1 /*
2 * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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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23 */
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/rangeinference.hpp"
33 #include "opto/subnode.hpp"
34 #include "utilities/powerOfTwo.hpp"
35
36 // Portions of code courtesy of Clifford Click
37
38
39 //=============================================================================
40 //------------------------------hash-------------------------------------------
41 // Hash function over MulNodes. Needs to be commutative; i.e., I swap
42 // (commute) inputs to MulNodes willy-nilly so the hash function must return
43 // the same value in the presence of edge swapping.
44 uint MulNode::hash() const {
45 return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
46 }
47
48 //------------------------------Identity---------------------------------------
49 // Multiplying a one preserves the other argument
50 Node* MulNode::Identity(PhaseGVN* phase) {
51 const Type *one = mul_id(); // The multiplicative identity
52 if( phase->type( in(1) )->higher_equal( one ) ) return in(2);
53 if( phase->type( in(2) )->higher_equal( one ) ) return in(1);
54
55 return this;
56 }
57
58 //------------------------------Ideal------------------------------------------
59 // We also canonicalize the Node, moving constants to the right input,
60 // and flatten expressions (so that 1+x+2 becomes x+3).
61 Node *MulNode::Ideal(PhaseGVN *phase, bool can_reshape) {
62 Node* in1 = in(1);
63 Node* in2 = in(2);
64 Node* progress = nullptr; // Progress flag
65
66 // This code is used by And nodes too, but some conversions are
67 // only valid for the actual Mul nodes.
68 uint op = Opcode();
69 bool real_mul = (op == Op_MulI) || (op == Op_MulL) ||
70 (op == Op_MulF) || (op == Op_MulD) ||
71 (op == Op_MulHF);
72
73 // Convert "(-a)*(-b)" into "a*b".
74 if (real_mul && in1->is_Sub() && in2->is_Sub()) {
75 if (phase->type(in1->in(1))->is_zero_type() &&
76 phase->type(in2->in(1))->is_zero_type()) {
77 set_req_X(1, in1->in(2), phase);
78 set_req_X(2, in2->in(2), phase);
79 in1 = in(1);
80 in2 = in(2);
81 progress = this;
82 }
83 }
84
85 // convert "max(a,b) * min(a,b)" into "a*b".
86 if ((in(1)->Opcode() == max_opcode() && in(2)->Opcode() == min_opcode())
87 || (in(1)->Opcode() == min_opcode() && in(2)->Opcode() == max_opcode())) {
88 Node *in11 = in(1)->in(1);
89 Node *in12 = in(1)->in(2);
90
91 Node *in21 = in(2)->in(1);
92 Node *in22 = in(2)->in(2);
93
94 if ((in11 == in21 && in12 == in22) ||
95 (in11 == in22 && in12 == in21)) {
96 set_req_X(1, in11, phase);
97 set_req_X(2, in12, phase);
98 in1 = in(1);
99 in2 = in(2);
100 progress = this;
101 }
102 }
103
104 const Type* t1 = phase->type(in1);
105 const Type* t2 = phase->type(in2);
106
107 // We are OK if right is a constant, or right is a load and
108 // left is a non-constant.
109 if( !(t2->singleton() ||
110 (in(2)->is_Load() && !(t1->singleton() || in(1)->is_Load())) ) ) {
111 if( t1->singleton() || // Left input is a constant?
112 // Otherwise, sort inputs (commutativity) to help value numbering.
113 (in(1)->_idx > in(2)->_idx) ) {
114 swap_edges(1, 2);
115 const Type *t = t1;
116 t1 = t2;
117 t2 = t;
118 progress = this; // Made progress
119 }
120 }
121
122 // If the right input is a constant, and the left input is a product of a
123 // constant, flatten the expression tree.
124 if( t2->singleton() && // Right input is a constant?
125 op != Op_MulF && // Float & double cannot reassociate
126 op != Op_MulD &&
127 op != Op_MulHF) {
128 if( t2 == Type::TOP ) return nullptr;
129 Node *mul1 = in(1);
130 #ifdef ASSERT
131 // Check for dead loop
132 int op1 = mul1->Opcode();
133 if ((mul1 == this) || (in(2) == this) ||
134 ((op1 == mul_opcode() || op1 == add_opcode()) &&
135 ((mul1->in(1) == this) || (mul1->in(2) == this) ||
136 (mul1->in(1) == mul1) || (mul1->in(2) == mul1)))) {
137 assert(false, "dead loop in MulNode::Ideal");
138 }
139 #endif
140
141 if( mul1->Opcode() == mul_opcode() ) { // Left input is a multiply?
142 // Mul of a constant?
143 const Type *t12 = phase->type( mul1->in(2) );
144 if( t12->singleton() && t12 != Type::TOP) { // Left input is an add of a constant?
145 // Compute new constant; check for overflow
146 const Type *tcon01 = ((MulNode*)mul1)->mul_ring(t2,t12);
147 if( tcon01->singleton() ) {
148 // The Mul of the flattened expression
149 set_req_X(1, mul1->in(1), phase);
150 set_req_X(2, phase->makecon(tcon01), phase);
151 t2 = tcon01;
152 progress = this; // Made progress
153 }
154 }
155 }
156 // If the right input is a constant, and the left input is an add of a
157 // constant, flatten the tree: (X+con1)*con0 ==> X*con0 + con1*con0
158 const Node *add1 = in(1);
159 if( add1->Opcode() == add_opcode() ) { // Left input is an add?
160 // Add of a constant?
161 const Type *t12 = phase->type( add1->in(2) );
162 if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
163 assert( add1->in(1) != add1, "dead loop in MulNode::Ideal" );
164 // Compute new constant; check for overflow
165 const Type *tcon01 = mul_ring(t2,t12);
166 if( tcon01->singleton() ) {
167
168 // Convert (X+con1)*con0 into X*con0
169 Node *mul = clone(); // mul = ()*con0
170 mul->set_req(1,add1->in(1)); // mul = X*con0
171 mul = phase->transform(mul);
172
173 Node *add2 = add1->clone();
174 add2->set_req(1, mul); // X*con0 + con0*con1
175 add2->set_req(2, phase->makecon(tcon01) );
176 progress = add2;
177 }
178 }
179 } // End of is left input an add
180 } // End of is right input a Mul
181
182 return progress;
183 }
184
185 //------------------------------Value-----------------------------------------
186 const Type* MulNode::Value(PhaseGVN* phase) const {
187 const Type *t1 = phase->type( in(1) );
188 const Type *t2 = phase->type( in(2) );
189 // Either input is TOP ==> the result is TOP
190 if( t1 == Type::TOP ) return Type::TOP;
191 if( t2 == Type::TOP ) return Type::TOP;
192
193 // Either input is ZERO ==> the result is ZERO.
194 // Not valid for floats or doubles since +0.0 * -0.0 --> +0.0
195 int op = Opcode();
196 if( op == Op_MulI || op == Op_AndI || op == Op_MulL || op == Op_AndL ) {
197 const Type *zero = add_id(); // The multiplicative zero
198 if( t1->higher_equal( zero ) ) return zero;
199 if( t2->higher_equal( zero ) ) return zero;
200 }
201
202 // TODO 8350865 Still needed? Yes, I think this is from PhaseMacroExpand::expand_mh_intrinsic_return
203 // Code pattern on return from a call that returns an __Value. Can
204 // be optimized away if the return value turns out to be an oop.
205 if (op == Op_AndX &&
206 in(1) != nullptr &&
207 in(1)->Opcode() == Op_CastP2X &&
208 in(1)->in(1) != nullptr &&
209 phase->type(in(1)->in(1))->isa_oopptr() &&
210 t2->isa_intptr_t()->_lo >= 0 &&
211 t2->isa_intptr_t()->_hi <= MinObjAlignmentInBytesMask) {
212 return add_id();
213 }
214
215 // Either input is BOTTOM ==> the result is the local BOTTOM
216 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
217 return bottom_type();
218
219 return mul_ring(t1,t2); // Local flavor of type multiplication
220 }
221
222 MulNode* MulNode::make(Node* in1, Node* in2, BasicType bt) {
223 switch (bt) {
224 case T_INT:
225 return new MulINode(in1, in2);
226 case T_LONG:
227 return new MulLNode(in1, in2);
228 default:
229 fatal("Not implemented for %s", type2name(bt));
230 }
231 return nullptr;
232 }
233
234 MulNode* MulNode::make_and(Node* in1, Node* in2, BasicType bt) {
235 switch (bt) {
236 case T_INT:
237 return new AndINode(in1, in2);
238 case T_LONG:
239 return new AndLNode(in1, in2);
240 default:
241 fatal("Not implemented for %s", type2name(bt));
242 }
243 return nullptr;
244 }
245
246
247 //=============================================================================
248 //------------------------------Ideal------------------------------------------
249 // Check for power-of-2 multiply, then try the regular MulNode::Ideal
250 Node *MulINode::Ideal(PhaseGVN *phase, bool can_reshape) {
251 const jint con = in(2)->find_int_con(0);
252 if (con == 0) {
253 // If in(2) is not a constant, call Ideal() of the parent class to
254 // try to move constant to the right side.
255 return MulNode::Ideal(phase, can_reshape);
256 }
257
258 // Now we have a constant Node on the right and the constant in con.
259 if (con == 1) {
260 // By one is handled by Identity call
261 return nullptr;
262 }
263
264 // Check for negative constant; if so negate the final result
265 bool sign_flip = false;
266
267 unsigned int abs_con = g_uabs(con);
268 if (abs_con != (unsigned int)con) {
269 sign_flip = true;
270 }
271
272 // Get low bit; check for being the only bit
273 Node *res = nullptr;
274 unsigned int bit1 = submultiple_power_of_2(abs_con);
275 if (bit1 == abs_con) { // Found a power of 2?
276 res = new LShiftINode(in(1), phase->intcon(log2i_exact(bit1)));
277 } else {
278 // Check for constant with 2 bits set
279 unsigned int bit2 = abs_con - bit1;
280 bit2 = bit2 & (0 - bit2); // Extract 2nd bit
281 if (bit2 + bit1 == abs_con) { // Found all bits in con?
282 Node *n1 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(bit1))));
283 Node *n2 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(bit2))));
284 res = new AddINode(n2, n1);
285 } else if (is_power_of_2(abs_con + 1)) {
286 // Sleezy: power-of-2 - 1. Next time be generic.
287 unsigned int temp = abs_con + 1;
288 Node *n1 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(temp))));
289 res = new SubINode(n1, in(1));
290 } else {
291 return MulNode::Ideal(phase, can_reshape);
292 }
293 }
294
295 if (sign_flip) { // Need to negate result?
296 res = phase->transform(res);// Transform, before making the zero con
297 res = new SubINode(phase->intcon(0),res);
298 }
299
300 return res; // Return final result
301 }
302
303 // This template class performs type multiplication for MulI/MulLNode. NativeType is either jint or jlong.
304 // In this class, the inputs of the MulNodes are named left and right with types [left_lo,left_hi] and [right_lo,right_hi].
305 //
306 // In general, the multiplication of two x-bit values could produce a result that consumes up to 2x bits if there is
307 // enough space to hold them all. We can therefore distinguish the following two cases for the product:
308 // - no overflow (i.e. product fits into x bits)
309 // - overflow (i.e. product does not fit into x bits)
310 //
311 // When multiplying the two x-bit inputs 'left' and 'right' with their x-bit types [left_lo,left_hi] and [right_lo,right_hi]
312 // we need to find the minimum and maximum of all possible products to define a new type. To do that, we compute the
313 // cross product of [left_lo,left_hi] and [right_lo,right_hi] in 2x-bit space where no over- or underflow can happen.
314 // The cross product consists of the following four multiplications with 2x-bit results:
315 // (1) left_lo * right_lo
316 // (2) left_lo * right_hi
317 // (3) left_hi * right_lo
318 // (4) left_hi * right_hi
319 //
320 // Let's define the following two functions:
321 // - Lx(i): Returns the lower x bits of the 2x-bit number i.
322 // - Ux(i): Returns the upper x bits of the 2x-bit number i.
323 //
324 // Let's first assume all products are positive where only overflows are possible but no underflows. If there is no
325 // overflow for a product p, then the upper x bits of the 2x-bit result p are all zero:
326 // Ux(p) = 0
327 // Lx(p) = p
328 //
329 // If none of the multiplications (1)-(4) overflow, we can truncate the upper x bits and use the following result type
330 // with x bits:
331 // [result_lo,result_hi] = [MIN(Lx(1),Lx(2),Lx(3),Lx(4)),MAX(Lx(1),Lx(2),Lx(3),Lx(4))]
332 //
333 // If any of these multiplications overflows, we could pessimistically take the bottom type for the x bit result
334 // (i.e. all values in the x-bit space could be possible):
335 // [result_lo,result_hi] = [NativeType_min,NativeType_max]
336 //
337 // However, in case of any overflow, we can do better by analyzing the upper x bits of all multiplications (1)-(4) with
338 // 2x-bit results. The upper x bits tell us something about how many times a multiplication has overflown the lower
339 // x bits. If the upper x bits of (1)-(4) are all equal, then we know that all of these multiplications overflowed
340 // the lower x bits the same number of times:
341 // Ux((1)) = Ux((2)) = Ux((3)) = Ux((4))
342 //
343 // If all upper x bits are equal, we can conclude:
344 // Lx(MIN((1),(2),(3),(4))) = MIN(Lx(1),Lx(2),Lx(3),Lx(4)))
345 // Lx(MAX((1),(2),(3),(4))) = MAX(Lx(1),Lx(2),Lx(3),Lx(4)))
346 //
347 // Therefore, we can use the same precise x-bit result type as for the no-overflow case:
348 // [result_lo,result_hi] = [(MIN(Lx(1),Lx(2),Lx(3),Lx(4))),MAX(Lx(1),Lx(2),Lx(3),Lx(4)))]
349 //
350 //
351 // Now let's assume that (1)-(4) are signed multiplications where over- and underflow could occur:
352 // Negative numbers are all sign extend with ones. Therefore, if a negative product does not underflow, then the
353 // 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,
354 // the upper x bits are decremented by the number of times an underflow occurred. The smallest possible negative product
355 // is NativeType_min*NativeType_max, where the upper x bits are set to NativeType_min / 2 (b11...0). It is therefore
356 // impossible to underflow the upper x bits. Thus, when having all ones (i.e. minus one) in the upper x bits, we know
357 // that there is no underflow.
358 //
359 // To be able to compare the number of over-/underflows of positive and negative products, respectively, we normalize
360 // the upper x bits of negative 2x-bit products by adding one. This way a product has no over- or underflow if the
361 // normalized upper x bits are zero. Now we can use the same improved type as for strictly positive products because we
362 // can compare the upper x bits in a unified way with N() being the normalization function:
363 // N(Ux((1))) = N(Ux((2))) = N(Ux((3)) = N(Ux((4)))
364 template<typename NativeType>
365 class IntegerTypeMultiplication {
366
367 NativeType _lo_left;
368 NativeType _lo_right;
369 NativeType _hi_left;
370 NativeType _hi_right;
371 short _widen_left;
372 short _widen_right;
373
374 static const Type* overflow_type();
375 static NativeType multiply_high(NativeType x, NativeType y);
376 const Type* create_type(NativeType lo, NativeType hi) const;
377
378 static NativeType multiply_high_signed_overflow_value(NativeType x, NativeType y) {
379 return normalize_overflow_value(x, y, multiply_high(x, y));
380 }
381
382 bool cross_product_not_same_overflow_value() const {
383 const NativeType lo_lo_high_product = multiply_high_signed_overflow_value(_lo_left, _lo_right);
384 const NativeType lo_hi_high_product = multiply_high_signed_overflow_value(_lo_left, _hi_right);
385 const NativeType hi_lo_high_product = multiply_high_signed_overflow_value(_hi_left, _lo_right);
386 const NativeType hi_hi_high_product = multiply_high_signed_overflow_value(_hi_left, _hi_right);
387 return lo_lo_high_product != lo_hi_high_product ||
388 lo_hi_high_product != hi_lo_high_product ||
389 hi_lo_high_product != hi_hi_high_product;
390 }
391
392 bool does_product_overflow(NativeType x, NativeType y) const {
393 return multiply_high_signed_overflow_value(x, y) != 0;
394 }
395
396 static NativeType normalize_overflow_value(const NativeType x, const NativeType y, NativeType result) {
397 return java_multiply(x, y) < 0 ? result + 1 : result;
398 }
399
400 public:
401 template<class IntegerType>
402 IntegerTypeMultiplication(const IntegerType* left, const IntegerType* right)
403 : _lo_left(left->_lo), _lo_right(right->_lo),
404 _hi_left(left->_hi), _hi_right(right->_hi),
405 _widen_left(left->_widen), _widen_right(right->_widen) {}
406
407 // Compute the product type by multiplying the two input type ranges. We take the minimum and maximum of all possible
408 // values (requires 4 multiplications of all possible combinations of the two range boundary values). If any of these
409 // multiplications overflows/underflows, we need to make sure that they all have the same number of overflows/underflows
410 // If that is not the case, we return the bottom type to cover all values due to the inconsistent overflows/underflows).
411 const Type* compute() const {
412 if (cross_product_not_same_overflow_value()) {
413 return overflow_type();
414 }
415
416 NativeType lo_lo_product = java_multiply(_lo_left, _lo_right);
417 NativeType lo_hi_product = java_multiply(_lo_left, _hi_right);
418 NativeType hi_lo_product = java_multiply(_hi_left, _lo_right);
419 NativeType hi_hi_product = java_multiply(_hi_left, _hi_right);
420 const NativeType min = MIN4(lo_lo_product, lo_hi_product, hi_lo_product, hi_hi_product);
421 const NativeType max = MAX4(lo_lo_product, lo_hi_product, hi_lo_product, hi_hi_product);
422 return create_type(min, max);
423 }
424
425 bool does_overflow() const {
426 return does_product_overflow(_lo_left, _lo_right) ||
427 does_product_overflow(_lo_left, _hi_right) ||
428 does_product_overflow(_hi_left, _lo_right) ||
429 does_product_overflow(_hi_left, _hi_right);
430 }
431 };
432
433 template <>
434 const Type* IntegerTypeMultiplication<jint>::overflow_type() {
435 return TypeInt::INT;
436 }
437
438 template <>
439 jint IntegerTypeMultiplication<jint>::multiply_high(const jint x, const jint y) {
440 const jlong x_64 = x;
441 const jlong y_64 = y;
442 const jlong product = x_64 * y_64;
443 return (jint)((uint64_t)product >> 32u);
444 }
445
446 template <>
447 const Type* IntegerTypeMultiplication<jint>::create_type(jint lo, jint hi) const {
448 return TypeInt::make(lo, hi, MAX2(_widen_left, _widen_right));
449 }
450
451 template <>
452 const Type* IntegerTypeMultiplication<jlong>::overflow_type() {
453 return TypeLong::LONG;
454 }
455
456 template <>
457 jlong IntegerTypeMultiplication<jlong>::multiply_high(const jlong x, const jlong y) {
458 return multiply_high_signed(x, y);
459 }
460
461 template <>
462 const Type* IntegerTypeMultiplication<jlong>::create_type(jlong lo, jlong hi) const {
463 return TypeLong::make(lo, hi, MAX2(_widen_left, _widen_right));
464 }
465
466 // Compute the product type of two integer ranges into this node.
467 const Type* MulINode::mul_ring(const Type* type_left, const Type* type_right) const {
468 const IntegerTypeMultiplication<jint> integer_multiplication(type_left->is_int(), type_right->is_int());
469 return integer_multiplication.compute();
470 }
471
472 bool MulINode::does_overflow(const TypeInt* type_left, const TypeInt* type_right) {
473 const IntegerTypeMultiplication<jint> integer_multiplication(type_left, type_right);
474 return integer_multiplication.does_overflow();
475 }
476
477 // Compute the product type of two long ranges into this node.
478 const Type* MulLNode::mul_ring(const Type* type_left, const Type* type_right) const {
479 const IntegerTypeMultiplication<jlong> integer_multiplication(type_left->is_long(), type_right->is_long());
480 return integer_multiplication.compute();
481 }
482
483 //=============================================================================
484 //------------------------------Ideal------------------------------------------
485 // Check for power-of-2 multiply, then try the regular MulNode::Ideal
486 Node *MulLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
487 const jlong con = in(2)->find_long_con(0);
488 if (con == 0) {
489 // If in(2) is not a constant, call Ideal() of the parent class to
490 // try to move constant to the right side.
491 return MulNode::Ideal(phase, can_reshape);
492 }
493
494 // Now we have a constant Node on the right and the constant in con.
495 if (con == 1) {
496 // By one is handled by Identity call
497 return nullptr;
498 }
499
500 // Check for negative constant; if so negate the final result
501 bool sign_flip = false;
502 julong abs_con = g_uabs(con);
503 if (abs_con != (julong)con) {
504 sign_flip = true;
505 }
506
507 // Get low bit; check for being the only bit
508 Node *res = nullptr;
509 julong bit1 = submultiple_power_of_2(abs_con);
510 if (bit1 == abs_con) { // Found a power of 2?
511 res = new LShiftLNode(in(1), phase->intcon(log2i_exact(bit1)));
512 } else {
513
514 // Check for constant with 2 bits set
515 julong bit2 = abs_con-bit1;
516 bit2 = bit2 & (0-bit2); // Extract 2nd bit
517 if (bit2 + bit1 == abs_con) { // Found all bits in con?
518 Node *n1 = phase->transform(new LShiftLNode(in(1), phase->intcon(log2i_exact(bit1))));
519 Node *n2 = phase->transform(new LShiftLNode(in(1), phase->intcon(log2i_exact(bit2))));
520 res = new AddLNode(n2, n1);
521
522 } else if (is_power_of_2(abs_con+1)) {
523 // Sleezy: power-of-2 -1. Next time be generic.
524 julong temp = abs_con + 1;
525 Node *n1 = phase->transform( new LShiftLNode(in(1), phase->intcon(log2i_exact(temp))));
526 res = new SubLNode(n1, in(1));
527 } else {
528 return MulNode::Ideal(phase, can_reshape);
529 }
530 }
531
532 if (sign_flip) { // Need to negate result?
533 res = phase->transform(res);// Transform, before making the zero con
534 res = new SubLNode(phase->longcon(0),res);
535 }
536
537 return res; // Return final result
538 }
539
540 //=============================================================================
541 //------------------------------mul_ring---------------------------------------
542 // Compute the product type of two double ranges into this node.
543 const Type *MulFNode::mul_ring(const Type *t0, const Type *t1) const {
544 if( t0 == Type::FLOAT || t1 == Type::FLOAT ) return Type::FLOAT;
545 return TypeF::make( t0->getf() * t1->getf() );
546 }
547
548 //------------------------------Ideal---------------------------------------
549 // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal
550 Node* MulFNode::Ideal(PhaseGVN* phase, bool can_reshape) {
551 const TypeF *t2 = phase->type(in(2))->isa_float_constant();
552
553 // x * 2 -> x + x
554 if (t2 != nullptr && t2->getf() == 2) {
555 Node* base = in(1);
556 return new AddFNode(base, base);
557 }
558 return MulNode::Ideal(phase, can_reshape);
559 }
560
561 //=============================================================================
562 //------------------------------Ideal------------------------------------------
563 // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal
564 Node* MulHFNode::Ideal(PhaseGVN* phase, bool can_reshape) {
565 const TypeH* t2 = phase->type(in(2))->isa_half_float_constant();
566
567 // x * 2 -> x + x
568 if (t2 != nullptr && t2->getf() == 2) {
569 Node* base = in(1);
570 return new AddHFNode(base, base);
571 }
572 return MulNode::Ideal(phase, can_reshape);
573 }
574
575 // Compute the product type of two half float ranges into this node.
576 const Type* MulHFNode::mul_ring(const Type* t0, const Type* t1) const {
577 if (t0 == Type::HALF_FLOAT || t1 == Type::HALF_FLOAT) {
578 return Type::HALF_FLOAT;
579 }
580 return TypeH::make(t0->getf() * t1->getf());
581 }
582
583 //=============================================================================
584 //------------------------------mul_ring---------------------------------------
585 // Compute the product type of two double ranges into this node.
586 const Type *MulDNode::mul_ring(const Type *t0, const Type *t1) const {
587 if( t0 == Type::DOUBLE || t1 == Type::DOUBLE ) return Type::DOUBLE;
588 // We must be multiplying 2 double constants.
589 return TypeD::make( t0->getd() * t1->getd() );
590 }
591
592 //------------------------------Ideal---------------------------------------
593 // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal
594 Node* MulDNode::Ideal(PhaseGVN* phase, bool can_reshape) {
595 const TypeD *t2 = phase->type(in(2))->isa_double_constant();
596
597 // x * 2 -> x + x
598 if (t2 != nullptr && t2->getd() == 2) {
599 Node* base = in(1);
600 return new AddDNode(base, base);
601 }
602
603 return MulNode::Ideal(phase, can_reshape);
604 }
605
606 //=============================================================================
607 //------------------------------Value------------------------------------------
608 const Type* MulHiLNode::Value(PhaseGVN* phase) const {
609 const Type *t1 = phase->type( in(1) );
610 const Type *t2 = phase->type( in(2) );
611 const Type *bot = bottom_type();
612 return MulHiValue(t1, t2, bot);
613 }
614
615 const Type* UMulHiLNode::Value(PhaseGVN* phase) const {
616 const Type *t1 = phase->type( in(1) );
617 const Type *t2 = phase->type( in(2) );
618 const Type *bot = bottom_type();
619 return MulHiValue(t1, t2, bot);
620 }
621
622 // A common routine used by UMulHiLNode and MulHiLNode
623 const Type* MulHiValue(const Type *t1, const Type *t2, const Type *bot) {
624 // Either input is TOP ==> the result is TOP
625 if( t1 == Type::TOP ) return Type::TOP;
626 if( t2 == Type::TOP ) return Type::TOP;
627
628 // Either input is BOTTOM ==> the result is the local BOTTOM
629 if( (t1 == bot) || (t2 == bot) ||
630 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
631 return bot;
632
633 // It is not worth trying to constant fold this stuff!
634 return TypeLong::LONG;
635 }
636
637 //=============================================================================
638 //------------------------------mul_ring---------------------------------------
639 // Supplied function returns the product of the inputs IN THE CURRENT RING.
640 // For the logical operations the ring's MUL is really a logical AND function.
641 // This also type-checks the inputs for sanity. Guaranteed never to
642 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
643 const Type* AndINode::mul_ring(const Type* t1, const Type* t2) const {
644 return RangeInference::infer_and(t1->is_int(), t2->is_int());
645 }
646
647 static bool AndIL_is_zero_element_under_mask(const PhaseGVN* phase, const Node* expr, const Node* mask, BasicType bt);
648
649 const Type* AndINode::Value(PhaseGVN* phase) const {
650 if (AndIL_is_zero_element_under_mask(phase, in(1), in(2), T_INT) ||
651 AndIL_is_zero_element_under_mask(phase, in(2), in(1), T_INT)) {
652 return TypeInt::ZERO;
653 }
654
655 return MulNode::Value(phase);
656 }
657
658 //------------------------------Identity---------------------------------------
659 // Masking off the high bits of an unsigned load is not required
660 Node* AndINode::Identity(PhaseGVN* phase) {
661
662 // x & x => x
663 if (in(1) == in(2)) {
664 return in(1);
665 }
666
667 const TypeInt* t1 = phase->type(in(1))->is_int();
668 const TypeInt* t2 = phase->type(in(2))->is_int();
669
670 if ((~t1->_bits._ones & ~t2->_bits._zeros) == 0) {
671 // All bits that might be 0 in in1 are known to be 0 in in2
672 return in(2);
673 }
674
675 if ((~t2->_bits._ones & ~t1->_bits._zeros) == 0) {
676 // All bits that might be 0 in in2 are known to be 0 in in1
677 return in(1);
678 }
679
680 return MulNode::Identity(phase);
681 }
682
683 //------------------------------Ideal------------------------------------------
684 Node *AndINode::Ideal(PhaseGVN *phase, bool can_reshape) {
685 // Simplify (v1 + v2) & mask to v1 & mask or v2 & mask when possible.
686 Node* progress = AndIL_sum_and_mask(phase, T_INT);
687 if (progress != nullptr) {
688 return progress;
689 }
690
691 // Convert "(~a) & (~b)" into "~(a | b)"
692 if (AddNode::is_not(phase, in(1), T_INT) && AddNode::is_not(phase, in(2), T_INT)) {
693 Node* or_a_b = new OrINode(in(1)->in(1), in(2)->in(1));
694 Node* tn = phase->transform(or_a_b);
695 return AddNode::make_not(phase, tn, T_INT);
696 }
697
698 // Special case constant AND mask
699 const TypeInt *t2 = phase->type( in(2) )->isa_int();
700 if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
701 const int mask = t2->get_con();
702 Node *load = in(1);
703 uint lop = load->Opcode();
704
705 // Masking bits off of a Character? Hi bits are already zero.
706 if( lop == Op_LoadUS &&
707 (mask & 0xFFFF0000) ) // Can we make a smaller mask?
708 return new AndINode(load,phase->intcon(mask&0xFFFF));
709
710 // Masking bits off of a Short? Loading a Character does some masking
711 if (can_reshape &&
712 load->outcnt() == 1 && load->unique_out() == this) {
713 if (lop == Op_LoadS && (mask & 0xFFFF0000) == 0 ) {
714 Node* ldus = load->as_Load()->convert_to_unsigned_load(*phase);
715 ldus = phase->transform(ldus);
716 return new AndINode(ldus, phase->intcon(mask & 0xFFFF));
717 }
718
719 // Masking sign bits off of a Byte? Do an unsigned byte load plus
720 // an and.
721 if (lop == Op_LoadB && (mask & 0xFFFFFF00) == 0) {
722 Node* ldub = load->as_Load()->convert_to_unsigned_load(*phase);
723 ldub = phase->transform(ldub);
724 return new AndINode(ldub, phase->intcon(mask));
725 }
726 }
727
728 // Masking off sign bits? Dont make them!
729 if( lop == Op_RShiftI ) {
730 const TypeInt *t12 = phase->type(load->in(2))->isa_int();
731 if( t12 && t12->is_con() ) { // Shift is by a constant
732 int shift = t12->get_con();
733 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
734 const int sign_bits_mask = ~right_n_bits(BitsPerJavaInteger - shift);
735 // If the AND'ing of the 2 masks has no bits, then only original shifted
736 // bits survive. NO sign-extension bits survive the maskings.
737 if( (sign_bits_mask & mask) == 0 ) {
738 // Use zero-fill shift instead
739 Node *zshift = phase->transform(new URShiftINode(load->in(1),load->in(2)));
740 return new AndINode( zshift, in(2) );
741 }
742 }
743 }
744
745 // Check for 'negate/and-1', a pattern emitted when someone asks for
746 // 'mod 2'. Negate leaves the low order bit unchanged (think: complement
747 // plus 1) and the mask is of the low order bit. Skip the negate.
748 if( lop == Op_SubI && mask == 1 && load->in(1) &&
749 phase->type(load->in(1)) == TypeInt::ZERO )
750 return new AndINode( load->in(2), in(2) );
751
752 return MulNode::Ideal(phase, can_reshape);
753 }
754
755 //=============================================================================
756 //------------------------------mul_ring---------------------------------------
757 // Supplied function returns the product of the inputs IN THE CURRENT RING.
758 // For the logical operations the ring's MUL is really a logical AND function.
759 // This also type-checks the inputs for sanity. Guaranteed never to
760 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
761 const Type* AndLNode::mul_ring(const Type* t1, const Type* t2) const {
762 return RangeInference::infer_and(t1->is_long(), t2->is_long());
763 }
764
765 const Type* AndLNode::Value(PhaseGVN* phase) const {
766 if (AndIL_is_zero_element_under_mask(phase, in(1), in(2), T_LONG) ||
767 AndIL_is_zero_element_under_mask(phase, in(2), in(1), T_LONG)) {
768 return TypeLong::ZERO;
769 }
770
771 return MulNode::Value(phase);
772 }
773
774 //------------------------------Identity---------------------------------------
775 // Masking off the high bits of an unsigned load is not required
776 Node* AndLNode::Identity(PhaseGVN* phase) {
777
778 // x & x => x
779 if (in(1) == in(2)) {
780 return in(1);
781 }
782
783 const TypeLong* t1 = phase->type(in(1))->is_long();
784 const TypeLong* t2 = phase->type(in(2))->is_long();
785
786 if ((~t1->_bits._ones & ~t2->_bits._zeros) == 0) {
787 // All bits that might be 0 in in1 are known to be 0 in in2
788 return in(2);
789 }
790
791 if ((~t2->_bits._ones & ~t1->_bits._zeros) == 0) {
792 // All bits that might be 0 in in2 are known to be 0 in in1
793 return in(1);
794 }
795
796 return MulNode::Identity(phase);
797 }
798
799 //------------------------------Ideal------------------------------------------
800 Node *AndLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
801 // Simplify (v1 + v2) & mask to v1 & mask or v2 & mask when possible.
802 Node* progress = AndIL_sum_and_mask(phase, T_LONG);
803 if (progress != nullptr) {
804 return progress;
805 }
806
807 // Convert "(~a) & (~b)" into "~(a | b)"
808 if (AddNode::is_not(phase, in(1), T_LONG) && AddNode::is_not(phase, in(2), T_LONG)) {
809 Node* or_a_b = new OrLNode(in(1)->in(1), in(2)->in(1));
810 Node* tn = phase->transform(or_a_b);
811 return AddNode::make_not(phase, tn, T_LONG);
812 }
813
814 // Special case constant AND mask
815 const TypeLong *t2 = phase->type( in(2) )->isa_long();
816 if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
817 const jlong mask = t2->get_con();
818
819 Node* in1 = in(1);
820 int op = in1->Opcode();
821
822 // Are we masking a long that was converted from an int with a mask
823 // that fits in 32-bits? Commute them and use an AndINode. Don't
824 // convert masks which would cause a sign extension of the integer
825 // value. This check includes UI2L masks (0x00000000FFFFFFFF) which
826 // would be optimized away later in Identity.
827 if (op == Op_ConvI2L && (mask & UCONST64(0xFFFFFFFF80000000)) == 0) {
828 Node* andi = new AndINode(in1->in(1), phase->intcon(mask));
829 andi = phase->transform(andi);
830 return new ConvI2LNode(andi);
831 }
832
833 // Masking off sign bits? Dont make them!
834 if (op == Op_RShiftL) {
835 const TypeInt* t12 = phase->type(in1->in(2))->isa_int();
836 if( t12 && t12->is_con() ) { // Shift is by a constant
837 int shift = t12->get_con();
838 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
839 if (shift != 0) {
840 const julong sign_bits_mask = ~(((julong)CONST64(1) << (julong)(BitsPerJavaLong - shift)) -1);
841 // If the AND'ing of the 2 masks has no bits, then only original shifted
842 // bits survive. NO sign-extension bits survive the maskings.
843 if( (sign_bits_mask & mask) == 0 ) {
844 // Use zero-fill shift instead
845 Node *zshift = phase->transform(new URShiftLNode(in1->in(1), in1->in(2)));
846 return new AndLNode(zshift, in(2));
847 }
848 }
849 }
850 }
851
852 // Search for GraphKit::mark_word_test patterns and fold the test if the result is statically known
853 Node* load1 = in(1);
854 Node* load2 = nullptr;
855 if (load1->is_Phi() && phase->type(load1)->isa_long()) {
856 load1 = in(1)->in(1);
857 load2 = in(1)->in(2);
858 }
859 if (load1 != nullptr && load1->is_Load() && phase->type(load1)->isa_long() &&
860 (load2 == nullptr || (load2->is_Load() && phase->type(load2)->isa_long()))) {
861 const TypePtr* adr_t1 = phase->type(load1->in(MemNode::Address))->isa_ptr();
862 const TypePtr* adr_t2 = (load2 != nullptr) ? phase->type(load2->in(MemNode::Address))->isa_ptr() : nullptr;
863 if (adr_t1 != nullptr && adr_t1->offset() == oopDesc::mark_offset_in_bytes() &&
864 (load2 == nullptr || (adr_t2 != nullptr && adr_t2->offset() == in_bytes(Klass::prototype_header_offset())))) {
865 if (mask == markWord::inline_type_pattern) {
866 if (adr_t1->is_inlinetypeptr()) {
867 set_req_X(1, in(2), phase);
868 return this;
869 } else if (!adr_t1->can_be_inline_type()) {
870 set_req_X(1, phase->longcon(0), phase);
871 return this;
872 }
873 } else if (mask == markWord::null_free_array_bit_in_place) {
874 if (adr_t1->is_null_free()) {
875 set_req_X(1, in(2), phase);
876 return this;
877 } else if (adr_t1->is_not_null_free()) {
878 set_req_X(1, phase->longcon(0), phase);
879 return this;
880 }
881 } else if (mask == markWord::flat_array_bit_in_place) {
882 if (adr_t1->is_flat()) {
883 set_req_X(1, in(2), phase);
884 return this;
885 } else if (adr_t1->is_not_flat()) {
886 set_req_X(1, phase->longcon(0), phase);
887 return this;
888 }
889 }
890 }
891 }
892
893 return MulNode::Ideal(phase, can_reshape);
894 }
895
896 LShiftNode* LShiftNode::make(Node* in1, Node* in2, BasicType bt) {
897 switch (bt) {
898 case T_INT:
899 return new LShiftINode(in1, in2);
900 case T_LONG:
901 return new LShiftLNode(in1, in2);
902 default:
903 fatal("Not implemented for %s", type2name(bt));
904 }
905 return nullptr;
906 }
907
908 // Returns whether the shift amount is constant or effectively constant (low bits known).
909 //
910 // Parameters:
911 // masked_shift - always initialized to 0; if the function returns true, it indicates
912 // the masked shift amount.
913 // replace - always initialized to false; if the function returns true, it indicates
914 // whether the shift_node's shift count input should be replaced with masked_shift.
915 static bool mask_shift_amount(PhaseGVN* phase, const Node* shift_node, uint num_bits, uint& masked_shift, bool& replace) {
916 masked_shift = 0;
917 replace = false;
918
919 const TypeInt* tcount = phase->type(shift_node->in(2))->isa_int();
920
921 if (tcount != nullptr) {
922 uint mask = num_bits - 1;
923 // Canonicalize shift count via type-level masking to expose constants
924 const TypeInt* masked_type = RangeInference::infer_and(tcount, TypeInt::make(mask));
925 if (masked_type != nullptr && masked_type->is_con()) {
926 masked_shift = masked_type->get_con();
927 replace = !tcount->is_con() || (tcount->get_con() != (int)masked_shift);
928 return true;
929 }
930 }
931 return false;
932 }
933
934 // Convenience for when we don't care about the 'replace' output.
935 static bool mask_shift_amount(PhaseGVN* phase, const Node* shift_node, uint num_bits, uint& masked_shift) {
936 bool unused;
937 return mask_shift_amount(phase, shift_node, num_bits, masked_shift, unused /*replace*/);
938 }
939
940 // Use this in ::Ideal only with shiftNode == this!
941 // Sets masked_shift to the effective masked shift amount if constant or 0 if not constant.
942 // Returns shift_node if the shift amount input node was modified, nullptr otherwise.
943 static Node* mask_and_replace_shift_amount(PhaseGVN* phase, Node* shift_node, uint num_bits, uint& masked_shift) {
944 if (bool replace; mask_shift_amount(phase, shift_node, num_bits, masked_shift, replace)) {
945 if (masked_shift == 0) {
946 // Let Identity() handle 0 shift count.
947 return nullptr;
948 }
949
950 if (replace) {
951 shift_node->set_req(2, phase->intcon(masked_shift)); // Replace shift count with masked value.
952
953 // We need to notify the caller that the graph was reshaped, as Ideal needs
954 // to return the root of the reshaped graph if any change was made.
955 return shift_node;
956 }
957 }
958
959 return nullptr;
960 }
961
962 // Called with
963 // outer_shift = (_ << rhs_outer)
964 // We are looking for the pattern:
965 // outer_shift = ((X << rhs_inner) << rhs_outer)
966 // where rhs_outer and rhs_inner are constant
967 // we denote inner_shift the nested expression (X << rhs_inner)
968 // con_inner = rhs_inner % nbits and con_outer = rhs_outer % nbits
969 // where nbits is the number of bits of the shifts
970 //
971 // There are 2 cases:
972 // if con_outer + con_inner >= nbits => 0
973 // if con_outer + con_inner < nbits => X << (con_outer + con_inner)
974 static Node* collapse_nested_shift_left(PhaseGVN* phase, const Node* outer_shift, uint con_outer, BasicType bt) {
975 assert(bt == T_LONG || bt == T_INT, "Unexpected type");
976 const Node* inner_shift = outer_shift->in(1);
977 if (inner_shift->Opcode() != Op_LShift(bt)) {
978 return nullptr;
979 }
980
981 uint nbits = bits_per_java_integer(bt);
982 uint con_inner;
983 if (!mask_shift_amount(phase, inner_shift, nbits, con_inner)) {
984 return nullptr;
985 }
986
987 if (con_inner == 0) {
988 // We let the Identity() of the inner shift do its job.
989 return nullptr;
990 }
991
992 if (con_outer + con_inner >= nbits) {
993 // While it might be tempting to use
994 // phase->zerocon(bt);
995 // it would be incorrect: zerocon caches nodes, while Ideal is only allowed
996 // to return a new node, this or nullptr, but not an old (cached) node.
997 return ConNode::make(TypeInteger::zero(bt));
998 }
999
1000 // con0 + con1 < nbits ==> actual shift happens now
1001 Node* con0_plus_con1 = phase->intcon(con_outer + con_inner);
1002 return LShiftNode::make(inner_shift->in(1), con0_plus_con1, bt);
1003 }
1004
1005 //------------------------------Identity---------------------------------------
1006 Node* LShiftINode::Identity(PhaseGVN* phase) {
1007 return IdentityIL(phase, T_INT);
1008 }
1009
1010 Node* LShiftNode::IdealIL(PhaseGVN* phase, bool can_reshape, BasicType bt) {
1011 uint con;
1012 uint num_bits = bits_per_java_integer(bt);
1013 Node* progress = mask_and_replace_shift_amount(phase, this, num_bits, con);
1014 if (con == 0) {
1015 return nullptr;
1016 }
1017
1018 // If the right input is a constant, and the left input is an add of a
1019 // constant, flatten the tree: (X+con1)<<con0 ==> X<<con0 + con1<<con0
1020 Node* add1 = in(1);
1021 int add1_op = add1->Opcode();
1022 if (add1_op == Op_Add(bt)) { // Left input is an add?
1023 assert(add1 != add1->in(1), "dead loop in LShiftINode::Ideal");
1024
1025 // Transform is legal, but check for profit. Avoid breaking 'i2s'
1026 // and 'i2b' patterns which typically fold into 'StoreC/StoreB'.
1027 if (bt != T_INT || con < 16) {
1028 // Left input is an add of the same number?
1029 if (con != (num_bits - 1) && add1->in(1) == add1->in(2)) {
1030 // Convert "(x + x) << c0" into "x << (c0 + 1)"
1031 // In general, this optimization cannot be applied for c0 == 31 (for LShiftI) since
1032 // 2x << 31 != x << 32 = x << 0 = x (e.g. x = 1: 2 << 31 = 0 != 1)
1033 // or c0 != 63 (for LShiftL) because:
1034 // (x + x) << 63 = 2x << 63, while
1035 // (x + x) << 63 --transform--> x << 64 = x << 0 = x (!= 2x << 63, for example for x = 1)
1036 // According to the Java spec, chapter 15.19, we only consider the six lowest-order bits of the right-hand operand
1037 // (i.e. "right-hand operand" & 0b111111). Therefore, x << 64 is the same as x << 0 (64 = 0b10000000 & 0b0111111 = 0).
1038 return LShiftNode::make(add1->in(1), phase->intcon(con + 1), bt);
1039 }
1040
1041 // Left input is an add of a constant?
1042 const TypeInteger* t12 = phase->type(add1->in(2))->isa_integer(bt);
1043 if (t12 != nullptr && t12->is_con()) { // Left input is an add of a con?
1044 // Compute X << con0
1045 Node* lsh = phase->transform(LShiftNode::make(add1->in(1), in(2), bt));
1046 // Compute X<<con0 + (con1<<con0)
1047 return AddNode::make(lsh, phase->integercon(java_shift_left(t12->get_con_as_long(bt), con, bt), bt), bt);
1048 }
1049 }
1050 }
1051 // Check for "(con0 - X) << con1"
1052 // Transform is legal, but check for profit. Avoid breaking 'i2s'
1053 // and 'i2b' patterns which typically fold into 'StoreC/StoreB'.
1054 if (add1_op == Op_Sub(bt) && (bt != T_INT || con < 16)) { // Left input is a sub?
1055 // Left input is a sub from a constant?
1056 const TypeInteger* t11 = phase->type(add1->in(1))->isa_integer(bt);
1057 if (t11 != nullptr && t11->is_con()) {
1058 // Compute X << con0
1059 Node* lsh = phase->transform(LShiftNode::make(add1->in(2), in(2), bt));
1060 // Compute (con1<<con0) - (X<<con0)
1061 return SubNode::make(phase->integercon(java_shift_left(t11->get_con_as_long(bt), con, bt), bt), lsh, bt);
1062 }
1063 }
1064
1065 // Check for "(x >> C1) << C2"
1066 if (add1_op == Op_RShift(bt) || add1_op == Op_URShift(bt)) {
1067 uint add1Con;
1068 mask_shift_amount(phase, add1, num_bits, add1Con);
1069
1070 // Special case C1 == C2, which just masks off low bits
1071 if (add1Con > 0 && con == add1Con) {
1072 // Convert to "(x & -(1 << C2))"
1073 return MulNode::make_and(add1->in(1), phase->integercon(java_negate(java_shift_left(1, con, bt), bt), bt), bt);
1074 } else {
1075 // Wait until the right shift has been sharpened to the correct count
1076 if (add1Con > 0) {
1077 // As loop parsing can produce LShiftI nodes, we should wait until the graph is fully formed
1078 // to apply optimizations, otherwise we can inadvertently stop vectorization opportunities.
1079 if (phase->is_IterGVN()) {
1080 if (con > add1Con) {
1081 // Creates "(x << (C2 - C1)) & -(1 << C2)"
1082 Node* lshift = phase->transform(LShiftNode::make(add1->in(1), phase->intcon(con - add1Con), bt));
1083 return MulNode::make_and(lshift, phase->integercon(java_negate(java_shift_left(1, con, bt), bt), bt), bt);
1084 } else {
1085 assert(con < add1Con, "must be (%d < %d)", con, add1Con);
1086 // Creates "(x >> (C1 - C2)) & -(1 << C2)"
1087
1088 // Handle logical and arithmetic shifts
1089 Node* rshift;
1090 if (add1_op == Op_RShift(bt)) {
1091 rshift = phase->transform(RShiftNode::make(add1->in(1), phase->intcon(add1Con - con), bt));
1092 } else {
1093 rshift = phase->transform(URShiftNode::make(add1->in(1), phase->intcon(add1Con - con), bt));
1094 }
1095
1096 return MulNode::make_and(rshift, phase->integercon(java_negate(java_shift_left(1, con, bt)), bt), bt);
1097 }
1098 } else {
1099 phase->record_for_igvn(this);
1100 }
1101 }
1102 }
1103 }
1104
1105 // Check for "((x >> C1) & Y) << C2"
1106 if (add1_op == Op_And(bt)) {
1107 Node* add2 = add1->in(1);
1108 int add2_op = add2->Opcode();
1109 if (add2_op == Op_RShift(bt) || add2_op == Op_URShift(bt)) {
1110 // Special case C1 == C2, which just masks off low bits
1111 if (add2->in(2) == in(2)) {
1112 // Convert to "(x & (Y << C2))"
1113 Node* y_sh = phase->transform(LShiftNode::make(add1->in(2), phase->intcon(con), bt));
1114 return MulNode::make_and(add2->in(1), y_sh, bt);
1115 }
1116
1117 uint add2Con;
1118 if (mask_shift_amount(phase, add2, num_bits, add2Con) && add2Con > 0) {
1119 if (phase->is_IterGVN()) {
1120 // Convert to "((x >> C1) << C2) & (Y << C2)"
1121
1122 // Make "(x >> C1) << C2", which will get folded away by the rule above
1123 Node* x_sh = phase->transform(LShiftNode::make(add2, phase->intcon(con), bt));
1124 // Make "Y << C2", which will simplify when Y is a constant
1125 Node* y_sh = phase->transform(LShiftNode::make(add1->in(2), phase->intcon(con), bt));
1126
1127 return MulNode::make_and(x_sh, y_sh, bt);
1128 } else {
1129 phase->record_for_igvn(this);
1130 }
1131 }
1132 }
1133 }
1134
1135 // Check for ((x & ((1<<(32-c0))-1)) << c0) which ANDs off high bits
1136 // before shifting them away.
1137 const jlong bits_mask = max_unsigned_integer(bt) >> con;
1138 assert(bt != T_INT || bits_mask == right_n_bits(num_bits - con), "inconsistent");
1139 if (add1_op == Op_And(bt) &&
1140 phase->type(add1->in(2)) == TypeInteger::make(bits_mask, bt)) {
1141 return LShiftNode::make(add1->in(1), in(2), bt);
1142 }
1143
1144 // Collapse nested left-shifts with constant rhs:
1145 // (X << con1) << con2 ==> X << (con1 + con2)
1146 Node* doubleShift = collapse_nested_shift_left(phase, this, con, bt);
1147 if (doubleShift != nullptr) {
1148 return doubleShift;
1149 }
1150
1151 return progress;
1152 }
1153
1154 //------------------------------Ideal------------------------------------------
1155 Node* LShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
1156 return IdealIL(phase, can_reshape, T_INT);
1157 }
1158
1159 const Type* LShiftNode::ValueIL(PhaseGVN* phase, BasicType bt) const {
1160 const Type* t1 = phase->type(in(1));
1161 const Type* t2 = phase->type(in(2));
1162 // Either input is TOP ==> the result is TOP
1163 if (t1 == Type::TOP) {
1164 return Type::TOP;
1165 }
1166 if (t2 == Type::TOP) {
1167 return Type::TOP;
1168 }
1169
1170 // Left input is ZERO ==> the result is ZERO.
1171 if (t1 == TypeInteger::zero(bt)) {
1172 return TypeInteger::zero(bt);
1173 }
1174 // Shift by zero does nothing
1175 if (t2 == TypeInt::ZERO) {
1176 return t1;
1177 }
1178
1179 // If nothing is known about the shift amount then the result is BOTTOM
1180 if (t2 == TypeInt::INT) {
1181 return TypeInteger::bottom(bt);
1182 }
1183
1184 const TypeInteger* r1 = t1->is_integer(bt); // Handy access
1185 // Since the shift semantics in Java take into account only the bottom five
1186 // bits for ints and the bottom six bits for longs, we can further constrain
1187 // the range of values of the shift amount by ANDing with the right mask based
1188 // on whether the type is int or long.
1189 const TypeInt* mask = TypeInt::make(bits_per_java_integer(bt) - 1);
1190 const TypeInt* r2 = RangeInference::infer_and(t2->is_int(), mask);
1191
1192 if (!r2->is_con()) {
1193 return TypeInteger::bottom(bt);
1194 }
1195
1196 uint shift = r2->get_con();
1197 // Shift by a multiple of 32/64 does nothing:
1198 if (shift == 0) {
1199 return t1;
1200 }
1201
1202 // If the shift is a constant, shift the bounds of the type,
1203 // unless this could lead to an overflow.
1204 if (!r1->is_con()) {
1205 #ifdef ASSERT
1206 if (bt == T_INT) {
1207 jlong lo = r1->lo_as_long(), hi = r1->hi_as_long();
1208 jint lo_int = r1->is_int()->_lo, hi_int = r1->is_int()->_hi;
1209 assert((java_shift_right(java_shift_left(lo, shift, bt), shift, bt) == lo) == (((lo_int << shift) >> shift) == lo_int), "inconsistent");
1210 assert((java_shift_right(java_shift_left(hi, shift, bt), shift, bt) == hi) == (((hi_int << shift) >> shift) == hi_int), "inconsistent");
1211 }
1212 #endif
1213
1214 if (bt == T_INT) {
1215 return RangeInference::infer_lshift(r1->is_int(), shift);
1216 }
1217
1218 return RangeInference::infer_lshift(r1->is_long(), shift);
1219 }
1220
1221 return TypeInteger::make(java_shift_left(r1->get_con_as_long(bt), shift, bt), bt);
1222 }
1223
1224 //------------------------------Value------------------------------------------
1225 const Type* LShiftINode::Value(PhaseGVN* phase) const {
1226 return ValueIL(phase, T_INT);
1227 }
1228
1229 Node* LShiftNode::IdentityIL(PhaseGVN* phase, BasicType bt) {
1230 uint count;
1231 if (mask_shift_amount(phase, this, bits_per_java_integer(bt), count) && count == 0) {
1232 // Shift by a multiple of 32/64 does nothing
1233 return in(1);
1234 }
1235 return this;
1236 }
1237
1238 //=============================================================================
1239 //------------------------------Identity---------------------------------------
1240 Node* LShiftLNode::Identity(PhaseGVN* phase) {
1241 return IdentityIL(phase, T_LONG);
1242 }
1243
1244 //------------------------------Ideal------------------------------------------
1245 Node* LShiftLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1246 return IdealIL(phase, can_reshape, T_LONG);
1247 }
1248
1249 //------------------------------Value------------------------------------------
1250 const Type* LShiftLNode::Value(PhaseGVN* phase) const {
1251 return ValueIL(phase, T_LONG);
1252 }
1253
1254 RShiftNode* RShiftNode::make(Node* in1, Node* in2, BasicType bt) {
1255 switch (bt) {
1256 case T_INT:
1257 return new RShiftINode(in1, in2);
1258 case T_LONG:
1259 return new RShiftLNode(in1, in2);
1260 default:
1261 fatal("Not implemented for %s", type2name(bt));
1262 }
1263 return nullptr;
1264 }
1265
1266
1267 //=============================================================================
1268 //------------------------------Identity---------------------------------------
1269 Node* RShiftNode::IdentityIL(PhaseGVN* phase, BasicType bt) {
1270 uint count;
1271 uint num_bits = bits_per_java_integer(bt);
1272 if (mask_shift_amount(phase, this, num_bits, count)) {
1273 if (count == 0) {
1274 // Shift by a multiple of 32/64 does nothing
1275 return in(1);
1276 }
1277 // Check for useless sign-masking
1278 uint lshift_count;
1279 if (in(1)->Opcode() == Op_LShift(bt) &&
1280 in(1)->req() == 3 &&
1281 // Compare shift counts by value, not by node pointer, to also match a not-yet-normalized
1282 // negative constant (e.g. -1 vs 31)
1283 mask_shift_amount(phase, in(1), num_bits, lshift_count)) {
1284 if (count == lshift_count) {
1285 // Compute masks for which this shifting doesn't change
1286 jlong lo = (CONST64(-1) << (num_bits - count - 1)); // FFFF8000
1287 jlong hi = ~lo; // 00007FFF
1288 const TypeInteger* t11 = phase->type(in(1)->in(1))->isa_integer(bt);
1289 if (t11 == nullptr) {
1290 return this;
1291 }
1292 // Does actual value fit inside of mask?
1293 if (lo <= t11->lo_as_long() && t11->hi_as_long() <= hi) {
1294 return in(1)->in(1); // Then shifting is a nop
1295 }
1296 }
1297 }
1298 }
1299 return this;
1300 }
1301
1302 Node* RShiftINode::Identity(PhaseGVN* phase) {
1303 return IdentityIL(phase, T_INT);
1304 }
1305
1306 Node* RShiftNode::IdealIL(PhaseGVN* phase, bool can_reshape, BasicType bt) {
1307 // Inputs may be TOP if they are dead.
1308 const TypeInteger* t1 = phase->type(in(1))->isa_integer(bt);
1309 if (t1 == nullptr) {
1310 return NodeSentinel; // Left input is an integer
1311 }
1312
1313 uint shift;
1314 Node* progress = mask_and_replace_shift_amount(phase, this, bits_per_java_integer(bt), shift);
1315 if (shift == 0) {
1316 return NodeSentinel;
1317 }
1318
1319 // Check for (x & 0xFF000000) >> 24, whose mask can be made smaller.
1320 // and convert to (x >> 24) & (0xFF000000 >> 24) = x >> 24
1321 // Such expressions arise normally from shift chains like (byte)(x >> 24).
1322 const Node* and_node = in(1);
1323 if (and_node->Opcode() != Op_And(bt)) {
1324 return progress;
1325 }
1326 const TypeInteger* mask_t = phase->type(and_node->in(2))->isa_integer(bt);
1327 if (mask_t != nullptr && mask_t->is_con()) {
1328 jlong maskbits = mask_t->get_con_as_long(bt);
1329 // Convert to "(x >> shift) & (mask >> shift)"
1330 Node* shr_nomask = phase->transform(RShiftNode::make(and_node->in(1), in(2), bt));
1331 return MulNode::make_and(shr_nomask, phase->integercon(maskbits >> shift, bt), bt);
1332 }
1333
1334 return progress;
1335 }
1336
1337 Node* RShiftINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1338 Node* progress = IdealIL(phase, can_reshape, T_INT);
1339 if (progress == NodeSentinel) {
1340 return nullptr;
1341 }
1342 if (progress != nullptr) {
1343 return progress;
1344 }
1345 uint shift;
1346 progress = mask_and_replace_shift_amount(phase, this, BitsPerJavaInteger, shift);
1347 assert(shift != 0, "handled by IdealIL");
1348
1349 // Check for "(short[i] <<16)>>16" which simply sign-extends
1350 const Node *shl = in(1);
1351 if (shl->Opcode() != Op_LShiftI) {
1352 return progress;
1353 }
1354
1355 const TypeInt* left_shift_t = phase->type(shl->in(2))->isa_int();
1356 if (left_shift_t == nullptr) {
1357 return progress;
1358 }
1359 if (shift == 16 && left_shift_t->is_con(16)) {
1360 Node *ld = shl->in(1);
1361 if (ld->Opcode() == Op_LoadS) {
1362 // Sign extension is just useless here. Return a RShiftI of zero instead
1363 // returning 'ld' directly. We cannot return an old Node directly as
1364 // that is the job of 'Identity' calls and Identity calls only work on
1365 // direct inputs ('ld' is an extra Node removed from 'this'). The
1366 // combined optimization requires Identity only return direct inputs.
1367 set_req_X(1, ld, phase);
1368 set_req_X(2, phase->intcon(0), phase);
1369 return this;
1370 }
1371 else if (can_reshape &&
1372 ld->Opcode() == Op_LoadUS &&
1373 ld->outcnt() == 1 && ld->unique_out() == shl)
1374 // Replace zero-extension-load with sign-extension-load
1375 return ld->as_Load()->convert_to_signed_load(*phase);
1376 }
1377
1378 // Check for "(byte[i] <<24)>>24" which simply sign-extends
1379 if (shift == 24 && left_shift_t->is_con(24)) {
1380 Node *ld = shl->in(1);
1381 if (ld->Opcode() == Op_LoadB) {
1382 // Sign extension is just useless here
1383 set_req_X(1, ld, phase);
1384 set_req_X(2, phase->intcon(0), phase);
1385 return this;
1386 }
1387 }
1388
1389 return progress;
1390 }
1391
1392 const Type* RShiftNode::ValueIL(PhaseGVN* phase, BasicType bt) const {
1393 const Type* t1 = phase->type(in(1));
1394 const Type* t2 = phase->type(in(2));
1395 // Either input is TOP ==> the result is TOP
1396 if (t1 == Type::TOP) {
1397 return Type::TOP;
1398 }
1399 if (t2 == Type::TOP) {
1400 return Type::TOP;
1401 }
1402
1403 // Left input is ZERO ==> the result is ZERO.
1404 if (t1 == TypeInteger::zero(bt)) {
1405 return TypeInteger::zero(bt);
1406 }
1407 // Shift by zero does nothing
1408 if (t2 == TypeInt::ZERO) {
1409 return t1;
1410 }
1411
1412 // Either input is BOTTOM ==> the result is BOTTOM
1413 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM) {
1414 return TypeInteger::bottom(bt);
1415 }
1416
1417 const TypeInteger* r1 = t1->isa_integer(bt);
1418 const TypeInt* r2 = t2->isa_int();
1419
1420 // If the shift is a constant, just shift the bounds of the type.
1421 // For example, if the shift is 31/63, we just propagate sign bits.
1422 if (!r1->is_con() && r2->is_con()) {
1423 uint shift = r2->get_con();
1424 shift &= bits_per_java_integer(bt) - 1; // semantics of Java shifts
1425 // Shift by a multiple of 32/64 does nothing:
1426 if (shift == 0) {
1427 return t1;
1428 }
1429 // Calculate reasonably aggressive bounds for the result.
1430 // This is necessary if we are to correctly type things
1431 // like (x<<24>>24) == ((byte)x).
1432 jlong lo = r1->lo_as_long() >> (jint)shift;
1433 jlong hi = r1->hi_as_long() >> (jint)shift;
1434 assert(lo <= hi, "must have valid bounds");
1435 #ifdef ASSERT
1436 if (bt == T_INT) {
1437 jint lo_verify = checked_cast<jint>(r1->lo_as_long()) >> (jint)shift;
1438 jint hi_verify = checked_cast<jint>(r1->hi_as_long()) >> (jint)shift;
1439 assert((checked_cast<jint>(lo) == lo_verify) && (checked_cast<jint>(hi) == hi_verify), "inconsistent");
1440 }
1441 #endif
1442 const TypeInteger* ti = TypeInteger::make(lo, hi, MAX2(r1->_widen,r2->_widen), bt);
1443 #ifdef ASSERT
1444 // Make sure we get the sign-capture idiom correct.
1445 if (shift == bits_per_java_integer(bt) - 1) {
1446 if (r1->lo_as_long() >= 0) {
1447 assert(ti == TypeInteger::zero(bt), ">>31/63 of + is 0");
1448 }
1449 if (r1->hi_as_long() < 0) {
1450 assert(ti == TypeInteger::minus_1(bt), ">>31/63 of - is -1");
1451 }
1452 }
1453 #endif
1454 return ti;
1455 }
1456
1457 if (!r1->is_con() || !r2->is_con()) {
1458 // If the left input is non-negative the result must also be non-negative, regardless of what the right input is.
1459 if (r1->lo_as_long() >= 0) {
1460 return TypeInteger::make(0, r1->hi_as_long(), MAX2(r1->_widen, r2->_widen), bt);
1461 }
1462
1463 // Conversely, if the left input is negative then the result must be negative.
1464 if (r1->hi_as_long() <= -1) {
1465 return TypeInteger::make(r1->lo_as_long(), -1, MAX2(r1->_widen, r2->_widen), bt);
1466 }
1467
1468 return TypeInteger::bottom(bt);
1469 }
1470
1471 // Signed shift right
1472 return TypeInteger::make(r1->get_con_as_long(bt) >> (r2->get_con() & (bits_per_java_integer(bt) - 1)), bt);
1473 }
1474
1475 const Type* RShiftINode::Value(PhaseGVN* phase) const {
1476 return ValueIL(phase, T_INT);
1477 }
1478
1479 //=============================================================================
1480 //------------------------------Identity---------------------------------------
1481 Node* RShiftLNode::Identity(PhaseGVN* phase) {
1482 return IdentityIL(phase, T_LONG);
1483 }
1484
1485 Node* RShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1486 Node* progress = IdealIL(phase, can_reshape, T_LONG);
1487 if (progress == NodeSentinel) {
1488 return nullptr;
1489 }
1490 return progress;
1491 }
1492
1493 const Type* RShiftLNode::Value(PhaseGVN* phase) const {
1494 return ValueIL(phase, T_LONG);
1495 }
1496
1497 URShiftNode* URShiftNode::make(Node* in1, Node* in2, BasicType bt) {
1498 switch (bt) {
1499 case T_INT:
1500 return new URShiftINode(in1, in2);
1501 case T_LONG:
1502 return new URShiftLNode(in1, in2);
1503 default:
1504 fatal("Not implemented for %s", type2name(bt));
1505 }
1506 return nullptr;
1507 }
1508
1509 //=============================================================================
1510 //------------------------------Identity---------------------------------------
1511 Node* URShiftINode::Identity(PhaseGVN* phase) {
1512 uint count;
1513 if (mask_shift_amount(phase, this, BitsPerJavaInteger, count) && count == 0) {
1514 // Shift by a multiple of 32 does nothing
1515 return in(1);
1516 }
1517
1518 // Check for "((x << LogBytesPerWord) + (wordSize-1)) >> LogBytesPerWord" which is just "x".
1519 // Happens during new-array length computation.
1520 // Safe if 'x' is in the range [0..(max_int>>LogBytesPerWord)]
1521 Node *add = in(1);
1522 if (add->Opcode() == Op_AddI) {
1523 const TypeInt *t2 = phase->type(add->in(2))->isa_int();
1524 if (t2 && t2->is_con(wordSize - 1) &&
1525 add->in(1)->Opcode() == Op_LShiftI) {
1526 // Check that shift_counts are LogBytesPerWord.
1527 Node *lshift_count = add->in(1)->in(2);
1528 const TypeInt *t_lshift_count = phase->type(lshift_count)->isa_int();
1529 if (t_lshift_count && t_lshift_count->is_con(LogBytesPerWord) &&
1530 t_lshift_count == phase->type(in(2))) {
1531 Node *x = add->in(1)->in(1);
1532 const TypeInt *t_x = phase->type(x)->isa_int();
1533 if (t_x != nullptr && 0 <= t_x->_lo && t_x->_hi <= (max_jint>>LogBytesPerWord)) {
1534 return x;
1535 }
1536 }
1537 }
1538 }
1539
1540 return (phase->type(in(2))->higher_equal(TypeInt::ZERO)) ? in(1) : this;
1541 }
1542
1543 //------------------------------Ideal------------------------------------------
1544 Node* URShiftINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1545 uint con;
1546 Node* progress = mask_and_replace_shift_amount(phase, this, BitsPerJavaInteger, con);
1547 if (con == 0) {
1548 return nullptr;
1549 }
1550
1551 // We'll be wanting the right-shift amount as a mask of that many bits
1552 const int mask = right_n_bits(BitsPerJavaInteger - con);
1553
1554 int in1_op = in(1)->Opcode();
1555
1556 // Check for ((x>>>a)>>>b) and replace with (x>>>(a+b)) when a+b < 32
1557 if( in1_op == Op_URShiftI ) {
1558 const TypeInt *t12 = phase->type( in(1)->in(2) )->isa_int();
1559 if( t12 && t12->is_con() ) { // Right input is a constant
1560 assert( in(1) != in(1)->in(1), "dead loop in URShiftINode::Ideal" );
1561 const int con2 = t12->get_con() & 31; // Shift count is always masked
1562 const int con3 = con+con2;
1563 if( con3 < 32 ) // Only merge shifts if total is < 32
1564 return new URShiftINode( in(1)->in(1), phase->intcon(con3) );
1565 }
1566 }
1567
1568 // Check for ((x << z) + Y) >>> z. Replace with x + con>>>z
1569 // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
1570 // If Q is "X << z" the rounding is useless. Look for patterns like
1571 // ((X<<Z) + Y) >>> Z and replace with (X + Y>>>Z) & Z-mask.
1572 Node *add = in(1);
1573 if (in1_op == Op_AddI) {
1574 Node *lshl = add->in(1);
1575 Node *y = add->in(2);
1576 if (lshl->Opcode() != Op_LShiftI) {
1577 lshl = add->in(2);
1578 y = add->in(1);
1579 }
1580 // Compare shift counts by value, not by node pointer, to also match a not-yet-normalized
1581 // negative constant (e.g. -1 vs 31)
1582 uint lshl_con;
1583 if (lshl->Opcode() == Op_LShiftI &&
1584 mask_shift_amount(phase, lshl, BitsPerJavaInteger, lshl_con) &&
1585 lshl_con == con) {
1586 Node *y_z = phase->transform(new URShiftINode(y, in(2)));
1587 Node *sum = phase->transform(new AddINode(lshl->in(1), y_z));
1588 return new AndINode(sum, phase->intcon(mask));
1589 }
1590 }
1591
1592 // Check for (x & mask) >>> z. Replace with (x >>> z) & (mask >>> z)
1593 // This shortens the mask. Also, if we are extracting a high byte and
1594 // storing it to a buffer, the mask will be removed completely.
1595 Node *andi = in(1);
1596 if( in1_op == Op_AndI ) {
1597 const TypeInt *t3 = phase->type( andi->in(2) )->isa_int();
1598 if( t3 && t3->is_con() ) { // Right input is a constant
1599 jint mask2 = t3->get_con();
1600 mask2 >>= con; // *signed* shift downward (high-order zeroes do not help)
1601 Node *newshr = phase->transform( new URShiftINode(andi->in(1), in(2)) );
1602 return new AndINode(newshr, phase->intcon(mask2));
1603 // The negative values are easier to materialize than positive ones.
1604 // A typical case from address arithmetic is ((x & ~15) >> 4).
1605 // It's better to change that to ((x >> 4) & ~0) versus
1606 // ((x >> 4) & 0x0FFFFFFF). The difference is greatest in LP64.
1607 }
1608 }
1609
1610 // Check for "(X << z ) >>> z" which simply zero-extends
1611 Node *shl = in(1);
1612 // Compare shift counts by value, not by node pointer, to also match a not-yet-normalized
1613 // negative constant (e.g. -1 vs 31)
1614 uint shl_con;
1615 if (in1_op == Op_LShiftI &&
1616 mask_shift_amount(phase, shl, BitsPerJavaInteger, shl_con) &&
1617 shl_con == con)
1618 return new AndINode(shl->in(1), phase->intcon(mask));
1619
1620 // Check for (x >> n) >>> 31. Replace with (x >>> 31)
1621 const TypeInt* t2 = phase->type(in(2))->isa_int();
1622 Node *shr = in(1);
1623 if ( in1_op == Op_RShiftI ) {
1624 Node *in11 = shr->in(1);
1625 Node *in12 = shr->in(2);
1626 const TypeInt *t11 = phase->type(in11)->isa_int();
1627 const TypeInt *t12 = phase->type(in12)->isa_int();
1628 if ( t11 && t2 && t2->is_con(31) && t12 && t12->is_con() ) {
1629 return new URShiftINode(in11, phase->intcon(31));
1630 }
1631 }
1632
1633 return progress;
1634 }
1635
1636 //------------------------------Value------------------------------------------
1637 // A URShiftINode shifts its input2 right by input1 amount.
1638 const Type* URShiftINode::Value(PhaseGVN* phase) const {
1639 // (This is a near clone of RShiftINode::Value.)
1640 const Type *t1 = phase->type( in(1) );
1641 const Type *t2 = phase->type( in(2) );
1642 // Either input is TOP ==> the result is TOP
1643 if( t1 == Type::TOP ) return Type::TOP;
1644 if( t2 == Type::TOP ) return Type::TOP;
1645
1646 // Left input is ZERO ==> the result is ZERO.
1647 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
1648 // Shift by zero does nothing
1649 if( t2 == TypeInt::ZERO ) return t1;
1650
1651 // Either input is BOTTOM ==> the result is BOTTOM
1652 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1653 return TypeInt::INT;
1654
1655 if (t2 == TypeInt::INT)
1656 return TypeInt::INT;
1657
1658 const TypeInt *r1 = t1->is_int(); // Handy access
1659 const TypeInt *r2 = t2->is_int(); // Handy access
1660
1661 if (r2->is_con()) {
1662 uint shift = r2->get_con();
1663 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
1664 // Shift by a multiple of 32 does nothing:
1665 if (shift == 0) return t1;
1666 // Calculate reasonably aggressive bounds for the result.
1667 jint lo = (juint)r1->_lo >> (juint)shift;
1668 jint hi = (juint)r1->_hi >> (juint)shift;
1669 if (r1->_hi >= 0 && r1->_lo < 0) {
1670 // If the type has both negative and positive values,
1671 // there are two separate sub-domains to worry about:
1672 // The positive half and the negative half.
1673 jint neg_lo = lo;
1674 jint neg_hi = (juint)-1 >> (juint)shift;
1675 jint pos_lo = (juint) 0 >> (juint)shift;
1676 jint pos_hi = hi;
1677 lo = MIN2(neg_lo, pos_lo); // == 0
1678 hi = MAX2(neg_hi, pos_hi); // == -1 >>> shift;
1679 }
1680 assert(lo <= hi, "must have valid bounds");
1681 const TypeInt* ti = TypeInt::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1682 #ifdef ASSERT
1683 // Make sure we get the sign-capture idiom correct.
1684 if (shift == BitsPerJavaInteger-1) {
1685 if (r1->_lo >= 0) assert(ti == TypeInt::ZERO, ">>>31 of + is 0");
1686 if (r1->_hi < 0) assert(ti == TypeInt::ONE, ">>>31 of - is +1");
1687 }
1688 #endif
1689 return ti;
1690 }
1691
1692 //
1693 // Do not support shifted oops in info for GC
1694 //
1695 // else if( t1->base() == Type::InstPtr ) {
1696 //
1697 // const TypeInstPtr *o = t1->is_instptr();
1698 // if( t1->singleton() )
1699 // return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift );
1700 // }
1701 // else if( t1->base() == Type::KlassPtr ) {
1702 // const TypeKlassPtr *o = t1->is_klassptr();
1703 // if( t1->singleton() )
1704 // return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift );
1705 // }
1706
1707 return TypeInt::INT;
1708 }
1709
1710 //=============================================================================
1711 //------------------------------Identity---------------------------------------
1712 Node* URShiftLNode::Identity(PhaseGVN* phase) {
1713 uint count;
1714 if (mask_shift_amount(phase, this, BitsPerJavaLong, count) && count == 0) {
1715 // Shift by a multiple of 64 does nothing
1716 return in(1);
1717 }
1718 return this;
1719 }
1720
1721 //------------------------------Ideal------------------------------------------
1722 Node* URShiftLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1723 uint con;
1724 Node* progress = mask_and_replace_shift_amount(phase, this, BitsPerJavaLong, con);
1725 if (con == 0) {
1726 return nullptr;
1727 }
1728
1729 // We'll be wanting the right-shift amount as a mask of that many bits
1730 const jlong mask = jlong(max_julong >> con);
1731
1732 // Check for ((x << z) + Y) >>> z. Replace with x + con>>>z
1733 // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
1734 // If Q is "X << z" the rounding is useless. Look for patterns like
1735 // ((X<<Z) + Y) >>> Z and replace with (X + Y>>>Z) & Z-mask.
1736 Node *add = in(1);
1737 const TypeInt *t2 = phase->type(in(2))->isa_int();
1738 if (add->Opcode() == Op_AddL) {
1739 Node *lshl = add->in(1);
1740 Node *y = add->in(2);
1741 if (lshl->Opcode() != Op_LShiftL) {
1742 lshl = add->in(2);
1743 y = add->in(1);
1744 }
1745 // Compare shift counts by value, not by node pointer, to also match a not-yet-normalized
1746 // negative constant (e.g. -1 vs 63)
1747 uint lshl_con;
1748 if (lshl->Opcode() == Op_LShiftL &&
1749 mask_shift_amount(phase, lshl, BitsPerJavaLong, lshl_con) &&
1750 lshl_con == con) {
1751 Node* y_z = phase->transform(new URShiftLNode(y, in(2)));
1752 Node* sum = phase->transform(new AddLNode(lshl->in(1), y_z));
1753 return new AndLNode(sum, phase->longcon(mask));
1754 }
1755 }
1756
1757 // Check for (x & mask) >>> z. Replace with (x >>> z) & (mask >>> z)
1758 // This shortens the mask. Also, if we are extracting a high byte and
1759 // storing it to a buffer, the mask will be removed completely.
1760 Node *andi = in(1);
1761 if( andi->Opcode() == Op_AndL ) {
1762 const TypeLong *t3 = phase->type( andi->in(2) )->isa_long();
1763 if( t3 && t3->is_con() ) { // Right input is a constant
1764 jlong mask2 = t3->get_con();
1765 mask2 >>= con; // *signed* shift downward (high-order zeroes do not help)
1766 Node *newshr = phase->transform( new URShiftLNode(andi->in(1), in(2)) );
1767 return new AndLNode(newshr, phase->longcon(mask2));
1768 }
1769 }
1770
1771 // Check for "(X << z ) >>> z" which simply zero-extends
1772 Node *shl = in(1);
1773 // Compare shift counts by value, not by node pointer, to also match a not-yet-normalized
1774 // negative constant (e.g. -1 vs 63)
1775 uint shl_con;
1776 if (shl->Opcode() == Op_LShiftL &&
1777 mask_shift_amount(phase, shl, BitsPerJavaLong, shl_con) &&
1778 shl_con == con) {
1779 return new AndLNode(shl->in(1), phase->longcon(mask));
1780 }
1781
1782 // Check for (x >> n) >>> 63. Replace with (x >>> 63)
1783 Node *shr = in(1);
1784 if ( shr->Opcode() == Op_RShiftL ) {
1785 Node *in11 = shr->in(1);
1786 Node *in12 = shr->in(2);
1787 const TypeLong *t11 = phase->type(in11)->isa_long();
1788 const TypeInt *t12 = phase->type(in12)->isa_int();
1789 if ( t11 && t2 && t2->is_con(63) && t12 && t12->is_con() ) {
1790 return new URShiftLNode(in11, phase->intcon(63));
1791 }
1792 }
1793
1794 return progress;
1795 }
1796
1797 //------------------------------Value------------------------------------------
1798 // A URShiftINode shifts its input2 right by input1 amount.
1799 const Type* URShiftLNode::Value(PhaseGVN* phase) const {
1800 // (This is a near clone of RShiftLNode::Value.)
1801 const Type *t1 = phase->type( in(1) );
1802 const Type *t2 = phase->type( in(2) );
1803 // Either input is TOP ==> the result is TOP
1804 if( t1 == Type::TOP ) return Type::TOP;
1805 if( t2 == Type::TOP ) return Type::TOP;
1806
1807 // Left input is ZERO ==> the result is ZERO.
1808 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
1809 // Shift by zero does nothing
1810 if( t2 == TypeInt::ZERO ) return t1;
1811
1812 // Either input is BOTTOM ==> the result is BOTTOM
1813 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1814 return TypeLong::LONG;
1815
1816 if (t2 == TypeInt::INT)
1817 return TypeLong::LONG;
1818
1819 const TypeLong *r1 = t1->is_long(); // Handy access
1820 const TypeInt *r2 = t2->is_int (); // Handy access
1821
1822 if (r2->is_con()) {
1823 uint shift = r2->get_con();
1824 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
1825 // Shift by a multiple of 64 does nothing:
1826 if (shift == 0) return t1;
1827 // Calculate reasonably aggressive bounds for the result.
1828 jlong lo = (julong)r1->_lo >> (juint)shift;
1829 jlong hi = (julong)r1->_hi >> (juint)shift;
1830 if (r1->_hi >= 0 && r1->_lo < 0) {
1831 // If the type has both negative and positive values,
1832 // there are two separate sub-domains to worry about:
1833 // The positive half and the negative half.
1834 jlong neg_lo = lo;
1835 jlong neg_hi = (julong)-1 >> (juint)shift;
1836 jlong pos_lo = (julong) 0 >> (juint)shift;
1837 jlong pos_hi = hi;
1838 //lo = MIN2(neg_lo, pos_lo); // == 0
1839 lo = neg_lo < pos_lo ? neg_lo : pos_lo;
1840 //hi = MAX2(neg_hi, pos_hi); // == -1 >>> shift;
1841 hi = neg_hi > pos_hi ? neg_hi : pos_hi;
1842 }
1843 assert(lo <= hi, "must have valid bounds");
1844 const TypeLong* tl = TypeLong::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1845 #ifdef ASSERT
1846 // Make sure we get the sign-capture idiom correct.
1847 if (shift == BitsPerJavaLong - 1) {
1848 if (r1->_lo >= 0) assert(tl == TypeLong::ZERO, ">>>63 of + is 0");
1849 if (r1->_hi < 0) assert(tl == TypeLong::ONE, ">>>63 of - is +1");
1850 }
1851 #endif
1852 return tl;
1853 }
1854
1855 return TypeLong::LONG; // Give up
1856 }
1857
1858 //=============================================================================
1859 //------------------------------Ideal------------------------------------------
1860 Node* FmaNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1861 // We canonicalize the node by converting "(-a)*b+c" into "b*(-a)+c"
1862 // This reduces the number of rules in the matcher, as we only need to check
1863 // for negations on the second argument, and not the symmetric case where
1864 // the first argument is negated.
1865 if (in(1)->is_Neg() && !in(2)->is_Neg()) {
1866 swap_edges(1, 2);
1867 return this;
1868 }
1869 return nullptr;
1870 }
1871
1872 //=============================================================================
1873 //------------------------------Value------------------------------------------
1874 const Type* FmaDNode::Value(PhaseGVN* phase) const {
1875 const Type *t1 = phase->type(in(1));
1876 if (t1 == Type::TOP) return Type::TOP;
1877 if (t1->base() != Type::DoubleCon) return Type::DOUBLE;
1878 const Type *t2 = phase->type(in(2));
1879 if (t2 == Type::TOP) return Type::TOP;
1880 if (t2->base() != Type::DoubleCon) return Type::DOUBLE;
1881 const Type *t3 = phase->type(in(3));
1882 if (t3 == Type::TOP) return Type::TOP;
1883 if (t3->base() != Type::DoubleCon) return Type::DOUBLE;
1884 #ifndef __STDC_IEC_559__
1885 return Type::DOUBLE;
1886 #else
1887 double d1 = t1->getd();
1888 double d2 = t2->getd();
1889 double d3 = t3->getd();
1890 return TypeD::make(fma(d1, d2, d3));
1891 #endif
1892 }
1893
1894 //=============================================================================
1895 //------------------------------Value------------------------------------------
1896 const Type* FmaFNode::Value(PhaseGVN* phase) const {
1897 const Type *t1 = phase->type(in(1));
1898 if (t1 == Type::TOP) return Type::TOP;
1899 if (t1->base() != Type::FloatCon) return Type::FLOAT;
1900 const Type *t2 = phase->type(in(2));
1901 if (t2 == Type::TOP) return Type::TOP;
1902 if (t2->base() != Type::FloatCon) return Type::FLOAT;
1903 const Type *t3 = phase->type(in(3));
1904 if (t3 == Type::TOP) return Type::TOP;
1905 if (t3->base() != Type::FloatCon) return Type::FLOAT;
1906 #ifndef __STDC_IEC_559__
1907 return Type::FLOAT;
1908 #else
1909 float f1 = t1->getf();
1910 float f2 = t2->getf();
1911 float f3 = t3->getf();
1912 return TypeF::make(fma(f1, f2, f3));
1913 #endif
1914 }
1915
1916 //=============================================================================
1917 //------------------------------Value------------------------------------------
1918 const Type* FmaHFNode::Value(PhaseGVN* phase) const {
1919 const Type* t1 = phase->type(in(1));
1920 if (t1 == Type::TOP) { return Type::TOP; }
1921 if (t1->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; }
1922 const Type* t2 = phase->type(in(2));
1923 if (t2 == Type::TOP) { return Type::TOP; }
1924 if (t2->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; }
1925 const Type* t3 = phase->type(in(3));
1926 if (t3 == Type::TOP) { return Type::TOP; }
1927 if (t3->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; }
1928 #ifndef __STDC_IEC_559__
1929 return Type::HALF_FLOAT;
1930 #else
1931 float f1 = t1->getf();
1932 float f2 = t2->getf();
1933 float f3 = t3->getf();
1934 return TypeH::make(fma(f1, f2, f3));
1935 #endif
1936 }
1937
1938 //=============================================================================
1939 //------------------------------hash-------------------------------------------
1940 // Hash function for MulAddS2INode. Operation is commutative with commutative pairs.
1941 // The hash function must return the same value when edge swapping is performed.
1942 uint MulAddS2INode::hash() const {
1943 return (uintptr_t)in(1) + (uintptr_t)in(2) + (uintptr_t)in(3) + (uintptr_t)in(4) + Opcode();
1944 }
1945
1946 //------------------------------Rotate Operations ------------------------------
1947
1948 Node* RotateLeftNode::Identity(PhaseGVN* phase) {
1949 const Type* t1 = phase->type(in(1));
1950 if (t1 == Type::TOP) {
1951 return this;
1952 }
1953 uint count;
1954 assert(t1->isa_int() || t1->isa_long(), "Unexpected type");
1955 uint num_bits = t1->isa_int() ? BitsPerJavaInteger : BitsPerJavaLong;
1956 if (mask_shift_amount(phase, this, num_bits, count) && count == 0) {
1957 // Rotate by a multiple of 32/64 does nothing
1958 return in(1);
1959 }
1960 return this;
1961 }
1962
1963 const Type* RotateLeftNode::Value(PhaseGVN* phase) const {
1964 const Type* t1 = phase->type(in(1));
1965 const Type* t2 = phase->type(in(2));
1966 // Either input is TOP ==> the result is TOP
1967 if (t1 == Type::TOP || t2 == Type::TOP) {
1968 return Type::TOP;
1969 }
1970
1971 if (t1->isa_int()) {
1972 const TypeInt* r1 = t1->is_int();
1973 const TypeInt* r2 = t2->is_int();
1974
1975 // Left input is ZERO ==> the result is ZERO.
1976 if (r1 == TypeInt::ZERO) {
1977 return TypeInt::ZERO;
1978 }
1979 // Rotate by zero does nothing
1980 if (r2 == TypeInt::ZERO) {
1981 return r1;
1982 }
1983 if (r1->is_con() && r2->is_con()) {
1984 juint r1_con = (juint)r1->get_con();
1985 juint shift = (juint)(r2->get_con()) & (juint)(BitsPerJavaInteger - 1); // semantics of Java shifts
1986 return TypeInt::make((r1_con << shift) | (r1_con >> (32 - shift)));
1987 }
1988 return TypeInt::INT;
1989 } else {
1990 assert(t1->isa_long(), "Type must be a long");
1991 const TypeLong* r1 = t1->is_long();
1992 const TypeInt* r2 = t2->is_int();
1993
1994 // Left input is ZERO ==> the result is ZERO.
1995 if (r1 == TypeLong::ZERO) {
1996 return TypeLong::ZERO;
1997 }
1998 // Rotate by zero does nothing
1999 if (r2 == TypeInt::ZERO) {
2000 return r1;
2001 }
2002 if (r1->is_con() && r2->is_con()) {
2003 julong r1_con = (julong)r1->get_con();
2004 julong shift = (julong)(r2->get_con()) & (julong)(BitsPerJavaLong - 1); // semantics of Java shifts
2005 return TypeLong::make((r1_con << shift) | (r1_con >> (64 - shift)));
2006 }
2007 return TypeLong::LONG;
2008 }
2009 }
2010
2011 Node* RotateLeftNode::Ideal(PhaseGVN *phase, bool can_reshape) {
2012 const Type* t1 = phase->type(in(1));
2013 const Type* t2 = phase->type(in(2));
2014 if (t2->isa_int() && t2->is_int()->is_con()) {
2015 if (t1->isa_int()) {
2016 int lshift = t2->is_int()->get_con() & 31;
2017 return new RotateRightNode(in(1), phase->intcon(32 - (lshift & 31)), TypeInt::INT);
2018 } else if (t1 != Type::TOP) {
2019 assert(t1->isa_long(), "Type must be a long");
2020 int lshift = t2->is_int()->get_con() & 63;
2021 return new RotateRightNode(in(1), phase->intcon(64 - (lshift & 63)), TypeLong::LONG);
2022 }
2023 }
2024 return nullptr;
2025 }
2026
2027 Node* RotateRightNode::Identity(PhaseGVN* phase) {
2028 const Type* t1 = phase->type(in(1));
2029 if (t1 == Type::TOP) {
2030 return this;
2031 }
2032 uint count;
2033 assert(t1->isa_int() || t1->isa_long(), "Unexpected type");
2034 uint num_bits = t1->isa_int() ? BitsPerJavaInteger : BitsPerJavaLong;
2035 if (mask_shift_amount(phase, this, num_bits, count) && count == 0) {
2036 // Rotate by a multiple of 32/64 does nothing
2037 return in(1);
2038 }
2039 return this;
2040 }
2041
2042 const Type* RotateRightNode::Value(PhaseGVN* phase) const {
2043 const Type* t1 = phase->type(in(1));
2044 const Type* t2 = phase->type(in(2));
2045 // Either input is TOP ==> the result is TOP
2046 if (t1 == Type::TOP || t2 == Type::TOP) {
2047 return Type::TOP;
2048 }
2049
2050 if (t1->isa_int()) {
2051 const TypeInt* r1 = t1->is_int();
2052 const TypeInt* r2 = t2->is_int();
2053
2054 // Left input is ZERO ==> the result is ZERO.
2055 if (r1 == TypeInt::ZERO) {
2056 return TypeInt::ZERO;
2057 }
2058 // Rotate by zero does nothing
2059 if (r2 == TypeInt::ZERO) {
2060 return r1;
2061 }
2062 if (r1->is_con() && r2->is_con()) {
2063 juint r1_con = (juint)r1->get_con();
2064 juint shift = (juint)(r2->get_con()) & (juint)(BitsPerJavaInteger - 1); // semantics of Java shifts
2065 return TypeInt::make((r1_con >> shift) | (r1_con << (32 - shift)));
2066 }
2067 return TypeInt::INT;
2068 } else {
2069 assert(t1->isa_long(), "Type must be a long");
2070 const TypeLong* r1 = t1->is_long();
2071 const TypeInt* r2 = t2->is_int();
2072 // Left input is ZERO ==> the result is ZERO.
2073 if (r1 == TypeLong::ZERO) {
2074 return TypeLong::ZERO;
2075 }
2076 // Rotate by zero does nothing
2077 if (r2 == TypeInt::ZERO) {
2078 return r1;
2079 }
2080 if (r1->is_con() && r2->is_con()) {
2081 julong r1_con = (julong)r1->get_con();
2082 julong shift = (julong)(r2->get_con()) & (julong)(BitsPerJavaLong - 1); // semantics of Java shifts
2083 return TypeLong::make((r1_con >> shift) | (r1_con << (64 - shift)));
2084 }
2085 return TypeLong::LONG;
2086 }
2087 }
2088
2089 //------------------------------ Sum & Mask ------------------------------
2090
2091 // Returns a lower bound on the number of trailing zeros in expr.
2092 static jint AndIL_min_trailing_zeros(const PhaseGVN* phase, const Node* expr, BasicType bt) {
2093 const TypeInteger* type = phase->type(expr)->isa_integer(bt);
2094 if (type == nullptr) {
2095 return 0;
2096 }
2097
2098 expr = expr->uncast();
2099 type = phase->type(expr)->isa_integer(bt);
2100 if (type == nullptr) {
2101 return 0;
2102 }
2103
2104 if (type->is_con()) {
2105 jlong con = type->get_con_as_long(bt);
2106 return con == 0L ? (type2aelembytes(bt) * BitsPerByte) : count_trailing_zeros(con);
2107 }
2108
2109 if (expr->Opcode() == Op_ConvI2L) {
2110 expr = expr->in(1)->uncast();
2111 bt = T_INT;
2112 type = phase->type(expr)->isa_int();
2113 }
2114
2115 // Pattern: expr = (x << shift)
2116 if (expr->Opcode() == Op_LShift(bt)) {
2117 const TypeInt* shift_t = phase->type(expr->in(2))->isa_int();
2118 if (shift_t == nullptr || !shift_t->is_con()) {
2119 return 0;
2120 }
2121 // We need to truncate the shift, as it may not have been canonicalized yet.
2122 // T_INT: 0..31 -> shift_mask = 4 * 8 - 1 = 31
2123 // T_LONG: 0..63 -> shift_mask = 8 * 8 - 1 = 63
2124 // (JLS: "Shift Operators")
2125 jint shift_mask = type2aelembytes(bt) * BitsPerByte - 1;
2126 return shift_t->get_con() & shift_mask;
2127 }
2128
2129 return 0;
2130 }
2131
2132 // Checks whether expr is neutral additive element (zero) under mask,
2133 // i.e. whether an expression of the form:
2134 // (AndX (AddX (expr addend) mask)
2135 // (expr + addend) & mask
2136 // is equivalent to
2137 // (AndX addend mask)
2138 // addend & mask
2139 // for any addend.
2140 // (The X in AndX must be I or L, depending on bt).
2141 //
2142 // We check for the sufficient condition when the lowest set bit in expr is higher than
2143 // the highest set bit in mask, i.e.:
2144 // expr: eeeeee0000000000000
2145 // mask: 000000mmmmmmmmmmmmm
2146 // <--w bits--->
2147 // We do not test for other cases.
2148 //
2149 // Correctness:
2150 // Given "expr" with at least "w" trailing zeros,
2151 // let "mod = 2^w", "suffix_mask = mod - 1"
2152 //
2153 // Since "mask" only has bits set where "suffix_mask" does, we have:
2154 // mask = suffix_mask & mask (SUFFIX_MASK)
2155 //
2156 // And since expr only has bits set above w, and suffix_mask only below:
2157 // expr & suffix_mask == 0 (NO_BIT_OVERLAP)
2158 //
2159 // From unsigned modular arithmetic (with unsigned modulo %), and since mod is
2160 // a power of 2, and we are computing in a ring of powers of 2, we know that
2161 // (x + y) % mod = (x % mod + y) % mod
2162 // (x + y) & suffix_mask = (x & suffix_mask + y) & suffix_mask (MOD_ARITH)
2163 //
2164 // We can now prove the equality:
2165 // (expr + addend) & mask
2166 // = (expr + addend) & suffix_mask & mask (SUFFIX_MASK)
2167 // = (expr & suffix_mask + addend) & suffix_mask & mask (MOD_ARITH)
2168 // = (0 + addend) & suffix_mask & mask (NO_BIT_OVERLAP)
2169 // = addend & mask (SUFFIX_MASK)
2170 //
2171 // Hence, an expr with at least w trailing zeros is a neutral additive element under any mask with bit width w.
2172 static bool AndIL_is_zero_element_under_mask(const PhaseGVN* phase, const Node* expr, const Node* mask, BasicType bt) {
2173 // When the mask is negative, it has the most significant bit set.
2174 const TypeInteger* mask_t = phase->type(mask)->isa_integer(bt);
2175 if (mask_t == nullptr || mask_t->lo_as_long() < 0) {
2176 return false;
2177 }
2178
2179 // When the mask is constant zero, we defer to MulNode::Value to eliminate the entire AndX operation.
2180 if (mask_t->hi_as_long() == 0) {
2181 assert(mask_t->lo_as_long() == 0, "checked earlier");
2182 return false;
2183 }
2184
2185 jint mask_bit_width = BitsPerLong - count_leading_zeros(mask_t->hi_as_long());
2186 jint expr_trailing_zeros = AndIL_min_trailing_zeros(phase, expr, bt);
2187 return expr_trailing_zeros >= mask_bit_width;
2188 }
2189
2190 // Reduces the pattern:
2191 // (AndX (AddX add1 add2) mask)
2192 // to
2193 // (AndX add1 mask), if add2 is neutral wrt mask (see above), and vice versa.
2194 Node* MulNode::AndIL_sum_and_mask(PhaseGVN* phase, BasicType bt) {
2195 Node* add = in(1);
2196 Node* mask = in(2);
2197 int addidx = 0;
2198 if (add->Opcode() == Op_Add(bt)) {
2199 addidx = 1;
2200 } else if (mask->Opcode() == Op_Add(bt)) {
2201 mask = add;
2202 addidx = 2;
2203 add = in(addidx);
2204 }
2205 if (addidx > 0) {
2206 Node* add1 = add->in(1);
2207 Node* add2 = add->in(2);
2208 if (AndIL_is_zero_element_under_mask(phase, add1, mask, bt)) {
2209 set_req_X(addidx, add2, phase);
2210 return this;
2211 } else if (AndIL_is_zero_element_under_mask(phase, add2, mask, bt)) {
2212 set_req_X(addidx, add1, phase);
2213 return this;
2214 }
2215 }
2216 return nullptr;
2217 }