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/castnode.hpp"
29 #include "opto/cfgnode.hpp"
30 #include "opto/connode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/movenode.hpp"
33 #include "opto/mulnode.hpp"
34 #include "opto/phaseX.hpp"
35 #include "opto/subnode.hpp"
36
37 // Portions of code courtesy of Clifford Click
38
39 // Classic Add functionality. This covers all the usual 'add' behaviors for
40 // an algebraic ring. Add-integer, add-float, add-double, and binary-or are
41 // all inherited from this class. The various identity values are supplied
42 // by virtual functions.
43
44
45 //=============================================================================
46 //------------------------------hash-------------------------------------------
47 // Hash function over AddNodes. Needs to be commutative; i.e., I swap
48 // (commute) inputs to AddNodes willy-nilly so the hash function must return
49 // the same value in the presence of edge swapping.
50 uint AddNode::hash() const {
51 return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
52 }
53
54 //------------------------------Identity---------------------------------------
55 // If either input is a constant 0, return the other input.
56 Node* AddNode::Identity(PhaseGVN* phase) {
57 const Type *zero = add_id(); // The additive identity
58 if( phase->type( in(1) )->higher_equal( zero ) ) return in(2);
59 if( phase->type( in(2) )->higher_equal( zero ) ) return in(1);
60 return this;
61 }
62
63 //------------------------------commute----------------------------------------
64 // Commute operands to move loads and constants to the right.
65 static bool commute(PhaseGVN* phase, Node* add) {
66 Node *in1 = add->in(1);
67 Node *in2 = add->in(2);
68
69 // convert "max(a,b) + min(a,b)" into "a+b".
70 if ((in1->Opcode() == add->as_Add()->max_opcode() && in2->Opcode() == add->as_Add()->min_opcode())
71 || (in1->Opcode() == add->as_Add()->min_opcode() && in2->Opcode() == add->as_Add()->max_opcode())) {
72 Node *in11 = in1->in(1);
73 Node *in12 = in1->in(2);
74
75 Node *in21 = in2->in(1);
76 Node *in22 = in2->in(2);
77
78 if ((in11 == in21 && in12 == in22) ||
79 (in11 == in22 && in12 == in21)) {
80 add->set_req_X(1, in11, phase);
81 add->set_req_X(2, in12, phase);
82 return true;
83 }
84 }
85
86 bool con_left = phase->type(in1)->singleton();
87 bool con_right = phase->type(in2)->singleton();
88
89 // Convert "1+x" into "x+1".
90 // Right is a constant; leave it
91 if( con_right ) return false;
92 // Left is a constant; move it right.
93 if( con_left ) {
94 add->swap_edges(1, 2);
95 return true;
96 }
97
98 // Convert "Load+x" into "x+Load".
99 // Now check for loads
100 if (in2->is_Load()) {
101 if (!in1->is_Load()) {
102 // already x+Load to return
103 return false;
104 }
105 // both are loads, so fall through to sort inputs by idx
106 } else if( in1->is_Load() ) {
107 // Left is a Load and Right is not; move it right.
108 add->swap_edges(1, 2);
109 return true;
110 }
111
112 PhiNode *phi;
113 // Check for tight loop increments: Loop-phi of Add of loop-phi
114 if (in1->is_Phi() && (phi = in1->as_Phi()) && phi->region()->is_Loop() && phi->in(2) == add)
115 return false;
116 if (in2->is_Phi() && (phi = in2->as_Phi()) && phi->region()->is_Loop() && phi->in(2) == add) {
117 add->swap_edges(1, 2);
118 return true;
119 }
120
121 // Otherwise, sort inputs (commutativity) to help value numbering.
122 if( in1->_idx > in2->_idx ) {
123 add->swap_edges(1, 2);
124 return true;
125 }
126 return false;
127 }
128
129 //------------------------------Idealize---------------------------------------
130 // If we get here, we assume we are associative!
131 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
132 const Type *t1 = phase->type(in(1));
133 const Type *t2 = phase->type(in(2));
134 bool con_left = t1->singleton();
135 bool con_right = t2->singleton();
136
137 // Check for commutative operation desired
138 if (commute(phase, this)) return this;
139
140 AddNode *progress = nullptr; // Progress flag
141
142 // Convert "(x+1)+2" into "x+(1+2)". If the right input is a
143 // constant, and the left input is an add of a constant, flatten the
144 // expression tree.
145 Node *add1 = in(1);
146 Node *add2 = in(2);
147 int add1_op = add1->Opcode();
148 int this_op = Opcode();
149 if (con_right && t2 != Type::TOP && // Right input is a constant?
150 add1_op == this_op) { // Left input is an Add?
151
152 // Type of left _in right input
153 const Type *t12 = phase->type(add1->in(2));
154 if (t12->singleton() && t12 != Type::TOP) { // Left input is an add of a constant?
155 // Check for rare case of closed data cycle which can happen inside
156 // unreachable loops. In these cases the computation is undefined.
157 #ifdef ASSERT
158 Node *add11 = add1->in(1);
159 int add11_op = add11->Opcode();
160 if ((add1 == add1->in(1))
161 || (add11_op == this_op && add11->in(1) == add1)) {
162 assert(false, "dead loop in AddNode::Ideal");
163 }
164 #endif
165 // The Add of the flattened expression
166 Node *x1 = add1->in(1);
167 Node *x2 = phase->makecon(add1->as_Add()->add_ring(t2, t12));
168 set_req_X(2, x2, phase);
169 set_req_X(1, x1, phase);
170 progress = this; // Made progress
171 add1 = in(1);
172 add1_op = add1->Opcode();
173 }
174 }
175
176 // Convert "(x+1)+y" into "(x+y)+1". Push constants down the expression tree.
177 if (add1_op == this_op && !con_right) {
178 Node *a12 = add1->in(2);
179 const Type *t12 = phase->type( a12 );
180 if (t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) &&
181 !(add1->in(1)->is_Phi() && (add1->in(1)->as_Phi()->is_tripcount(T_INT) || add1->in(1)->as_Phi()->is_tripcount(T_LONG)))) {
182 assert(add1->in(1) != this, "dead loop in AddNode::Ideal");
183 add2 = add1->clone();
184 add2->set_req(2, in(2));
185 add2 = phase->transform(add2);
186 set_req_X(1, add2, phase);
187 set_req_X(2, a12, phase);
188 progress = this;
189 add2 = a12;
190 }
191 }
192
193 // Convert "x+(y+1)" into "(x+y)+1". Push constants down the expression tree.
194 int add2_op = add2->Opcode();
195 if (add2_op == this_op && !con_left) {
196 Node *a22 = add2->in(2);
197 const Type *t22 = phase->type( a22 );
198 if (t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) &&
199 !(add2->in(1)->is_Phi() && (add2->in(1)->as_Phi()->is_tripcount(T_INT) || add2->in(1)->as_Phi()->is_tripcount(T_LONG)))) {
200 assert(add2->in(1) != this, "dead loop in AddNode::Ideal");
201 Node *addx = add2->clone();
202 addx->set_req(1, in(1));
203 addx->set_req(2, add2->in(1));
204 addx = phase->transform(addx);
205 set_req_X(1, addx, phase);
206 set_req_X(2, a22, phase);
207 progress = this;
208 }
209 }
210
211 return progress;
212 }
213
214 //------------------------------Value-----------------------------------------
215 // An add node sums it's two _in. If one input is an RSD, we must mixin
216 // the other input's symbols.
217 const Type* AddNode::Value(PhaseGVN* phase) const {
218 // Either input is TOP ==> the result is TOP
219 const Type* t1 = phase->type(in(1));
220 const Type* t2 = phase->type(in(2));
221 if (t1 == Type::TOP || t2 == Type::TOP) {
222 return Type::TOP;
223 }
224
225 // Check for an addition involving the additive identity
226 const Type* tadd = add_of_identity(t1, t2);
227 if (tadd != nullptr) {
228 return tadd;
229 }
230
231 return add_ring(t1, t2); // Local flavor of type addition
232 }
233
234 //------------------------------add_identity-----------------------------------
235 // Check for addition of the identity
236 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
237 const Type *zero = add_id(); // The additive identity
238 if( t1->higher_equal( zero ) ) return t2;
239 if( t2->higher_equal( zero ) ) return t1;
240
241 return nullptr;
242 }
243
244 AddNode* AddNode::make(Node* in1, Node* in2, BasicType bt) {
245 switch (bt) {
246 case T_INT:
247 return new AddINode(in1, in2);
248 case T_LONG:
249 return new AddLNode(in1, in2);
250 default:
251 fatal("Not implemented for %s", type2name(bt));
252 }
253 return nullptr;
254 }
255
256 bool AddNode::is_not(PhaseGVN* phase, Node* n, BasicType bt) {
257 return n->Opcode() == Op_Xor(bt) && phase->type(n->in(2)) == TypeInteger::minus_1(bt);
258 }
259
260 AddNode* AddNode::make_not(PhaseGVN* phase, Node* n, BasicType bt) {
261 switch (bt) {
262 case T_INT:
263 return new XorINode(n, phase->intcon(-1));
264 case T_LONG:
265 return new XorLNode(n, phase->longcon(-1L));
266 default:
267 fatal("Not implemented for %s", type2name(bt));
268 }
269 return nullptr;
270 }
271
272 //=============================================================================
273 //------------------------------Idealize---------------------------------------
274 Node* AddNode::IdealIL(PhaseGVN* phase, bool can_reshape, BasicType bt) {
275 Node* in1 = in(1);
276 Node* in2 = in(2);
277 int op1 = in1->Opcode();
278 int op2 = in2->Opcode();
279 // Fold (con1-x)+con2 into (con1+con2)-x
280 if (op1 == Op_Add(bt) && op2 == Op_Sub(bt)) {
281 // Swap edges to try optimizations below
282 in1 = in2;
283 in2 = in(1);
284 op1 = op2;
285 op2 = in2->Opcode();
286 }
287 if (op1 == Op_Sub(bt)) {
288 const Type* t_sub1 = phase->type(in1->in(1));
289 const Type* t_2 = phase->type(in2 );
290 if (t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP) {
291 return SubNode::make(phase->makecon(add_ring(t_sub1, t_2)), in1->in(2), bt);
292 }
293 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
294 if (op2 == Op_Sub(bt)) {
295 // Check for dead cycle: d = (a-b)+(c-d)
296 assert( in1->in(2) != this && in2->in(2) != this,
297 "dead loop in AddINode::Ideal" );
298 Node* sub = SubNode::make(nullptr, nullptr, bt);
299 Node* sub_in1;
300 PhaseIterGVN* igvn = phase->is_IterGVN();
301 // During IGVN, if both inputs of the new AddNode are a tree of SubNodes, this same transformation will be applied
302 // to every node of the tree. Calling transform() causes the transformation to be applied recursively, once per
303 // tree node whether some subtrees are identical or not. Pushing to the IGVN worklist instead, causes the transform
304 // to be applied once per unique subtrees (because all uses of a subtree are updated with the result of the
305 // transformation). In case of a large tree, this can make a difference in compilation time.
306 if (igvn != nullptr) {
307 sub_in1 = igvn->register_new_node_with_optimizer(AddNode::make(in1->in(1), in2->in(1), bt));
308 } else {
309 sub_in1 = phase->transform(AddNode::make(in1->in(1), in2->in(1), bt));
310 }
311 Node* sub_in2;
312 if (igvn != nullptr) {
313 sub_in2 = igvn->register_new_node_with_optimizer(AddNode::make(in1->in(2), in2->in(2), bt));
314 } else {
315 sub_in2 = phase->transform(AddNode::make(in1->in(2), in2->in(2), bt));
316 }
317 sub->init_req(1, sub_in1);
318 sub->init_req(2, sub_in2);
319 return sub;
320 }
321 // Convert "(a-b)+(b+c)" into "(a+c)"
322 if (op2 == Op_Add(bt) && in1->in(2) == in2->in(1)) {
323 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal/AddLNode::Ideal");
324 return AddNode::make(in1->in(1), in2->in(2), bt);
325 }
326 // Convert "(a-b)+(c+b)" into "(a+c)"
327 if (op2 == Op_Add(bt) && in1->in(2) == in2->in(2)) {
328 assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal/AddLNode::Ideal");
329 return AddNode::make(in1->in(1), in2->in(1), bt);
330 }
331 }
332
333 // Convert (con - y) + x into "(x - y) + con"
334 if (op1 == Op_Sub(bt) && in1->in(1)->Opcode() == Op_ConIL(bt)
335 && in1 != in1->in(2) && !(in1->in(2)->is_Phi() && in1->in(2)->as_Phi()->is_tripcount(bt))) {
336 return AddNode::make(phase->transform(SubNode::make(in2, in1->in(2), bt)), in1->in(1), bt);
337 }
338
339 // Convert x + (con - y) into "(x - y) + con"
340 if (op2 == Op_Sub(bt) && in2->in(1)->Opcode() == Op_ConIL(bt)
341 && in2 != in2->in(2) && !(in2->in(2)->is_Phi() && in2->in(2)->as_Phi()->is_tripcount(bt))) {
342 return AddNode::make(phase->transform(SubNode::make(in1, in2->in(2), bt)), in2->in(1), bt);
343 }
344
345 // Associative
346 if (op1 == Op_Mul(bt) && op2 == Op_Mul(bt)) {
347 Node* add_in1 = nullptr;
348 Node* add_in2 = nullptr;
349 Node* mul_in = nullptr;
350
351 if (in1->in(1) == in2->in(1)) {
352 // Convert "a*b+a*c into a*(b+c)
353 add_in1 = in1->in(2);
354 add_in2 = in2->in(2);
355 mul_in = in1->in(1);
356 } else if (in1->in(2) == in2->in(1)) {
357 // Convert a*b+b*c into b*(a+c)
358 add_in1 = in1->in(1);
359 add_in2 = in2->in(2);
360 mul_in = in1->in(2);
361 } else if (in1->in(2) == in2->in(2)) {
362 // Convert a*c+b*c into (a+b)*c
363 add_in1 = in1->in(1);
364 add_in2 = in2->in(1);
365 mul_in = in1->in(2);
366 } else if (in1->in(1) == in2->in(2)) {
367 // Convert a*b+c*a into a*(b+c)
368 add_in1 = in1->in(2);
369 add_in2 = in2->in(1);
370 mul_in = in1->in(1);
371 }
372
373 if (mul_in != nullptr) {
374 Node* add = phase->transform(AddNode::make(add_in1, add_in2, bt));
375 return MulNode::make(mul_in, add, bt);
376 }
377 }
378
379 // Convert (x >>> rshift) + (x << lshift) into RotateRight(x, rshift)
380 if (Matcher::match_rule_supported(Op_RotateRight) &&
381 ((op1 == Op_URShift(bt) && op2 == Op_LShift(bt)) || (op1 == Op_LShift(bt) && op2 == Op_URShift(bt))) &&
382 in1->in(1) != nullptr && in1->in(1) == in2->in(1)) {
383 Node* rshift = op1 == Op_URShift(bt) ? in1->in(2) : in2->in(2);
384 Node* lshift = op1 == Op_URShift(bt) ? in2->in(2) : in1->in(2);
385 if (rshift != nullptr && lshift != nullptr) {
386 const TypeInt* rshift_t = phase->type(rshift)->isa_int();
387 const TypeInt* lshift_t = phase->type(lshift)->isa_int();
388 int bits = bt == T_INT ? 32 : 64;
389 int mask = bt == T_INT ? 0x1F : 0x3F;
390 if (lshift_t != nullptr && lshift_t->is_con() &&
391 rshift_t != nullptr && rshift_t->is_con() &&
392 ((lshift_t->get_con() & mask) == (bits - (rshift_t->get_con() & mask)))) {
393 return new RotateRightNode(in1->in(1), phase->intcon(rshift_t->get_con() & mask), TypeInteger::bottom(bt));
394 }
395 }
396 }
397
398 // Convert a + a + ... + a into a*n
399 Node* serial_additions = convert_serial_additions(phase, bt);
400 if (serial_additions != nullptr) {
401 return serial_additions;
402 }
403
404 return AddNode::Ideal(phase, can_reshape);
405 }
406
407 // Try to convert a serial of additions into a single multiplication. Also convert `(a * CON) + a` to `(CON + 1) * a` as
408 // a side effect. On success, a new MulNode is returned.
409 Node* AddNode::convert_serial_additions(PhaseGVN* phase, BasicType bt) {
410 // We need to make sure that the current AddNode is not part of a MulNode that has already been optimized to a
411 // power-of-2 addition (e.g., 3 * a => (a << 2) + a). Without this check, GVN would keep trying to optimize the same
412 // node and can't progress. For example, 3 * a => (a << 2) + a => 3 * a => (a << 2) + a => ...
413 if (find_power_of_two_addition_pattern(this, bt, nullptr) != nullptr) {
414 return nullptr;
415 }
416
417 Node* in1 = in(1);
418 Node* in2 = in(2);
419 jlong multiplier;
420
421 // While multiplications can be potentially optimized to power-of-2 subtractions (e.g., a * 7 => (a << 3) - a),
422 // (x - y) + y => x is already handled by the Identity() methods. So, we don't need to check for that pattern here.
423 if (find_simple_addition_pattern(in1, bt, &multiplier) == in2
424 || find_simple_lshift_pattern(in1, bt, &multiplier) == in2
425 || find_simple_multiplication_pattern(in1, bt, &multiplier) == in2
426 || find_power_of_two_addition_pattern(in1, bt, &multiplier) == in2) {
427 multiplier++; // +1 for the in2 term
428
429 Node* con = (bt == T_INT)
430 ? (Node*) phase->intcon((jint) multiplier) // intentional type narrowing to allow overflow at max_jint
431 : (Node*) phase->longcon(multiplier);
432 return MulNode::make(con, in2, bt);
433 }
434
435 return nullptr;
436 }
437
438 // Try to match `a + a`. On success, return `a` and set `2` as `multiplier`.
439 // The method matches `n` for pattern: AddNode(a, a).
440 Node* AddNode::find_simple_addition_pattern(Node* n, BasicType bt, jlong* multiplier) {
441 if (n->Opcode() == Op_Add(bt) && n->in(1) == n->in(2)) {
442 *multiplier = 2;
443 return n->in(1);
444 }
445
446 return nullptr;
447 }
448
449 // Try to match `a << CON`. On success, return `a` and set `1 << CON` as `multiplier`.
450 // Match `n` for pattern: LShiftNode(a, CON).
451 // Note that the power-of-2 multiplication optimization could potentially convert a MulNode to this pattern.
452 Node* AddNode::find_simple_lshift_pattern(Node* n, BasicType bt, jlong* multiplier) {
453 // Note that power-of-2 multiplication optimization could potentially convert a MulNode to this pattern
454 if (n->Opcode() == Op_LShift(bt) && n->in(2)->is_Con()) {
455 Node* con = n->in(2);
456 if (con->is_top()) {
457 return nullptr;
458 }
459
460 *multiplier = ((jlong) 1 << con->get_int());
461 return n->in(1);
462 }
463
464 return nullptr;
465 }
466
467 // Try to match `CON * a`. On success, return `a` and set `CON` as `multiplier`.
468 // Match `n` for patterns:
469 // - MulNode(CON, a)
470 // - MulNode(a, CON)
471 Node* AddNode::find_simple_multiplication_pattern(Node* n, BasicType bt, jlong* multiplier) {
472 // This optimization technically only produces MulNode(CON, a), but we might as match MulNode(a, CON), too.
473 if (n->Opcode() == Op_Mul(bt) && (n->in(1)->is_Con() || n->in(2)->is_Con())) {
474 Node* con = n->in(1);
475 Node* base = n->in(2);
476
477 // swap ConNode to lhs for easier matching
478 if (!con->is_Con()) {
479 swap(con, base);
480 }
481
482 if (con->is_top()) {
483 return nullptr;
484 }
485
486 *multiplier = con->get_integer_as_long(bt);
487 return base;
488 }
489
490 return nullptr;
491 }
492
493 // Try to match `(a << CON1) + (a << CON2)`. On success, return `a` and set `(1 << CON1) + (1 << CON2)` as `multiplier`.
494 // Match `n` for patterns:
495 // - AddNode(LShiftNode(a, CON), LShiftNode(a, CON)/a)
496 // - AddNode(LShiftNode(a, CON)/a, LShiftNode(a, CON))
497 // given that lhs is different from rhs.
498 // Note that one of the term of the addition could simply be `a` (i.e., a << 0). Calling this function with `multiplier`
499 // being null is safe.
500 Node* AddNode::find_power_of_two_addition_pattern(Node* n, BasicType bt, jlong* multiplier) {
501 if (n->Opcode() == Op_Add(bt) && n->in(1) != n->in(2)) {
502 Node* lhs = n->in(1);
503 Node* rhs = n->in(2);
504
505 // swap LShiftNode to lhs for easier matching
506 if (lhs->Opcode() != Op_LShift(bt)) {
507 swap(lhs, rhs);
508 }
509
510 // AddNode(LShiftNode(a, CON), *)?
511 if (lhs->Opcode() != Op_LShift(bt) || !lhs->in(2)->is_Con()) {
512 return nullptr;
513 }
514
515 jlong lhs_multiplier = 0;
516 if (multiplier != nullptr) {
517 Node* con = lhs->in(2);
518 if (con->is_top()) {
519 return nullptr;
520 }
521
522 lhs_multiplier = (jlong) 1 << con->get_int();
523 }
524
525 // AddNode(LShiftNode(a, CON), a)?
526 if (lhs->in(1) == rhs) {
527 if (multiplier != nullptr) {
528 *multiplier = lhs_multiplier + 1;
529 }
530
531 return rhs;
532 }
533
534 // AddNode(LShiftNode(a, CON), LShiftNode(a, CON2))?
535 if (rhs->Opcode() == Op_LShift(bt) && lhs->in(1) == rhs->in(1) && rhs->in(2)->is_Con()) {
536 if (multiplier != nullptr) {
537 Node* con = rhs->in(2);
538 if (con->is_top()) {
539 return nullptr;
540 }
541
542 *multiplier = lhs_multiplier + ((jlong) 1 << con->get_int());
543 }
544
545 return lhs->in(1);
546 }
547 return nullptr;
548 }
549 return nullptr;
550 }
551
552 Node* AddINode::Ideal(PhaseGVN* phase, bool can_reshape) {
553 Node* in1 = in(1);
554 Node* in2 = in(2);
555 int op1 = in1->Opcode();
556 int op2 = in2->Opcode();
557
558 // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
559 // Helps with array allocation math constant folding
560 // See 4790063:
561 // Unrestricted transformation is unsafe for some runtime values of 'x'
562 // ( x == 0, z == 1, y == -1 ) fails
563 // ( x == -5, z == 1, y == 1 ) fails
564 // Transform works for small z and small negative y when the addition
565 // (x + (y << z)) does not cross zero.
566 // Implement support for negative y and (x >= -(y << z))
567 // Have not observed cases where type information exists to support
568 // positive y and (x <= -(y << z))
569 if (op1 == Op_URShiftI && op2 == Op_ConI &&
570 in1->in(2)->Opcode() == Op_ConI) {
571 jint z = phase->type(in1->in(2))->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
572 jint y = phase->type(in2)->is_int()->get_con();
573
574 if (z < 5 && -5 < y && y < 0) {
575 const Type* t_in11 = phase->type(in1->in(1));
576 if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z))) {
577 Node* a = phase->transform(new AddINode( in1->in(1), phase->intcon(y<<z)));
578 return new URShiftINode(a, in1->in(2));
579 }
580 }
581 }
582
583 return AddNode::IdealIL(phase, can_reshape, T_INT);
584 }
585
586
587 //------------------------------Identity---------------------------------------
588 // Fold (x-y)+y OR y+(x-y) into x
589 Node* AddINode::Identity(PhaseGVN* phase) {
590 if (in(1)->Opcode() == Op_SubI && in(1)->in(2) == in(2)) {
591 return in(1)->in(1);
592 } else if (in(2)->Opcode() == Op_SubI && in(2)->in(2) == in(1)) {
593 return in(2)->in(1);
594 }
595 return AddNode::Identity(phase);
596 }
597
598
599 //------------------------------add_ring---------------------------------------
600 // Supplied function returns the sum of the inputs. Guaranteed never
601 // to be passed a TOP or BOTTOM type, these are filtered out by
602 // pre-check.
603 const Type *AddINode::add_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 lo = java_add(r0->_lo, r1->_lo);
607 int hi = java_add(r0->_hi, r1->_hi);
608 if( !(r0->is_con() && r1->is_con()) ) {
609 // Not both constants, compute approximate result
610 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
611 lo = min_jint; hi = max_jint; // Underflow on the low side
612 }
613 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
614 lo = min_jint; hi = max_jint; // Overflow on the high side
615 }
616 if( lo > hi ) { // Handle overflow
617 lo = min_jint; hi = max_jint;
618 }
619 } else {
620 // both constants, compute precise result using 'lo' and 'hi'
621 // Semantics define overflow and underflow for integer addition
622 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
623 }
624 return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
625 }
626
627
628 //=============================================================================
629 //------------------------------Idealize---------------------------------------
630 Node* AddLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
631 return AddNode::IdealIL(phase, can_reshape, T_LONG);
632 }
633
634
635 //------------------------------Identity---------------------------------------
636 // Fold (x-y)+y OR y+(x-y) into x
637 Node* AddLNode::Identity(PhaseGVN* phase) {
638 if (in(1)->Opcode() == Op_SubL && in(1)->in(2) == in(2)) {
639 return in(1)->in(1);
640 } else if (in(2)->Opcode() == Op_SubL && in(2)->in(2) == in(1)) {
641 return in(2)->in(1);
642 }
643 return AddNode::Identity(phase);
644 }
645
646
647 //------------------------------add_ring---------------------------------------
648 // Supplied function returns the sum of the inputs. Guaranteed never
649 // to be passed a TOP or BOTTOM type, these are filtered out by
650 // pre-check.
651 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
652 const TypeLong *r0 = t0->is_long(); // Handy access
653 const TypeLong *r1 = t1->is_long();
654 jlong lo = java_add(r0->_lo, r1->_lo);
655 jlong hi = java_add(r0->_hi, r1->_hi);
656 if( !(r0->is_con() && r1->is_con()) ) {
657 // Not both constants, compute approximate result
658 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
659 lo =min_jlong; hi = max_jlong; // Underflow on the low side
660 }
661 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
662 lo = min_jlong; hi = max_jlong; // Overflow on the high side
663 }
664 if( lo > hi ) { // Handle overflow
665 lo = min_jlong; hi = max_jlong;
666 }
667 } else {
668 // both constants, compute precise result using 'lo' and 'hi'
669 // Semantics define overflow and underflow for integer addition
670 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
671 }
672 return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
673 }
674
675
676 //=============================================================================
677 //------------------------------add_of_identity--------------------------------
678 // Check for addition of the identity
679 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
680 // x ADD 0 should return x unless 'x' is a -zero
681 //
682 // const Type *zero = add_id(); // The additive identity
683 // jfloat f1 = t1->getf();
684 // jfloat f2 = t2->getf();
685 //
686 // if( t1->higher_equal( zero ) ) return t2;
687 // if( t2->higher_equal( zero ) ) return t1;
688
689 return nullptr;
690 }
691
692 //------------------------------add_ring---------------------------------------
693 // Supplied function returns the sum of the inputs.
694 // This also type-checks the inputs for sanity. Guaranteed never to
695 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
696 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
697 if (!t0->isa_float_constant() || !t1->isa_float_constant()) {
698 return bottom_type();
699 }
700 return TypeF::make( t0->getf() + t1->getf() );
701 }
702
703 //------------------------------Ideal------------------------------------------
704 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
705 // Floating point additions are not associative because of boundary conditions (infinity)
706 return commute(phase, this) ? this : nullptr;
707 }
708
709
710 //=============================================================================
711 //------------------------------add_of_identity--------------------------------
712 // Check for addition of the identity
713 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
714 // x ADD 0 should return x unless 'x' is a -zero
715 //
716 // const Type *zero = add_id(); // The additive identity
717 // jfloat f1 = t1->getf();
718 // jfloat f2 = t2->getf();
719 //
720 // if( t1->higher_equal( zero ) ) return t2;
721 // if( t2->higher_equal( zero ) ) return t1;
722
723 return nullptr;
724 }
725 //------------------------------add_ring---------------------------------------
726 // Supplied function returns the sum of the inputs.
727 // This also type-checks the inputs for sanity. Guaranteed never to
728 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
729 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
730 if (!t0->isa_double_constant() || !t1->isa_double_constant()) {
731 return bottom_type();
732 }
733 return TypeD::make( t0->getd() + t1->getd() );
734 }
735
736 //------------------------------Ideal------------------------------------------
737 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
738 // Floating point additions are not associative because of boundary conditions (infinity)
739 return commute(phase, this) ? this : nullptr;
740 }
741
742
743 //=============================================================================
744 //------------------------------Identity---------------------------------------
745 // If one input is a constant 0, return the other input.
746 Node* AddPNode::Identity(PhaseGVN* phase) {
747 return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
748 }
749
750 //------------------------------Idealize---------------------------------------
751 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
752 // Bail out if dead inputs
753 if( phase->type( in(Address) ) == Type::TOP ) return nullptr;
754
755 // If the left input is an add of a constant, flatten the expression tree.
756 const Node *n = in(Address);
757 if (n->is_AddP() && n->in(Base) == in(Base)) {
758 const AddPNode *addp = n->as_AddP(); // Left input is an AddP
759 assert( !addp->in(Address)->is_AddP() ||
760 addp->in(Address)->as_AddP() != addp,
761 "dead loop in AddPNode::Ideal" );
762 // Type of left input's right input
763 const Type *t = phase->type( addp->in(Offset) );
764 if( t == Type::TOP ) return nullptr;
765 const TypeX *t12 = t->is_intptr_t();
766 if( t12->is_con() ) { // Left input is an add of a constant?
767 // If the right input is a constant, combine constants
768 const Type *temp_t2 = phase->type( in(Offset) );
769 if( temp_t2 == Type::TOP ) return nullptr;
770 const TypeX *t2 = temp_t2->is_intptr_t();
771 Node* address;
772 Node* offset;
773 if( t2->is_con() ) {
774 // The Add of the flattened expression
775 address = addp->in(Address);
776 offset = phase->MakeConX(t2->get_con() + t12->get_con());
777 } else {
778 // Else move the constant to the right. ((A+con)+B) into ((A+B)+con)
779 address = phase->transform(new AddPNode(in(Base),addp->in(Address),in(Offset)));
780 offset = addp->in(Offset);
781 }
782 set_req_X(Address, address, phase);
783 set_req_X(Offset, offset, phase);
784 return this;
785 }
786 }
787
788 // Raw pointers?
789 if( in(Base)->bottom_type() == Type::TOP ) {
790 // If this is a null+long form (from unsafe accesses), switch to a rawptr.
791 if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
792 Node* offset = in(Offset);
793 return new CastX2PNode(offset);
794 }
795 }
796
797 // If the right is an add of a constant, push the offset down.
798 // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
799 // The idea is to merge array_base+scaled_index groups together,
800 // and only have different constant offsets from the same base.
801 const Node *add = in(Offset);
802 if( add->Opcode() == Op_AddX && add->in(1) != add ) {
803 const Type *t22 = phase->type( add->in(2) );
804 if( t22->singleton() && (t22 != Type::TOP) ) { // Right input is an add of a constant?
805 set_req(Address, phase->transform(new AddPNode(in(Base),in(Address),add->in(1))));
806 set_req_X(Offset, add->in(2), phase); // puts add on igvn worklist if needed
807 return this; // Made progress
808 }
809 }
810
811 return nullptr; // No progress
812 }
813
814 //------------------------------bottom_type------------------------------------
815 // Bottom-type is the pointer-type with unknown offset.
816 const Type *AddPNode::bottom_type() const {
817 if (in(Address) == nullptr) return TypePtr::BOTTOM;
818 const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
819 if( !tp ) return Type::TOP; // TOP input means TOP output
820 assert( in(Offset)->Opcode() != Op_ConP, "" );
821 const Type *t = in(Offset)->bottom_type();
822 if( t == Type::TOP )
823 return tp->add_offset(Type::OffsetTop);
824 const TypeX *tx = t->is_intptr_t();
825 intptr_t txoffset = Type::OffsetBot;
826 if (tx->is_con()) { // Left input is an add of a constant?
827 txoffset = tx->get_con();
828 }
829 return tp->add_offset(txoffset);
830 }
831
832 //------------------------------Value------------------------------------------
833 const Type* AddPNode::Value(PhaseGVN* phase) const {
834 // Either input is TOP ==> the result is TOP
835 const Type *t1 = phase->type( in(Address) );
836 const Type *t2 = phase->type( in(Offset) );
837 if( t1 == Type::TOP ) return Type::TOP;
838 if( t2 == Type::TOP ) return Type::TOP;
839
840 // Left input is a pointer
841 const TypePtr *p1 = t1->isa_ptr();
842 // Right input is an int
843 const TypeX *p2 = t2->is_intptr_t();
844 // Add 'em
845 intptr_t p2offset = Type::OffsetBot;
846 if (p2->is_con()) { // Left input is an add of a constant?
847 p2offset = p2->get_con();
848 }
849 return p1->add_offset(p2offset);
850 }
851
852 //------------------------Ideal_base_and_offset--------------------------------
853 // Split an oop pointer into a base and offset.
854 // (The offset might be Type::OffsetBot in the case of an array.)
855 // Return the base, or null if failure.
856 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseValues* phase,
857 // second return value:
858 intptr_t& offset) {
859 if (ptr->is_AddP()) {
860 Node* base = ptr->in(AddPNode::Base);
861 Node* addr = ptr->in(AddPNode::Address);
862 Node* offs = ptr->in(AddPNode::Offset);
863 if (base == addr || base->is_top()) {
864 offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
865 if (offset != Type::OffsetBot) {
866 return addr;
867 }
868 }
869 }
870 offset = Type::OffsetBot;
871 return nullptr;
872 }
873
874 //------------------------------unpack_offsets----------------------------------
875 // Collect the AddP offset values into the elements array, giving up
876 // if there are more than length.
877 int AddPNode::unpack_offsets(Node* elements[], int length) const {
878 int count = 0;
879 Node const* addr = this;
880 Node* base = addr->in(AddPNode::Base);
881 while (addr->is_AddP()) {
882 if (addr->in(AddPNode::Base) != base) {
883 // give up
884 return -1;
885 }
886 elements[count++] = addr->in(AddPNode::Offset);
887 if (count == length) {
888 // give up
889 return -1;
890 }
891 addr = addr->in(AddPNode::Address);
892 }
893 if (addr != base) {
894 return -1;
895 }
896 return count;
897 }
898
899 //------------------------------match_edge-------------------------------------
900 // Do we Match on this edge index or not? Do not match base pointer edge
901 uint AddPNode::match_edge(uint idx) const {
902 return idx > Base;
903 }
904
905 //=============================================================================
906 //------------------------------Identity---------------------------------------
907 Node* OrINode::Identity(PhaseGVN* phase) {
908 // x | x => x
909 if (in(1) == in(2)) {
910 return in(1);
911 }
912
913 return AddNode::Identity(phase);
914 }
915
916 // Find shift value for Integer or Long OR.
917 static Node* rotate_shift(PhaseGVN* phase, Node* lshift, Node* rshift, int mask) {
918 // val << norm_con_shift | val >> ({32|64} - norm_con_shift) => rotate_left val, norm_con_shift
919 const TypeInt* lshift_t = phase->type(lshift)->isa_int();
920 const TypeInt* rshift_t = phase->type(rshift)->isa_int();
921 if (lshift_t != nullptr && lshift_t->is_con() &&
922 rshift_t != nullptr && rshift_t->is_con() &&
923 ((lshift_t->get_con() & mask) == ((mask + 1) - (rshift_t->get_con() & mask)))) {
924 return phase->intcon(lshift_t->get_con() & mask);
925 }
926 // val << var_shift | val >> ({0|32|64} - var_shift) => rotate_left val, var_shift
927 if (rshift->Opcode() == Op_SubI && rshift->in(2) == lshift && rshift->in(1)->is_Con()){
928 const TypeInt* shift_t = phase->type(rshift->in(1))->isa_int();
929 if (shift_t != nullptr && shift_t->is_con() &&
930 (shift_t->get_con() == 0 || shift_t->get_con() == (mask + 1))) {
931 return lshift;
932 }
933 }
934 return nullptr;
935 }
936
937 Node* OrINode::Ideal(PhaseGVN* phase, bool can_reshape) {
938 int lopcode = in(1)->Opcode();
939 int ropcode = in(2)->Opcode();
940 if (Matcher::match_rule_supported(Op_RotateLeft) &&
941 lopcode == Op_LShiftI && ropcode == Op_URShiftI && in(1)->in(1) == in(2)->in(1)) {
942 Node* lshift = in(1)->in(2);
943 Node* rshift = in(2)->in(2);
944 Node* shift = rotate_shift(phase, lshift, rshift, 0x1F);
945 if (shift != nullptr) {
946 return new RotateLeftNode(in(1)->in(1), shift, TypeInt::INT);
947 }
948 return nullptr;
949 }
950 if (Matcher::match_rule_supported(Op_RotateRight) &&
951 lopcode == Op_URShiftI && ropcode == Op_LShiftI && in(1)->in(1) == in(2)->in(1)) {
952 Node* rshift = in(1)->in(2);
953 Node* lshift = in(2)->in(2);
954 Node* shift = rotate_shift(phase, rshift, lshift, 0x1F);
955 if (shift != nullptr) {
956 return new RotateRightNode(in(1)->in(1), shift, TypeInt::INT);
957 }
958 }
959
960 // Convert "~a | ~b" into "~(a & b)"
961 if (AddNode::is_not(phase, in(1), T_INT) && AddNode::is_not(phase, in(2), T_INT)) {
962 Node* and_a_b = new AndINode(in(1)->in(1), in(2)->in(1));
963 Node* tn = phase->transform(and_a_b);
964 return AddNode::make_not(phase, tn, T_INT);
965 }
966 return nullptr;
967 }
968
969 //------------------------------add_ring---------------------------------------
970 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
971 // the logical operations the ring's ADD is really a logical OR function.
972 // This also type-checks the inputs for sanity. Guaranteed never to
973 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
974 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
975 const TypeInt *r0 = t0->is_int(); // Handy access
976 const TypeInt *r1 = t1->is_int();
977
978 // If both args are bool, can figure out better types
979 if ( r0 == TypeInt::BOOL ) {
980 if ( r1 == TypeInt::ONE) {
981 return TypeInt::ONE;
982 } else if ( r1 == TypeInt::BOOL ) {
983 return TypeInt::BOOL;
984 }
985 } else if ( r0 == TypeInt::ONE ) {
986 if ( r1 == TypeInt::BOOL ) {
987 return TypeInt::ONE;
988 }
989 }
990
991 // If either input is not a constant, just return all integers.
992 if( !r0->is_con() || !r1->is_con() )
993 return TypeInt::INT; // Any integer, but still no symbols.
994
995 // Otherwise just OR them bits.
996 return TypeInt::make( r0->get_con() | r1->get_con() );
997 }
998
999 //=============================================================================
1000 //------------------------------Identity---------------------------------------
1001 Node* OrLNode::Identity(PhaseGVN* phase) {
1002 // x | x => x
1003 if (in(1) == in(2)) {
1004 return in(1);
1005 }
1006
1007 return AddNode::Identity(phase);
1008 }
1009
1010 Node* OrLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1011 int lopcode = in(1)->Opcode();
1012 int ropcode = in(2)->Opcode();
1013 if (Matcher::match_rule_supported(Op_RotateLeft) &&
1014 lopcode == Op_LShiftL && ropcode == Op_URShiftL && in(1)->in(1) == in(2)->in(1)) {
1015 Node* lshift = in(1)->in(2);
1016 Node* rshift = in(2)->in(2);
1017 Node* shift = rotate_shift(phase, lshift, rshift, 0x3F);
1018 if (shift != nullptr) {
1019 return new RotateLeftNode(in(1)->in(1), shift, TypeLong::LONG);
1020 }
1021 return nullptr;
1022 }
1023 if (Matcher::match_rule_supported(Op_RotateRight) &&
1024 lopcode == Op_URShiftL && ropcode == Op_LShiftL && in(1)->in(1) == in(2)->in(1)) {
1025 Node* rshift = in(1)->in(2);
1026 Node* lshift = in(2)->in(2);
1027 Node* shift = rotate_shift(phase, rshift, lshift, 0x3F);
1028 if (shift != nullptr) {
1029 return new RotateRightNode(in(1)->in(1), shift, TypeLong::LONG);
1030 }
1031 }
1032
1033 // Convert "~a | ~b" into "~(a & b)"
1034 if (AddNode::is_not(phase, in(1), T_LONG) && AddNode::is_not(phase, in(2), T_LONG)) {
1035 Node* and_a_b = new AndLNode(in(1)->in(1), in(2)->in(1));
1036 Node* tn = phase->transform(and_a_b);
1037 return AddNode::make_not(phase, tn, T_LONG);
1038 }
1039
1040 return nullptr;
1041 }
1042
1043 //------------------------------add_ring---------------------------------------
1044 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
1045 const TypeLong *r0 = t0->is_long(); // Handy access
1046 const TypeLong *r1 = t1->is_long();
1047
1048 // If either input is not a constant, just return all integers.
1049 if( !r0->is_con() || !r1->is_con() )
1050 return TypeLong::LONG; // Any integer, but still no symbols.
1051
1052 // Otherwise just OR them bits.
1053 return TypeLong::make( r0->get_con() | r1->get_con() );
1054 }
1055
1056 //---------------------------Helper -------------------------------------------
1057 /* Decide if the given node is used only in arithmetic expressions(add or sub).
1058 */
1059 static bool is_used_in_only_arithmetic(Node* n, BasicType bt) {
1060 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1061 Node* u = n->fast_out(i);
1062 if (u->Opcode() != Op_Add(bt) && u->Opcode() != Op_Sub(bt)) {
1063 return false;
1064 }
1065 }
1066 return true;
1067 }
1068
1069 //=============================================================================
1070 //------------------------------Idealize---------------------------------------
1071 Node* XorINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1072 Node* in1 = in(1);
1073 Node* in2 = in(2);
1074
1075 // Convert ~x into -1-x when ~x is used in an arithmetic expression
1076 // or x itself is an expression.
1077 if (phase->type(in2) == TypeInt::MINUS_1) { // follows LHS^(-1), i.e., ~LHS
1078 if (phase->is_IterGVN()) {
1079 if (is_used_in_only_arithmetic(this, T_INT)
1080 // LHS is arithmetic
1081 || (in1->Opcode() == Op_AddI || in1->Opcode() == Op_SubI)) {
1082 return new SubINode(in2, in1);
1083 }
1084 } else {
1085 // graph could be incomplete in GVN so we postpone to IGVN
1086 phase->record_for_igvn(this);
1087 }
1088 }
1089
1090 // Propagate xor through constant cmoves. This pattern can occur after expansion of Conv2B nodes.
1091 const TypeInt* in2_type = phase->type(in2)->isa_int();
1092 if (in1->Opcode() == Op_CMoveI && in2_type != nullptr && in2_type->is_con()) {
1093 int in2_val = in2_type->get_con();
1094
1095 // Get types of both sides of the CMove
1096 const TypeInt* left = phase->type(in1->in(CMoveNode::IfFalse))->isa_int();
1097 const TypeInt* right = phase->type(in1->in(CMoveNode::IfTrue))->isa_int();
1098
1099 // Ensure that both sides are int constants
1100 if (left != nullptr && right != nullptr && left->is_con() && right->is_con()) {
1101 Node* cond = in1->in(CMoveNode::Condition);
1102
1103 // Check that the comparison is a bool and that the cmp node type is correct
1104 if (cond->is_Bool()) {
1105 int cmp_op = cond->in(1)->Opcode();
1106
1107 if (cmp_op == Op_CmpI || cmp_op == Op_CmpP) {
1108 int l_val = left->get_con();
1109 int r_val = right->get_con();
1110
1111 return new CMoveINode(cond, phase->intcon(l_val ^ in2_val), phase->intcon(r_val ^ in2_val), TypeInt::INT);
1112 }
1113 }
1114 }
1115 }
1116
1117 return AddNode::Ideal(phase, can_reshape);
1118 }
1119
1120 const Type* XorINode::Value(PhaseGVN* phase) const {
1121 Node* in1 = in(1);
1122 Node* in2 = in(2);
1123 const Type* t1 = phase->type(in1);
1124 const Type* t2 = phase->type(in2);
1125 if (t1 == Type::TOP || t2 == Type::TOP) {
1126 return Type::TOP;
1127 }
1128 // x ^ x ==> 0
1129 if (in1->eqv_uncast(in2)) {
1130 return add_id();
1131 }
1132 // result of xor can only have bits sets where any of the
1133 // inputs have bits set. lo can always become 0.
1134 const TypeInt* t1i = t1->is_int();
1135 const TypeInt* t2i = t2->is_int();
1136 if ((t1i->_lo >= 0) &&
1137 (t1i->_hi > 0) &&
1138 (t2i->_lo >= 0) &&
1139 (t2i->_hi > 0)) {
1140 // hi - set all bits below the highest bit. Using round_down to avoid overflow.
1141 const TypeInt* t1x = TypeInt::make(0, round_down_power_of_2(t1i->_hi) + (round_down_power_of_2(t1i->_hi) - 1), t1i->_widen);
1142 const TypeInt* t2x = TypeInt::make(0, round_down_power_of_2(t2i->_hi) + (round_down_power_of_2(t2i->_hi) - 1), t2i->_widen);
1143 return t1x->meet(t2x);
1144 }
1145 return AddNode::Value(phase);
1146 }
1147
1148
1149 //------------------------------add_ring---------------------------------------
1150 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
1151 // the logical operations the ring's ADD is really a logical OR function.
1152 // This also type-checks the inputs for sanity. Guaranteed never to
1153 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
1154 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
1155 const TypeInt *r0 = t0->is_int(); // Handy access
1156 const TypeInt *r1 = t1->is_int();
1157
1158 // Complementing a boolean?
1159 if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
1160 || r1 == TypeInt::BOOL))
1161 return TypeInt::BOOL;
1162
1163 if( !r0->is_con() || !r1->is_con() ) // Not constants
1164 return TypeInt::INT; // Any integer, but still no symbols.
1165
1166 // Otherwise just XOR them bits.
1167 return TypeInt::make( r0->get_con() ^ r1->get_con() );
1168 }
1169
1170 //=============================================================================
1171 //------------------------------add_ring---------------------------------------
1172 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
1173 const TypeLong *r0 = t0->is_long(); // Handy access
1174 const TypeLong *r1 = t1->is_long();
1175
1176 // If either input is not a constant, just return all integers.
1177 if( !r0->is_con() || !r1->is_con() )
1178 return TypeLong::LONG; // Any integer, but still no symbols.
1179
1180 // Otherwise just OR them bits.
1181 return TypeLong::make( r0->get_con() ^ r1->get_con() );
1182 }
1183
1184 Node* XorLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1185 Node* in1 = in(1);
1186 Node* in2 = in(2);
1187
1188 // Convert ~x into -1-x when ~x is used in an arithmetic expression
1189 // or x itself is an arithmetic expression.
1190 if (phase->type(in2) == TypeLong::MINUS_1) { // follows LHS^(-1), i.e., ~LHS
1191 if (phase->is_IterGVN()) {
1192 if (is_used_in_only_arithmetic(this, T_LONG)
1193 // LHS is arithmetic
1194 || (in1->Opcode() == Op_AddL || in1->Opcode() == Op_SubL)) {
1195 return new SubLNode(in2, in1);
1196 }
1197 } else {
1198 // graph could be incomplete in GVN so we postpone to IGVN
1199 phase->record_for_igvn(this);
1200 }
1201 }
1202 return AddNode::Ideal(phase, can_reshape);
1203 }
1204
1205 const Type* XorLNode::Value(PhaseGVN* phase) const {
1206 Node* in1 = in(1);
1207 Node* in2 = in(2);
1208 const Type* t1 = phase->type(in1);
1209 const Type* t2 = phase->type(in2);
1210 if (t1 == Type::TOP || t2 == Type::TOP) {
1211 return Type::TOP;
1212 }
1213 // x ^ x ==> 0
1214 if (in1->eqv_uncast(in2)) {
1215 return add_id();
1216 }
1217 // result of xor can only have bits sets where any of the
1218 // inputs have bits set. lo can always become 0.
1219 const TypeLong* t1l = t1->is_long();
1220 const TypeLong* t2l = t2->is_long();
1221 if ((t1l->_lo >= 0) &&
1222 (t1l->_hi > 0) &&
1223 (t2l->_lo >= 0) &&
1224 (t2l->_hi > 0)) {
1225 // hi - set all bits below the highest bit. Using round_down to avoid overflow.
1226 const TypeLong* t1x = TypeLong::make(0, round_down_power_of_2(t1l->_hi) + (round_down_power_of_2(t1l->_hi) - 1), t1l->_widen);
1227 const TypeLong* t2x = TypeLong::make(0, round_down_power_of_2(t2l->_hi) + (round_down_power_of_2(t2l->_hi) - 1), t2l->_widen);
1228 return t1x->meet(t2x);
1229 }
1230 return AddNode::Value(phase);
1231 }
1232
1233 Node* MaxNode::build_min_max_int(Node* a, Node* b, bool is_max) {
1234 if (is_max) {
1235 return new MaxINode(a, b);
1236 } else {
1237 return new MinINode(a, b);
1238 }
1239 }
1240
1241 Node* MaxNode::build_min_max_long(PhaseGVN* phase, Node* a, Node* b, bool is_max) {
1242 if (is_max) {
1243 return new MaxLNode(phase->C, a, b);
1244 } else {
1245 return new MinLNode(phase->C, a, b);
1246 }
1247 }
1248
1249 Node* MaxNode::build_min_max(Node* a, Node* b, bool is_max, bool is_unsigned, const Type* t, PhaseGVN& gvn) {
1250 bool is_int = gvn.type(a)->isa_int();
1251 assert(is_int || gvn.type(a)->isa_long(), "int or long inputs");
1252 assert(is_int == (gvn.type(b)->isa_int() != nullptr), "inconsistent inputs");
1253 BasicType bt = is_int ? T_INT: T_LONG;
1254 Node* hook = nullptr;
1255 if (gvn.is_IterGVN()) {
1256 // Make sure a and b are not destroyed
1257 hook = new Node(2);
1258 hook->init_req(0, a);
1259 hook->init_req(1, b);
1260 }
1261 Node* res = nullptr;
1262 if (is_int && !is_unsigned) {
1263 res = gvn.transform(build_min_max_int(a, b, is_max));
1264 assert(gvn.type(res)->is_int()->_lo >= t->is_int()->_lo && gvn.type(res)->is_int()->_hi <= t->is_int()->_hi, "type doesn't match");
1265 } else {
1266 Node* cmp = nullptr;
1267 if (is_max) {
1268 cmp = gvn.transform(CmpNode::make(a, b, bt, is_unsigned));
1269 } else {
1270 cmp = gvn.transform(CmpNode::make(b, a, bt, is_unsigned));
1271 }
1272 Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::lt));
1273 res = gvn.transform(CMoveNode::make(nullptr, bol, a, b, t));
1274 }
1275 if (hook != nullptr) {
1276 hook->destruct(&gvn);
1277 }
1278 return res;
1279 }
1280
1281 Node* MaxNode::build_min_max_diff_with_zero(Node* a, Node* b, bool is_max, const Type* t, PhaseGVN& gvn) {
1282 bool is_int = gvn.type(a)->isa_int();
1283 assert(is_int || gvn.type(a)->isa_long(), "int or long inputs");
1284 assert(is_int == (gvn.type(b)->isa_int() != nullptr), "inconsistent inputs");
1285 BasicType bt = is_int ? T_INT: T_LONG;
1286 Node* zero = gvn.integercon(0, bt);
1287 Node* hook = nullptr;
1288 if (gvn.is_IterGVN()) {
1289 // Make sure a and b are not destroyed
1290 hook = new Node(2);
1291 hook->init_req(0, a);
1292 hook->init_req(1, b);
1293 }
1294 Node* cmp = nullptr;
1295 if (is_max) {
1296 cmp = gvn.transform(CmpNode::make(a, b, bt, false));
1297 } else {
1298 cmp = gvn.transform(CmpNode::make(b, a, bt, false));
1299 }
1300 Node* sub = gvn.transform(SubNode::make(a, b, bt));
1301 Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::lt));
1302 Node* res = gvn.transform(CMoveNode::make(nullptr, bol, sub, zero, t));
1303 if (hook != nullptr) {
1304 hook->destruct(&gvn);
1305 }
1306 return res;
1307 }
1308
1309 // Check if addition of an integer with type 't' and a constant 'c' can overflow.
1310 static bool can_overflow(const TypeInt* t, jint c) {
1311 jint t_lo = t->_lo;
1312 jint t_hi = t->_hi;
1313 return ((c < 0 && (java_add(t_lo, c) > t_lo)) ||
1314 (c > 0 && (java_add(t_hi, c) < t_hi)));
1315 }
1316
1317 // Let <x, x_off> = x_operands and <y, y_off> = y_operands.
1318 // If x == y and neither add(x, x_off) nor add(y, y_off) overflow, return
1319 // add(x, op(x_off, y_off)). Otherwise, return nullptr.
1320 Node* MaxNode::extract_add(PhaseGVN* phase, ConstAddOperands x_operands, ConstAddOperands y_operands) {
1321 Node* x = x_operands.first;
1322 Node* y = y_operands.first;
1323 int opcode = Opcode();
1324 assert(opcode == Op_MaxI || opcode == Op_MinI, "Unexpected opcode");
1325 const TypeInt* tx = phase->type(x)->isa_int();
1326 jint x_off = x_operands.second;
1327 jint y_off = y_operands.second;
1328 if (x == y && tx != nullptr &&
1329 !can_overflow(tx, x_off) &&
1330 !can_overflow(tx, y_off)) {
1331 jint c = opcode == Op_MinI ? MIN2(x_off, y_off) : MAX2(x_off, y_off);
1332 return new AddINode(x, phase->intcon(c));
1333 }
1334 return nullptr;
1335 }
1336
1337 // Try to cast n as an integer addition with a constant. Return:
1338 // <x, C>, if n == add(x, C), where 'C' is a non-TOP constant;
1339 // <nullptr, 0>, if n == add(x, C), where 'C' is a TOP constant; or
1340 // <n, 0>, otherwise.
1341 static ConstAddOperands as_add_with_constant(Node* n) {
1342 if (n->Opcode() != Op_AddI) {
1343 return ConstAddOperands(n, 0);
1344 }
1345 Node* x = n->in(1);
1346 Node* c = n->in(2);
1347 if (!c->is_Con()) {
1348 return ConstAddOperands(n, 0);
1349 }
1350 const Type* c_type = c->bottom_type();
1351 if (c_type == Type::TOP) {
1352 return ConstAddOperands(nullptr, 0);
1353 }
1354 return ConstAddOperands(x, c_type->is_int()->get_con());
1355 }
1356
1357 Node* MaxNode::IdealI(PhaseGVN* phase, bool can_reshape) {
1358 int opcode = Opcode();
1359 assert(opcode == Op_MinI || opcode == Op_MaxI, "Unexpected opcode");
1360 // Try to transform the following pattern, in any of its four possible
1361 // permutations induced by op's commutativity:
1362 // op(op(add(inner, inner_off), inner_other), add(outer, outer_off))
1363 // into
1364 // op(add(inner, op(inner_off, outer_off)), inner_other),
1365 // where:
1366 // op is either MinI or MaxI, and
1367 // inner == outer, and
1368 // the additions cannot overflow.
1369 for (uint inner_op_index = 1; inner_op_index <= 2; inner_op_index++) {
1370 if (in(inner_op_index)->Opcode() != opcode) {
1371 continue;
1372 }
1373 Node* outer_add = in(inner_op_index == 1 ? 2 : 1);
1374 ConstAddOperands outer_add_operands = as_add_with_constant(outer_add);
1375 if (outer_add_operands.first == nullptr) {
1376 return nullptr; // outer_add has a TOP input, no need to continue.
1377 }
1378 // One operand is a MinI/MaxI and the other is an integer addition with
1379 // constant. Test the operands of the inner MinI/MaxI.
1380 for (uint inner_add_index = 1; inner_add_index <= 2; inner_add_index++) {
1381 Node* inner_op = in(inner_op_index);
1382 Node* inner_add = inner_op->in(inner_add_index);
1383 ConstAddOperands inner_add_operands = as_add_with_constant(inner_add);
1384 if (inner_add_operands.first == nullptr) {
1385 return nullptr; // inner_add has a TOP input, no need to continue.
1386 }
1387 // Try to extract the inner add.
1388 Node* add_extracted = extract_add(phase, inner_add_operands, outer_add_operands);
1389 if (add_extracted == nullptr) {
1390 continue;
1391 }
1392 Node* add_transformed = phase->transform(add_extracted);
1393 Node* inner_other = inner_op->in(inner_add_index == 1 ? 2 : 1);
1394 return build_min_max_int(add_transformed, inner_other, opcode == Op_MaxI);
1395 }
1396 }
1397 // Try to transform
1398 // op(add(x, x_off), add(y, y_off))
1399 // into
1400 // add(x, op(x_off, y_off)),
1401 // where:
1402 // op is either MinI or MaxI, and
1403 // inner == outer, and
1404 // the additions cannot overflow.
1405 ConstAddOperands xC = as_add_with_constant(in(1));
1406 ConstAddOperands yC = as_add_with_constant(in(2));
1407 if (xC.first == nullptr || yC.first == nullptr) return nullptr;
1408 return extract_add(phase, xC, yC);
1409 }
1410
1411 // Ideal transformations for MaxINode
1412 Node* MaxINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1413 return IdealI(phase, can_reshape);
1414 }
1415
1416 //=============================================================================
1417 //------------------------------add_ring---------------------------------------
1418 // Supplied function returns the sum of the inputs.
1419 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
1420 const TypeInt *r0 = t0->is_int(); // Handy access
1421 const TypeInt *r1 = t1->is_int();
1422
1423 // Otherwise just MAX them bits.
1424 return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
1425 }
1426
1427 //=============================================================================
1428 //------------------------------Idealize---------------------------------------
1429 // MINs show up in range-check loop limit calculations. Look for
1430 // "MIN2(x+c0,MIN2(y,x+c1))". Pick the smaller constant: "MIN2(x+c0,y)"
1431 Node* MinINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1432 return IdealI(phase, can_reshape);
1433 }
1434
1435 //------------------------------add_ring---------------------------------------
1436 // Supplied function returns the sum of the inputs.
1437 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
1438 const TypeInt *r0 = t0->is_int(); // Handy access
1439 const TypeInt *r1 = t1->is_int();
1440
1441 // Otherwise just MIN them bits.
1442 return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
1443 }
1444
1445 // Collapse the "addition with overflow-protection" pattern, and the symmetrical
1446 // "subtraction with underflow-protection" pattern. These are created during the
1447 // unrolling, when we have to adjust the limit by subtracting the stride, but want
1448 // to protect against underflow: MaxL(SubL(limit, stride), min_jint).
1449 // If we have more than one of those in a sequence:
1450 //
1451 // x con2
1452 // | |
1453 // AddL clamp2
1454 // | |
1455 // Max/MinL con1
1456 // | |
1457 // AddL clamp1
1458 // | |
1459 // Max/MinL (n)
1460 //
1461 // We want to collapse it to:
1462 //
1463 // x con1 con2
1464 // | | |
1465 // | AddLNode (new_con)
1466 // | |
1467 // AddLNode clamp1
1468 // | |
1469 // Max/MinL (n)
1470 //
1471 // Note: we assume that SubL was already replaced by an AddL, and that the stride
1472 // has its sign flipped: SubL(limit, stride) -> AddL(limit, -stride).
1473 static Node* fold_subI_no_underflow_pattern(Node* n, PhaseGVN* phase) {
1474 assert(n->Opcode() == Op_MaxL || n->Opcode() == Op_MinL, "sanity");
1475 // Check that the two clamps have the correct values.
1476 jlong clamp = (n->Opcode() == Op_MaxL) ? min_jint : max_jint;
1477 auto is_clamp = [&](Node* c) {
1478 const TypeLong* t = phase->type(c)->isa_long();
1479 return t != nullptr && t->is_con() &&
1480 t->get_con() == clamp;
1481 };
1482 // Check that the constants are negative if MaxL, and positive if MinL.
1483 auto is_sub_con = [&](Node* c) {
1484 const TypeLong* t = phase->type(c)->isa_long();
1485 return t != nullptr && t->is_con() &&
1486 t->get_con() < max_jint && t->get_con() > min_jint &&
1487 (t->get_con() < 0) == (n->Opcode() == Op_MaxL);
1488 };
1489 // Verify the graph level by level:
1490 Node* add1 = n->in(1);
1491 Node* clamp1 = n->in(2);
1492 if (add1->Opcode() == Op_AddL && is_clamp(clamp1)) {
1493 Node* max2 = add1->in(1);
1494 Node* con1 = add1->in(2);
1495 if (max2->Opcode() == n->Opcode() && is_sub_con(con1)) {
1496 Node* add2 = max2->in(1);
1497 Node* clamp2 = max2->in(2);
1498 if (add2->Opcode() == Op_AddL && is_clamp(clamp2)) {
1499 Node* x = add2->in(1);
1500 Node* con2 = add2->in(2);
1501 if (is_sub_con(con2)) {
1502 Node* new_con = phase->transform(new AddLNode(con1, con2));
1503 Node* new_sub = phase->transform(new AddLNode(x, new_con));
1504 n->set_req_X(1, new_sub, phase);
1505 return n;
1506 }
1507 }
1508 }
1509 }
1510 return nullptr;
1511 }
1512
1513 const Type* MaxLNode::add_ring(const Type* t0, const Type* t1) const {
1514 const TypeLong* r0 = t0->is_long();
1515 const TypeLong* r1 = t1->is_long();
1516
1517 return TypeLong::make(MAX2(r0->_lo, r1->_lo), MAX2(r0->_hi, r1->_hi), MAX2(r0->_widen, r1->_widen));
1518 }
1519
1520 Node* MaxLNode::Identity(PhaseGVN* phase) {
1521 const TypeLong* t1 = phase->type(in(1))->is_long();
1522 const TypeLong* t2 = phase->type(in(2))->is_long();
1523
1524 // Can we determine maximum statically?
1525 if (t1->_lo >= t2->_hi) {
1526 return in(1);
1527 } else if (t2->_lo >= t1->_hi) {
1528 return in(2);
1529 }
1530
1531 return MaxNode::Identity(phase);
1532 }
1533
1534 Node* MaxLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1535 Node* n = AddNode::Ideal(phase, can_reshape);
1536 if (n != nullptr) {
1537 return n;
1538 }
1539 if (can_reshape) {
1540 return fold_subI_no_underflow_pattern(this, phase);
1541 }
1542 return nullptr;
1543 }
1544
1545 const Type* MinLNode::add_ring(const Type* t0, const Type* t1) const {
1546 const TypeLong* r0 = t0->is_long();
1547 const TypeLong* r1 = t1->is_long();
1548
1549 return TypeLong::make(MIN2(r0->_lo, r1->_lo), MIN2(r0->_hi, r1->_hi), MIN2(r0->_widen, r1->_widen));
1550 }
1551
1552 Node* MinLNode::Identity(PhaseGVN* phase) {
1553 const TypeLong* t1 = phase->type(in(1))->is_long();
1554 const TypeLong* t2 = phase->type(in(2))->is_long();
1555
1556 // Can we determine minimum statically?
1557 if (t1->_lo >= t2->_hi) {
1558 return in(2);
1559 } else if (t2->_lo >= t1->_hi) {
1560 return in(1);
1561 }
1562
1563 return MaxNode::Identity(phase);
1564 }
1565
1566 Node* MinLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1567 Node* n = AddNode::Ideal(phase, can_reshape);
1568 if (n != nullptr) {
1569 return n;
1570 }
1571 if (can_reshape) {
1572 return fold_subI_no_underflow_pattern(this, phase);
1573 }
1574 return nullptr;
1575 }
1576
1577 Node* MaxNode::Identity(PhaseGVN* phase) {
1578 if (in(1) == in(2)) {
1579 return in(1);
1580 }
1581
1582 return AddNode::Identity(phase);
1583 }
1584
1585 //------------------------------add_ring---------------------------------------
1586 const Type* MinFNode::add_ring(const Type* t0, const Type* t1 ) const {
1587 const TypeF* r0 = t0->isa_float_constant();
1588 const TypeF* r1 = t1->isa_float_constant();
1589 if (r0 == nullptr || r1 == nullptr) {
1590 return bottom_type();
1591 }
1592
1593 if (r0->is_nan()) {
1594 return r0;
1595 }
1596 if (r1->is_nan()) {
1597 return r1;
1598 }
1599
1600 float f0 = r0->getf();
1601 float f1 = r1->getf();
1602 if (f0 != 0.0f || f1 != 0.0f) {
1603 return f0 < f1 ? r0 : r1;
1604 }
1605
1606 // handle min of 0.0, -0.0 case.
1607 return (jint_cast(f0) < jint_cast(f1)) ? r0 : r1;
1608 }
1609
1610 //------------------------------add_ring---------------------------------------
1611 const Type* MinDNode::add_ring(const Type* t0, const Type* t1) const {
1612 const TypeD* r0 = t0->isa_double_constant();
1613 const TypeD* r1 = t1->isa_double_constant();
1614 if (r0 == nullptr || r1 == nullptr) {
1615 return bottom_type();
1616 }
1617
1618 if (r0->is_nan()) {
1619 return r0;
1620 }
1621 if (r1->is_nan()) {
1622 return r1;
1623 }
1624
1625 double d0 = r0->getd();
1626 double d1 = r1->getd();
1627 if (d0 != 0.0 || d1 != 0.0) {
1628 return d0 < d1 ? r0 : r1;
1629 }
1630
1631 // handle min of 0.0, -0.0 case.
1632 return (jlong_cast(d0) < jlong_cast(d1)) ? r0 : r1;
1633 }
1634
1635 //------------------------------add_ring---------------------------------------
1636 const Type* MaxFNode::add_ring(const Type* t0, const Type* t1) const {
1637 const TypeF* r0 = t0->isa_float_constant();
1638 const TypeF* r1 = t1->isa_float_constant();
1639 if (r0 == nullptr || r1 == nullptr) {
1640 return bottom_type();
1641 }
1642
1643 if (r0->is_nan()) {
1644 return r0;
1645 }
1646 if (r1->is_nan()) {
1647 return r1;
1648 }
1649
1650 float f0 = r0->getf();
1651 float f1 = r1->getf();
1652 if (f0 != 0.0f || f1 != 0.0f) {
1653 return f0 > f1 ? r0 : r1;
1654 }
1655
1656 // handle max of 0.0,-0.0 case.
1657 return (jint_cast(f0) > jint_cast(f1)) ? r0 : r1;
1658 }
1659
1660 //------------------------------add_ring---------------------------------------
1661 const Type* MaxDNode::add_ring(const Type* t0, const Type* t1) const {
1662 const TypeD* r0 = t0->isa_double_constant();
1663 const TypeD* r1 = t1->isa_double_constant();
1664 if (r0 == nullptr || r1 == nullptr) {
1665 return bottom_type();
1666 }
1667
1668 if (r0->is_nan()) {
1669 return r0;
1670 }
1671 if (r1->is_nan()) {
1672 return r1;
1673 }
1674
1675 double d0 = r0->getd();
1676 double d1 = r1->getd();
1677 if (d0 != 0.0 || d1 != 0.0) {
1678 return d0 > d1 ? r0 : r1;
1679 }
1680
1681 // handle max of 0.0, -0.0 case.
1682 return (jlong_cast(d0) > jlong_cast(d1)) ? r0 : r1;
1683 }