1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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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23 */
24
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "opto/addnode.hpp"
28 #include "opto/connode.hpp"
29 #include "opto/convertnode.hpp"
30 #include "opto/memnode.hpp"
31 #include "opto/mulnode.hpp"
32 #include "opto/phaseX.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
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 if( t2 == Type::TOP ) return nullptr;
127 Node *mul1 = in(1);
128 #ifdef ASSERT
129 // Check for dead loop
130 int op1 = mul1->Opcode();
131 if ((mul1 == this) || (in(2) == this) ||
132 ((op1 == mul_opcode() || op1 == add_opcode()) &&
133 ((mul1->in(1) == this) || (mul1->in(2) == this) ||
134 (mul1->in(1) == mul1) || (mul1->in(2) == mul1)))) {
135 assert(false, "dead loop in MulNode::Ideal");
136 }
137 #endif
138
139 if( mul1->Opcode() == mul_opcode() ) { // Left input is a multiply?
140 // Mul of a constant?
141 const Type *t12 = phase->type( mul1->in(2) );
142 if( t12->singleton() && t12 != Type::TOP) { // Left input is an add of a constant?
143 // Compute new constant; check for overflow
144 const Type *tcon01 = ((MulNode*)mul1)->mul_ring(t2,t12);
145 if( tcon01->singleton() ) {
146 // The Mul of the flattened expression
147 set_req_X(1, mul1->in(1), phase);
148 set_req_X(2, phase->makecon(tcon01), phase);
149 t2 = tcon01;
150 progress = this; // Made progress
151 }
152 }
153 }
154 // If the right input is a constant, and the left input is an add of a
155 // constant, flatten the tree: (X+con1)*con0 ==> X*con0 + con1*con0
156 const Node *add1 = in(1);
157 if( add1->Opcode() == add_opcode() ) { // Left input is an add?
158 // Add of a constant?
159 const Type *t12 = phase->type( add1->in(2) );
160 if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
161 assert( add1->in(1) != add1, "dead loop in MulNode::Ideal" );
162 // Compute new constant; check for overflow
163 const Type *tcon01 = mul_ring(t2,t12);
164 if( tcon01->singleton() ) {
165
166 // Convert (X+con1)*con0 into X*con0
167 Node *mul = clone(); // mul = ()*con0
168 mul->set_req(1,add1->in(1)); // mul = X*con0
169 mul = phase->transform(mul);
170
171 Node *add2 = add1->clone();
172 add2->set_req(1, mul); // X*con0 + con0*con1
173 add2->set_req(2, phase->makecon(tcon01) );
174 progress = add2;
175 }
176 }
177 } // End of is left input an add
178 } // End of is right input a Mul
179
180 return progress;
181 }
182
183 //------------------------------Value-----------------------------------------
184 const Type* MulNode::Value(PhaseGVN* phase) const {
185 const Type *t1 = phase->type( in(1) );
186 const Type *t2 = phase->type( in(2) );
187 // Either input is TOP ==> the result is TOP
188 if( t1 == Type::TOP ) return Type::TOP;
189 if( t2 == Type::TOP ) return Type::TOP;
190
191 // Either input is ZERO ==> the result is ZERO.
192 // Not valid for floats or doubles since +0.0 * -0.0 --> +0.0
193 int op = Opcode();
194 if( op == Op_MulI || op == Op_AndI || op == Op_MulL || op == Op_AndL ) {
195 const Type *zero = add_id(); // The multiplicative zero
196 if( t1->higher_equal( zero ) ) return zero;
197 if( t2->higher_equal( zero ) ) return zero;
198 }
199
200 // Code pattern on return from a call that returns an __Value. Can
201 // be optimized away if the return value turns out to be an oop.
202 if (op == Op_AndX &&
203 in(1) != nullptr &&
204 in(1)->Opcode() == Op_CastP2X &&
205 in(1)->in(1) != nullptr &&
206 phase->type(in(1)->in(1))->isa_oopptr() &&
207 t2->isa_intptr_t()->_lo >= 0 &&
208 t2->isa_intptr_t()->_hi <= MinObjAlignmentInBytesMask) {
209 return add_id();
210 }
211
212 // Either input is BOTTOM ==> the result is the local BOTTOM
213 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
214 return bottom_type();
215
216 #if defined(IA32)
217 // Can't trust native compilers to properly fold strict double
218 // multiplication with round-to-zero on this platform.
219 if (op == Op_MulD) {
220 return TypeD::DOUBLE;
221 }
222 #endif
223
224 return mul_ring(t1,t2); // Local flavor of type multiplication
225 }
226
227 MulNode* MulNode::make(Node* in1, Node* in2, BasicType bt) {
228 switch (bt) {
229 case T_INT:
230 return new MulINode(in1, in2);
231 case T_LONG:
232 return new MulLNode(in1, in2);
233 default:
234 fatal("Not implemented for %s", type2name(bt));
235 }
236 return nullptr;
237 }
238
239
240 //=============================================================================
241 //------------------------------Ideal------------------------------------------
242 // Check for power-of-2 multiply, then try the regular MulNode::Ideal
243 Node *MulINode::Ideal(PhaseGVN *phase, bool can_reshape) {
244 const jint con = in(2)->find_int_con(0);
245 if (con == 0) {
246 // If in(2) is not a constant, call Ideal() of the parent class to
247 // try to move constant to the right side.
248 return MulNode::Ideal(phase, can_reshape);
249 }
250
251 // Now we have a constant Node on the right and the constant in con.
252 if (con == 1) {
253 // By one is handled by Identity call
254 return nullptr;
255 }
256
257 // Check for negative constant; if so negate the final result
258 bool sign_flip = false;
259
260 unsigned int abs_con = uabs(con);
261 if (abs_con != (unsigned int)con) {
262 sign_flip = true;
263 }
264
265 // Get low bit; check for being the only bit
266 Node *res = nullptr;
267 unsigned int bit1 = submultiple_power_of_2(abs_con);
268 if (bit1 == abs_con) { // Found a power of 2?
269 res = new LShiftINode(in(1), phase->intcon(log2i_exact(bit1)));
270 } else {
271 // Check for constant with 2 bits set
272 unsigned int bit2 = abs_con - bit1;
273 bit2 = bit2 & (0 - bit2); // Extract 2nd bit
274 if (bit2 + bit1 == abs_con) { // Found all bits in con?
275 Node *n1 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(bit1))));
276 Node *n2 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(bit2))));
277 res = new AddINode(n2, n1);
278 } else if (is_power_of_2(abs_con + 1)) {
279 // Sleezy: power-of-2 - 1. Next time be generic.
280 unsigned int temp = abs_con + 1;
281 Node *n1 = phase->transform(new LShiftINode(in(1), phase->intcon(log2i_exact(temp))));
282 res = new SubINode(n1, in(1));
283 } else {
284 return MulNode::Ideal(phase, can_reshape);
285 }
286 }
287
288 if (sign_flip) { // Need to negate result?
289 res = phase->transform(res);// Transform, before making the zero con
290 res = new SubINode(phase->intcon(0),res);
291 }
292
293 return res; // Return final result
294 }
295
296 // This template class performs type multiplication for MulI/MulLNode. NativeType is either jint or jlong.
297 // In this class, the inputs of the MulNodes are named left and right with types [left_lo,left_hi] and [right_lo,right_hi].
298 //
299 // In general, the multiplication of two x-bit values could produce a result that consumes up to 2x bits if there is
300 // enough space to hold them all. We can therefore distinguish the following two cases for the product:
301 // - no overflow (i.e. product fits into x bits)
302 // - overflow (i.e. product does not fit into x bits)
303 //
304 // When multiplying the two x-bit inputs 'left' and 'right' with their x-bit types [left_lo,left_hi] and [right_lo,right_hi]
305 // we need to find the minimum and maximum of all possible products to define a new type. To do that, we compute the
306 // cross product of [left_lo,left_hi] and [right_lo,right_hi] in 2x-bit space where no over- or underflow can happen.
307 // The cross product consists of the following four multiplications with 2x-bit results:
308 // (1) left_lo * right_lo
309 // (2) left_lo * right_hi
310 // (3) left_hi * right_lo
311 // (4) left_hi * right_hi
312 //
313 // Let's define the following two functions:
314 // - Lx(i): Returns the lower x bits of the 2x-bit number i.
315 // - Ux(i): Returns the upper x bits of the 2x-bit number i.
316 //
317 // Let's first assume all products are positive where only overflows are possible but no underflows. If there is no
318 // overflow for a product p, then the upper x bits of the 2x-bit result p are all zero:
319 // Ux(p) = 0
320 // Lx(p) = p
321 //
322 // If none of the multiplications (1)-(4) overflow, we can truncate the upper x bits and use the following result type
323 // with x bits:
324 // [result_lo,result_hi] = [MIN(Lx(1),Lx(2),Lx(3),Lx(4)),MAX(Lx(1),Lx(2),Lx(3),Lx(4))]
325 //
326 // If any of these multiplications overflows, we could pessimistically take the bottom type for the x bit result
327 // (i.e. all values in the x-bit space could be possible):
328 // [result_lo,result_hi] = [NativeType_min,NativeType_max]
329 //
330 // However, in case of any overflow, we can do better by analyzing the upper x bits of all multiplications (1)-(4) with
331 // 2x-bit results. The upper x bits tell us something about how many times a multiplication has overflown the lower
332 // x bits. If the upper x bits of (1)-(4) are all equal, then we know that all of these multiplications overflowed
333 // the lower x bits the same number of times:
334 // Ux((1)) = Ux((2)) = Ux((3)) = Ux((4))
335 //
336 // If all upper x bits are equal, we can conclude:
337 // Lx(MIN((1),(2),(3),(4))) = MIN(Lx(1),Lx(2),Lx(3),Lx(4)))
338 // Lx(MAX((1),(2),(3),(4))) = MAX(Lx(1),Lx(2),Lx(3),Lx(4)))
339 //
340 // Therefore, we can use the same precise x-bit result type as for the no-overflow case:
341 // [result_lo,result_hi] = [(MIN(Lx(1),Lx(2),Lx(3),Lx(4))),MAX(Lx(1),Lx(2),Lx(3),Lx(4)))]
342 //
343 //
344 // Now let's assume that (1)-(4) are signed multiplications where over- and underflow could occur:
345 // Negative numbers are all sign extend with ones. Therefore, if a negative product does not underflow, then the
346 // 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,
347 // the upper x bits are decremented by the number of times an underflow occurred. The smallest possible negative product
348 // is NativeType_min*NativeType_max, where the upper x bits are set to NativeType_min / 2 (b11...0). It is therefore
349 // impossible to underflow the upper x bits. Thus, when having all ones (i.e. minus one) in the upper x bits, we know
350 // that there is no underflow.
351 //
352 // To be able to compare the number of over-/underflows of positive and negative products, respectively, we normalize
353 // the upper x bits of negative 2x-bit products by adding one. This way a product has no over- or underflow if the
354 // normalized upper x bits are zero. Now we can use the same improved type as for strictly positive products because we
355 // can compare the upper x bits in a unified way with N() being the normalization function:
356 // N(Ux((1))) = N(Ux((2))) = N(Ux((3)) = N(Ux((4)))
357 template<typename NativeType>
358 class IntegerTypeMultiplication {
359
360 NativeType _lo_left;
361 NativeType _lo_right;
362 NativeType _hi_left;
363 NativeType _hi_right;
364 short _widen_left;
365 short _widen_right;
366
367 static const Type* overflow_type();
368 static NativeType multiply_high(NativeType x, NativeType y);
369 const Type* create_type(NativeType lo, NativeType hi) const;
370
371 static NativeType multiply_high_signed_overflow_value(NativeType x, NativeType y) {
372 return normalize_overflow_value(x, y, multiply_high(x, y));
373 }
374
375 bool cross_product_not_same_overflow_value() const {
376 const NativeType lo_lo_high_product = multiply_high_signed_overflow_value(_lo_left, _lo_right);
377 const NativeType lo_hi_high_product = multiply_high_signed_overflow_value(_lo_left, _hi_right);
378 const NativeType hi_lo_high_product = multiply_high_signed_overflow_value(_hi_left, _lo_right);
379 const NativeType hi_hi_high_product = multiply_high_signed_overflow_value(_hi_left, _hi_right);
380 return lo_lo_high_product != lo_hi_high_product ||
381 lo_hi_high_product != hi_lo_high_product ||
382 hi_lo_high_product != hi_hi_high_product;
383 }
384
385 bool does_product_overflow(NativeType x, NativeType y) const {
386 return multiply_high_signed_overflow_value(x, y) != 0;
387 }
388
389 static NativeType normalize_overflow_value(const NativeType x, const NativeType y, NativeType result) {
390 return java_multiply(x, y) < 0 ? result + 1 : result;
391 }
392
393 public:
394 template<class IntegerType>
395 IntegerTypeMultiplication(const IntegerType* left, const IntegerType* right)
396 : _lo_left(left->_lo), _lo_right(right->_lo),
397 _hi_left(left->_hi), _hi_right(right->_hi),
398 _widen_left(left->_widen), _widen_right(right->_widen) {}
399
400 // Compute the product type by multiplying the two input type ranges. We take the minimum and maximum of all possible
401 // values (requires 4 multiplications of all possible combinations of the two range boundary values). If any of these
402 // multiplications overflows/underflows, we need to make sure that they all have the same number of overflows/underflows
403 // If that is not the case, we return the bottom type to cover all values due to the inconsistent overflows/underflows).
404 const Type* compute() const {
405 if (cross_product_not_same_overflow_value()) {
406 return overflow_type();
407 }
408
409 NativeType lo_lo_product = java_multiply(_lo_left, _lo_right);
410 NativeType lo_hi_product = java_multiply(_lo_left, _hi_right);
411 NativeType hi_lo_product = java_multiply(_hi_left, _lo_right);
412 NativeType hi_hi_product = java_multiply(_hi_left, _hi_right);
413 const NativeType min = MIN4(lo_lo_product, lo_hi_product, hi_lo_product, hi_hi_product);
414 const NativeType max = MAX4(lo_lo_product, lo_hi_product, hi_lo_product, hi_hi_product);
415 return create_type(min, max);
416 }
417
418 bool does_overflow() const {
419 return does_product_overflow(_lo_left, _lo_right) ||
420 does_product_overflow(_lo_left, _hi_right) ||
421 does_product_overflow(_hi_left, _lo_right) ||
422 does_product_overflow(_hi_left, _hi_right);
423 }
424 };
425
426 template <>
427 const Type* IntegerTypeMultiplication<jint>::overflow_type() {
428 return TypeInt::INT;
429 }
430
431 template <>
432 jint IntegerTypeMultiplication<jint>::multiply_high(const jint x, const jint y) {
433 const jlong x_64 = x;
434 const jlong y_64 = y;
435 const jlong product = x_64 * y_64;
436 return (jint)((uint64_t)product >> 32u);
437 }
438
439 template <>
440 const Type* IntegerTypeMultiplication<jint>::create_type(jint lo, jint hi) const {
441 return TypeInt::make(lo, hi, MAX2(_widen_left, _widen_right));
442 }
443
444 template <>
445 const Type* IntegerTypeMultiplication<jlong>::overflow_type() {
446 return TypeLong::LONG;
447 }
448
449 template <>
450 jlong IntegerTypeMultiplication<jlong>::multiply_high(const jlong x, const jlong y) {
451 return multiply_high_signed(x, y);
452 }
453
454 template <>
455 const Type* IntegerTypeMultiplication<jlong>::create_type(jlong lo, jlong hi) const {
456 return TypeLong::make(lo, hi, MAX2(_widen_left, _widen_right));
457 }
458
459 // Compute the product type of two integer ranges into this node.
460 const Type* MulINode::mul_ring(const Type* type_left, const Type* type_right) const {
461 const IntegerTypeMultiplication<jint> integer_multiplication(type_left->is_int(), type_right->is_int());
462 return integer_multiplication.compute();
463 }
464
465 bool MulINode::does_overflow(const TypeInt* type_left, const TypeInt* type_right) {
466 const IntegerTypeMultiplication<jint> integer_multiplication(type_left, type_right);
467 return integer_multiplication.does_overflow();
468 }
469
470 // Compute the product type of two long ranges into this node.
471 const Type* MulLNode::mul_ring(const Type* type_left, const Type* type_right) const {
472 const IntegerTypeMultiplication<jlong> integer_multiplication(type_left->is_long(), type_right->is_long());
473 return integer_multiplication.compute();
474 }
475
476 //=============================================================================
477 //------------------------------Ideal------------------------------------------
478 // Check for power-of-2 multiply, then try the regular MulNode::Ideal
479 Node *MulLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
480 const jlong con = in(2)->find_long_con(0);
481 if (con == 0) {
482 // If in(2) is not a constant, call Ideal() of the parent class to
483 // try to move constant to the right side.
484 return MulNode::Ideal(phase, can_reshape);
485 }
486
487 // Now we have a constant Node on the right and the constant in con.
488 if (con == 1) {
489 // By one is handled by Identity call
490 return nullptr;
491 }
492
493 // Check for negative constant; if so negate the final result
494 bool sign_flip = false;
495 julong abs_con = uabs(con);
496 if (abs_con != (julong)con) {
497 sign_flip = true;
498 }
499
500 // Get low bit; check for being the only bit
501 Node *res = nullptr;
502 julong bit1 = submultiple_power_of_2(abs_con);
503 if (bit1 == abs_con) { // Found a power of 2?
504 res = new LShiftLNode(in(1), phase->intcon(log2i_exact(bit1)));
505 } else {
506
507 // Check for constant with 2 bits set
508 julong bit2 = abs_con-bit1;
509 bit2 = bit2 & (0-bit2); // Extract 2nd bit
510 if (bit2 + bit1 == abs_con) { // Found all bits in con?
511 Node *n1 = phase->transform(new LShiftLNode(in(1), phase->intcon(log2i_exact(bit1))));
512 Node *n2 = phase->transform(new LShiftLNode(in(1), phase->intcon(log2i_exact(bit2))));
513 res = new AddLNode(n2, n1);
514
515 } else if (is_power_of_2(abs_con+1)) {
516 // Sleezy: power-of-2 -1. Next time be generic.
517 julong temp = abs_con + 1;
518 Node *n1 = phase->transform( new LShiftLNode(in(1), phase->intcon(log2i_exact(temp))));
519 res = new SubLNode(n1, in(1));
520 } else {
521 return MulNode::Ideal(phase, can_reshape);
522 }
523 }
524
525 if (sign_flip) { // Need to negate result?
526 res = phase->transform(res);// Transform, before making the zero con
527 res = new SubLNode(phase->longcon(0),res);
528 }
529
530 return res; // Return final result
531 }
532
533 //=============================================================================
534 //------------------------------mul_ring---------------------------------------
535 // Compute the product type of two double ranges into this node.
536 const Type *MulFNode::mul_ring(const Type *t0, const Type *t1) const {
537 if( t0 == Type::FLOAT || t1 == Type::FLOAT ) return Type::FLOAT;
538 return TypeF::make( t0->getf() * t1->getf() );
539 }
540
541 //------------------------------Ideal---------------------------------------
542 // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal
543 Node* MulFNode::Ideal(PhaseGVN* phase, bool can_reshape) {
544 const TypeF *t2 = phase->type(in(2))->isa_float_constant();
545
546 // x * 2 -> x + x
547 if (t2 != nullptr && t2->getf() == 2) {
548 Node* base = in(1);
549 return new AddFNode(base, base);
550 }
551
552 return MulNode::Ideal(phase, can_reshape);
553 }
554
555 //=============================================================================
556 //------------------------------mul_ring---------------------------------------
557 // Compute the product type of two double ranges into this node.
558 const Type *MulDNode::mul_ring(const Type *t0, const Type *t1) const {
559 if( t0 == Type::DOUBLE || t1 == Type::DOUBLE ) return Type::DOUBLE;
560 // We must be multiplying 2 double constants.
561 return TypeD::make( t0->getd() * t1->getd() );
562 }
563
564 //------------------------------Ideal---------------------------------------
565 // Check to see if we are multiplying by a constant 2 and convert to add, then try the regular MulNode::Ideal
566 Node* MulDNode::Ideal(PhaseGVN* phase, bool can_reshape) {
567 const TypeD *t2 = phase->type(in(2))->isa_double_constant();
568
569 // x * 2 -> x + x
570 if (t2 != nullptr && t2->getd() == 2) {
571 Node* base = in(1);
572 return new AddDNode(base, base);
573 }
574
575 return MulNode::Ideal(phase, can_reshape);
576 }
577
578 //=============================================================================
579 //------------------------------Value------------------------------------------
580 const Type* MulHiLNode::Value(PhaseGVN* phase) const {
581 const Type *t1 = phase->type( in(1) );
582 const Type *t2 = phase->type( in(2) );
583 const Type *bot = bottom_type();
584 return MulHiValue(t1, t2, bot);
585 }
586
587 const Type* UMulHiLNode::Value(PhaseGVN* phase) const {
588 const Type *t1 = phase->type( in(1) );
589 const Type *t2 = phase->type( in(2) );
590 const Type *bot = bottom_type();
591 return MulHiValue(t1, t2, bot);
592 }
593
594 // A common routine used by UMulHiLNode and MulHiLNode
595 const Type* MulHiValue(const Type *t1, const Type *t2, const Type *bot) {
596 // Either input is TOP ==> the result is TOP
597 if( t1 == Type::TOP ) return Type::TOP;
598 if( t2 == Type::TOP ) return Type::TOP;
599
600 // Either input is BOTTOM ==> the result is the local BOTTOM
601 if( (t1 == bot) || (t2 == bot) ||
602 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
603 return bot;
604
605 // It is not worth trying to constant fold this stuff!
606 return TypeLong::LONG;
607 }
608
609 //=============================================================================
610 //------------------------------mul_ring---------------------------------------
611 // Supplied function returns the product of the inputs IN THE CURRENT RING.
612 // For the logical operations the ring's MUL is really a logical AND function.
613 // This also type-checks the inputs for sanity. Guaranteed never to
614 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
615 const Type *AndINode::mul_ring( const Type *t0, const Type *t1 ) const {
616 const TypeInt *r0 = t0->is_int(); // Handy access
617 const TypeInt *r1 = t1->is_int();
618 int widen = MAX2(r0->_widen,r1->_widen);
619
620 // If either input is a constant, might be able to trim cases
621 if( !r0->is_con() && !r1->is_con() )
622 return TypeInt::INT; // No constants to be had
623
624 // Both constants? Return bits
625 if( r0->is_con() && r1->is_con() )
626 return TypeInt::make( r0->get_con() & r1->get_con() );
627
628 if( r0->is_con() && r0->get_con() > 0 )
629 return TypeInt::make(0, r0->get_con(), widen);
630
631 if( r1->is_con() && r1->get_con() > 0 )
632 return TypeInt::make(0, r1->get_con(), widen);
633
634 if( r0 == TypeInt::BOOL || r1 == TypeInt::BOOL ) {
635 return TypeInt::BOOL;
636 }
637
638 return TypeInt::INT; // No constants to be had
639 }
640
641 const Type* AndINode::Value(PhaseGVN* phase) const {
642 // patterns similar to (v << 2) & 3
643 if (AndIL_shift_and_mask_is_always_zero(phase, in(1), in(2), T_INT, true)) {
644 return TypeInt::ZERO;
645 }
646
647 return MulNode::Value(phase);
648 }
649
650 //------------------------------Identity---------------------------------------
651 // Masking off the high bits of an unsigned load is not required
652 Node* AndINode::Identity(PhaseGVN* phase) {
653
654 // x & x => x
655 if (in(1) == in(2)) {
656 return in(1);
657 }
658
659 Node* in1 = in(1);
660 uint op = in1->Opcode();
661 const TypeInt* t2 = phase->type(in(2))->isa_int();
662 if (t2 && t2->is_con()) {
663 int con = t2->get_con();
664 // Masking off high bits which are always zero is useless.
665 const TypeInt* t1 = phase->type(in(1))->isa_int();
666 if (t1 != nullptr && t1->_lo >= 0) {
667 jint t1_support = right_n_bits(1 + log2i_graceful(t1->_hi));
668 if ((t1_support & con) == t1_support)
669 return in1;
670 }
671 // Masking off the high bits of a unsigned-shift-right is not
672 // needed either.
673 if (op == Op_URShiftI) {
674 const TypeInt* t12 = phase->type(in1->in(2))->isa_int();
675 if (t12 && t12->is_con()) { // Shift is by a constant
676 int shift = t12->get_con();
677 shift &= BitsPerJavaInteger - 1; // semantics of Java shifts
678 int mask = max_juint >> shift;
679 if ((mask & con) == mask) // If AND is useless, skip it
680 return in1;
681 }
682 }
683 }
684 return MulNode::Identity(phase);
685 }
686
687 //------------------------------Ideal------------------------------------------
688 Node *AndINode::Ideal(PhaseGVN *phase, bool can_reshape) {
689 // pattern similar to (v1 + (v2 << 2)) & 3 transformed to v1 & 3
690 Node* progress = AndIL_add_shift_and_mask(phase, T_INT);
691 if (progress != nullptr) {
692 return progress;
693 }
694
695 // Convert "(~a) & (~b)" into "~(a | b)"
696 if (AddNode::is_not(phase, in(1), T_INT) && AddNode::is_not(phase, in(2), T_INT)) {
697 Node* or_a_b = new OrINode(in(1)->in(1), in(2)->in(1));
698 Node* tn = phase->transform(or_a_b);
699 return AddNode::make_not(phase, tn, T_INT);
700 }
701
702 // Special case constant AND mask
703 const TypeInt *t2 = phase->type( in(2) )->isa_int();
704 if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
705 const int mask = t2->get_con();
706 Node *load = in(1);
707 uint lop = load->Opcode();
708
709 // Masking bits off of a Character? Hi bits are already zero.
710 if( lop == Op_LoadUS &&
711 (mask & 0xFFFF0000) ) // Can we make a smaller mask?
712 return new AndINode(load,phase->intcon(mask&0xFFFF));
713
714 // Masking bits off of a Short? Loading a Character does some masking
715 if (can_reshape &&
716 load->outcnt() == 1 && load->unique_out() == this) {
717 if (lop == Op_LoadS && (mask & 0xFFFF0000) == 0 ) {
718 Node* ldus = load->as_Load()->convert_to_unsigned_load(*phase);
719 ldus = phase->transform(ldus);
720 return new AndINode(ldus, phase->intcon(mask & 0xFFFF));
721 }
722
723 // Masking sign bits off of a Byte? Do an unsigned byte load plus
724 // an and.
725 if (lop == Op_LoadB && (mask & 0xFFFFFF00) == 0) {
726 Node* ldub = load->as_Load()->convert_to_unsigned_load(*phase);
727 ldub = phase->transform(ldub);
728 return new AndINode(ldub, phase->intcon(mask));
729 }
730 }
731
732 // Masking off sign bits? Dont make them!
733 if( lop == Op_RShiftI ) {
734 const TypeInt *t12 = phase->type(load->in(2))->isa_int();
735 if( t12 && t12->is_con() ) { // Shift is by a constant
736 int shift = t12->get_con();
737 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
738 const int sign_bits_mask = ~right_n_bits(BitsPerJavaInteger - shift);
739 // If the AND'ing of the 2 masks has no bits, then only original shifted
740 // bits survive. NO sign-extension bits survive the maskings.
741 if( (sign_bits_mask & mask) == 0 ) {
742 // Use zero-fill shift instead
743 Node *zshift = phase->transform(new URShiftINode(load->in(1),load->in(2)));
744 return new AndINode( zshift, in(2) );
745 }
746 }
747 }
748
749 // Check for 'negate/and-1', a pattern emitted when someone asks for
750 // 'mod 2'. Negate leaves the low order bit unchanged (think: complement
751 // plus 1) and the mask is of the low order bit. Skip the negate.
752 if( lop == Op_SubI && mask == 1 && load->in(1) &&
753 phase->type(load->in(1)) == TypeInt::ZERO )
754 return new AndINode( load->in(2), in(2) );
755
756 return MulNode::Ideal(phase, can_reshape);
757 }
758
759 //=============================================================================
760 //------------------------------mul_ring---------------------------------------
761 // Supplied function returns the product of the inputs IN THE CURRENT RING.
762 // For the logical operations the ring's MUL is really a logical AND function.
763 // This also type-checks the inputs for sanity. Guaranteed never to
764 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
765 const Type *AndLNode::mul_ring( const Type *t0, const Type *t1 ) const {
766 const TypeLong *r0 = t0->is_long(); // Handy access
767 const TypeLong *r1 = t1->is_long();
768 int widen = MAX2(r0->_widen,r1->_widen);
769
770 // If either input is a constant, might be able to trim cases
771 if( !r0->is_con() && !r1->is_con() )
772 return TypeLong::LONG; // No constants to be had
773
774 // Both constants? Return bits
775 if( r0->is_con() && r1->is_con() )
776 return TypeLong::make( r0->get_con() & r1->get_con() );
777
778 if( r0->is_con() && r0->get_con() > 0 )
779 return TypeLong::make(CONST64(0), r0->get_con(), widen);
780
781 if( r1->is_con() && r1->get_con() > 0 )
782 return TypeLong::make(CONST64(0), r1->get_con(), widen);
783
784 return TypeLong::LONG; // No constants to be had
785 }
786
787 const Type* AndLNode::Value(PhaseGVN* phase) const {
788 // patterns similar to (v << 2) & 3
789 if (AndIL_shift_and_mask_is_always_zero(phase, in(1), in(2), T_LONG, true)) {
790 return TypeLong::ZERO;
791 }
792
793 return MulNode::Value(phase);
794 }
795
796 //------------------------------Identity---------------------------------------
797 // Masking off the high bits of an unsigned load is not required
798 Node* AndLNode::Identity(PhaseGVN* phase) {
799
800 // x & x => x
801 if (in(1) == in(2)) {
802 return in(1);
803 }
804
805 Node *usr = in(1);
806 const TypeLong *t2 = phase->type( in(2) )->isa_long();
807 if( t2 && t2->is_con() ) {
808 jlong con = t2->get_con();
809 // Masking off high bits which are always zero is useless.
810 const TypeLong* t1 = phase->type( in(1) )->isa_long();
811 if (t1 != nullptr && t1->_lo >= 0) {
812 int bit_count = log2i_graceful(t1->_hi) + 1;
813 jlong t1_support = jlong(max_julong >> (BitsPerJavaLong - bit_count));
814 if ((t1_support & con) == t1_support)
815 return usr;
816 }
817 uint lop = usr->Opcode();
818 // Masking off the high bits of a unsigned-shift-right is not
819 // needed either.
820 if( lop == Op_URShiftL ) {
821 const TypeInt *t12 = phase->type( usr->in(2) )->isa_int();
822 if( t12 && t12->is_con() ) { // Shift is by a constant
823 int shift = t12->get_con();
824 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
825 jlong mask = max_julong >> shift;
826 if( (mask&con) == mask ) // If AND is useless, skip it
827 return usr;
828 }
829 }
830 }
831 return MulNode::Identity(phase);
832 }
833
834 //------------------------------Ideal------------------------------------------
835 Node *AndLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
836 // pattern similar to (v1 + (v2 << 2)) & 3 transformed to v1 & 3
837 Node* progress = AndIL_add_shift_and_mask(phase, T_LONG);
838 if (progress != nullptr) {
839 return progress;
840 }
841
842 // Convert "(~a) & (~b)" into "~(a | b)"
843 if (AddNode::is_not(phase, in(1), T_LONG) && AddNode::is_not(phase, in(2), T_LONG)) {
844 Node* or_a_b = new OrLNode(in(1)->in(1), in(2)->in(1));
845 Node* tn = phase->transform(or_a_b);
846 return AddNode::make_not(phase, tn, T_LONG);
847 }
848
849 // Special case constant AND mask
850 const TypeLong *t2 = phase->type( in(2) )->isa_long();
851 if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
852 const jlong mask = t2->get_con();
853
854 Node* in1 = in(1);
855 int op = in1->Opcode();
856
857 // Are we masking a long that was converted from an int with a mask
858 // that fits in 32-bits? Commute them and use an AndINode. Don't
859 // convert masks which would cause a sign extension of the integer
860 // value. This check includes UI2L masks (0x00000000FFFFFFFF) which
861 // would be optimized away later in Identity.
862 if (op == Op_ConvI2L && (mask & UCONST64(0xFFFFFFFF80000000)) == 0) {
863 Node* andi = new AndINode(in1->in(1), phase->intcon(mask));
864 andi = phase->transform(andi);
865 return new ConvI2LNode(andi);
866 }
867
868 // Masking off sign bits? Dont make them!
869 if (op == Op_RShiftL) {
870 const TypeInt* t12 = phase->type(in1->in(2))->isa_int();
871 if( t12 && t12->is_con() ) { // Shift is by a constant
872 int shift = t12->get_con();
873 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
874 const julong sign_bits_mask = ~(((julong)CONST64(1) << (julong)(BitsPerJavaLong - shift)) -1);
875 // If the AND'ing of the 2 masks has no bits, then only original shifted
876 // bits survive. NO sign-extension bits survive the maskings.
877 if( (sign_bits_mask & mask) == 0 ) {
878 // Use zero-fill shift instead
879 Node *zshift = phase->transform(new URShiftLNode(in1->in(1), in1->in(2)));
880 return new AndLNode(zshift, in(2));
881 }
882 }
883 }
884
885 // Search for GraphKit::mark_word_test patterns and fold the test if the result is statically known
886 Node* load1 = in(1);
887 Node* load2 = nullptr;
888 if (load1->is_Phi() && phase->type(load1)->isa_long()) {
889 load1 = in(1)->in(1);
890 load2 = in(1)->in(2);
891 }
892 if (load1 != nullptr && load1->is_Load() && phase->type(load1)->isa_long() &&
893 (load2 == nullptr || (load2->is_Load() && phase->type(load2)->isa_long()))) {
894 const TypePtr* adr_t1 = phase->type(load1->in(MemNode::Address))->isa_ptr();
895 const TypePtr* adr_t2 = (load2 != nullptr) ? phase->type(load2->in(MemNode::Address))->isa_ptr() : nullptr;
896 if (adr_t1 != nullptr && adr_t1->offset() == oopDesc::mark_offset_in_bytes() &&
897 (load2 == nullptr || (adr_t2 != nullptr && adr_t2->offset() == in_bytes(Klass::prototype_header_offset())))) {
898 if (mask == markWord::inline_type_pattern) {
899 if (adr_t1->is_inlinetypeptr()) {
900 set_req_X(1, in(2), phase);
901 return this;
902 } else if (!adr_t1->can_be_inline_type()) {
903 set_req_X(1, phase->longcon(0), phase);
904 return this;
905 }
906 } else if (mask == markWord::null_free_array_bit_in_place) {
907 if (adr_t1->is_null_free()) {
908 set_req_X(1, in(2), phase);
909 return this;
910 } else if (adr_t1->is_not_null_free()) {
911 set_req_X(1, phase->longcon(0), phase);
912 return this;
913 }
914 } else if (mask == markWord::flat_array_bit_in_place) {
915 if (adr_t1->is_flat()) {
916 set_req_X(1, in(2), phase);
917 return this;
918 } else if (adr_t1->is_not_flat()) {
919 set_req_X(1, phase->longcon(0), phase);
920 return this;
921 }
922 }
923 }
924 }
925
926 return MulNode::Ideal(phase, can_reshape);
927 }
928
929 LShiftNode* LShiftNode::make(Node* in1, Node* in2, BasicType bt) {
930 switch (bt) {
931 case T_INT:
932 return new LShiftINode(in1, in2);
933 case T_LONG:
934 return new LShiftLNode(in1, in2);
935 default:
936 fatal("Not implemented for %s", type2name(bt));
937 }
938 return nullptr;
939 }
940
941 //=============================================================================
942
943 static bool const_shift_count(PhaseGVN* phase, Node* shiftNode, int* count) {
944 const TypeInt* tcount = phase->type(shiftNode->in(2))->isa_int();
945 if (tcount != nullptr && tcount->is_con()) {
946 *count = tcount->get_con();
947 return true;
948 }
949 return false;
950 }
951
952 static int maskShiftAmount(PhaseGVN* phase, Node* shiftNode, int nBits) {
953 int count = 0;
954 if (const_shift_count(phase, shiftNode, &count)) {
955 int maskedShift = count & (nBits - 1);
956 if (maskedShift == 0) {
957 // Let Identity() handle 0 shift count.
958 return 0;
959 }
960
961 if (count != maskedShift) {
962 shiftNode->set_req(2, phase->intcon(maskedShift)); // Replace shift count with masked value.
963 PhaseIterGVN* igvn = phase->is_IterGVN();
964 if (igvn) {
965 igvn->rehash_node_delayed(shiftNode);
966 }
967 }
968 return maskedShift;
969 }
970 return 0;
971 }
972
973 //------------------------------Identity---------------------------------------
974 Node* LShiftINode::Identity(PhaseGVN* phase) {
975 int count = 0;
976 if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaInteger - 1)) == 0) {
977 // Shift by a multiple of 32 does nothing
978 return in(1);
979 }
980 return this;
981 }
982
983 //------------------------------Ideal------------------------------------------
984 // If the right input is a constant, and the left input is an add of a
985 // constant, flatten the tree: (X+con1)<<con0 ==> X<<con0 + con1<<con0
986 Node *LShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
987 int con = maskShiftAmount(phase, this, BitsPerJavaInteger);
988 if (con == 0) {
989 return nullptr;
990 }
991
992 // Left input is an add?
993 Node *add1 = in(1);
994 int add1_op = add1->Opcode();
995 if( add1_op == Op_AddI ) { // Left input is an add?
996 assert( add1 != add1->in(1), "dead loop in LShiftINode::Ideal" );
997
998 // Transform is legal, but check for profit. Avoid breaking 'i2s'
999 // and 'i2b' patterns which typically fold into 'StoreC/StoreB'.
1000 if( con < 16 ) {
1001 // Left input is an add of the same number?
1002 if (add1->in(1) == add1->in(2)) {
1003 // Convert "(x + x) << c0" into "x << (c0 + 1)"
1004 // In general, this optimization cannot be applied for c0 == 31 since
1005 // 2x << 31 != x << 32 = x << 0 = x (e.g. x = 1: 2 << 31 = 0 != 1)
1006 return new LShiftINode(add1->in(1), phase->intcon(con + 1));
1007 }
1008
1009 // Left input is an add of a constant?
1010 const TypeInt *t12 = phase->type(add1->in(2))->isa_int();
1011 if( t12 && t12->is_con() ){ // Left input is an add of a con?
1012 // Compute X << con0
1013 Node *lsh = phase->transform( new LShiftINode( add1->in(1), in(2) ) );
1014 // Compute X<<con0 + (con1<<con0)
1015 return new AddINode( lsh, phase->intcon(t12->get_con() << con));
1016 }
1017 }
1018 }
1019
1020 // Check for "(x >> C1) << C2"
1021 if (add1_op == Op_RShiftI || add1_op == Op_URShiftI) {
1022 int add1Con = 0;
1023 const_shift_count(phase, add1, &add1Con);
1024
1025 // Special case C1 == C2, which just masks off low bits
1026 if (add1Con > 0 && con == add1Con) {
1027 // Convert to "(x & -(1 << C2))"
1028 return new AndINode(add1->in(1), phase->intcon(java_negate(jint(1 << con))));
1029 } else {
1030 // Wait until the right shift has been sharpened to the correct count
1031 if (add1Con > 0 && add1Con < BitsPerJavaInteger) {
1032 // As loop parsing can produce LShiftI nodes, we should wait until the graph is fully formed
1033 // to apply optimizations, otherwise we can inadvertently stop vectorization opportunities.
1034 if (phase->is_IterGVN()) {
1035 if (con > add1Con) {
1036 // Creates "(x << (C2 - C1)) & -(1 << C2)"
1037 Node* lshift = phase->transform(new LShiftINode(add1->in(1), phase->intcon(con - add1Con)));
1038 return new AndINode(lshift, phase->intcon(java_negate(jint(1 << con))));
1039 } else {
1040 assert(con < add1Con, "must be (%d < %d)", con, add1Con);
1041 // Creates "(x >> (C1 - C2)) & -(1 << C2)"
1042
1043 // Handle logical and arithmetic shifts
1044 Node* rshift;
1045 if (add1_op == Op_RShiftI) {
1046 rshift = phase->transform(new RShiftINode(add1->in(1), phase->intcon(add1Con - con)));
1047 } else {
1048 rshift = phase->transform(new URShiftINode(add1->in(1), phase->intcon(add1Con - con)));
1049 }
1050
1051 return new AndINode(rshift, phase->intcon(java_negate(jint(1 << con))));
1052 }
1053 } else {
1054 phase->record_for_igvn(this);
1055 }
1056 }
1057 }
1058 }
1059
1060 // Check for "((x >> C1) & Y) << C2"
1061 if (add1_op == Op_AndI) {
1062 Node *add2 = add1->in(1);
1063 int add2_op = add2->Opcode();
1064 if (add2_op == Op_RShiftI || add2_op == Op_URShiftI) {
1065 // Special case C1 == C2, which just masks off low bits
1066 if (add2->in(2) == in(2)) {
1067 // Convert to "(x & (Y << C2))"
1068 Node* y_sh = phase->transform(new LShiftINode(add1->in(2), phase->intcon(con)));
1069 return new AndINode(add2->in(1), y_sh);
1070 }
1071
1072 int add2Con = 0;
1073 const_shift_count(phase, add2, &add2Con);
1074 if (add2Con > 0 && add2Con < BitsPerJavaInteger) {
1075 if (phase->is_IterGVN()) {
1076 // Convert to "((x >> C1) << C2) & (Y << C2)"
1077
1078 // Make "(x >> C1) << C2", which will get folded away by the rule above
1079 Node* x_sh = phase->transform(new LShiftINode(add2, phase->intcon(con)));
1080 // Make "Y << C2", which will simplify when Y is a constant
1081 Node* y_sh = phase->transform(new LShiftINode(add1->in(2), phase->intcon(con)));
1082
1083 return new AndINode(x_sh, y_sh);
1084 } else {
1085 phase->record_for_igvn(this);
1086 }
1087 }
1088 }
1089 }
1090
1091 // Check for ((x & ((1<<(32-c0))-1)) << c0) which ANDs off high bits
1092 // before shifting them away.
1093 const jint bits_mask = right_n_bits(BitsPerJavaInteger-con);
1094 if( add1_op == Op_AndI &&
1095 phase->type(add1->in(2)) == TypeInt::make( bits_mask ) )
1096 return new LShiftINode( add1->in(1), in(2) );
1097
1098 return nullptr;
1099 }
1100
1101 //------------------------------Value------------------------------------------
1102 // A LShiftINode shifts its input2 left by input1 amount.
1103 const Type* LShiftINode::Value(PhaseGVN* phase) const {
1104 const Type *t1 = phase->type( in(1) );
1105 const Type *t2 = phase->type( in(2) );
1106 // Either input is TOP ==> the result is TOP
1107 if( t1 == Type::TOP ) return Type::TOP;
1108 if( t2 == Type::TOP ) return Type::TOP;
1109
1110 // Left input is ZERO ==> the result is ZERO.
1111 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
1112 // Shift by zero does nothing
1113 if( t2 == TypeInt::ZERO ) return t1;
1114
1115 // Either input is BOTTOM ==> the result is BOTTOM
1116 if( (t1 == TypeInt::INT) || (t2 == TypeInt::INT) ||
1117 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
1118 return TypeInt::INT;
1119
1120 const TypeInt *r1 = t1->is_int(); // Handy access
1121 const TypeInt *r2 = t2->is_int(); // Handy access
1122
1123 if (!r2->is_con())
1124 return TypeInt::INT;
1125
1126 uint shift = r2->get_con();
1127 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
1128 // Shift by a multiple of 32 does nothing:
1129 if (shift == 0) return t1;
1130
1131 // If the shift is a constant, shift the bounds of the type,
1132 // unless this could lead to an overflow.
1133 if (!r1->is_con()) {
1134 jint lo = r1->_lo, hi = r1->_hi;
1135 if (((lo << shift) >> shift) == lo &&
1136 ((hi << shift) >> shift) == hi) {
1137 // No overflow. The range shifts up cleanly.
1138 return TypeInt::make((jint)lo << (jint)shift,
1139 (jint)hi << (jint)shift,
1140 MAX2(r1->_widen,r2->_widen));
1141 }
1142 return TypeInt::INT;
1143 }
1144
1145 return TypeInt::make( (jint)r1->get_con() << (jint)shift );
1146 }
1147
1148 //=============================================================================
1149 //------------------------------Identity---------------------------------------
1150 Node* LShiftLNode::Identity(PhaseGVN* phase) {
1151 int count = 0;
1152 if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaLong - 1)) == 0) {
1153 // Shift by a multiple of 64 does nothing
1154 return in(1);
1155 }
1156 return this;
1157 }
1158
1159 //------------------------------Ideal------------------------------------------
1160 // If the right input is a constant, and the left input is an add of a
1161 // constant, flatten the tree: (X+con1)<<con0 ==> X<<con0 + con1<<con0
1162 Node *LShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1163 int con = maskShiftAmount(phase, this, BitsPerJavaLong);
1164 if (con == 0) {
1165 return nullptr;
1166 }
1167
1168 // Left input is an add?
1169 Node *add1 = in(1);
1170 int add1_op = add1->Opcode();
1171 if( add1_op == Op_AddL ) { // Left input is an add?
1172 // Avoid dead data cycles from dead loops
1173 assert( add1 != add1->in(1), "dead loop in LShiftLNode::Ideal" );
1174
1175 // Left input is an add of the same number?
1176 if (con != (BitsPerJavaLong - 1) && add1->in(1) == add1->in(2)) {
1177 // Convert "(x + x) << c0" into "x << (c0 + 1)"
1178 // Can only be applied if c0 != 63 because:
1179 // (x + x) << 63 = 2x << 63, while
1180 // (x + x) << 63 --transform--> x << 64 = x << 0 = x (!= 2x << 63, for example for x = 1)
1181 // According to the Java spec, chapter 15.19, we only consider the six lowest-order bits of the right-hand operand
1182 // (i.e. "right-hand operand" & 0b111111). Therefore, x << 64 is the same as x << 0 (64 = 0b10000000 & 0b0111111 = 0).
1183 return new LShiftLNode(add1->in(1), phase->intcon(con + 1));
1184 }
1185
1186 // Left input is an add of a constant?
1187 const TypeLong *t12 = phase->type(add1->in(2))->isa_long();
1188 if( t12 && t12->is_con() ){ // Left input is an add of a con?
1189 // Compute X << con0
1190 Node *lsh = phase->transform( new LShiftLNode( add1->in(1), in(2) ) );
1191 // Compute X<<con0 + (con1<<con0)
1192 return new AddLNode( lsh, phase->longcon(t12->get_con() << con));
1193 }
1194 }
1195
1196 // Check for "(x >> C1) << C2"
1197 if (add1_op == Op_RShiftL || add1_op == Op_URShiftL) {
1198 int add1Con = 0;
1199 const_shift_count(phase, add1, &add1Con);
1200
1201 // Special case C1 == C2, which just masks off low bits
1202 if (add1Con > 0 && con == add1Con) {
1203 // Convert to "(x & -(1 << C2))"
1204 return new AndLNode(add1->in(1), phase->longcon(java_negate(jlong(CONST64(1) << con))));
1205 } else {
1206 // Wait until the right shift has been sharpened to the correct count
1207 if (add1Con > 0 && add1Con < BitsPerJavaLong) {
1208 // As loop parsing can produce LShiftI nodes, we should wait until the graph is fully formed
1209 // to apply optimizations, otherwise we can inadvertently stop vectorization opportunities.
1210 if (phase->is_IterGVN()) {
1211 if (con > add1Con) {
1212 // Creates "(x << (C2 - C1)) & -(1 << C2)"
1213 Node* lshift = phase->transform(new LShiftLNode(add1->in(1), phase->intcon(con - add1Con)));
1214 return new AndLNode(lshift, phase->longcon(java_negate(jlong(CONST64(1) << con))));
1215 } else {
1216 assert(con < add1Con, "must be (%d < %d)", con, add1Con);
1217 // Creates "(x >> (C1 - C2)) & -(1 << C2)"
1218
1219 // Handle logical and arithmetic shifts
1220 Node* rshift;
1221 if (add1_op == Op_RShiftL) {
1222 rshift = phase->transform(new RShiftLNode(add1->in(1), phase->intcon(add1Con - con)));
1223 } else {
1224 rshift = phase->transform(new URShiftLNode(add1->in(1), phase->intcon(add1Con - con)));
1225 }
1226
1227 return new AndLNode(rshift, phase->longcon(java_negate(jlong(CONST64(1) << con))));
1228 }
1229 } else {
1230 phase->record_for_igvn(this);
1231 }
1232 }
1233 }
1234 }
1235
1236 // Check for "((x >> C1) & Y) << C2"
1237 if (add1_op == Op_AndL) {
1238 Node* add2 = add1->in(1);
1239 int add2_op = add2->Opcode();
1240 if (add2_op == Op_RShiftL || add2_op == Op_URShiftL) {
1241 // Special case C1 == C2, which just masks off low bits
1242 if (add2->in(2) == in(2)) {
1243 // Convert to "(x & (Y << C2))"
1244 Node* y_sh = phase->transform(new LShiftLNode(add1->in(2), phase->intcon(con)));
1245 return new AndLNode(add2->in(1), y_sh);
1246 }
1247
1248 int add2Con = 0;
1249 const_shift_count(phase, add2, &add2Con);
1250 if (add2Con > 0 && add2Con < BitsPerJavaLong) {
1251 if (phase->is_IterGVN()) {
1252 // Convert to "((x >> C1) << C2) & (Y << C2)"
1253
1254 // Make "(x >> C1) << C2", which will get folded away by the rule above
1255 Node* x_sh = phase->transform(new LShiftLNode(add2, phase->intcon(con)));
1256 // Make "Y << C2", which will simplify when Y is a constant
1257 Node* y_sh = phase->transform(new LShiftLNode(add1->in(2), phase->intcon(con)));
1258
1259 return new AndLNode(x_sh, y_sh);
1260 } else {
1261 phase->record_for_igvn(this);
1262 }
1263 }
1264 }
1265 }
1266
1267 // Check for ((x & ((CONST64(1)<<(64-c0))-1)) << c0) which ANDs off high bits
1268 // before shifting them away.
1269 const jlong bits_mask = jlong(max_julong >> con);
1270 if( add1_op == Op_AndL &&
1271 phase->type(add1->in(2)) == TypeLong::make( bits_mask ) )
1272 return new LShiftLNode( add1->in(1), in(2) );
1273
1274 return nullptr;
1275 }
1276
1277 //------------------------------Value------------------------------------------
1278 // A LShiftLNode shifts its input2 left by input1 amount.
1279 const Type* LShiftLNode::Value(PhaseGVN* phase) const {
1280 const Type *t1 = phase->type( in(1) );
1281 const Type *t2 = phase->type( in(2) );
1282 // Either input is TOP ==> the result is TOP
1283 if( t1 == Type::TOP ) return Type::TOP;
1284 if( t2 == Type::TOP ) return Type::TOP;
1285
1286 // Left input is ZERO ==> the result is ZERO.
1287 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
1288 // Shift by zero does nothing
1289 if( t2 == TypeInt::ZERO ) return t1;
1290
1291 // Either input is BOTTOM ==> the result is BOTTOM
1292 if( (t1 == TypeLong::LONG) || (t2 == TypeInt::INT) ||
1293 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
1294 return TypeLong::LONG;
1295
1296 const TypeLong *r1 = t1->is_long(); // Handy access
1297 const TypeInt *r2 = t2->is_int(); // Handy access
1298
1299 if (!r2->is_con())
1300 return TypeLong::LONG;
1301
1302 uint shift = r2->get_con();
1303 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
1304 // Shift by a multiple of 64 does nothing:
1305 if (shift == 0) return t1;
1306
1307 // If the shift is a constant, shift the bounds of the type,
1308 // unless this could lead to an overflow.
1309 if (!r1->is_con()) {
1310 jlong lo = r1->_lo, hi = r1->_hi;
1311 if (((lo << shift) >> shift) == lo &&
1312 ((hi << shift) >> shift) == hi) {
1313 // No overflow. The range shifts up cleanly.
1314 return TypeLong::make((jlong)lo << (jint)shift,
1315 (jlong)hi << (jint)shift,
1316 MAX2(r1->_widen,r2->_widen));
1317 }
1318 return TypeLong::LONG;
1319 }
1320
1321 return TypeLong::make( (jlong)r1->get_con() << (jint)shift );
1322 }
1323
1324 //=============================================================================
1325 //------------------------------Identity---------------------------------------
1326 Node* RShiftINode::Identity(PhaseGVN* phase) {
1327 int count = 0;
1328 if (const_shift_count(phase, this, &count)) {
1329 if ((count & (BitsPerJavaInteger - 1)) == 0) {
1330 // Shift by a multiple of 32 does nothing
1331 return in(1);
1332 }
1333 // Check for useless sign-masking
1334 if (in(1)->Opcode() == Op_LShiftI &&
1335 in(1)->req() == 3 &&
1336 in(1)->in(2) == in(2)) {
1337 count &= BitsPerJavaInteger-1; // semantics of Java shifts
1338 // Compute masks for which this shifting doesn't change
1339 int lo = (-1 << (BitsPerJavaInteger - ((uint)count)-1)); // FFFF8000
1340 int hi = ~lo; // 00007FFF
1341 const TypeInt* t11 = phase->type(in(1)->in(1))->isa_int();
1342 if (t11 == nullptr) {
1343 return this;
1344 }
1345 // Does actual value fit inside of mask?
1346 if (lo <= t11->_lo && t11->_hi <= hi) {
1347 return in(1)->in(1); // Then shifting is a nop
1348 }
1349 }
1350 }
1351 return this;
1352 }
1353
1354 //------------------------------Ideal------------------------------------------
1355 Node *RShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
1356 // Inputs may be TOP if they are dead.
1357 const TypeInt *t1 = phase->type(in(1))->isa_int();
1358 if (!t1) return nullptr; // Left input is an integer
1359 const TypeInt *t3; // type of in(1).in(2)
1360 int shift = maskShiftAmount(phase, this, BitsPerJavaInteger);
1361 if (shift == 0) {
1362 return nullptr;
1363 }
1364
1365 // Check for (x & 0xFF000000) >> 24, whose mask can be made smaller.
1366 // Such expressions arise normally from shift chains like (byte)(x >> 24).
1367 const Node *mask = in(1);
1368 if( mask->Opcode() == Op_AndI &&
1369 (t3 = phase->type(mask->in(2))->isa_int()) &&
1370 t3->is_con() ) {
1371 Node *x = mask->in(1);
1372 jint maskbits = t3->get_con();
1373 // Convert to "(x >> shift) & (mask >> shift)"
1374 Node *shr_nomask = phase->transform( new RShiftINode(mask->in(1), in(2)) );
1375 return new AndINode(shr_nomask, phase->intcon( maskbits >> shift));
1376 }
1377
1378 // Check for "(short[i] <<16)>>16" which simply sign-extends
1379 const Node *shl = in(1);
1380 if( shl->Opcode() != Op_LShiftI ) return nullptr;
1381
1382 if( shift == 16 &&
1383 (t3 = phase->type(shl->in(2))->isa_int()) &&
1384 t3->is_con(16) ) {
1385 Node *ld = shl->in(1);
1386 if( ld->Opcode() == Op_LoadS ) {
1387 // Sign extension is just useless here. Return a RShiftI of zero instead
1388 // returning 'ld' directly. We cannot return an old Node directly as
1389 // that is the job of 'Identity' calls and Identity calls only work on
1390 // direct inputs ('ld' is an extra Node removed from 'this'). The
1391 // combined optimization requires Identity only return direct inputs.
1392 set_req_X(1, ld, phase);
1393 set_req_X(2, phase->intcon(0), phase);
1394 return this;
1395 }
1396 else if (can_reshape &&
1397 ld->Opcode() == Op_LoadUS &&
1398 ld->outcnt() == 1 && ld->unique_out() == shl)
1399 // Replace zero-extension-load with sign-extension-load
1400 return ld->as_Load()->convert_to_signed_load(*phase);
1401 }
1402
1403 // Check for "(byte[i] <<24)>>24" which simply sign-extends
1404 if( shift == 24 &&
1405 (t3 = phase->type(shl->in(2))->isa_int()) &&
1406 t3->is_con(24) ) {
1407 Node *ld = shl->in(1);
1408 if (ld->Opcode() == Op_LoadB) {
1409 // Sign extension is just useless here
1410 set_req_X(1, ld, phase);
1411 set_req_X(2, phase->intcon(0), phase);
1412 return this;
1413 }
1414 }
1415
1416 return nullptr;
1417 }
1418
1419 //------------------------------Value------------------------------------------
1420 // A RShiftINode shifts its input2 right by input1 amount.
1421 const Type* RShiftINode::Value(PhaseGVN* phase) const {
1422 const Type *t1 = phase->type( in(1) );
1423 const Type *t2 = phase->type( in(2) );
1424 // Either input is TOP ==> the result is TOP
1425 if( t1 == Type::TOP ) return Type::TOP;
1426 if( t2 == Type::TOP ) return Type::TOP;
1427
1428 // Left input is ZERO ==> the result is ZERO.
1429 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
1430 // Shift by zero does nothing
1431 if( t2 == TypeInt::ZERO ) return t1;
1432
1433 // Either input is BOTTOM ==> the result is BOTTOM
1434 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1435 return TypeInt::INT;
1436
1437 const TypeInt *r1 = t1->is_int(); // Handy access
1438 const TypeInt *r2 = t2->is_int(); // Handy access
1439
1440 // If the shift is a constant, just shift the bounds of the type.
1441 // For example, if the shift is 31, we just propagate sign bits.
1442 if (!r1->is_con() && r2->is_con()) {
1443 uint shift = r2->get_con();
1444 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
1445 // Shift by a multiple of 32 does nothing:
1446 if (shift == 0) return t1;
1447 // Calculate reasonably aggressive bounds for the result.
1448 // This is necessary if we are to correctly type things
1449 // like (x<<24>>24) == ((byte)x).
1450 jint lo = (jint)r1->_lo >> (jint)shift;
1451 jint hi = (jint)r1->_hi >> (jint)shift;
1452 assert(lo <= hi, "must have valid bounds");
1453 const TypeInt* ti = TypeInt::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1454 #ifdef ASSERT
1455 // Make sure we get the sign-capture idiom correct.
1456 if (shift == BitsPerJavaInteger-1) {
1457 if (r1->_lo >= 0) assert(ti == TypeInt::ZERO, ">>31 of + is 0");
1458 if (r1->_hi < 0) assert(ti == TypeInt::MINUS_1, ">>31 of - is -1");
1459 }
1460 #endif
1461 return ti;
1462 }
1463
1464 if (!r1->is_con() || !r2->is_con()) {
1465 // If the left input is non-negative the result must also be non-negative, regardless of what the right input is.
1466 if (r1->_lo >= 0) {
1467 return TypeInt::make(0, r1->_hi, MAX2(r1->_widen, r2->_widen));
1468 }
1469
1470 // Conversely, if the left input is negative then the result must be negative.
1471 if (r1->_hi <= -1) {
1472 return TypeInt::make(r1->_lo, -1, MAX2(r1->_widen, r2->_widen));
1473 }
1474
1475 return TypeInt::INT;
1476 }
1477
1478 // Signed shift right
1479 return TypeInt::make(r1->get_con() >> (r2->get_con() & 31));
1480 }
1481
1482 //=============================================================================
1483 //------------------------------Identity---------------------------------------
1484 Node* RShiftLNode::Identity(PhaseGVN* phase) {
1485 const TypeInt *ti = phase->type(in(2))->isa_int(); // Shift count is an int.
1486 return (ti && ti->is_con() && (ti->get_con() & (BitsPerJavaLong - 1)) == 0) ? in(1) : this;
1487 }
1488
1489 //------------------------------Value------------------------------------------
1490 // A RShiftLNode shifts its input2 right by input1 amount.
1491 const Type* RShiftLNode::Value(PhaseGVN* phase) const {
1492 const Type *t1 = phase->type( in(1) );
1493 const Type *t2 = phase->type( in(2) );
1494 // Either input is TOP ==> the result is TOP
1495 if( t1 == Type::TOP ) return Type::TOP;
1496 if( t2 == Type::TOP ) return Type::TOP;
1497
1498 // Left input is ZERO ==> the result is ZERO.
1499 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
1500 // Shift by zero does nothing
1501 if( t2 == TypeInt::ZERO ) return t1;
1502
1503 // Either input is BOTTOM ==> the result is BOTTOM
1504 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1505 return TypeLong::LONG;
1506
1507 const TypeLong *r1 = t1->is_long(); // Handy access
1508 const TypeInt *r2 = t2->is_int (); // Handy access
1509
1510 // If the shift is a constant, just shift the bounds of the type.
1511 // For example, if the shift is 63, we just propagate sign bits.
1512 if (!r1->is_con() && r2->is_con()) {
1513 uint shift = r2->get_con();
1514 shift &= (2*BitsPerJavaInteger)-1; // semantics of Java shifts
1515 // Shift by a multiple of 64 does nothing:
1516 if (shift == 0) return t1;
1517 // Calculate reasonably aggressive bounds for the result.
1518 // This is necessary if we are to correctly type things
1519 // like (x<<24>>24) == ((byte)x).
1520 jlong lo = (jlong)r1->_lo >> (jlong)shift;
1521 jlong hi = (jlong)r1->_hi >> (jlong)shift;
1522 assert(lo <= hi, "must have valid bounds");
1523 const TypeLong* tl = TypeLong::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1524 #ifdef ASSERT
1525 // Make sure we get the sign-capture idiom correct.
1526 if (shift == (2*BitsPerJavaInteger)-1) {
1527 if (r1->_lo >= 0) assert(tl == TypeLong::ZERO, ">>63 of + is 0");
1528 if (r1->_hi < 0) assert(tl == TypeLong::MINUS_1, ">>63 of - is -1");
1529 }
1530 #endif
1531 return tl;
1532 }
1533
1534 if (!r1->is_con() || !r2->is_con()) {
1535 // If the left input is non-negative the result must also be non-negative, regardless of what the right input is.
1536 if (r1->_lo >= 0) {
1537 return TypeLong::make(0, r1->_hi, MAX2(r1->_widen, r2->_widen));
1538 }
1539
1540 // Conversely, if the left input is negative then the result must be negative.
1541 if (r1->_hi <= -1) {
1542 return TypeLong::make(r1->_lo, -1, MAX2(r1->_widen, r2->_widen));
1543 }
1544
1545 return TypeLong::LONG;
1546 }
1547
1548 return TypeLong::make(r1->get_con() >> (r2->get_con() & 63));
1549 }
1550
1551 //=============================================================================
1552 //------------------------------Identity---------------------------------------
1553 Node* URShiftINode::Identity(PhaseGVN* phase) {
1554 int count = 0;
1555 if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaInteger - 1)) == 0) {
1556 // Shift by a multiple of 32 does nothing
1557 return in(1);
1558 }
1559
1560 // Check for "((x << LogBytesPerWord) + (wordSize-1)) >> LogBytesPerWord" which is just "x".
1561 // Happens during new-array length computation.
1562 // Safe if 'x' is in the range [0..(max_int>>LogBytesPerWord)]
1563 Node *add = in(1);
1564 if (add->Opcode() == Op_AddI) {
1565 const TypeInt *t2 = phase->type(add->in(2))->isa_int();
1566 if (t2 && t2->is_con(wordSize - 1) &&
1567 add->in(1)->Opcode() == Op_LShiftI) {
1568 // Check that shift_counts are LogBytesPerWord.
1569 Node *lshift_count = add->in(1)->in(2);
1570 const TypeInt *t_lshift_count = phase->type(lshift_count)->isa_int();
1571 if (t_lshift_count && t_lshift_count->is_con(LogBytesPerWord) &&
1572 t_lshift_count == phase->type(in(2))) {
1573 Node *x = add->in(1)->in(1);
1574 const TypeInt *t_x = phase->type(x)->isa_int();
1575 if (t_x != nullptr && 0 <= t_x->_lo && t_x->_hi <= (max_jint>>LogBytesPerWord)) {
1576 return x;
1577 }
1578 }
1579 }
1580 }
1581
1582 return (phase->type(in(2))->higher_equal(TypeInt::ZERO)) ? in(1) : this;
1583 }
1584
1585 //------------------------------Ideal------------------------------------------
1586 Node *URShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
1587 int con = maskShiftAmount(phase, this, BitsPerJavaInteger);
1588 if (con == 0) {
1589 return nullptr;
1590 }
1591
1592 // We'll be wanting the right-shift amount as a mask of that many bits
1593 const int mask = right_n_bits(BitsPerJavaInteger - con);
1594
1595 int in1_op = in(1)->Opcode();
1596
1597 // Check for ((x>>>a)>>>b) and replace with (x>>>(a+b)) when a+b < 32
1598 if( in1_op == Op_URShiftI ) {
1599 const TypeInt *t12 = phase->type( in(1)->in(2) )->isa_int();
1600 if( t12 && t12->is_con() ) { // Right input is a constant
1601 assert( in(1) != in(1)->in(1), "dead loop in URShiftINode::Ideal" );
1602 const int con2 = t12->get_con() & 31; // Shift count is always masked
1603 const int con3 = con+con2;
1604 if( con3 < 32 ) // Only merge shifts if total is < 32
1605 return new URShiftINode( in(1)->in(1), phase->intcon(con3) );
1606 }
1607 }
1608
1609 // Check for ((x << z) + Y) >>> z. Replace with x + con>>>z
1610 // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
1611 // If Q is "X << z" the rounding is useless. Look for patterns like
1612 // ((X<<Z) + Y) >>> Z and replace with (X + Y>>>Z) & Z-mask.
1613 Node *add = in(1);
1614 const TypeInt *t2 = phase->type(in(2))->isa_int();
1615 if (in1_op == Op_AddI) {
1616 Node *lshl = add->in(1);
1617 if( lshl->Opcode() == Op_LShiftI &&
1618 phase->type(lshl->in(2)) == t2 ) {
1619 Node *y_z = phase->transform( new URShiftINode(add->in(2),in(2)) );
1620 Node *sum = phase->transform( new AddINode( lshl->in(1), y_z ) );
1621 return new AndINode( sum, phase->intcon(mask) );
1622 }
1623 }
1624
1625 // Check for (x & mask) >>> z. Replace with (x >>> z) & (mask >>> z)
1626 // This shortens the mask. Also, if we are extracting a high byte and
1627 // storing it to a buffer, the mask will be removed completely.
1628 Node *andi = in(1);
1629 if( in1_op == Op_AndI ) {
1630 const TypeInt *t3 = phase->type( andi->in(2) )->isa_int();
1631 if( t3 && t3->is_con() ) { // Right input is a constant
1632 jint mask2 = t3->get_con();
1633 mask2 >>= con; // *signed* shift downward (high-order zeroes do not help)
1634 Node *newshr = phase->transform( new URShiftINode(andi->in(1), in(2)) );
1635 return new AndINode(newshr, phase->intcon(mask2));
1636 // The negative values are easier to materialize than positive ones.
1637 // A typical case from address arithmetic is ((x & ~15) >> 4).
1638 // It's better to change that to ((x >> 4) & ~0) versus
1639 // ((x >> 4) & 0x0FFFFFFF). The difference is greatest in LP64.
1640 }
1641 }
1642
1643 // Check for "(X << z ) >>> z" which simply zero-extends
1644 Node *shl = in(1);
1645 if( in1_op == Op_LShiftI &&
1646 phase->type(shl->in(2)) == t2 )
1647 return new AndINode( shl->in(1), phase->intcon(mask) );
1648
1649 // Check for (x >> n) >>> 31. Replace with (x >>> 31)
1650 Node *shr = in(1);
1651 if ( in1_op == Op_RShiftI ) {
1652 Node *in11 = shr->in(1);
1653 Node *in12 = shr->in(2);
1654 const TypeInt *t11 = phase->type(in11)->isa_int();
1655 const TypeInt *t12 = phase->type(in12)->isa_int();
1656 if ( t11 && t2 && t2->is_con(31) && t12 && t12->is_con() ) {
1657 return new URShiftINode(in11, phase->intcon(31));
1658 }
1659 }
1660
1661 return nullptr;
1662 }
1663
1664 //------------------------------Value------------------------------------------
1665 // A URShiftINode shifts its input2 right by input1 amount.
1666 const Type* URShiftINode::Value(PhaseGVN* phase) const {
1667 // (This is a near clone of RShiftINode::Value.)
1668 const Type *t1 = phase->type( in(1) );
1669 const Type *t2 = phase->type( in(2) );
1670 // Either input is TOP ==> the result is TOP
1671 if( t1 == Type::TOP ) return Type::TOP;
1672 if( t2 == Type::TOP ) return Type::TOP;
1673
1674 // Left input is ZERO ==> the result is ZERO.
1675 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
1676 // Shift by zero does nothing
1677 if( t2 == TypeInt::ZERO ) return t1;
1678
1679 // Either input is BOTTOM ==> the result is BOTTOM
1680 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1681 return TypeInt::INT;
1682
1683 if (t2 == TypeInt::INT)
1684 return TypeInt::INT;
1685
1686 const TypeInt *r1 = t1->is_int(); // Handy access
1687 const TypeInt *r2 = t2->is_int(); // Handy access
1688
1689 if (r2->is_con()) {
1690 uint shift = r2->get_con();
1691 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
1692 // Shift by a multiple of 32 does nothing:
1693 if (shift == 0) return t1;
1694 // Calculate reasonably aggressive bounds for the result.
1695 jint lo = (juint)r1->_lo >> (juint)shift;
1696 jint hi = (juint)r1->_hi >> (juint)shift;
1697 if (r1->_hi >= 0 && r1->_lo < 0) {
1698 // If the type has both negative and positive values,
1699 // there are two separate sub-domains to worry about:
1700 // The positive half and the negative half.
1701 jint neg_lo = lo;
1702 jint neg_hi = (juint)-1 >> (juint)shift;
1703 jint pos_lo = (juint) 0 >> (juint)shift;
1704 jint pos_hi = hi;
1705 lo = MIN2(neg_lo, pos_lo); // == 0
1706 hi = MAX2(neg_hi, pos_hi); // == -1 >>> shift;
1707 }
1708 assert(lo <= hi, "must have valid bounds");
1709 const TypeInt* ti = TypeInt::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1710 #ifdef ASSERT
1711 // Make sure we get the sign-capture idiom correct.
1712 if (shift == BitsPerJavaInteger-1) {
1713 if (r1->_lo >= 0) assert(ti == TypeInt::ZERO, ">>>31 of + is 0");
1714 if (r1->_hi < 0) assert(ti == TypeInt::ONE, ">>>31 of - is +1");
1715 }
1716 #endif
1717 return ti;
1718 }
1719
1720 //
1721 // Do not support shifted oops in info for GC
1722 //
1723 // else if( t1->base() == Type::InstPtr ) {
1724 //
1725 // const TypeInstPtr *o = t1->is_instptr();
1726 // if( t1->singleton() )
1727 // return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift );
1728 // }
1729 // else if( t1->base() == Type::KlassPtr ) {
1730 // const TypeKlassPtr *o = t1->is_klassptr();
1731 // if( t1->singleton() )
1732 // return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift );
1733 // }
1734
1735 return TypeInt::INT;
1736 }
1737
1738 //=============================================================================
1739 //------------------------------Identity---------------------------------------
1740 Node* URShiftLNode::Identity(PhaseGVN* phase) {
1741 int count = 0;
1742 if (const_shift_count(phase, this, &count) && (count & (BitsPerJavaLong - 1)) == 0) {
1743 // Shift by a multiple of 64 does nothing
1744 return in(1);
1745 }
1746 return this;
1747 }
1748
1749 //------------------------------Ideal------------------------------------------
1750 Node *URShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1751 int con = maskShiftAmount(phase, this, BitsPerJavaLong);
1752 if (con == 0) {
1753 return nullptr;
1754 }
1755
1756 // We'll be wanting the right-shift amount as a mask of that many bits
1757 const jlong mask = jlong(max_julong >> con);
1758
1759 // Check for ((x << z) + Y) >>> z. Replace with x + con>>>z
1760 // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
1761 // If Q is "X << z" the rounding is useless. Look for patterns like
1762 // ((X<<Z) + Y) >>> Z and replace with (X + Y>>>Z) & Z-mask.
1763 Node *add = in(1);
1764 const TypeInt *t2 = phase->type(in(2))->isa_int();
1765 if (add->Opcode() == Op_AddL) {
1766 Node *lshl = add->in(1);
1767 if( lshl->Opcode() == Op_LShiftL &&
1768 phase->type(lshl->in(2)) == t2 ) {
1769 Node *y_z = phase->transform( new URShiftLNode(add->in(2),in(2)) );
1770 Node *sum = phase->transform( new AddLNode( lshl->in(1), y_z ) );
1771 return new AndLNode( sum, phase->longcon(mask) );
1772 }
1773 }
1774
1775 // Check for (x & mask) >>> z. Replace with (x >>> z) & (mask >>> z)
1776 // This shortens the mask. Also, if we are extracting a high byte and
1777 // storing it to a buffer, the mask will be removed completely.
1778 Node *andi = in(1);
1779 if( andi->Opcode() == Op_AndL ) {
1780 const TypeLong *t3 = phase->type( andi->in(2) )->isa_long();
1781 if( t3 && t3->is_con() ) { // Right input is a constant
1782 jlong mask2 = t3->get_con();
1783 mask2 >>= con; // *signed* shift downward (high-order zeroes do not help)
1784 Node *newshr = phase->transform( new URShiftLNode(andi->in(1), in(2)) );
1785 return new AndLNode(newshr, phase->longcon(mask2));
1786 }
1787 }
1788
1789 // Check for "(X << z ) >>> z" which simply zero-extends
1790 Node *shl = in(1);
1791 if( shl->Opcode() == Op_LShiftL &&
1792 phase->type(shl->in(2)) == t2 )
1793 return new AndLNode( shl->in(1), phase->longcon(mask) );
1794
1795 // Check for (x >> n) >>> 63. Replace with (x >>> 63)
1796 Node *shr = in(1);
1797 if ( shr->Opcode() == Op_RShiftL ) {
1798 Node *in11 = shr->in(1);
1799 Node *in12 = shr->in(2);
1800 const TypeLong *t11 = phase->type(in11)->isa_long();
1801 const TypeInt *t12 = phase->type(in12)->isa_int();
1802 if ( t11 && t2 && t2->is_con(63) && t12 && t12->is_con() ) {
1803 return new URShiftLNode(in11, phase->intcon(63));
1804 }
1805 }
1806 return nullptr;
1807 }
1808
1809 //------------------------------Value------------------------------------------
1810 // A URShiftINode shifts its input2 right by input1 amount.
1811 const Type* URShiftLNode::Value(PhaseGVN* phase) const {
1812 // (This is a near clone of RShiftLNode::Value.)
1813 const Type *t1 = phase->type( in(1) );
1814 const Type *t2 = phase->type( in(2) );
1815 // Either input is TOP ==> the result is TOP
1816 if( t1 == Type::TOP ) return Type::TOP;
1817 if( t2 == Type::TOP ) return Type::TOP;
1818
1819 // Left input is ZERO ==> the result is ZERO.
1820 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
1821 // Shift by zero does nothing
1822 if( t2 == TypeInt::ZERO ) return t1;
1823
1824 // Either input is BOTTOM ==> the result is BOTTOM
1825 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1826 return TypeLong::LONG;
1827
1828 if (t2 == TypeInt::INT)
1829 return TypeLong::LONG;
1830
1831 const TypeLong *r1 = t1->is_long(); // Handy access
1832 const TypeInt *r2 = t2->is_int (); // Handy access
1833
1834 if (r2->is_con()) {
1835 uint shift = r2->get_con();
1836 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
1837 // Shift by a multiple of 64 does nothing:
1838 if (shift == 0) return t1;
1839 // Calculate reasonably aggressive bounds for the result.
1840 jlong lo = (julong)r1->_lo >> (juint)shift;
1841 jlong hi = (julong)r1->_hi >> (juint)shift;
1842 if (r1->_hi >= 0 && r1->_lo < 0) {
1843 // If the type has both negative and positive values,
1844 // there are two separate sub-domains to worry about:
1845 // The positive half and the negative half.
1846 jlong neg_lo = lo;
1847 jlong neg_hi = (julong)-1 >> (juint)shift;
1848 jlong pos_lo = (julong) 0 >> (juint)shift;
1849 jlong pos_hi = hi;
1850 //lo = MIN2(neg_lo, pos_lo); // == 0
1851 lo = neg_lo < pos_lo ? neg_lo : pos_lo;
1852 //hi = MAX2(neg_hi, pos_hi); // == -1 >>> shift;
1853 hi = neg_hi > pos_hi ? neg_hi : pos_hi;
1854 }
1855 assert(lo <= hi, "must have valid bounds");
1856 const TypeLong* tl = TypeLong::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1857 #ifdef ASSERT
1858 // Make sure we get the sign-capture idiom correct.
1859 if (shift == BitsPerJavaLong - 1) {
1860 if (r1->_lo >= 0) assert(tl == TypeLong::ZERO, ">>>63 of + is 0");
1861 if (r1->_hi < 0) assert(tl == TypeLong::ONE, ">>>63 of - is +1");
1862 }
1863 #endif
1864 return tl;
1865 }
1866
1867 return TypeLong::LONG; // Give up
1868 }
1869
1870 //=============================================================================
1871 //------------------------------Ideal------------------------------------------
1872 Node* FmaNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1873 // We canonicalize the node by converting "(-a)*b+c" into "b*(-a)+c"
1874 // This reduces the number of rules in the matcher, as we only need to check
1875 // for negations on the second argument, and not the symmetric case where
1876 // the first argument is negated.
1877 if (in(1)->is_Neg() && !in(2)->is_Neg()) {
1878 swap_edges(1, 2);
1879 return this;
1880 }
1881 return nullptr;
1882 }
1883
1884 //=============================================================================
1885 //------------------------------Value------------------------------------------
1886 const Type* FmaDNode::Value(PhaseGVN* phase) const {
1887 const Type *t1 = phase->type(in(1));
1888 if (t1 == Type::TOP) return Type::TOP;
1889 if (t1->base() != Type::DoubleCon) return Type::DOUBLE;
1890 const Type *t2 = phase->type(in(2));
1891 if (t2 == Type::TOP) return Type::TOP;
1892 if (t2->base() != Type::DoubleCon) return Type::DOUBLE;
1893 const Type *t3 = phase->type(in(3));
1894 if (t3 == Type::TOP) return Type::TOP;
1895 if (t3->base() != Type::DoubleCon) return Type::DOUBLE;
1896 #ifndef __STDC_IEC_559__
1897 return Type::DOUBLE;
1898 #else
1899 double d1 = t1->getd();
1900 double d2 = t2->getd();
1901 double d3 = t3->getd();
1902 return TypeD::make(fma(d1, d2, d3));
1903 #endif
1904 }
1905
1906 //=============================================================================
1907 //------------------------------Value------------------------------------------
1908 const Type* FmaFNode::Value(PhaseGVN* phase) const {
1909 const Type *t1 = phase->type(in(1));
1910 if (t1 == Type::TOP) return Type::TOP;
1911 if (t1->base() != Type::FloatCon) return Type::FLOAT;
1912 const Type *t2 = phase->type(in(2));
1913 if (t2 == Type::TOP) return Type::TOP;
1914 if (t2->base() != Type::FloatCon) return Type::FLOAT;
1915 const Type *t3 = phase->type(in(3));
1916 if (t3 == Type::TOP) return Type::TOP;
1917 if (t3->base() != Type::FloatCon) return Type::FLOAT;
1918 #ifndef __STDC_IEC_559__
1919 return Type::FLOAT;
1920 #else
1921 float f1 = t1->getf();
1922 float f2 = t2->getf();
1923 float f3 = t3->getf();
1924 return TypeF::make(fma(f1, f2, f3));
1925 #endif
1926 }
1927
1928 //=============================================================================
1929 //------------------------------hash-------------------------------------------
1930 // Hash function for MulAddS2INode. Operation is commutative with commutative pairs.
1931 // The hash function must return the same value when edge swapping is performed.
1932 uint MulAddS2INode::hash() const {
1933 return (uintptr_t)in(1) + (uintptr_t)in(2) + (uintptr_t)in(3) + (uintptr_t)in(4) + Opcode();
1934 }
1935
1936 //------------------------------Rotate Operations ------------------------------
1937
1938 Node* RotateLeftNode::Identity(PhaseGVN* phase) {
1939 const Type* t1 = phase->type(in(1));
1940 if (t1 == Type::TOP) {
1941 return this;
1942 }
1943 int count = 0;
1944 assert(t1->isa_int() || t1->isa_long(), "Unexpected type");
1945 int mask = (t1->isa_int() ? BitsPerJavaInteger : BitsPerJavaLong) - 1;
1946 if (const_shift_count(phase, this, &count) && (count & mask) == 0) {
1947 // Rotate by a multiple of 32/64 does nothing
1948 return in(1);
1949 }
1950 return this;
1951 }
1952
1953 const Type* RotateLeftNode::Value(PhaseGVN* phase) const {
1954 const Type* t1 = phase->type(in(1));
1955 const Type* t2 = phase->type(in(2));
1956 // Either input is TOP ==> the result is TOP
1957 if (t1 == Type::TOP || t2 == Type::TOP) {
1958 return Type::TOP;
1959 }
1960
1961 if (t1->isa_int()) {
1962 const TypeInt* r1 = t1->is_int();
1963 const TypeInt* r2 = t2->is_int();
1964
1965 // Left input is ZERO ==> the result is ZERO.
1966 if (r1 == TypeInt::ZERO) {
1967 return TypeInt::ZERO;
1968 }
1969 // Rotate by zero does nothing
1970 if (r2 == TypeInt::ZERO) {
1971 return r1;
1972 }
1973 if (r1->is_con() && r2->is_con()) {
1974 juint r1_con = (juint)r1->get_con();
1975 juint shift = (juint)(r2->get_con()) & (juint)(BitsPerJavaInteger - 1); // semantics of Java shifts
1976 return TypeInt::make((r1_con << shift) | (r1_con >> (32 - shift)));
1977 }
1978 return TypeInt::INT;
1979 } else {
1980 assert(t1->isa_long(), "Type must be a long");
1981 const TypeLong* r1 = t1->is_long();
1982 const TypeInt* r2 = t2->is_int();
1983
1984 // Left input is ZERO ==> the result is ZERO.
1985 if (r1 == TypeLong::ZERO) {
1986 return TypeLong::ZERO;
1987 }
1988 // Rotate by zero does nothing
1989 if (r2 == TypeInt::ZERO) {
1990 return r1;
1991 }
1992 if (r1->is_con() && r2->is_con()) {
1993 julong r1_con = (julong)r1->get_con();
1994 julong shift = (julong)(r2->get_con()) & (julong)(BitsPerJavaLong - 1); // semantics of Java shifts
1995 return TypeLong::make((r1_con << shift) | (r1_con >> (64 - shift)));
1996 }
1997 return TypeLong::LONG;
1998 }
1999 }
2000
2001 Node* RotateLeftNode::Ideal(PhaseGVN *phase, bool can_reshape) {
2002 const Type* t1 = phase->type(in(1));
2003 const Type* t2 = phase->type(in(2));
2004 if (t2->isa_int() && t2->is_int()->is_con()) {
2005 if (t1->isa_int()) {
2006 int lshift = t2->is_int()->get_con() & 31;
2007 return new RotateRightNode(in(1), phase->intcon(32 - (lshift & 31)), TypeInt::INT);
2008 } else if (t1 != Type::TOP) {
2009 assert(t1->isa_long(), "Type must be a long");
2010 int lshift = t2->is_int()->get_con() & 63;
2011 return new RotateRightNode(in(1), phase->intcon(64 - (lshift & 63)), TypeLong::LONG);
2012 }
2013 }
2014 return nullptr;
2015 }
2016
2017 Node* RotateRightNode::Identity(PhaseGVN* phase) {
2018 const Type* t1 = phase->type(in(1));
2019 if (t1 == Type::TOP) {
2020 return this;
2021 }
2022 int count = 0;
2023 assert(t1->isa_int() || t1->isa_long(), "Unexpected type");
2024 int mask = (t1->isa_int() ? BitsPerJavaInteger : BitsPerJavaLong) - 1;
2025 if (const_shift_count(phase, this, &count) && (count & mask) == 0) {
2026 // Rotate by a multiple of 32/64 does nothing
2027 return in(1);
2028 }
2029 return this;
2030 }
2031
2032 const Type* RotateRightNode::Value(PhaseGVN* phase) const {
2033 const Type* t1 = phase->type(in(1));
2034 const Type* t2 = phase->type(in(2));
2035 // Either input is TOP ==> the result is TOP
2036 if (t1 == Type::TOP || t2 == Type::TOP) {
2037 return Type::TOP;
2038 }
2039
2040 if (t1->isa_int()) {
2041 const TypeInt* r1 = t1->is_int();
2042 const TypeInt* r2 = t2->is_int();
2043
2044 // Left input is ZERO ==> the result is ZERO.
2045 if (r1 == TypeInt::ZERO) {
2046 return TypeInt::ZERO;
2047 }
2048 // Rotate by zero does nothing
2049 if (r2 == TypeInt::ZERO) {
2050 return r1;
2051 }
2052 if (r1->is_con() && r2->is_con()) {
2053 juint r1_con = (juint)r1->get_con();
2054 juint shift = (juint)(r2->get_con()) & (juint)(BitsPerJavaInteger - 1); // semantics of Java shifts
2055 return TypeInt::make((r1_con >> shift) | (r1_con << (32 - shift)));
2056 }
2057 return TypeInt::INT;
2058 } else {
2059 assert(t1->isa_long(), "Type must be a long");
2060 const TypeLong* r1 = t1->is_long();
2061 const TypeInt* r2 = t2->is_int();
2062 // Left input is ZERO ==> the result is ZERO.
2063 if (r1 == TypeLong::ZERO) {
2064 return TypeLong::ZERO;
2065 }
2066 // Rotate by zero does nothing
2067 if (r2 == TypeInt::ZERO) {
2068 return r1;
2069 }
2070 if (r1->is_con() && r2->is_con()) {
2071 julong r1_con = (julong)r1->get_con();
2072 julong shift = (julong)(r2->get_con()) & (julong)(BitsPerJavaLong - 1); // semantics of Java shifts
2073 return TypeLong::make((r1_con >> shift) | (r1_con << (64 - shift)));
2074 }
2075 return TypeLong::LONG;
2076 }
2077 }
2078
2079 // Given an expression (AndX shift mask) or (AndX mask shift),
2080 // determine if the AndX must always produce zero, because the
2081 // the shift (x<<N) is bitwise disjoint from the mask #M.
2082 // The X in AndX must be I or L, depending on bt.
2083 // Specifically, the following cases fold to zero,
2084 // when the shift value N is large enough to zero out
2085 // all the set positions of the and-mask M.
2086 // (AndI (LShiftI _ #N) #M) => #0
2087 // (AndL (LShiftL _ #N) #M) => #0
2088 // (AndL (ConvI2L (LShiftI _ #N)) #M) => #0
2089 // The M and N values must satisfy ((-1 << N) & M) == 0.
2090 // Because the optimization might work for a non-constant
2091 // mask M, we check the AndX for both operand orders.
2092 bool MulNode::AndIL_shift_and_mask_is_always_zero(PhaseGVN* phase, Node* shift, Node* mask, BasicType bt, bool check_reverse) {
2093 if (mask == nullptr || shift == nullptr) {
2094 return false;
2095 }
2096 const TypeInteger* mask_t = phase->type(mask)->isa_integer(bt);
2097 if (mask_t == nullptr || phase->type(shift)->isa_integer(bt) == nullptr) {
2098 return false;
2099 }
2100 shift = shift->uncast();
2101 if (shift == nullptr) {
2102 return false;
2103 }
2104 if (phase->type(shift)->isa_integer(bt) == nullptr) {
2105 return false;
2106 }
2107 BasicType shift_bt = bt;
2108 if (bt == T_LONG && shift->Opcode() == Op_ConvI2L) {
2109 bt = T_INT;
2110 Node* val = shift->in(1);
2111 if (val == nullptr) {
2112 return false;
2113 }
2114 val = val->uncast();
2115 if (val == nullptr) {
2116 return false;
2117 }
2118 if (val->Opcode() == Op_LShiftI) {
2119 shift_bt = T_INT;
2120 shift = val;
2121 if (phase->type(shift)->isa_integer(bt) == nullptr) {
2122 return false;
2123 }
2124 }
2125 }
2126 if (shift->Opcode() != Op_LShift(shift_bt)) {
2127 if (check_reverse &&
2128 (mask->Opcode() == Op_LShift(bt) ||
2129 (bt == T_LONG && mask->Opcode() == Op_ConvI2L))) {
2130 // try it the other way around
2131 return AndIL_shift_and_mask_is_always_zero(phase, mask, shift, bt, false);
2132 }
2133 return false;
2134 }
2135 Node* shift2 = shift->in(2);
2136 if (shift2 == nullptr) {
2137 return false;
2138 }
2139 const Type* shift2_t = phase->type(shift2);
2140 if (!shift2_t->isa_int() || !shift2_t->is_int()->is_con()) {
2141 return false;
2142 }
2143
2144 jint shift_con = shift2_t->is_int()->get_con() & ((shift_bt == T_INT ? BitsPerJavaInteger : BitsPerJavaLong) - 1);
2145 if ((((jlong)1) << shift_con) > mask_t->hi_as_long() && mask_t->lo_as_long() >= 0) {
2146 return true;
2147 }
2148
2149 return false;
2150 }
2151
2152 // Given an expression (AndX (AddX v1 (LShiftX v2 #N)) #M)
2153 // determine if the AndX must always produce (AndX v1 #M),
2154 // because the shift (v2<<N) is bitwise disjoint from the mask #M.
2155 // The X in AndX will be I or L, depending on bt.
2156 // Specifically, the following cases fold,
2157 // when the shift value N is large enough to zero out
2158 // all the set positions of the and-mask M.
2159 // (AndI (AddI v1 (LShiftI _ #N)) #M) => (AndI v1 #M)
2160 // (AndL (AddI v1 (LShiftL _ #N)) #M) => (AndL v1 #M)
2161 // (AndL (AddL v1 (ConvI2L (LShiftI _ #N))) #M) => (AndL v1 #M)
2162 // The M and N values must satisfy ((-1 << N) & M) == 0.
2163 // Because the optimization might work for a non-constant
2164 // mask M, and because the AddX operands can come in either
2165 // order, we check for every operand order.
2166 Node* MulNode::AndIL_add_shift_and_mask(PhaseGVN* phase, BasicType bt) {
2167 Node* add = in(1);
2168 Node* mask = in(2);
2169 if (add == nullptr || mask == nullptr) {
2170 return nullptr;
2171 }
2172 int addidx = 0;
2173 if (add->Opcode() == Op_Add(bt)) {
2174 addidx = 1;
2175 } else if (mask->Opcode() == Op_Add(bt)) {
2176 mask = add;
2177 addidx = 2;
2178 add = in(addidx);
2179 }
2180 if (addidx > 0) {
2181 Node* add1 = add->in(1);
2182 Node* add2 = add->in(2);
2183 if (add1 != nullptr && add2 != nullptr) {
2184 if (AndIL_shift_and_mask_is_always_zero(phase, add1, mask, bt, false)) {
2185 set_req_X(addidx, add2, phase);
2186 return this;
2187 } else if (AndIL_shift_and_mask_is_always_zero(phase, add2, mask, bt, false)) {
2188 set_req_X(addidx, add1, phase);
2189 return this;
2190 }
2191 }
2192 }
2193 return nullptr;
2194 }