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