Masking off the high bits of a unsigned-shift-right is not
 740     // needed either.
 741     if (op == Op_URShiftI) {
 742       const TypeInt* t12 = phase->type(in1->in(2))->isa_int();
 743       if (t12 && t12->is_con()) {  // Shift is by a constant
 744         int shift = t12->get_con();
 745         shift &= BitsPerJavaInteger - 1;  // semantics of Java shifts
 746         int mask = max_juint >> shift;
 747         if ((mask & con) == mask)  // If AND is useless, skip it
 748           return in1;
 749       }
 750     }
 751   }
 752   return MulNode::Identity(phase);
 753 }
 754 
 755 //------------------------------Ideal------------------------------------------
 756 Node *AndINode::Ideal(PhaseGVN *phase, bool can_reshape) {
 757   // Simplify (v1 + v2) & mask to v1 & mask or v2 & mask when possible.
 758   Node* progress = AndIL_sum_and_mask(phase, T_INT);
 759   if (progress != nullptr) {
 760     return progress;
 761   }
 762 
 763   // Convert "(~a) & (~b)" into "~(a | b)"
 764   if (AddNode::is_not(phase, in(1), T_INT) && AddNode::is_not(phase, in(2), T_INT)) {
 765     Node* or_a_b = new OrINode(in(1)->in(1), in(2)->in(1));
 766     Node* tn = phase->transform(or_a_b);
 767     return AddNode::make_not(phase, tn, T_INT);
 768   }
 769 
 770   // Special case constant AND mask
 771   const TypeInt *t2 = phase->type( in(2) )->isa_int();
 772   if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
 773   const int mask = t2->get_con();
 774   Node *load = in(1);
 775   uint lop = load->Opcode();
 776 
 777   // Masking bits off of a Character?  Hi bits are already zero.
 778   if( lop == Op_LoadUS &&
 779       (mask & 0xFFFF0000) )     // Can we make a smaller mask?
 780     return new AndINode(load,phase->intcon(mask&0xFFFF));
 781 
 782   // Masking bits off of a Short?  Loading a Character does some masking
 783   if (can_reshape &&
 784       load->outcnt() == 1 && load->unique_out() == this) {
 785     if (lop == Op_LoadS && (mask & 0xFFFF0000) == 0 ) {
 786       Node* ldus = load->as_Load()->convert_to_unsigned_load(*phase);
 787       ldus = phase->transform(ldus);
 788       return new AndINode(ldus, phase->intcon(mask & 0xFFFF));
 789     }
 790 
 791     // Masking sign bits off of a Byte?  Do an unsigned byte load plus
 792     // an and.
 793     if (lop == Op_LoadB && (mask & 0xFFFFFF00) == 0) {
 794       Node* ldub = load->as_Load()->convert_to_unsigned_load(*phase);
 795       ldub = phase->transform(ldub);
 796       return new AndINode(ldub, phase->intcon(mask));
 797     }
 798   }
 799 
 800   // Masking off sign bits?  Dont make them!
 801   if( lop == Op_RShiftI ) {
 802     const TypeInt *t12 = phase->type(load->in(2))->isa_int();
 803     if( t12 && t12->is_con() ) { // Shift is by a constant
 804       int shift = t12->get_con();
 805       shift &= BitsPerJavaInteger-1;  // semantics of Java shifts
 806       const int sign_bits_mask = ~right_n_bits(BitsPerJavaInteger - shift);
 807       // If the AND'ing of the 2 masks has no bits, then only original shifted
 808       // bits survive.  NO sign-extension bits survive the maskings.
 809       if( (sign_bits_mask & mask) == 0 ) {
 810         // Use zero-fill shift instead
 811         Node *zshift = phase->transform(new URShiftINode(load->in(1),load->in(2)));
 812         return new AndINode( zshift, in(2) );
 813       }
 814     }
 815   }
 816 
 817   // Check for 'negate/and-1', a pattern emitted when someone asks for
 818   // 'mod 2'.  Negate leaves the low order bit unchanged (think: complement
 819   // plus 1) and the mask is of the low order bit.  Skip the negate.
 820   if( lop == Op_SubI && mask == 1 && load->in(1) &&
 821       phase->type(load->in(1)) == TypeInt::ZERO )
 822     return new AndINode( load->in(2), in(2) );
 823 
 824   return MulNode::Ideal(phase, can_reshape);
 825 }
 826 
 827 //=============================================================================
 828 //------------------------------mul_ring---------------------------------------
 829 // Supplied function returns the product of the inputs IN THE CURRENT RING.
 830 // For the logical operations the ring's MUL is really a logical AND function.
 831 // This also type-checks the inputs for sanity.  Guaranteed never to
 832 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 833 const Type *AndLNode::mul_ring( const Type *t0, const Type *t1 ) const {
 834   const TypeLong* r0 = t0->is_long();
 835   const TypeLong* r1 = t1->is_long();
 836 
 837   return and_value<TypeLong>(r0, r1);
 838 }
 839 
 840 const Type* AndLNode::Value(PhaseGVN* phase) const {
 841   if (AndIL_is_zero_element_under_mask(phase, in(1), in(2), T_LONG) ||
 842       AndIL_is_zero_element_under_mask(phase, in(2), in(1), T_LONG)) {
 843     return TypeLong::ZERO;
 844   }
 845 
 846   return MulNode::Value(phase);
 847 }
 848 
 849 //------------------------------Identity---------------------------------------
 850 // Masking off the high bits of an unsigned load is not required
 851 Node* AndLNode::Identity(PhaseGVN* phase) {
 852 
 853   // x & x => x
 854   if (in(1) == in(2)) {
 855     return in(1);
 856   }
 857 
 858   Node *usr = in(1);
 859   const TypeLong *t2 = phase->type( in(2) )->isa_long();
 860   if( t2 && t2->is_con() ) {
 861     jlong con = t2->get_con();
 862     // Masking off high bits which are always zero is useless.
 863     const TypeLong* t1 = phase->type( in(1) )->isa_long();
 864     if (t1 != nullptr && t1->_lo >= 0) {
 865       int bit_count = log2i_graceful(t1->_hi) + 1;
 866       jlong t1_support = jlong(max_julong >> (BitsPerJavaLong - bit_count));
 867       if ((t1_support & con) == t1_support)
 868         return usr;
 869     }
 870     uint lop = usr->Opcode();
 871     // Masking off the high bits of a unsigned-shift-right is not
 872     // needed either.
 873     if( lop == Op_URShiftL ) {
 874       const TypeInt *t12 = phase->type( usr->in(2) )->isa_int();
 875       if( t12 && t12->is_con() ) {  // Shift is by a constant
 876         int shift = t12->get_con();
 877         shift &= BitsPerJavaLong - 1;  // semantics of Java shifts
 878         jlong mask = max_julong >> shift;
 879         if( (mask&con) == mask )  // If AND is useless, skip it
 880           return usr;
 881       }
 882     }
 883   }
 884   return MulNode::Identity(phase);
 885 }
 886 
 887 //------------------------------Ideal------------------------------------------
 888 Node *AndLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 889   // Simplify (v1 + v2) & mask to v1 & mask or v2 & mask when possible.
 890   Node* progress = AndIL_sum_and_mask(phase, T_LONG);
 891   if (progress != nullptr) {
 892     return progress;
 893   }
 894 
 895   // Convert "(~a) & (~b)" into "~(a | b)"
 896   if (AddNode::is_not(phase, in(1), T_LONG) && AddNode::is_not(phase, in(2), T_LONG)) {
 897     Node* or_a_b = new OrLNode(in(1)->in(1), in(2)->in(1));
 898     Node* tn = phase->transform(or_a_b);
 899     return AddNode::make_not(phase, tn, T_LONG);
 900   }
 901 
 902   // Special case constant AND mask
 903   const TypeLong *t2 = phase->type( in(2) )->isa_long();
 904   if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
 905   const jlong mask = t2->get_con();
 906 
 907   Node* in1 = in(1);
 908   int op = in1->Opcode();
 909 
 910   // Are we masking a long that was converted from an int with a mask
 911   // that fits in 32-bits?  Commute them and use an AndINode.  Don't
 912   // convert masks which would cause a sign extension of the integer
 913   // value.  This check includes UI2L masks (0x00000000FFFFFFFF) which
 914   // would be optimized away later in Identity.
 915   if (op == Op_ConvI2L && (mask & UCONST64(0xFFFFFFFF80000000)) == 0) {
 916     Node* andi = new AndINode(in1->in(1), phase->intcon(mask));
 917     andi = phase->transform(andi);
 918     return new ConvI2LNode(andi);
 919   }
 920 
 921   // Masking off sign bits?  Dont make them!
 922   if (op == Op_RShiftL) {
 923     const TypeInt* t12 = phase->type(in1->in(2))->isa_int();
 924     if( t12 && t12->is_con() ) { // Shift is by a constant
 925       int shift = t12->get_con();
 926       shift &= BitsPerJavaLong - 1;  // semantics of Java shifts
 927       const julong sign_bits_mask = ~(((julong)CONST64(1) << (julong)(BitsPerJavaLong - shift)) -1);
 928       // If the AND'ing of the 2 masks has no bits, then only original shifted
 929       // bits survive.  NO sign-extension bits survive the maskings.
 930       if( (sign_bits_mask & mask) == 0 ) {
 931         // Use zero-fill shift instead
 932         Node *zshift = phase->transform(new URShiftLNode(in1->in(1), in1->in(2)));
 933         return new AndLNode(zshift, in(2));
 934       }
 935     }
 936   }
 937 
 938   return MulNode::Ideal(phase, can_reshape);
 939 }
 940 
 941 LShiftNode* LShiftNode::make(Node* in1, Node* in2, BasicType bt) {
 942   switch (bt) {
 943     case T_INT:
 944       return new LShiftINode(in1, in2);
 945     case T_LONG:
 946       return new LShiftLNode(in1, in2);
 947     default:
 948       fatal("Not implemented for %s", type2name(bt));
 949   }
 950   return nullptr;
 951 }
 952 
 953 // Returns whether the shift amount is constant. If so, sets count.
 954 static bool const_shift_count(PhaseGVN* phase, const Node* shift_node, int* count) {
 955   const TypeInt* tcount = phase->type(shift_node->in(2))->isa_int();
 956   if (tcount != nullptr && tcount->is_con()) {
 957     *count = tcount->get_con();
 958     return true;
 959   }
 960   return false;
 961 }
 962 
 963 // Returns whether the shift amount is constant. If so, sets real_shift and masked_shift.
 964 static bool mask_shift_amount(PhaseGVN* phase, const Node* shift_node, uint nBits, int& real_shift, int& masked_shift) {
 965   if (const_shift_count(phase, shift_node, &real_shift)) {
 966     masked_shift = real_shift & (nBits - 1);
 967     return true;
 968   }
 969   return false;
 970 }
 971 
 972 // Convenience for when we don't care about the real amount
 973 static bool mask_shift_amount(PhaseGVN* phase, const Node* shift_node, uint nBits, int& masked_shift) {
 974   int real_shift;
 975   return mask_shift_amount(phase, shift_node, nBits, real_shift, masked_shift);
 976 }
 977 
 978 // Use this in ::Ideal only with shiftNode == this!
 979 // Returns the masked shift amount if constant or 0 if not constant.
 980 static int mask_and_replace_shift_amount(PhaseGVN* phase, Node* shift_node, uint nBits) {
 981   int real_shift;
 982   int masked_shift;
 983   if (mask_shift_amount(phase, shift_node, nBits, real_shift, masked_shift)) {
 984     if (masked_shift == 0) {
 985       // Let Identity() handle 0 shift count.
 986       return 0;
 987     }
 988 
 989     if (real_shift != masked_shift) {
 990       PhaseIterGVN* igvn = phase->is_IterGVN();
 991       if (igvn != nullptr) {
 992         igvn->_worklist.push(shift_node);
 993       }
 994       shift_node->set_req(2, phase->intcon(masked_shift)); // Replace shift count with masked value.
 995     }
 996     return masked_shift;
 997   }
 998   // Not a shift by a constant.
 999   return 0;
1000 }
1001 
1002 // Called with
1003 //   outer_shift = (_ << rhs_outer)
1004 // We are looking for the pattern:
1005 //   outer_shift = ((X << rhs_inner) << rhs_outer)
1006 //   where rhs_outer and rhs_inner are constant
1007 //   we denote inner_shift the nested expression (X << rhs_inner)
1008 //   con_inner = rhs_inner % nbits and con_outer = rhs_outer % nbits
1009 //   where nbits is the number of bits of the shifts
1010 //
1011 // There are 2 cases:
1012 // if con_outer + con_inner >= nbits => 0
1013 // if con_outer + con_inner < nbits => X << (con_outer + con_inner)
1014 static Node* collapse_nested_shift_left(PhaseGVN* phase, const Node* outer_shift, int con_outer, BasicType bt) {
1015   assert(bt == T_LONG || bt == T_INT, "Unexpected type");
1016   const Node* inner_shift = outer_shift->in(1);
1017   if (inner_shift->Opcode() != Op_LShift(bt)) {
1018     return nullptr;
1019   }
1020 
1021   int nbits = static_cast<int>(bits_per_java_integer(bt));
1022   int con_inner;
1023   if (!mask_shift_amount(phase, inner_shift, nbits, con_inner)) {
1024     return nullptr;
1025   }
1026 
1027   if (con_inner == 0) {
1028     // We let the Identity() of the inner shift do its job.
1029     return nullptr;
1030   }
1031 
1032   if (con_outer + con_inner >= nbits) {
1033     // While it might be tempting to use
1034     // phase->zerocon(bt);
1035     // it would be incorrect: zerocon caches nodes, while Ideal is only allowed
1036     // to return a new node, this or nullptr, but not an old (cached) node.
1037     return ConNode::make(TypeInteger::zero(bt));
1038   }
1039 
1040   // con0 + con1 < nbits ==> actual shift happens now
1041   Node* con0_plus_con1 = phase->intcon(con_outer + con_inner);
1042   return LShiftNode::make(inner_shift->in(1), con0_plus_con1, bt);
1043 }
1044 
1045 //------------------------------Identity---------------------------------------
1046 Node* LShiftINode::Identity(PhaseGVN* phase) {
1047   int count = 0;
1048   if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaInteger - 1)) == 0) {
1049     // Shift by a multiple of 32 does nothing
1050     return in(1);
1051   }
1052   return this;
1053 }
1054 
1055 //------------------------------Ideal------------------------------------------
1056 // If the right input is a constant, and the left input is an add of a
1057 // constant, flatten the tree: (X+con1)<<con0 ==> X<<con0 + con1<<con0
1058 //
1059 // Also collapse nested left-shifts with constant rhs:
1060 // (X << con1) << con2 ==> X << (con1 + con2)
1061 Node *LShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
1062   int con = mask_and_replace_shift_amount(phase, this, BitsPerJavaInteger);
1063   if (con == 0) {
1064     return nullptr;
1065   }
1066 
1067   // Left input is an add?
1068   Node *add1 = in(1);
1069   int add1_op = add1->Opcode();
1070   if( add1_op == Op_AddI ) {    // Left input is an add?
1071     assert( add1 != add1->in(1), "dead loop in LShiftINode::Ideal" );
1072 
1073     // Transform is legal, but check for profit.  Avoid breaking 'i2s'
1074     // and 'i2b' patterns which typically fold into 'StoreC/StoreB'.
1075     if( con < 16 ) {
1076       // Left input is an add of the same number?
1077       if (add1->in(1) == add1->in(2)) {
1078         // Convert "(x + x) << c0" into "x << (c0 + 1)"
1079         // In general, this optimization cannot be applied for c0 == 31 since
1080         // 2x << 31 != x << 32 = x << 0 = x (e.g. x = 1: 2 << 31 = 0 != 1)
1081         return new LShiftINode(add1->in(1), phase->intcon(con + 1));
1082       }
1083 
1084       // Left input is an add of a constant?
1085       const TypeInt *t12 = phase->type(add1->in(2))->isa_int();
1086       if( t12 && t12->is_con() ){ // Left input is an add of a con?
1087         // Compute X << con0
1088         Node *lsh = phase->transform( new LShiftINode( add1->in(1), in(2) ) );
1089         // Compute X<<con0 + (con1<<con0)
1090         return new AddINode( lsh, phase->intcon(t12->get_con() << con));
1091       }
1092     }
1093   }
1094 
1095   // Check for "(x >> C1) << C2"
1096   if (add1_op == Op_RShiftI || add1_op == Op_URShiftI) {
1097     int add1Con = 0;
1098     const_shift_count(phase, add1, &add1Con);
1099 
1100     // Special case C1 == C2, which just masks off low bits
1101     if (add1Con > 0 && con == add1Con) {
1102       // Convert to "(x & -(1 << C2))"
1103       return new AndINode(add1->in(1), phase->intcon(java_negate(jint(1 << con))));
1104     } else {
1105       // Wait until the right shift has been sharpened to the correct count
1106       if (add1Con > 0 && add1Con < BitsPerJavaInteger) {
1107         // As loop parsing can produce LShiftI nodes, we should wait until the graph is fully formed
1108         // to apply optimizations, otherwise we can inadvertently stop vectorization opportunities.
1109         if (phase->is_IterGVN()) {
1110           if (con > add1Con) {
1111             // Creates "(x << (C2 - C1)) & -(1 << C2)"
1112             Node* lshift = phase->transform(new LShiftINode(add1->in(1), phase->intcon(con - add1Con)));
1113             return new AndINode(lshift, phase->intcon(java_negate(jint(1 << con))));
1114           } else {
1115             assert(con < add1Con, "must be (%d < %d)", con, add1Con);
1116             // Creates "(x >> (C1 - C2)) & -(1 << C2)"
1117 
1118             // Handle logical and arithmetic shifts
1119             Node* rshift;
1120             if (add1_op == Op_RShiftI) {
1121               rshift = phase->transform(new RShiftINode(add1->in(1), phase->intcon(add1Con - con)));
1122             } else {
1123               rshift = phase->transform(new URShiftINode(add1->in(1), phase->intcon(add1Con - con)));
1124             }
1125 
1126             return new AndINode(rshift, phase->intcon(java_negate(jint(1 << con))));
1127           }
1128         } else {
1129           phase->record_for_igvn(this);
1130         }
1131       }
1132     }
1133   }
1134 
1135   // Check for "((x >> C1) & Y) << C2"
1136   if (add1_op == Op_AndI) {
1137     Node *add2 = add1->in(1);
1138     int add2_op = add2->Opcode();
1139     if (add2_op == Op_RShiftI || add2_op == Op_URShiftI) {
1140       // Special case C1 == C2, which just masks off low bits
1141       if (add2->in(2) == in(2)) {
1142         // Convert to "(x & (Y << C2))"
1143         Node* y_sh = phase->transform(new LShiftINode(add1->in(2), phase->intcon(con)));
1144         return new AndINode(add2->in(1), y_sh);
1145       }
1146 
1147       int add2Con = 0;
1148       const_shift_count(phase, add2, &add2Con);
1149       if (add2Con > 0 && add2Con < BitsPerJavaInteger) {
1150         if (phase->is_IterGVN()) {
1151           // Convert to "((x >> C1) << C2) & (Y << C2)"
1152 
1153           // Make "(x >> C1) << C2", which will get folded away by the rule above
1154           Node* x_sh = phase->transform(new LShiftINode(add2, phase->intcon(con)));
1155           // Make "Y << C2", which will simplify when Y is a constant
1156           Node* y_sh = phase->transform(new LShiftINode(add1->in(2), phase->intcon(con)));
1157 
1158           return new AndINode(x_sh, y_sh);
1159         } else {
1160           phase->record_for_igvn(this);
1161         }
1162       }
1163     }
1164   }
1165 
1166   // Check for ((x & ((1<<(32-c0))-1)) << c0) which ANDs off high bits
1167   // before shifting them away.
1168   const jint bits_mask = right_n_bits(BitsPerJavaInteger-con);
1169   if( add1_op == Op_AndI &&
1170       phase->type(add1->in(2)) == TypeInt::make( bits_mask ) )
1171     return new LShiftINode( add1->in(1), in(2) );
1172 
1173   // Performs:
1174   // (X << con1) << con2 ==> X << (con1 + con2)
1175   Node* doubleShift = collapse_nested_shift_left(phase, this, con, T_INT);
1176   if (doubleShift != nullptr) {
1177     return doubleShift;
1178   }
1179 
1180   return nullptr;
1181 }
1182 
1183 //------------------------------Value------------------------------------------
1184 // A LShiftINode shifts its input2 left by input1 amount.
1185 const Type* LShiftINode::Value(PhaseGVN* phase) const {
1186   const Type *t1 = phase->type( in(1) );
1187   const Type *t2 = phase->type( in(2) );
1188   // Either input is TOP ==> the result is TOP
1189   if( t1 == Type::TOP ) return Type::TOP;
1190   if( t2 == Type::TOP ) return Type::TOP;
1191 
1192   // Left input is ZERO ==> the result is ZERO.
1193   if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
1194   // Shift by zero does nothing
1195   if( t2 == TypeInt::ZERO ) return t1;
1196 
1197   // Either input is BOTTOM ==> the result is BOTTOM
1198   if( (t1 == TypeInt::INT) || (t2 == TypeInt::INT) ||
1199       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
1200     return TypeInt::INT;
1201 
1202   const TypeInt *r1 = t1->is_int(); // Handy access
1203   const TypeInt *r2 = t2->is_int(); // Handy access
1204 
1205   if (!r2->is_con())
1206     return TypeInt::INT;
1207 
1208   uint shift = r2->get_con();
1209   shift &= BitsPerJavaInteger-1;  // semantics of Java shifts
1210   // Shift by a multiple of 32 does nothing:
1211   if (shift == 0)  return t1;
1212 
1213   // If the shift is a constant, shift the bounds of the type,
1214   // unless this could lead to an overflow.
1215   if (!r1->is_con()) {
1216     jint lo = r1->_lo, hi = r1->_hi;
1217     if (((lo << shift) >> shift) == lo &&
1218         ((hi << shift) >> shift) == hi) {
1219       // No overflow.  The range shifts up cleanly.
1220       return TypeInt::make((jint)lo << (jint)shift,
1221                            (jint)hi << (jint)shift,
1222                            MAX2(r1->_widen,r2->_widen));
1223     }
1224     return TypeInt::INT;
1225   }
1226 
1227   return TypeInt::make( (jint)r1->get_con() << (jint)shift );
1228 }
1229 
1230 //=============================================================================
1231 //------------------------------Identity---------------------------------------
1232 Node* LShiftLNode::Identity(PhaseGVN* phase) {
1233   int count = 0;
1234   if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaLong - 1)) == 0) {
1235     // Shift by a multiple of 64 does nothing
1236     return in(1);
1237   }
1238   return this;
1239 }
1240 
1241 //------------------------------Ideal------------------------------------------
1242 // If the right input is a constant, and the left input is an add of a
1243 // constant, flatten the tree: (X+con1)<<con0 ==> X<<con0 + con1<<con0
1244 //
1245 // Also collapse nested left-shifts with constant rhs:
1246 // (X << con1) << con2 ==> X << (con1 + con2)
1247 Node *LShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1248   int con = mask_and_replace_shift_amount(phase, this, BitsPerJavaLong);
1249   if (con == 0) {
1250     return nullptr;
1251   }
1252 
1253   // Left input is an add?
1254   Node *add1 = in(1);
1255   int add1_op = add1->Opcode();
1256   if( add1_op == Op_AddL ) {    // Left input is an add?
1257     // Avoid dead data cycles from dead loops
1258     assert( add1 != add1->in(1), "dead loop in LShiftLNode::Ideal" );
1259 
1260     // Left input is an add of the same number?
1261     if (con != (BitsPerJavaLong - 1) && add1->in(1) == add1->in(2)) {
1262       // Convert "(x + x) << c0" into "x << (c0 + 1)"
1263       // Can only be applied if c0 != 63 because:
1264       // (x + x) << 63 = 2x << 63, while
1265       // (x + x) << 63 --transform--> x << 64 = x << 0 = x (!= 2x << 63, for example for x = 1)
1266       // According to the Java spec, chapter 15.19, we only consider the six lowest-order bits of the right-hand operand
1267       // (i.e. "right-hand operand" & 0b111111). Therefore, x << 64 is the same as x << 0 (64 = 0b10000000 & 0b0111111 = 0).
1268       return new LShiftLNode(add1->in(1), phase->intcon(con + 1));
1269     }
1270 
1271     // Left input is an add of a constant?
1272     const TypeLong *t12 = phase->type(add1->in(2))->isa_long();
1273     if( t12 && t12->is_con() ){ // Left input is an add of a con?
1274       // Compute X << con0
1275       Node *lsh = phase->transform( new LShiftLNode( add1->in(1), in(2) ) );
1276       // Compute X<<con0 + (con1<<con0)
1277       return new AddLNode( lsh, phase->longcon(t12->get_con() << con));
1278     }
1279   }
1280 
1281   // Check for "(x >> C1) << C2"
1282   if (add1_op == Op_RShiftL || add1_op == Op_URShiftL) {
1283     int add1Con = 0;
1284     const_shift_count(phase, add1, &add1Con);
1285 
1286     // Special case C1 == C2, which just masks off low bits
1287     if (add1Con > 0 && con == add1Con) {
1288       // Convert to "(x & -(1 << C2))"
1289       return new AndLNode(add1->in(1), phase->longcon(java_negate(jlong(CONST64(1) << con))));
1290     } else {
1291       // Wait until the right shift has been sharpened to the correct count
1292       if (add1Con > 0 && add1Con < BitsPerJavaLong) {
1293         // As loop parsing can produce LShiftI nodes, we should wait until the graph is fully formed
1294         // to apply optimizations, otherwise we can inadvertently stop vectorization opportunities.
1295         if (phase->is_IterGVN()) {
1296           if (con > add1Con) {
1297             // Creates "(x << (C2 - C1)) & -(1 << C2)"
1298             Node* lshift = phase->transform(new LShiftLNode(add1->in(1), phase->intcon(con - add1Con)));
1299             return new AndLNode(lshift, phase->longcon(java_negate(jlong(CONST64(1) << con))));
1300           } else {
1301             assert(con < add1Con, "must be (%d < %d)", con, add1Con);
1302             // Creates "(x >> (C1 - C2)) & -(1 << C2)"
1303 
1304             // Handle logical and arithmetic shifts
1305             Node* rshift;
1306             if (add1_op == Op_RShiftL) {
1307               rshift = phase->transform(new RShiftLNode(add1->in(1), phase->intcon(add1Con - con)));
1308             } else {
1309               rshift = phase->transform(new URShiftLNode(add1->in(1), phase->intcon(add1Con - con)));
1310             }
1311 
1312             return new AndLNode(rshift, phase->longcon(java_negate(jlong(CONST64(1) << con))));
1313           }
1314         } else {
1315           phase->record_for_igvn(this);
1316         }
1317       }
1318     }
1319   }
1320 
1321   // Check for "((x >> C1) & Y) << C2"
1322   if (add1_op == Op_AndL) {
1323     Node* add2 = add1->in(1);
1324     int add2_op = add2->Opcode();
1325     if (add2_op == Op_RShiftL || add2_op == Op_URShiftL) {
1326       // Special case C1 == C2, which just masks off low bits
1327       if (add2->in(2) == in(2)) {
1328         // Convert to "(x & (Y << C2))"
1329         Node* y_sh = phase->transform(new LShiftLNode(add1->in(2), phase->intcon(con)));
1330         return new AndLNode(add2->in(1), y_sh);
1331       }
1332 
1333       int add2Con = 0;
1334       const_shift_count(phase, add2, &add2Con);
1335       if (add2Con > 0 && add2Con < BitsPerJavaLong) {
1336         if (phase->is_IterGVN()) {
1337           // Convert to "((x >> C1) << C2) & (Y << C2)"
1338 
1339           // Make "(x >> C1) << C2", which will get folded away by the rule above
1340           Node* x_sh = phase->transform(new LShiftLNode(add2, phase->intcon(con)));
1341           // Make "Y << C2", which will simplify when Y is a constant
1342           Node* y_sh = phase->transform(new LShiftLNode(add1->in(2), phase->intcon(con)));
1343 
1344           return new AndLNode(x_sh, y_sh);
1345         } else {
1346           phase->record_for_igvn(this);
1347         }
1348       }
1349     }
1350   }
1351 
1352   // Check for ((x & ((CONST64(1)<<(64-c0))-1)) << c0) which ANDs off high bits
1353   // before shifting them away.
1354   const jlong bits_mask = jlong(max_julong >> con);
1355   if( add1_op == Op_AndL &&
1356       phase->type(add1->in(2)) == TypeLong::make( bits_mask ) )
1357     return new LShiftLNode( add1->in(1), in(2) );
1358 
1359   // Performs:
1360   // (X << con1) << con2 ==> X << (con1 + con2)
1361   Node* doubleShift = collapse_nested_shift_left(phase, this, con, T_LONG);
1362   if (doubleShift != nullptr) {
1363     return doubleShift;
1364   }
1365 
1366   return nullptr;
1367 }
1368 
1369 //------------------------------Value------------------------------------------
1370 // A LShiftLNode shifts its input2 left by input1 amount.
1371 const Type* LShiftLNode::Value(PhaseGVN* phase) const {
1372   const Type *t1 = phase->type( in(1) );
1373   const Type *t2 = phase->type( in(2) );
1374   // Either input is TOP ==> the result is TOP
1375   if( t1 == Type::TOP ) return Type::TOP;
1376   if( t2 == Type::TOP ) return Type::TOP;
1377 
1378   // Left input is ZERO ==> the result is ZERO.
1379   if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
1380   // Shift by zero does nothing
1381   if( t2 == TypeInt::ZERO ) return t1;
1382 
1383   // Either input is BOTTOM ==> the result is BOTTOM
1384   if( (t1 == TypeLong::LONG) || (t2 == TypeInt::INT) ||
1385       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
1386     return TypeLong::LONG;
1387 
1388   const TypeLong *r1 = t1->is_long(); // Handy access
1389   const TypeInt  *r2 = t2->is_int();  // Handy access
1390 
1391   if (!r2->is_con())
1392     return TypeLong::LONG;
1393 
1394   uint shift = r2->get_con();
1395   shift &= BitsPerJavaLong - 1;  // semantics of Java shifts
1396   // Shift by a multiple of 64 does nothing:
1397   if (shift == 0)  return t1;
1398 
1399   // If the shift is a constant, shift the bounds of the type,
1400   // unless this could lead to an overflow.
1401   if (!r1->is_con()) {
1402     jlong lo = r1->_lo, hi = r1->_hi;
1403     if (((lo << shift) >> shift) == lo &&
1404         ((hi << shift) >> shift) == hi) {
1405       // No overflow.  The range shifts up cleanly.
1406       return TypeLong::make((jlong)lo << (jint)shift,
1407                             (jlong)hi << (jint)shift,
1408                             MAX2(r1->_widen,r2->_widen));
1409     }
1410     return TypeLong::LONG;
1411   }
1412 
1413   return TypeLong::make( (jlong)r1->get_con() << (jint)shift );
1414 }
1415 
1416 RShiftNode* RShiftNode::make(Node* in1, Node* in2, BasicType bt) {
1417   switch (bt) {
1418     case T_INT:
1419       return new RShiftINode(in1, in2);
1420     case T_LONG:
1421       return new RShiftLNode(in1, in2);
1422     default:
1423       fatal("Not implemented for %s", type2name(bt));
1424   }
1425   return nullptr;
1426 }
1427 
1428 
1429 //=============================================================================
1430 //------------------------------Identity---------------------------------------
1431 Node* RShiftNode::IdentityIL(PhaseGVN* phase, BasicType bt) {
1432   int count = 0;
1433   if (const_shift_count(phase, this, &count)) {
1434     if ((count & (bits_per_java_integer(bt) - 1)) == 0) {
1435       // Shift by a multiple of 32/64 does nothing
1436       return in(1);
1437     }
1438     // Check for useless sign-masking
1439     if (in(1)->Opcode() == Op_LShift(bt) &&
1440         in(1)->req() == 3 &&
1441         in(1)->in(2) == in(2)) {
1442       count &= bits_per_java_integer(bt) - 1; // semantics of Java shifts
1443       // Compute masks for which this shifting doesn't change
1444       jlong lo = (CONST64(-1) << (bits_per_java_integer(bt) - ((uint)count)-1)); // FFFF8000
1445       jlong hi = ~lo;                                                            // 00007FFF
1446       const TypeInteger* t11 = phase->type(in(1)->in(1))->isa_integer(bt);
1447       if (t11 == nullptr) {
1448         return this;
1449       }
1450       // Does actual value fit inside of mask?
1451       if (lo <= t11->lo_as_long() && t11->hi_as_long() <= hi) {
1452         return in(1)->in(1);      // Then shifting is a nop
1453       }
1454     }
1455   }
1456   return this;
1457 }
1458 
1459 Node* RShiftINode::Identity(PhaseGVN* phase) {
1460   return IdentityIL(phase, T_INT);
1461 }
1462 
1463 Node* RShiftNode::IdealIL(PhaseGVN* phase, bool can_reshape, BasicType bt) {
1464   // Inputs may be TOP if they are dead.
1465   const TypeInteger* t1 = phase->type(in(1))->isa_integer(bt);
1466   if (t1 == nullptr) {
1467     return NodeSentinel;        // Left input is an integer
1468   }
1469   int shift = mask_and_replace_shift_amount(phase, this, bits_per_java_integer(bt));
1470   if (shift == 0) {
1471     return NodeSentinel;
1472   }
1473 
1474   // Check for (x & 0xFF000000) >> 24, whose mask can be made smaller.
1475   // and convert to (x >> 24) & (0xFF000000 >> 24) = x >> 24
1476   // Such expressions arise normally from shift chains like (byte)(x >> 24).
1477   const Node* and_node = in(1);
1478   if (and_node->Opcode() != Op_And(bt)) {
1479     return nullptr;
1480   }
1481   const TypeInteger* mask_t = phase->type(and_node->in(2))->isa_integer(bt);
1482   if (mask_t != nullptr && mask_t->is_con()) {
1483     jlong maskbits = mask_t->get_con_as_long(bt);
1484     // Convert to "(x >> shift) & (mask >> shift)"
1485     Node* shr_nomask = phase->transform(RShiftNode::make(and_node->in(1), in(2), bt));
1486     return MulNode::make_and(shr_nomask, phase->integercon(maskbits >> shift, bt), bt);
1487   }
1488   return nullptr;
1489 }
1490 
1491 Node* RShiftINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1492   Node* progress = IdealIL(phase, can_reshape, T_INT);
1493   if (progress == NodeSentinel) {
1494     return nullptr;
1495   }
1496   if (progress != nullptr) {
1497     return progress;
1498   }
1499   int shift = mask_and_replace_shift_amount(phase, this, BitsPerJavaInteger);
1500   assert(shift != 0, "handled by IdealIL");
1501 
1502   // Check for "(short[i] <<16)>>16" which simply sign-extends
1503   const Node *shl = in(1);
1504   if (shl->Opcode() != Op_LShiftI) {
1505     return nullptr;
1506   }
1507 
1508   const TypeInt* left_shift_t = phase->type(shl->in(2))->isa_int();
1509   if (left_shift_t == nullptr) {
1510     return nullptr;
1511   }
1512   if (shift == 16 && left_shift_t->is_con(16)) {
1513     Node *ld = shl->in(1);
1514     if (ld->Opcode() == Op_LoadS) {
1515       // Sign extension is just useless here.  Return a RShiftI of zero instead
1516       // returning 'ld' directly.  We cannot return an old Node directly as
1517       // that is the job of 'Identity' calls and Identity calls only work on
1518       // direct inputs ('ld' is an extra Node removed from 'this').  The
1519       // combined optimization requires Identity only return direct inputs.
1520       set_req_X(1, ld, phase);
1521       set_req_X(2, phase->intcon(0), phase);
1522       return this;
1523     }
1524     else if (can_reshape &&
1525              ld->Opcode() == Op_LoadUS &&
1526              ld->outcnt() == 1 && ld->unique_out() == shl)
1527       // Replace zero-extension-load with sign-extension-load
1528       return ld->as_Load()->convert_to_signed_load(*phase);
1529   }
1530 
1531   // Check for "(byte[i] <<24)>>24" which simply sign-extends
1532   if (shift == 24 && left_shift_t->is_con(24)) {
1533     Node *ld = shl->in(1);
1534     if (ld->Opcode() == Op_LoadB) {
1535       // Sign extension is just useless here
1536       set_req_X(1, ld, phase);
1537       set_req_X(2, phase->intcon(0), phase);
1538       return this;
1539     }
1540   }
1541 
1542   return nullptr;
1543 }
1544 
1545 const Type* RShiftNode::ValueIL(PhaseGVN* phase, BasicType bt) const {
1546   const Type* t1 = phase->type(in(1));
1547   const Type* t2 = phase->type(in(2));
1548   // Either input is TOP ==> the result is TOP
1549   if (t1 == Type::TOP) {
1550     return Type::TOP;
1551   }
1552   if (t2 == Type::TOP) {
1553     return Type::TOP;
1554   }
1555 
1556   // Left input is ZERO ==> the result is ZERO.
1557   if (t1 == TypeInteger::zero(bt)) {
1558     return TypeInteger::zero(bt);
1559   }
1560   // Shift by zero does nothing
1561   if (t2 == TypeInt::ZERO) {
1562     return t1;
1563   }
1564 
1565   // Either input is BOTTOM ==> the result is BOTTOM
1566   if (t1 == Type::BOTTOM || t2 == Type::BOTTOM) {
1567     return TypeInteger::bottom(bt);
1568   }
1569 
1570   const TypeInteger* r1 = t1->isa_integer(bt);
1571   const TypeInt* r2 = t2->isa_int();
1572 
1573   // If the shift is a constant, just shift the bounds of the type.
1574   // For example, if the shift is 31/63, we just propagate sign bits.
1575   if (!r1->is_con() && r2->is_con()) {
1576     uint shift = r2->get_con();
1577     shift &= bits_per_java_integer(bt) - 1;  // semantics of Java shifts
1578     // Shift by a multiple of 32/64 does nothing:
1579     if (shift == 0) {
1580       return t1;
1581     }
1582     // Calculate reasonably aggressive bounds for the result.
1583     // This is necessary if we are to correctly type things
1584     // like (x<<24>>24) == ((byte)x).
1585     jlong lo = r1->lo_as_long() >> (jint)shift;
1586     jlong hi = r1->hi_as_long() >> (jint)shift;
1587     assert(lo <= hi, "must have valid bounds");
1588 #ifdef ASSERT
1589    if (bt == T_INT) {
1590      jint lo_verify = checked_cast<jint>(r1->lo_as_long()) >> (jint)shift;
1591      jint hi_verify = checked_cast<jint>(r1->hi_as_long()) >> (jint)shift;
1592      assert((checked_cast<jint>(lo) == lo_verify) && (checked_cast<jint>(hi) == hi_verify), "inconsistent");
1593    }
1594 #endif
1595     const TypeInteger* ti = TypeInteger::make(lo, hi, MAX2(r1->_widen,r2->_widen), bt);
1596 #ifdef ASSERT
1597     // Make sure we get the sign-capture idiom correct.
1598     if (shift == bits_per_java_integer(bt) - 1) {
1599       if (r1->lo_as_long() >= 0) {
1600         assert(ti == TypeInteger::zero(bt),    ">>31/63 of + is  0");
1601       }
1602       if (r1->hi_as_long() <  0) {
1603         assert(ti == TypeInteger::minus_1(bt), ">>31/63 of - is -1");
1604       }
1605     }
1606 #endif
1607     return ti;
1608   }
1609 
1610   if (!r1->is_con() || !r2->is_con()) {
1611     // If the left input is non-negative the result must also be non-negative, regardless of what the right input is.
1612     if (r1->lo_as_long() >= 0) {
1613       return TypeInteger::make(0, r1->hi_as_long(), MAX2(r1->_widen, r2->_widen), bt);
1614     }
1615 
1616     // Conversely, if the left input is negative then the result must be negative.
1617     if (r1->hi_as_long() <= -1) {
1618       return TypeInteger::make(r1->lo_as_long(), -1, MAX2(r1->_widen, r2->_widen), bt);
1619     }
1620 
1621     return TypeInteger::bottom(bt);
1622   }
1623 
1624   // Signed shift right
1625   return TypeInteger::make(r1->get_con_as_long(bt) >> (r2->get_con() & (bits_per_java_integer(bt) - 1)), bt);
1626 }
1627 
1628 const Type* RShiftINode::Value(PhaseGVN* phase) const {
1629   return ValueIL(phase, T_INT);
1630 }
1631 
1632 //=============================================================================
1633 //------------------------------Identity---------------------------------------
1634 Node* RShiftLNode::Identity(PhaseGVN* phase) {
1635   return IdentityIL(phase, T_LONG);
1636 }
1637 
1638 Node* RShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1639   Node* progress = IdealIL(phase, can_reshape, T_LONG);
1640   if (progress == NodeSentinel) {
1641     return nullptr;
1642   }
1643   return progress;
1644 }
1645 
1646 const Type* RShiftLNode::Value(PhaseGVN* phase) const {
1647   return ValueIL(phase, T_LONG);
1648 }
1649 
1650 //=============================================================================
1651 //------------------------------Identity---------------------------------------
1652 Node* URShiftINode::Identity(PhaseGVN* phase) {
1653   int count = 0;
1654   if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaInteger - 1)) == 0) {
1655     // Shift by a multiple of 32 does nothing
1656     return in(1);
1657   }
1658 
1659   // Check for "((x << LogBytesPerWord) + (wordSize-1)) >> LogBytesPerWord" which is just "x".
1660   // Happens during new-array length computation.
1661   // Safe if 'x' is in the range [0..(max_int>>LogBytesPerWord)]
1662   Node *add = in(1);
1663   if (add->Opcode() == Op_AddI) {
1664     const TypeInt *t2 = phase->type(add->in(2))->isa_int();
1665     if (t2 && t2->is_con(wordSize - 1) &&
1666         add->in(1)->Opcode() == Op_LShiftI) {
1667       // Check that shift_counts are LogBytesPerWord.
1668       Node          *lshift_count   = add->in(1)->in(2);
1669       const TypeInt *t_lshift_count = phase->type(lshift_count)->isa_int();
1670       if (t_lshift_count && t_lshift_count->is_con(LogBytesPerWord) &&
1671           t_lshift_count == phase->type(in(2))) {
1672         Node          *x   = add->in(1)->in(1);
1673         const TypeInt *t_x = phase->type(x)->isa_int();
1674         if (t_x != nullptr && 0 <= t_x->_lo && t_x->_hi <= (max_jint>>LogBytesPerWord)) {
1675           return x;
1676         }
1677       }
1678     }
1679   }
1680 
1681   return (phase->type(in(2))->higher_equal(TypeInt::ZERO)) ? in(1) : this;
1682 }
1683 
1684 //------------------------------Ideal------------------------------------------
1685 Node *URShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
1686   int con = mask_and_replace_shift_amount(phase, this, BitsPerJavaInteger);
1687   if (con == 0) {
1688     return nullptr;
1689   }
1690 
1691   // We'll be wanting the right-shift amount as a mask of that many bits
1692   const int mask = right_n_bits(BitsPerJavaInteger - con);
1693 
1694   int in1_op = in(1)->Opcode();
1695 
1696   // Check for ((x>>>a)>>>b) and replace with (x>>>(a+b)) when a+b < 32
1697   if( in1_op == Op_URShiftI ) {
1698     const TypeInt *t12 = phase->type( in(1)->in(2) )->isa_int();
1699     if( t12 && t12->is_con() ) { // Right input is a constant
1700       assert( in(1) != in(1)->in(1), "dead loop in URShiftINode::Ideal" );
1701       const int con2 = t12->get_con() & 31; // Shift count is always masked
1702       const int con3 = con+con2;
1703       if( con3 < 32 )           // Only merge shifts if total is < 32
1704         return new URShiftINode( in(1)->in(1), phase->intcon(con3) );
1705     }
1706   }
1707 
1708   // Check for ((x << z) + Y) >>> z.  Replace with x + con>>>z
1709   // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
1710   // If Q is "X << z" the rounding is useless.  Look for patterns like
1711   // ((X<<Z) + Y) >>> Z  and replace with (X + Y>>>Z) & Z-mask.
1712   Node *add = in(1);
1713   const TypeInt *t2 = phase->type(in(2))->isa_int();
1714   if (in1_op == Op_AddI) {
1715     Node *lshl = add->in(1);
1716     if( lshl->Opcode() == Op_LShiftI &&
1717         phase->type(lshl->in(2)) == t2 ) {
1718       Node *y_z = phase->transform( new URShiftINode(add->in(2),in(2)) );
1719       Node *sum = phase->transform( new AddINode( lshl->in(1), y_z ) );
1720       return new AndINode( sum, phase->intcon(mask) );
1721     }
1722   }
1723 
1724   // Check for (x & mask) >>> z.  Replace with (x >>> z) & (mask >>> z)
1725   // This shortens the mask.  Also, if we are extracting a high byte and
1726   // storing it to a buffer, the mask will be removed completely.
1727   Node *andi = in(1);
1728   if( in1_op == Op_AndI ) {
1729     const TypeInt *t3 = phase->type( andi->in(2) )->isa_int();
1730     if( t3 && t3->is_con() ) { // Right input is a constant
1731       jint mask2 = t3->get_con();
1732       mask2 >>= con;  // *signed* shift downward (high-order zeroes do not help)
1733       Node *newshr = phase->transform( new URShiftINode(andi->in(1), in(2)) );
1734       return new AndINode(newshr, phase->intcon(mask2));
1735       // The negative values are easier to materialize than positive ones.
1736       // A typical case from address arithmetic is ((x & ~15) >> 4).
1737       // It's better to change that to ((x >> 4) & ~0) versus
1738       // ((x >> 4) & 0x0FFFFFFF).  The difference is greatest in LP64.
1739     }
1740   }
1741 
1742   // Check for "(X << z ) >>> z" which simply zero-extends
1743   Node *shl = in(1);
1744   if( in1_op == Op_LShiftI &&
1745       phase->type(shl->in(2)) == t2 )
1746     return new AndINode( shl->in(1), phase->intcon(mask) );
1747 
1748   // Check for (x >> n) >>> 31. Replace with (x >>> 31)
1749   Node *shr = in(1);
1750   if ( in1_op == Op_RShiftI ) {
1751     Node *in11 = shr->in(1);
1752     Node *in12 = shr->in(2);
1753     const TypeInt *t11 = phase->type(in11)->isa_int();
1754     const TypeInt *t12 = phase->type(in12)->isa_int();
1755     if ( t11 && t2 && t2->is_con(31) && t12 && t12->is_con() ) {
1756       return new URShiftINode(in11, phase->intcon(31));
1757     }
1758   }
1759 
1760   return nullptr;
1761 }
1762 
1763 //------------------------------Value------------------------------------------
1764 // A URShiftINode shifts its input2 right by input1 amount.
1765 const Type* URShiftINode::Value(PhaseGVN* phase) const {
1766   // (This is a near clone of RShiftINode::Value.)
1767   const Type *t1 = phase->type( in(1) );
1768   const Type *t2 = phase->type( in(2) );
1769   // Either input is TOP ==> the result is TOP
1770   if( t1 == Type::TOP ) return Type::TOP;
1771   if( t2 == Type::TOP ) return Type::TOP;
1772 
1773   // Left input is ZERO ==> the result is ZERO.
1774   if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
1775   // Shift by zero does nothing
1776   if( t2 == TypeInt::ZERO ) return t1;
1777 
1778   // Either input is BOTTOM ==> the result is BOTTOM
1779   if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1780     return TypeInt::INT;
1781 
1782   if (t2 == TypeInt::INT)
1783     return TypeInt::INT;
1784 
1785   const TypeInt *r1 = t1->is_int();     // Handy access
1786   const TypeInt *r2 = t2->is_int();     // Handy access
1787 
1788   if (r2->is_con()) {
1789     uint shift = r2->get_con();
1790     shift &= BitsPerJavaInteger-1;  // semantics of Java shifts
1791     // Shift by a multiple of 32 does nothing:
1792     if (shift == 0)  return t1;
1793     // Calculate reasonably aggressive bounds for the result.
1794     jint lo = (juint)r1->_lo >> (juint)shift;
1795     jint hi = (juint)r1->_hi >> (juint)shift;
1796     if (r1->_hi >= 0 && r1->_lo < 0) {
1797       // If the type has both negative and positive values,
1798       // there are two separate sub-domains to worry about:
1799       // The positive half and the negative half.
1800       jint neg_lo = lo;
1801       jint neg_hi = (juint)-1 >> (juint)shift;
1802       jint pos_lo = (juint) 0 >> (juint)shift;
1803       jint pos_hi = hi;
1804       lo = MIN2(neg_lo, pos_lo);  // == 0
1805       hi = MAX2(neg_hi, pos_hi);  // == -1 >>> shift;
1806     }
1807     assert(lo <= hi, "must have valid bounds");
1808     const TypeInt* ti = TypeInt::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1809     #ifdef ASSERT
1810     // Make sure we get the sign-capture idiom correct.
1811     if (shift == BitsPerJavaInteger-1) {
1812       if (r1->_lo >= 0) assert(ti == TypeInt::ZERO, ">>>31 of + is 0");
1813       if (r1->_hi < 0)  assert(ti == TypeInt::ONE,  ">>>31 of - is +1");
1814     }
1815     #endif
1816     return ti;
1817   }
1818 
1819   //
1820   // Do not support shifted oops in info for GC
1821   //
1822   // else if( t1->base() == Type::InstPtr ) {
1823   //
1824   //   const TypeInstPtr *o = t1->is_instptr();
1825   //   if( t1->singleton() )
1826   //     return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift );
1827   // }
1828   // else if( t1->base() == Type::KlassPtr ) {
1829   //   const TypeKlassPtr *o = t1->is_klassptr();
1830   //   if( t1->singleton() )
1831   //     return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift );
1832   // }
1833 
1834   return TypeInt::INT;
1835 }
1836 
1837 //=============================================================================
1838 //------------------------------Identity---------------------------------------
1839 Node* URShiftLNode::Identity(PhaseGVN* phase) {
1840   int count = 0;
1841   if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaLong - 1)) == 0) {
1842     // Shift by a multiple of 64 does nothing
1843     return in(1);
1844   }
1845   return this;
1846 }
1847 
1848 //------------------------------Ideal------------------------------------------
1849 Node *URShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1850   int con = mask_and_replace_shift_amount(phase, this, BitsPerJavaLong);
1851   if (con == 0) {
1852     return nullptr;
1853   }
1854 
1855   // We'll be wanting the right-shift amount as a mask of that many bits
1856   const jlong mask = jlong(max_julong >> con);
1857 
1858   // Check for ((x << z) + Y) >>> z.  Replace with x + con>>>z
1859   // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
1860   // If Q is "X << z" the rounding is useless.  Look for patterns like
1861   // ((X<<Z) + Y) >>> Z  and replace with (X + Y>>>Z) & Z-mask.
1862   Node *add = in(1);
1863   const TypeInt *t2 = phase->type(in(2))->isa_int();
1864   if (add->Opcode() == Op_AddL) {
1865     Node *lshl = add->in(1);
1866     if( lshl->Opcode() == Op_LShiftL &&
1867         phase->type(lshl->in(2)) == t2 ) {
1868       Node *y_z = phase->transform( new URShiftLNode(add->in(2),in(2)) );
1869       Node *sum = phase->transform( new AddLNode( lshl->in(1), y_z ) );
1870       return new AndLNode( sum, phase->longcon(mask) );
1871     }
1872   }
1873 
1874   // Check for (x & mask) >>> z.  Replace with (x >>> z) & (mask >>> z)
1875   // This shortens the mask.  Also, if we are extracting a high byte and
1876   // storing it to a buffer, the mask will be removed completely.
1877   Node *andi = in(1);
1878   if( andi->Opcode() == Op_AndL ) {
1879     const TypeLong *t3 = phase->type( andi->in(2) )->isa_long();
1880     if( t3 && t3->is_con() ) { // Right input is a constant
1881       jlong mask2 = t3->get_con();
1882       mask2 >>= con;  // *signed* shift downward (high-order zeroes do not help)
1883       Node *newshr = phase->transform( new URShiftLNode(andi->in(1), in(2)) );
1884       return new AndLNode(newshr, phase->longcon(mask2));
1885     }
1886   }
1887 
1888   // Check for "(X << z ) >>> z" which simply zero-extends
1889   Node *shl = in(1);
1890   if( shl->Opcode() == Op_LShiftL &&
1891       phase->type(shl->in(2)) == t2 )
1892     return new AndLNode( shl->in(1), phase->longcon(mask) );
1893 
1894   // Check for (x >> n) >>> 63. Replace with (x >>> 63)
1895   Node *shr = in(1);
1896   if ( shr->Opcode() == Op_RShiftL ) {
1897     Node *in11 = shr->in(1);
1898     Node *in12 = shr->in(2);
1899     const TypeLong *t11 = phase->type(in11)->isa_long();
1900     const TypeInt *t12 = phase->type(in12)->isa_int();
1901     if ( t11 && t2 && t2->is_con(63) && t12 && t12->is_con() ) {
1902       return new URShiftLNode(in11, phase->intcon(63));
1903     }
1904   }
1905   return nullptr;
1906 }
1907 
1908 //------------------------------Value------------------------------------------
1909 // A URShiftINode shifts its input2 right by input1 amount.
1910 const Type* URShiftLNode::Value(PhaseGVN* phase) const {
1911   // (This is a near clone of RShiftLNode::Value.)
1912   const Type *t1 = phase->type( in(1) );
1913   const Type *t2 = phase->type( in(2) );
1914   // Either input is TOP ==> the result is TOP
1915   if( t1 == Type::TOP ) return Type::TOP;
1916   if( t2 == Type::TOP ) return Type::TOP;
1917 
1918   // Left input is ZERO ==> the result is ZERO.
1919   if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
1920   // Shift by zero does nothing
1921   if( t2 == TypeInt::ZERO ) return t1;
1922 
1923   // Either input is BOTTOM ==> the result is BOTTOM
1924   if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1925     return TypeLong::LONG;
1926 
1927   if (t2 == TypeInt::INT)
1928     return TypeLong::LONG;
1929 
1930   const TypeLong *r1 = t1->is_long(); // Handy access
1931   const TypeInt  *r2 = t2->is_int (); // Handy access
1932 
1933   if (r2->is_con()) {
1934     uint shift = r2->get_con();
1935     shift &= BitsPerJavaLong - 1;  // semantics of Java shifts
1936     // Shift by a multiple of 64 does nothing:
1937     if (shift == 0)  return t1;
1938     // Calculate reasonably aggressive bounds for the result.
1939     jlong lo = (julong)r1->_lo >> (juint)shift;
1940     jlong hi = (julong)r1->_hi >> (juint)shift;
1941     if (r1->_hi >= 0 && r1->_lo < 0) {
1942       // If the type has both negative and positive values,
1943       // there are two separate sub-domains to worry about:
1944       // The positive half and the negative half.
1945       jlong neg_lo = lo;
1946       jlong neg_hi = (julong)-1 >> (juint)shift;
1947       jlong pos_lo = (julong) 0 >> (juint)shift;
1948       jlong pos_hi = hi;
1949       //lo = MIN2(neg_lo, pos_lo);  // == 0
1950       lo = neg_lo < pos_lo ? neg_lo : pos_lo;
1951       //hi = MAX2(neg_hi, pos_hi);  // == -1 >>> shift;
1952       hi = neg_hi > pos_hi ? neg_hi : pos_hi;
1953     }
1954     assert(lo <= hi, "must have valid bounds");
1955     const TypeLong* tl = TypeLong::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1956     #ifdef ASSERT
1957     // Make sure we get the sign-capture idiom correct.
1958     if (shift == BitsPerJavaLong - 1) {
1959       if (r1->_lo >= 0) assert(tl == TypeLong::ZERO, ">>>63 of + is 0");
1960       if (r1->_hi < 0)  assert(tl == TypeLong::ONE,  ">>>63 of - is +1");
1961     }
1962     #endif
1963     return tl;
1964   }
1965 
1966   return TypeLong::LONG;                // Give up
1967 }
1968 
1969 //=============================================================================
1970 //------------------------------Ideal------------------------------------------
1971 Node* FmaNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1972   // We canonicalize the node by converting "(-a)*b+c" into "b*(-a)+c"
1973   // This reduces the number of rules in the matcher, as we only need to check
1974   // for negations on the second argument, and not the symmetric case where
1975   // the first argument is negated.
1976   if (in(1)->is_Neg() && !in(2)->is_Neg()) {
1977     swap_edges(1, 2);
1978     return this;
1979   }
1980   return nullptr;
1981 }
1982 
1983 //=============================================================================
1984 //------------------------------Value------------------------------------------
1985 const Type* FmaDNode::Value(PhaseGVN* phase) const {
1986   const Type *t1 = phase->type(in(1));
1987   if (t1 == Type::TOP) return Type::TOP;
1988   if (t1->base() != Type::DoubleCon) return Type::DOUBLE;
1989   const Type *t2 = phase->type(in(2));
1990   if (t2 == Type::TOP) return Type::TOP;
1991   if (t2->base() != Type::DoubleCon) return Type::DOUBLE;
1992   const Type *t3 = phase->type(in(3));
1993   if (t3 == Type::TOP) return Type::TOP;
1994   if (t3->base() != Type::DoubleCon) return Type::DOUBLE;
1995 #ifndef __STDC_IEC_559__
1996   return Type::DOUBLE;
1997 #else
1998   double d1 = t1->getd();
1999   double d2 = t2->getd();
2000   double d3 = t3->getd();
2001   return TypeD::make(fma(d1, d2, d3));
2002 #endif
2003 }
2004 
2005 //=============================================================================
2006 //------------------------------Value------------------------------------------
2007 const Type* FmaFNode::Value(PhaseGVN* phase) const {
2008   const Type *t1 = phase->type(in(1));
2009   if (t1 == Type::TOP) return Type::TOP;
2010   if (t1->base() != Type::FloatCon) return Type::FLOAT;
2011   const Type *t2 = phase->type(in(2));
2012   if (t2 == Type::TOP) return Type::TOP;
2013   if (t2->base() != Type::FloatCon) return Type::FLOAT;
2014   const Type *t3 = phase->type(in(3));
2015   if (t3 == Type::TOP) return Type::TOP;
2016   if (t3->base() != Type::FloatCon) return Type::FLOAT;
2017 #ifndef __STDC_IEC_559__
2018   return Type::FLOAT;
2019 #else
2020   float f1 = t1->getf();
2021   float f2 = t2->getf();
2022   float f3 = t3->getf();
2023   return TypeF::make(fma(f1, f2, f3));
2024 #endif
2025 }
2026 
2027 //=============================================================================
2028 //------------------------------Value------------------------------------------
2029 const Type* FmaHFNode::Value(PhaseGVN* phase) const {
2030   const Type* t1 = phase->type(in(1));
2031   if (t1 == Type::TOP) { return Type::TOP; }
2032   if (t1->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; }
2033   const Type* t2 = phase->type(in(2));
2034   if (t2 == Type::TOP) { return Type::TOP; }
2035   if (t2->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; }
2036   const Type* t3 = phase->type(in(3));
2037   if (t3 == Type::TOP) { return Type::TOP; }
2038   if (t3->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; }
2039 #ifndef __STDC_IEC_559__
2040   return Type::HALF_FLOAT;
2041 #else
2042   float f1 = t1->getf();
2043   float f2 = t2->getf();
2044   float f3 = t3->getf();
2045   return TypeH::make(fma(f1, f2, f3));
2046 #endif
2047 }
2048 
2049 //=============================================================================
2050 //------------------------------hash-------------------------------------------
2051 // Hash function for MulAddS2INode.  Operation is commutative with commutative pairs.
2052 // The hash function must return the same value when edge swapping is performed.
2053 uint MulAddS2INode::hash() const {
2054   return (uintptr_t)in(1) + (uintptr_t)in(2) + (uintptr_t)in(3) + (uintptr_t)in(4) + Opcode();
2055 }
2056 
2057 //------------------------------Rotate Operations ------------------------------
2058 
2059 Node* RotateLeftNode::Identity(PhaseGVN* phase) {
2060   const Type* t1 = phase->type(in(1));
2061   if (t1 == Type::TOP) {
2062     return this;
2063   }
2064   int count = 0;
2065   assert(t1->isa_int() || t1->isa_long(), "Unexpected type");
2066   int mask = (t1->isa_int() ? BitsPerJavaInteger : BitsPerJavaLong) - 1;
2067   if (const_shift_count(phase, this, &count) && (count & mask) == 0) {
2068     // Rotate by a multiple of 32/64 does nothing
2069     return in(1);
2070   }
2071   return this;
2072 }
2073 
2074 const Type* RotateLeftNode::Value(PhaseGVN* phase) const {
2075   const Type* t1 = phase->type(in(1));
2076   const Type* t2 = phase->type(in(2));
2077   // Either input is TOP ==> the result is TOP
2078   if (t1 == Type::TOP || t2 == Type::TOP) {
2079     return Type::TOP;
2080   }
2081 
2082   if (t1->isa_int()) {
2083     const TypeInt* r1 = t1->is_int();
2084     const TypeInt* r2 = t2->is_int();
2085 
2086     // Left input is ZERO ==> the result is ZERO.
2087     if (r1 == TypeInt::ZERO) {
2088       return TypeInt::ZERO;
2089     }
2090     // Rotate by zero does nothing
2091     if (r2 == TypeInt::ZERO) {
2092       return r1;
2093     }
2094     if (r1->is_con() && r2->is_con()) {
2095       juint r1_con = (juint)r1->get_con();
2096       juint shift = (juint)(r2->get_con()) & (juint)(BitsPerJavaInteger - 1); // semantics of Java shifts
2097       return TypeInt::make((r1_con << shift) | (r1_con >> (32 - shift)));
2098     }
2099     return TypeInt::INT;
2100   } else {
2101     assert(t1->isa_long(), "Type must be a long");
2102     const TypeLong* r1 = t1->is_long();
2103     const TypeInt*  r2 = t2->is_int();
2104 
2105     // Left input is ZERO ==> the result is ZERO.
2106     if (r1 == TypeLong::ZERO) {
2107       return TypeLong::ZERO;
2108     }
2109     // Rotate by zero does nothing
2110     if (r2 == TypeInt::ZERO) {
2111       return r1;
2112     }
2113     if (r1->is_con() && r2->is_con()) {
2114       julong r1_con = (julong)r1->get_con();
2115       julong shift = (julong)(r2->get_con()) & (julong)(BitsPerJavaLong - 1); // semantics of Java shifts
2116       return TypeLong::make((r1_con << shift) | (r1_con >> (64 - shift)));
2117     }
2118     return TypeLong::LONG;
2119   }
2120 }
2121 
2122 Node* RotateLeftNode::Ideal(PhaseGVN *phase, bool can_reshape) {
2123   const Type* t1 = phase->type(in(1));
2124   const Type* t2 = phase->type(in(2));
2125   if (t2->isa_int() && t2->is_int()->is_con()) {
2126     if (t1->isa_int()) {
2127       int lshift = t2->is_int()->get_con() & 31;
2128       return new RotateRightNode(in(1), phase->intcon(32 - (lshift & 31)), TypeInt::INT);
2129     } else if (t1 != Type::TOP) {
2130       assert(t1->isa_long(), "Type must be a long");
2131       int lshift = t2->is_int()->get_con() & 63;
2132       return new RotateRightNode(in(1), phase->intcon(64 - (lshift & 63)), TypeLong::LONG);
2133     }
2134   }
2135   return nullptr;
2136 }
2137 
2138 Node* RotateRightNode::Identity(PhaseGVN* phase) {
2139   const Type* t1 = phase->type(in(1));
2140   if (t1 == Type::TOP) {
2141     return this;
2142   }
2143   int count = 0;
2144   assert(t1->isa_int() || t1->isa_long(), "Unexpected type");
2145   int mask = (t1->isa_int() ? BitsPerJavaInteger : BitsPerJavaLong) - 1;
2146   if (const_shift_count(phase, this, &count) && (count & mask) == 0) {
2147     // Rotate by a multiple of 32/64 does nothing
2148     return in(1);
2149   }
2150   return this;
2151 }
2152 
2153 const Type* RotateRightNode::Value(PhaseGVN* phase) const {
2154   const Type* t1 = phase->type(in(1));
2155   const Type* t2 = phase->type(in(2));
2156   // Either input is TOP ==> the result is TOP
2157   if (t1 == Type::TOP || t2 == Type::TOP) {
2158     return Type::TOP;
2159   }
2160 
2161   if (t1->isa_int()) {
2162     const TypeInt* r1 = t1->is_int();
2163     const TypeInt* r2 = t2->is_int();
2164 
2165     // Left input is ZERO ==> the result is ZERO.
2166     if (r1 == TypeInt::ZERO) {
2167       return TypeInt::ZERO;
2168     }
2169     // Rotate by zero does nothing
2170     if (r2 == TypeInt::ZERO) {
2171       return r1;
2172     }
2173     if (r1->is_con() && r2->is_con()) {
2174       juint r1_con = (juint)r1->get_con();
2175       juint shift = (juint)(r2->get_con()) & (juint)(BitsPerJavaInteger - 1); // semantics of Java shifts
2176       return TypeInt::make((r1_con >> shift) | (r1_con << (32 - shift)));
2177     }
2178     return TypeInt::INT;
2179   } else {
2180     assert(t1->isa_long(), "Type must be a long");
2181     const TypeLong* r1 = t1->is_long();
2182     const TypeInt*  r2 = t2->is_int();
2183     // Left input is ZERO ==> the result is ZERO.
2184     if (r1 == TypeLong::ZERO) {
2185       return TypeLong::ZERO;
2186     }
2187     // Rotate by zero does nothing
2188     if (r2 == TypeInt::ZERO) {
2189       return r1;
2190     }
2191     if (r1->is_con() && r2->is_con()) {
2192       julong r1_con = (julong)r1->get_con();
2193       julong shift = (julong)(r2->get_con()) & (julong)(BitsPerJavaLong - 1); // semantics of Java shifts
2194       return TypeLong::make((r1_con >> shift) | (r1_con << (64 - shift)));
2195     }
2196     return TypeLong::LONG;
2197   }
2198 }
2199 
2200 //------------------------------ Sum & Mask ------------------------------
2201 
2202 // Returns a lower bound on the number of trailing zeros in expr.
2203 static jint AndIL_min_trailing_zeros(const PhaseGVN* phase, const Node* expr, BasicType bt) {
2204   const TypeInteger* type = phase->type(expr)->isa_integer(bt);
2205   if (type == nullptr) {
2206     return 0;
2207   }
2208 
2209   expr = expr->uncast();
2210   type = phase->type(expr)->isa_integer(bt);
2211   if (type == nullptr) {
2212     return 0;
2213   }
2214 
2215   if (type->is_con()) {
2216     jlong con = type->get_con_as_long(bt);
2217     return con == 0L ? (type2aelembytes(bt) * BitsPerByte) : count_trailing_zeros(con);
2218   }
2219 
2220   if (expr->Opcode() == Op_ConvI2L) {
2221     expr = expr->in(1)->uncast();
2222     bt = T_INT;
2223     type = phase->type(expr)->isa_int();
2224   }
2225 
2226   // Pattern: expr = (x << shift)
2227   if (expr->Opcode() == Op_LShift(bt)) {
2228     const TypeInt* shift_t = phase->type(expr->in(2))->isa_int();
2229     if (shift_t == nullptr || !shift_t->is_con()) {
2230       return 0;
2231     }
2232     // We need to truncate the shift, as it may not have been canonicalized yet.
2233     // T_INT:  0..31 -> shift_mask = 4 * 8 - 1 = 31
2234     // T_LONG: 0..63 -> shift_mask = 8 * 8 - 1 = 63
2235     // (JLS: "Shift Operators")
2236     jint shift_mask = type2aelembytes(bt) * BitsPerByte - 1;
2237     return shift_t->get_con() & shift_mask;
2238   }
2239 
2240   return 0;
2241 }
2242 
2243 // Checks whether expr is neutral additive element (zero) under mask,
2244 // i.e. whether an expression of the form:
2245 //   (AndX (AddX (expr addend) mask)
2246 //   (expr + addend) & mask
2247 // is equivalent to
2248 //   (AndX addend mask)
2249 //   addend & mask
2250 // for any addend.
2251 // (The X in AndX must be I or L, depending on bt).
2252 //
2253 // We check for the sufficient condition when the lowest set bit in expr is higher than
2254 // the highest set bit in mask, i.e.:
2255 // expr: eeeeee0000000000000
2256 // mask: 000000mmmmmmmmmmmmm
2257 //             <--w bits--->
2258 // We do not test for other cases.
2259 //
2260 // Correctness:
2261 //   Given "expr" with at least "w" trailing zeros,
2262 //   let "mod = 2^w", "suffix_mask = mod - 1"
2263 //
2264 //   Since "mask" only has bits set where "suffix_mask" does, we have:
2265 //     mask = suffix_mask & mask     (SUFFIX_MASK)
2266 //
2267 //   And since expr only has bits set above w, and suffix_mask only below:
2268 //     expr & suffix_mask == 0     (NO_BIT_OVERLAP)
2269 //
2270 //   From unsigned modular arithmetic (with unsigned modulo %), and since mod is
2271 //   a power of 2, and we are computing in a ring of powers of 2, we know that
2272 //     (x + y) % mod         = (x % mod         + y) % mod
2273 //     (x + y) & suffix_mask = (x & suffix_mask + y) & suffix_mask       (MOD_ARITH)
2274 //
2275 //   We can now prove the equality:
2276 //     (expr               + addend)               & mask
2277 //   = (expr               + addend) & suffix_mask & mask    (SUFFIX_MASK)
2278 //   = (expr & suffix_mask + addend) & suffix_mask & mask    (MOD_ARITH)
2279 //   = (0                  + addend) & suffix_mask & mask    (NO_BIT_OVERLAP)
2280 //   =                       addend                & mask    (SUFFIX_MASK)
2281 //
2282 // Hence, an expr with at least w trailing zeros is a neutral additive element under any mask with bit width w.
2283 static bool AndIL_is_zero_element_under_mask(const PhaseGVN* phase, const Node* expr, const Node* mask, BasicType bt) {
2284   // When the mask is negative, it has the most significant bit set.
2285   const TypeInteger* mask_t = phase->type(mask)->isa_integer(bt);
2286   if (mask_t == nullptr || mask_t->lo_as_long() < 0) {
2287     return false;
2288   }
2289 
2290   // When the mask is constant zero, we defer to MulNode::Value to eliminate the entire AndX operation.
2291   if (mask_t->hi_as_long() == 0) {
2292     assert(mask_t->lo_as_long() == 0, "checked earlier");
2293     return false;
2294   }
2295 
2296   jint mask_bit_width = BitsPerLong - count_leading_zeros(mask_t->hi_as_long());
2297   jint expr_trailing_zeros = AndIL_min_trailing_zeros(phase, expr, bt);
2298   return expr_trailing_zeros >= mask_bit_width;
2299 }
2300 
2301 // Reduces the pattern:
2302 //   (AndX (AddX add1 add2) mask)
2303 // to
2304 //   (AndX add1 mask), if add2 is neutral wrt mask (see above), and vice versa.
2305 Node* MulNode::AndIL_sum_and_mask(PhaseGVN* phase, BasicType bt) {
2306   Node* add = in(1);
2307   Node* mask = in(2);
2308   int addidx = 0;
2309   if (add->Opcode() == Op_Add(bt)) {
2310     addidx = 1;
2311   } else if (mask->Opcode() == Op_Add(bt)) {
2312     mask = add;
2313     addidx = 2;
2314     add = in(addidx);
2315   }
2316   if (addidx > 0) {
2317     Node* add1 = add->in(1);
2318     Node* add2 = add->in(2);
2319     if (AndIL_is_zero_element_under_mask(phase, add1, mask, bt)) {
2320       set_req_X(addidx, add2, phase);
2321       return this;
2322     } else if (AndIL_is_zero_element_under_mask(phase, add2, mask, bt)) {
2323       set_req_X(addidx, add1, phase);
2324       return this;
2325     }
2326   }
2327   return nullptr;
2328 }