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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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 return AddNode::Ideal(phase, can_reshape);
399 }
400
401
402 Node* AddINode::Ideal(PhaseGVN* phase, bool can_reshape) {
403 Node* in1 = in(1);
404 Node* in2 = in(2);
405 int op1 = in1->Opcode();
406 int op2 = in2->Opcode();
407
408 // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
409 // Helps with array allocation math constant folding
410 // See 4790063:
411 // Unrestricted transformation is unsafe for some runtime values of 'x'
412 // ( x == 0, z == 1, y == -1 ) fails
413 // ( x == -5, z == 1, y == 1 ) fails
414 // Transform works for small z and small negative y when the addition
415 // (x + (y << z)) does not cross zero.
416 // Implement support for negative y and (x >= -(y << z))
417 // Have not observed cases where type information exists to support
418 // positive y and (x <= -(y << z))
419 if (op1 == Op_URShiftI && op2 == Op_ConI &&
420 in1->in(2)->Opcode() == Op_ConI) {
421 jint z = phase->type(in1->in(2))->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
422 jint y = phase->type(in2)->is_int()->get_con();
423
424 if (z < 5 && -5 < y && y < 0) {
425 const Type* t_in11 = phase->type(in1->in(1));
426 if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z))) {
427 Node* a = phase->transform(new AddINode( in1->in(1), phase->intcon(y<<z)));
428 return new URShiftINode(a, in1->in(2));
429 }
430 }
431 }
432
433 return AddNode::IdealIL(phase, can_reshape, T_INT);
434 }
435
436
437 //------------------------------Identity---------------------------------------
438 // Fold (x-y)+y OR y+(x-y) into x
439 Node* AddINode::Identity(PhaseGVN* phase) {
440 if (in(1)->Opcode() == Op_SubI && in(1)->in(2) == in(2)) {
441 return in(1)->in(1);
442 } else if (in(2)->Opcode() == Op_SubI && in(2)->in(2) == in(1)) {
443 return in(2)->in(1);
444 }
445 return AddNode::Identity(phase);
446 }
447
448
449 //------------------------------add_ring---------------------------------------
450 // Supplied function returns the sum of the inputs. Guaranteed never
451 // to be passed a TOP or BOTTOM type, these are filtered out by
452 // pre-check.
453 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
454 const TypeInt *r0 = t0->is_int(); // Handy access
455 const TypeInt *r1 = t1->is_int();
456 int lo = java_add(r0->_lo, r1->_lo);
457 int hi = java_add(r0->_hi, r1->_hi);
458 if( !(r0->is_con() && r1->is_con()) ) {
459 // Not both constants, compute approximate result
460 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
461 lo = min_jint; hi = max_jint; // Underflow on the low side
462 }
463 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
464 lo = min_jint; hi = max_jint; // Overflow on the high side
465 }
466 if( lo > hi ) { // Handle overflow
467 lo = min_jint; hi = max_jint;
468 }
469 } else {
470 // both constants, compute precise result using 'lo' and 'hi'
471 // Semantics define overflow and underflow for integer addition
472 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
473 }
474 return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
475 }
476
477
478 //=============================================================================
479 //------------------------------Idealize---------------------------------------
480 Node* AddLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
481 return AddNode::IdealIL(phase, can_reshape, T_LONG);
482 }
483
484
485 //------------------------------Identity---------------------------------------
486 // Fold (x-y)+y OR y+(x-y) into x
487 Node* AddLNode::Identity(PhaseGVN* phase) {
488 if (in(1)->Opcode() == Op_SubL && in(1)->in(2) == in(2)) {
489 return in(1)->in(1);
490 } else if (in(2)->Opcode() == Op_SubL && in(2)->in(2) == in(1)) {
491 return in(2)->in(1);
492 }
493 return AddNode::Identity(phase);
494 }
495
496
497 //------------------------------add_ring---------------------------------------
498 // Supplied function returns the sum of the inputs. Guaranteed never
499 // to be passed a TOP or BOTTOM type, these are filtered out by
500 // pre-check.
501 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
502 const TypeLong *r0 = t0->is_long(); // Handy access
503 const TypeLong *r1 = t1->is_long();
504 jlong lo = java_add(r0->_lo, r1->_lo);
505 jlong hi = java_add(r0->_hi, r1->_hi);
506 if( !(r0->is_con() && r1->is_con()) ) {
507 // Not both constants, compute approximate result
508 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
509 lo =min_jlong; hi = max_jlong; // Underflow on the low side
510 }
511 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
512 lo = min_jlong; hi = max_jlong; // Overflow on the high side
513 }
514 if( lo > hi ) { // Handle overflow
515 lo = min_jlong; hi = max_jlong;
516 }
517 } else {
518 // both constants, compute precise result using 'lo' and 'hi'
519 // Semantics define overflow and underflow for integer addition
520 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
521 }
522 return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
523 }
524
525
526 //=============================================================================
527 //------------------------------add_of_identity--------------------------------
528 // Check for addition of the identity
529 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
530 // x ADD 0 should return x unless 'x' is a -zero
531 //
532 // const Type *zero = add_id(); // The additive identity
533 // jfloat f1 = t1->getf();
534 // jfloat f2 = t2->getf();
535 //
536 // if( t1->higher_equal( zero ) ) return t2;
537 // if( t2->higher_equal( zero ) ) return t1;
538
539 return nullptr;
540 }
541
542 //------------------------------add_ring---------------------------------------
543 // Supplied function returns the sum of the inputs.
544 // This also type-checks the inputs for sanity. Guaranteed never to
545 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
546 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
547 if (!t0->isa_float_constant() || !t1->isa_float_constant()) {
548 return bottom_type();
549 }
550 return TypeF::make( t0->getf() + t1->getf() );
551 }
552
553 //------------------------------Ideal------------------------------------------
554 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
555 // Floating point additions are not associative because of boundary conditions (infinity)
556 return commute(phase, this) ? this : nullptr;
557 }
558
559
560 //=============================================================================
561 //------------------------------add_of_identity--------------------------------
562 // Check for addition of the identity
563 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
564 // x ADD 0 should return x unless 'x' is a -zero
565 //
566 // const Type *zero = add_id(); // The additive identity
567 // jfloat f1 = t1->getf();
568 // jfloat f2 = t2->getf();
569 //
570 // if( t1->higher_equal( zero ) ) return t2;
571 // if( t2->higher_equal( zero ) ) return t1;
572
573 return nullptr;
574 }
575 //------------------------------add_ring---------------------------------------
576 // Supplied function returns the sum of the inputs.
577 // This also type-checks the inputs for sanity. Guaranteed never to
578 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
579 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
580 if (!t0->isa_double_constant() || !t1->isa_double_constant()) {
581 return bottom_type();
582 }
583 return TypeD::make( t0->getd() + t1->getd() );
584 }
585
586 //------------------------------Ideal------------------------------------------
587 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
588 // Floating point additions are not associative because of boundary conditions (infinity)
589 return commute(phase, this) ? this : nullptr;
590 }
591
592
593 //=============================================================================
594 //------------------------------Identity---------------------------------------
595 // If one input is a constant 0, return the other input.
596 Node* AddPNode::Identity(PhaseGVN* phase) {
597 return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
598 }
599
600 //------------------------------Idealize---------------------------------------
601 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
602 // Bail out if dead inputs
603 if( phase->type( in(Address) ) == Type::TOP ) return nullptr;
604
605 // If the left input is an add of a constant, flatten the expression tree.
606 const Node *n = in(Address);
607 if (n->is_AddP() && n->in(Base) == in(Base)) {
608 const AddPNode *addp = n->as_AddP(); // Left input is an AddP
609 assert( !addp->in(Address)->is_AddP() ||
610 addp->in(Address)->as_AddP() != addp,
611 "dead loop in AddPNode::Ideal" );
612 // Type of left input's right input
613 const Type *t = phase->type( addp->in(Offset) );
614 if( t == Type::TOP ) return nullptr;
615 const TypeX *t12 = t->is_intptr_t();
616 if( t12->is_con() ) { // Left input is an add of a constant?
617 // If the right input is a constant, combine constants
618 const Type *temp_t2 = phase->type( in(Offset) );
619 if( temp_t2 == Type::TOP ) return nullptr;
620 const TypeX *t2 = temp_t2->is_intptr_t();
621 Node* address;
622 Node* offset;
623 if( t2->is_con() ) {
624 // The Add of the flattened expression
625 address = addp->in(Address);
626 offset = phase->MakeConX(t2->get_con() + t12->get_con());
627 } else {
628 // Else move the constant to the right. ((A+con)+B) into ((A+B)+con)
629 address = phase->transform(new AddPNode(in(Base),addp->in(Address),in(Offset)));
630 offset = addp->in(Offset);
631 }
632 set_req_X(Address, address, phase);
633 set_req_X(Offset, offset, phase);
634 return this;
635 }
636 }
637
638 // Raw pointers?
639 if( in(Base)->bottom_type() == Type::TOP ) {
640 // If this is a null+long form (from unsafe accesses), switch to a rawptr.
641 if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
642 Node* offset = in(Offset);
643 return new CastX2PNode(offset);
644 }
645 }
646
647 // If the right is an add of a constant, push the offset down.
648 // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
649 // The idea is to merge array_base+scaled_index groups together,
650 // and only have different constant offsets from the same base.
651 const Node *add = in(Offset);
652 if( add->Opcode() == Op_AddX && add->in(1) != add ) {
653 const Type *t22 = phase->type( add->in(2) );
654 if( t22->singleton() && (t22 != Type::TOP) ) { // Right input is an add of a constant?
655 set_req(Address, phase->transform(new AddPNode(in(Base),in(Address),add->in(1))));
656 set_req_X(Offset, add->in(2), phase); // puts add on igvn worklist if needed
657 return this; // Made progress
658 }
659 }
660
661 return nullptr; // No progress
662 }
663
664 //------------------------------bottom_type------------------------------------
665 // Bottom-type is the pointer-type with unknown offset.
666 const Type *AddPNode::bottom_type() const {
667 if (in(Address) == nullptr) return TypePtr::BOTTOM;
668 const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
669 if( !tp ) return Type::TOP; // TOP input means TOP output
670 assert( in(Offset)->Opcode() != Op_ConP, "" );
671 const Type *t = in(Offset)->bottom_type();
672 if( t == Type::TOP )
673 return tp->add_offset(Type::OffsetTop);
674 const TypeX *tx = t->is_intptr_t();
675 intptr_t txoffset = Type::OffsetBot;
676 if (tx->is_con()) { // Left input is an add of a constant?
677 txoffset = tx->get_con();
678 }
679 return tp->add_offset(txoffset);
680 }
681
682 //------------------------------Value------------------------------------------
683 const Type* AddPNode::Value(PhaseGVN* phase) const {
684 // Either input is TOP ==> the result is TOP
685 const Type *t1 = phase->type( in(Address) );
686 const Type *t2 = phase->type( in(Offset) );
687 if( t1 == Type::TOP ) return Type::TOP;
688 if( t2 == Type::TOP ) return Type::TOP;
689
690 // Left input is a pointer
691 const TypePtr *p1 = t1->isa_ptr();
692 // Right input is an int
693 const TypeX *p2 = t2->is_intptr_t();
694 // Add 'em
695 intptr_t p2offset = Type::OffsetBot;
696 if (p2->is_con()) { // Left input is an add of a constant?
697 p2offset = p2->get_con();
698 }
699 return p1->add_offset(p2offset);
700 }
701
702 //------------------------Ideal_base_and_offset--------------------------------
703 // Split an oop pointer into a base and offset.
704 // (The offset might be Type::OffsetBot in the case of an array.)
705 // Return the base, or null if failure.
706 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseValues* phase,
707 // second return value:
708 intptr_t& offset) {
709 if (ptr->is_AddP()) {
710 Node* base = ptr->in(AddPNode::Base);
711 Node* addr = ptr->in(AddPNode::Address);
712 Node* offs = ptr->in(AddPNode::Offset);
713 if (base == addr || base->is_top()) {
714 offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
715 if (offset != Type::OffsetBot) {
716 return addr;
717 }
718 }
719 }
720 offset = Type::OffsetBot;
721 return nullptr;
722 }
723
724 //------------------------------unpack_offsets----------------------------------
725 // Collect the AddP offset values into the elements array, giving up
726 // if there are more than length.
727 int AddPNode::unpack_offsets(Node* elements[], int length) {
728 int count = 0;
729 Node* addr = this;
730 Node* base = addr->in(AddPNode::Base);
731 while (addr->is_AddP()) {
732 if (addr->in(AddPNode::Base) != base) {
733 // give up
734 return -1;
735 }
736 elements[count++] = addr->in(AddPNode::Offset);
737 if (count == length) {
738 // give up
739 return -1;
740 }
741 addr = addr->in(AddPNode::Address);
742 }
743 if (addr != base) {
744 return -1;
745 }
746 return count;
747 }
748
749 //------------------------------match_edge-------------------------------------
750 // Do we Match on this edge index or not? Do not match base pointer edge
751 uint AddPNode::match_edge(uint idx) const {
752 return idx > Base;
753 }
754
755 //=============================================================================
756 //------------------------------Identity---------------------------------------
757 Node* OrINode::Identity(PhaseGVN* phase) {
758 // x | x => x
759 if (in(1) == in(2)) {
760 return in(1);
761 }
762
763 return AddNode::Identity(phase);
764 }
765
766 // Find shift value for Integer or Long OR.
767 static Node* rotate_shift(PhaseGVN* phase, Node* lshift, Node* rshift, int mask) {
768 // val << norm_con_shift | val >> ({32|64} - norm_con_shift) => rotate_left val, norm_con_shift
769 const TypeInt* lshift_t = phase->type(lshift)->isa_int();
770 const TypeInt* rshift_t = phase->type(rshift)->isa_int();
771 if (lshift_t != nullptr && lshift_t->is_con() &&
772 rshift_t != nullptr && rshift_t->is_con() &&
773 ((lshift_t->get_con() & mask) == ((mask + 1) - (rshift_t->get_con() & mask)))) {
774 return phase->intcon(lshift_t->get_con() & mask);
775 }
776 // val << var_shift | val >> ({0|32|64} - var_shift) => rotate_left val, var_shift
777 if (rshift->Opcode() == Op_SubI && rshift->in(2) == lshift && rshift->in(1)->is_Con()){
778 const TypeInt* shift_t = phase->type(rshift->in(1))->isa_int();
779 if (shift_t != nullptr && shift_t->is_con() &&
780 (shift_t->get_con() == 0 || shift_t->get_con() == (mask + 1))) {
781 return lshift;
782 }
783 }
784 return nullptr;
785 }
786
787 Node* OrINode::Ideal(PhaseGVN* phase, bool can_reshape) {
788 int lopcode = in(1)->Opcode();
789 int ropcode = in(2)->Opcode();
790 if (Matcher::match_rule_supported(Op_RotateLeft) &&
791 lopcode == Op_LShiftI && ropcode == Op_URShiftI && in(1)->in(1) == in(2)->in(1)) {
792 Node* lshift = in(1)->in(2);
793 Node* rshift = in(2)->in(2);
794 Node* shift = rotate_shift(phase, lshift, rshift, 0x1F);
795 if (shift != nullptr) {
796 return new RotateLeftNode(in(1)->in(1), shift, TypeInt::INT);
797 }
798 return nullptr;
799 }
800 if (Matcher::match_rule_supported(Op_RotateRight) &&
801 lopcode == Op_URShiftI && ropcode == Op_LShiftI && in(1)->in(1) == in(2)->in(1)) {
802 Node* rshift = in(1)->in(2);
803 Node* lshift = in(2)->in(2);
804 Node* shift = rotate_shift(phase, rshift, lshift, 0x1F);
805 if (shift != nullptr) {
806 return new RotateRightNode(in(1)->in(1), shift, TypeInt::INT);
807 }
808 }
809
810 // Convert "~a | ~b" into "~(a & b)"
811 if (AddNode::is_not(phase, in(1), T_INT) && AddNode::is_not(phase, in(2), T_INT)) {
812 Node* and_a_b = new AndINode(in(1)->in(1), in(2)->in(1));
813 Node* tn = phase->transform(and_a_b);
814 return AddNode::make_not(phase, tn, T_INT);
815 }
816 return nullptr;
817 }
818
819 //------------------------------add_ring---------------------------------------
820 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
821 // the logical operations the ring's ADD is really a logical OR function.
822 // This also type-checks the inputs for sanity. Guaranteed never to
823 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
824 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
825 const TypeInt *r0 = t0->is_int(); // Handy access
826 const TypeInt *r1 = t1->is_int();
827
828 // If both args are bool, can figure out better types
829 if ( r0 == TypeInt::BOOL ) {
830 if ( r1 == TypeInt::ONE) {
831 return TypeInt::ONE;
832 } else if ( r1 == TypeInt::BOOL ) {
833 return TypeInt::BOOL;
834 }
835 } else if ( r0 == TypeInt::ONE ) {
836 if ( r1 == TypeInt::BOOL ) {
837 return TypeInt::ONE;
838 }
839 }
840
841 // If either input is not a constant, just return all integers.
842 if( !r0->is_con() || !r1->is_con() )
843 return TypeInt::INT; // Any integer, but still no symbols.
844
845 // Otherwise just OR them bits.
846 return TypeInt::make( r0->get_con() | r1->get_con() );
847 }
848
849 //=============================================================================
850 //------------------------------Identity---------------------------------------
851 Node* OrLNode::Identity(PhaseGVN* phase) {
852 // x | x => x
853 if (in(1) == in(2)) {
854 return in(1);
855 }
856
857 return AddNode::Identity(phase);
858 }
859
860 Node* OrLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
861 int lopcode = in(1)->Opcode();
862 int ropcode = in(2)->Opcode();
863 if (Matcher::match_rule_supported(Op_RotateLeft) &&
864 lopcode == Op_LShiftL && ropcode == Op_URShiftL && in(1)->in(1) == in(2)->in(1)) {
865 Node* lshift = in(1)->in(2);
866 Node* rshift = in(2)->in(2);
867 Node* shift = rotate_shift(phase, lshift, rshift, 0x3F);
868 if (shift != nullptr) {
869 return new RotateLeftNode(in(1)->in(1), shift, TypeLong::LONG);
870 }
871 return nullptr;
872 }
873 if (Matcher::match_rule_supported(Op_RotateRight) &&
874 lopcode == Op_URShiftL && ropcode == Op_LShiftL && in(1)->in(1) == in(2)->in(1)) {
875 Node* rshift = in(1)->in(2);
876 Node* lshift = in(2)->in(2);
877 Node* shift = rotate_shift(phase, rshift, lshift, 0x3F);
878 if (shift != nullptr) {
879 return new RotateRightNode(in(1)->in(1), shift, TypeLong::LONG);
880 }
881 }
882
883 // Convert "~a | ~b" into "~(a & b)"
884 if (AddNode::is_not(phase, in(1), T_LONG) && AddNode::is_not(phase, in(2), T_LONG)) {
885 Node* and_a_b = new AndLNode(in(1)->in(1), in(2)->in(1));
886 Node* tn = phase->transform(and_a_b);
887 return AddNode::make_not(phase, tn, T_LONG);
888 }
889
890 return nullptr;
891 }
892
893 //------------------------------add_ring---------------------------------------
894 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
895 const TypeLong *r0 = t0->is_long(); // Handy access
896 const TypeLong *r1 = t1->is_long();
897
898 // If either input is not a constant, just return all integers.
899 if( !r0->is_con() || !r1->is_con() )
900 return TypeLong::LONG; // Any integer, but still no symbols.
901
902 // Otherwise just OR them bits.
903 return TypeLong::make( r0->get_con() | r1->get_con() );
904 }
905
906 //---------------------------Helper -------------------------------------------
907 /* Decide if the given node is used only in arithmetic expressions(add or sub).
908 */
909 static bool is_used_in_only_arithmetic(Node* n, BasicType bt) {
910 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
911 Node* u = n->fast_out(i);
912 if (u->Opcode() != Op_Add(bt) && u->Opcode() != Op_Sub(bt)) {
913 return false;
914 }
915 }
916 return true;
917 }
918
919 //=============================================================================
920 //------------------------------Idealize---------------------------------------
921 Node* XorINode::Ideal(PhaseGVN* phase, bool can_reshape) {
922 Node* in1 = in(1);
923 Node* in2 = in(2);
924
925 // Convert ~x into -1-x when ~x is used in an arithmetic expression
926 // or x itself is an expression.
927 if (phase->type(in2) == TypeInt::MINUS_1) { // follows LHS^(-1), i.e., ~LHS
928 if (phase->is_IterGVN()) {
929 if (is_used_in_only_arithmetic(this, T_INT)
930 // LHS is arithmetic
931 || (in1->Opcode() == Op_AddI || in1->Opcode() == Op_SubI)) {
932 return new SubINode(in2, in1);
933 }
934 } else {
935 // graph could be incomplete in GVN so we postpone to IGVN
936 phase->record_for_igvn(this);
937 }
938 }
939
940 // Propagate xor through constant cmoves. This pattern can occur after expansion of Conv2B nodes.
941 const TypeInt* in2_type = phase->type(in2)->isa_int();
942 if (in1->Opcode() == Op_CMoveI && in2_type != nullptr && in2_type->is_con()) {
943 int in2_val = in2_type->get_con();
944
945 // Get types of both sides of the CMove
946 const TypeInt* left = phase->type(in1->in(CMoveNode::IfFalse))->isa_int();
947 const TypeInt* right = phase->type(in1->in(CMoveNode::IfTrue))->isa_int();
948
949 // Ensure that both sides are int constants
950 if (left != nullptr && right != nullptr && left->is_con() && right->is_con()) {
951 Node* cond = in1->in(CMoveNode::Condition);
952
953 // Check that the comparison is a bool and that the cmp node type is correct
954 if (cond->is_Bool()) {
955 int cmp_op = cond->in(1)->Opcode();
956
957 if (cmp_op == Op_CmpI || cmp_op == Op_CmpP) {
958 int l_val = left->get_con();
959 int r_val = right->get_con();
960
961 return new CMoveINode(cond, phase->intcon(l_val ^ in2_val), phase->intcon(r_val ^ in2_val), TypeInt::INT);
962 }
963 }
964 }
965 }
966
967 return AddNode::Ideal(phase, can_reshape);
968 }
969
970 const Type* XorINode::Value(PhaseGVN* phase) const {
971 Node* in1 = in(1);
972 Node* in2 = in(2);
973 const Type* t1 = phase->type(in1);
974 const Type* t2 = phase->type(in2);
975 if (t1 == Type::TOP || t2 == Type::TOP) {
976 return Type::TOP;
977 }
978 // x ^ x ==> 0
979 if (in1->eqv_uncast(in2)) {
980 return add_id();
981 }
982 // result of xor can only have bits sets where any of the
983 // inputs have bits set. lo can always become 0.
984 const TypeInt* t1i = t1->is_int();
985 const TypeInt* t2i = t2->is_int();
986 if ((t1i->_lo >= 0) &&
987 (t1i->_hi > 0) &&
988 (t2i->_lo >= 0) &&
989 (t2i->_hi > 0)) {
990 // hi - set all bits below the highest bit. Using round_down to avoid overflow.
991 const TypeInt* t1x = TypeInt::make(0, round_down_power_of_2(t1i->_hi) + (round_down_power_of_2(t1i->_hi) - 1), t1i->_widen);
992 const TypeInt* t2x = TypeInt::make(0, round_down_power_of_2(t2i->_hi) + (round_down_power_of_2(t2i->_hi) - 1), t2i->_widen);
993 return t1x->meet(t2x);
994 }
995 return AddNode::Value(phase);
996 }
997
998
999 //------------------------------add_ring---------------------------------------
1000 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
1001 // the logical operations the ring's ADD is really a logical OR function.
1002 // This also type-checks the inputs for sanity. Guaranteed never to
1003 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
1004 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
1005 const TypeInt *r0 = t0->is_int(); // Handy access
1006 const TypeInt *r1 = t1->is_int();
1007
1008 // Complementing a boolean?
1009 if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
1010 || r1 == TypeInt::BOOL))
1011 return TypeInt::BOOL;
1012
1013 if( !r0->is_con() || !r1->is_con() ) // Not constants
1014 return TypeInt::INT; // Any integer, but still no symbols.
1015
1016 // Otherwise just XOR them bits.
1017 return TypeInt::make( r0->get_con() ^ r1->get_con() );
1018 }
1019
1020 //=============================================================================
1021 //------------------------------add_ring---------------------------------------
1022 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
1023 const TypeLong *r0 = t0->is_long(); // Handy access
1024 const TypeLong *r1 = t1->is_long();
1025
1026 // If either input is not a constant, just return all integers.
1027 if( !r0->is_con() || !r1->is_con() )
1028 return TypeLong::LONG; // Any integer, but still no symbols.
1029
1030 // Otherwise just OR them bits.
1031 return TypeLong::make( r0->get_con() ^ r1->get_con() );
1032 }
1033
1034 Node* XorLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1035 Node* in1 = in(1);
1036 Node* in2 = in(2);
1037
1038 // Convert ~x into -1-x when ~x is used in an arithmetic expression
1039 // or x itself is an arithmetic expression.
1040 if (phase->type(in2) == TypeLong::MINUS_1) { // follows LHS^(-1), i.e., ~LHS
1041 if (phase->is_IterGVN()) {
1042 if (is_used_in_only_arithmetic(this, T_LONG)
1043 // LHS is arithmetic
1044 || (in1->Opcode() == Op_AddL || in1->Opcode() == Op_SubL)) {
1045 return new SubLNode(in2, in1);
1046 }
1047 } else {
1048 // graph could be incomplete in GVN so we postpone to IGVN
1049 phase->record_for_igvn(this);
1050 }
1051 }
1052 return AddNode::Ideal(phase, can_reshape);
1053 }
1054
1055 const Type* XorLNode::Value(PhaseGVN* phase) const {
1056 Node* in1 = in(1);
1057 Node* in2 = in(2);
1058 const Type* t1 = phase->type(in1);
1059 const Type* t2 = phase->type(in2);
1060 if (t1 == Type::TOP || t2 == Type::TOP) {
1061 return Type::TOP;
1062 }
1063 // x ^ x ==> 0
1064 if (in1->eqv_uncast(in2)) {
1065 return add_id();
1066 }
1067 // result of xor can only have bits sets where any of the
1068 // inputs have bits set. lo can always become 0.
1069 const TypeLong* t1l = t1->is_long();
1070 const TypeLong* t2l = t2->is_long();
1071 if ((t1l->_lo >= 0) &&
1072 (t1l->_hi > 0) &&
1073 (t2l->_lo >= 0) &&
1074 (t2l->_hi > 0)) {
1075 // hi - set all bits below the highest bit. Using round_down to avoid overflow.
1076 const TypeLong* t1x = TypeLong::make(0, round_down_power_of_2(t1l->_hi) + (round_down_power_of_2(t1l->_hi) - 1), t1l->_widen);
1077 const TypeLong* t2x = TypeLong::make(0, round_down_power_of_2(t2l->_hi) + (round_down_power_of_2(t2l->_hi) - 1), t2l->_widen);
1078 return t1x->meet(t2x);
1079 }
1080 return AddNode::Value(phase);
1081 }
1082
1083 static Node* build_min_max_int(Node* a, Node* b, bool is_max) {
1084 if (is_max) {
1085 return new MaxINode(a, b);
1086 } else {
1087 return new MinINode(a, b);
1088 }
1089 }
1090
1091 Node* MaxNode::build_min_max(Node* a, Node* b, bool is_max, bool is_unsigned, const Type* t, PhaseGVN& gvn) {
1092 bool is_int = gvn.type(a)->isa_int();
1093 assert(is_int || gvn.type(a)->isa_long(), "int or long inputs");
1094 assert(is_int == (gvn.type(b)->isa_int() != nullptr), "inconsistent inputs");
1095 BasicType bt = is_int ? T_INT: T_LONG;
1096 Node* hook = nullptr;
1097 if (gvn.is_IterGVN()) {
1098 // Make sure a and b are not destroyed
1099 hook = new Node(2);
1100 hook->init_req(0, a);
1101 hook->init_req(1, b);
1102 }
1103 Node* res = nullptr;
1104 if (is_int && !is_unsigned) {
1105 res = gvn.transform(build_min_max_int(a, b, is_max));
1106 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");
1107 } else {
1108 Node* cmp = nullptr;
1109 if (is_max) {
1110 cmp = gvn.transform(CmpNode::make(a, b, bt, is_unsigned));
1111 } else {
1112 cmp = gvn.transform(CmpNode::make(b, a, bt, is_unsigned));
1113 }
1114 Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::lt));
1115 res = gvn.transform(CMoveNode::make(nullptr, bol, a, b, t));
1116 }
1117 if (hook != nullptr) {
1118 hook->destruct(&gvn);
1119 }
1120 return res;
1121 }
1122
1123 Node* MaxNode::build_min_max_diff_with_zero(Node* a, Node* b, bool is_max, const Type* t, PhaseGVN& gvn) {
1124 bool is_int = gvn.type(a)->isa_int();
1125 assert(is_int || gvn.type(a)->isa_long(), "int or long inputs");
1126 assert(is_int == (gvn.type(b)->isa_int() != nullptr), "inconsistent inputs");
1127 BasicType bt = is_int ? T_INT: T_LONG;
1128 Node* zero = gvn.integercon(0, bt);
1129 Node* hook = nullptr;
1130 if (gvn.is_IterGVN()) {
1131 // Make sure a and b are not destroyed
1132 hook = new Node(2);
1133 hook->init_req(0, a);
1134 hook->init_req(1, b);
1135 }
1136 Node* cmp = nullptr;
1137 if (is_max) {
1138 cmp = gvn.transform(CmpNode::make(a, b, bt, false));
1139 } else {
1140 cmp = gvn.transform(CmpNode::make(b, a, bt, false));
1141 }
1142 Node* sub = gvn.transform(SubNode::make(a, b, bt));
1143 Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::lt));
1144 Node* res = gvn.transform(CMoveNode::make(nullptr, bol, sub, zero, t));
1145 if (hook != nullptr) {
1146 hook->destruct(&gvn);
1147 }
1148 return res;
1149 }
1150
1151 // Check if addition of an integer with type 't' and a constant 'c' can overflow.
1152 static bool can_overflow(const TypeInt* t, jint c) {
1153 jint t_lo = t->_lo;
1154 jint t_hi = t->_hi;
1155 return ((c < 0 && (java_add(t_lo, c) > t_lo)) ||
1156 (c > 0 && (java_add(t_hi, c) < t_hi)));
1157 }
1158
1159 // Let <x, x_off> = x_operands and <y, y_off> = y_operands.
1160 // If x == y and neither add(x, x_off) nor add(y, y_off) overflow, return
1161 // add(x, op(x_off, y_off)). Otherwise, return nullptr.
1162 Node* MaxNode::extract_add(PhaseGVN* phase, ConstAddOperands x_operands, ConstAddOperands y_operands) {
1163 Node* x = x_operands.first;
1164 Node* y = y_operands.first;
1165 int opcode = Opcode();
1166 assert(opcode == Op_MaxI || opcode == Op_MinI, "Unexpected opcode");
1167 const TypeInt* tx = phase->type(x)->isa_int();
1168 jint x_off = x_operands.second;
1169 jint y_off = y_operands.second;
1170 if (x == y && tx != nullptr &&
1171 !can_overflow(tx, x_off) &&
1172 !can_overflow(tx, y_off)) {
1173 jint c = opcode == Op_MinI ? MIN2(x_off, y_off) : MAX2(x_off, y_off);
1174 return new AddINode(x, phase->intcon(c));
1175 }
1176 return nullptr;
1177 }
1178
1179 // Try to cast n as an integer addition with a constant. Return:
1180 // <x, C>, if n == add(x, C), where 'C' is a non-TOP constant;
1181 // <nullptr, 0>, if n == add(x, C), where 'C' is a TOP constant; or
1182 // <n, 0>, otherwise.
1183 static ConstAddOperands as_add_with_constant(Node* n) {
1184 if (n->Opcode() != Op_AddI) {
1185 return ConstAddOperands(n, 0);
1186 }
1187 Node* x = n->in(1);
1188 Node* c = n->in(2);
1189 if (!c->is_Con()) {
1190 return ConstAddOperands(n, 0);
1191 }
1192 const Type* c_type = c->bottom_type();
1193 if (c_type == Type::TOP) {
1194 return ConstAddOperands(nullptr, 0);
1195 }
1196 return ConstAddOperands(x, c_type->is_int()->get_con());
1197 }
1198
1199 Node* MaxNode::IdealI(PhaseGVN* phase, bool can_reshape) {
1200 int opcode = Opcode();
1201 assert(opcode == Op_MinI || opcode == Op_MaxI, "Unexpected opcode");
1202 // Try to transform the following pattern, in any of its four possible
1203 // permutations induced by op's commutativity:
1204 // op(op(add(inner, inner_off), inner_other), add(outer, outer_off))
1205 // into
1206 // op(add(inner, op(inner_off, outer_off)), inner_other),
1207 // where:
1208 // op is either MinI or MaxI, and
1209 // inner == outer, and
1210 // the additions cannot overflow.
1211 for (uint inner_op_index = 1; inner_op_index <= 2; inner_op_index++) {
1212 if (in(inner_op_index)->Opcode() != opcode) {
1213 continue;
1214 }
1215 Node* outer_add = in(inner_op_index == 1 ? 2 : 1);
1216 ConstAddOperands outer_add_operands = as_add_with_constant(outer_add);
1217 if (outer_add_operands.first == nullptr) {
1218 return nullptr; // outer_add has a TOP input, no need to continue.
1219 }
1220 // One operand is a MinI/MaxI and the other is an integer addition with
1221 // constant. Test the operands of the inner MinI/MaxI.
1222 for (uint inner_add_index = 1; inner_add_index <= 2; inner_add_index++) {
1223 Node* inner_op = in(inner_op_index);
1224 Node* inner_add = inner_op->in(inner_add_index);
1225 ConstAddOperands inner_add_operands = as_add_with_constant(inner_add);
1226 if (inner_add_operands.first == nullptr) {
1227 return nullptr; // inner_add has a TOP input, no need to continue.
1228 }
1229 // Try to extract the inner add.
1230 Node* add_extracted = extract_add(phase, inner_add_operands, outer_add_operands);
1231 if (add_extracted == nullptr) {
1232 continue;
1233 }
1234 Node* add_transformed = phase->transform(add_extracted);
1235 Node* inner_other = inner_op->in(inner_add_index == 1 ? 2 : 1);
1236 return build_min_max_int(add_transformed, inner_other, opcode == Op_MaxI);
1237 }
1238 }
1239 // Try to transform
1240 // op(add(x, x_off), add(y, y_off))
1241 // into
1242 // add(x, op(x_off, y_off)),
1243 // where:
1244 // op is either MinI or MaxI, and
1245 // inner == outer, and
1246 // the additions cannot overflow.
1247 ConstAddOperands xC = as_add_with_constant(in(1));
1248 ConstAddOperands yC = as_add_with_constant(in(2));
1249 if (xC.first == nullptr || yC.first == nullptr) return nullptr;
1250 return extract_add(phase, xC, yC);
1251 }
1252
1253 // Ideal transformations for MaxINode
1254 Node* MaxINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1255 return IdealI(phase, can_reshape);
1256 }
1257
1258 //=============================================================================
1259 //------------------------------add_ring---------------------------------------
1260 // Supplied function returns the sum of the inputs.
1261 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
1262 const TypeInt *r0 = t0->is_int(); // Handy access
1263 const TypeInt *r1 = t1->is_int();
1264
1265 // Otherwise just MAX them bits.
1266 return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
1267 }
1268
1269 //=============================================================================
1270 //------------------------------Idealize---------------------------------------
1271 // MINs show up in range-check loop limit calculations. Look for
1272 // "MIN2(x+c0,MIN2(y,x+c1))". Pick the smaller constant: "MIN2(x+c0,y)"
1273 Node* MinINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1274 return IdealI(phase, can_reshape);
1275 }
1276
1277 //------------------------------add_ring---------------------------------------
1278 // Supplied function returns the sum of the inputs.
1279 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
1280 const TypeInt *r0 = t0->is_int(); // Handy access
1281 const TypeInt *r1 = t1->is_int();
1282
1283 // Otherwise just MIN them bits.
1284 return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
1285 }
1286
1287 // Collapse the "addition with overflow-protection" pattern, and the symmetrical
1288 // "subtraction with underflow-protection" pattern. These are created during the
1289 // unrolling, when we have to adjust the limit by subtracting the stride, but want
1290 // to protect against underflow: MaxL(SubL(limit, stride), min_jint).
1291 // If we have more than one of those in a sequence:
1292 //
1293 // x con2
1294 // | |
1295 // AddL clamp2
1296 // | |
1297 // Max/MinL con1
1298 // | |
1299 // AddL clamp1
1300 // | |
1301 // Max/MinL (n)
1302 //
1303 // We want to collapse it to:
1304 //
1305 // x con1 con2
1306 // | | |
1307 // | AddLNode (new_con)
1308 // | |
1309 // AddLNode clamp1
1310 // | |
1311 // Max/MinL (n)
1312 //
1313 // Note: we assume that SubL was already replaced by an AddL, and that the stride
1314 // has its sign flipped: SubL(limit, stride) -> AddL(limit, -stride).
1315 static Node* fold_subI_no_underflow_pattern(Node* n, PhaseGVN* phase) {
1316 assert(n->Opcode() == Op_MaxL || n->Opcode() == Op_MinL, "sanity");
1317 // Check that the two clamps have the correct values.
1318 jlong clamp = (n->Opcode() == Op_MaxL) ? min_jint : max_jint;
1319 auto is_clamp = [&](Node* c) {
1320 const TypeLong* t = phase->type(c)->isa_long();
1321 return t != nullptr && t->is_con() &&
1322 t->get_con() == clamp;
1323 };
1324 // Check that the constants are negative if MaxL, and positive if MinL.
1325 auto is_sub_con = [&](Node* c) {
1326 const TypeLong* t = phase->type(c)->isa_long();
1327 return t != nullptr && t->is_con() &&
1328 t->get_con() < max_jint && t->get_con() > min_jint &&
1329 (t->get_con() < 0) == (n->Opcode() == Op_MaxL);
1330 };
1331 // Verify the graph level by level:
1332 Node* add1 = n->in(1);
1333 Node* clamp1 = n->in(2);
1334 if (add1->Opcode() == Op_AddL && is_clamp(clamp1)) {
1335 Node* max2 = add1->in(1);
1336 Node* con1 = add1->in(2);
1337 if (max2->Opcode() == n->Opcode() && is_sub_con(con1)) {
1338 Node* add2 = max2->in(1);
1339 Node* clamp2 = max2->in(2);
1340 if (add2->Opcode() == Op_AddL && is_clamp(clamp2)) {
1341 Node* x = add2->in(1);
1342 Node* con2 = add2->in(2);
1343 if (is_sub_con(con2)) {
1344 Node* new_con = phase->transform(new AddLNode(con1, con2));
1345 Node* new_sub = phase->transform(new AddLNode(x, new_con));
1346 n->set_req_X(1, new_sub, phase);
1347 return n;
1348 }
1349 }
1350 }
1351 }
1352 return nullptr;
1353 }
1354
1355 const Type* MaxLNode::add_ring(const Type* t0, const Type* t1) const {
1356 const TypeLong* r0 = t0->is_long();
1357 const TypeLong* r1 = t1->is_long();
1358
1359 return TypeLong::make(MAX2(r0->_lo, r1->_lo), MAX2(r0->_hi, r1->_hi), MAX2(r0->_widen, r1->_widen));
1360 }
1361
1362 Node* MaxLNode::Identity(PhaseGVN* phase) {
1363 const TypeLong* t1 = phase->type(in(1))->is_long();
1364 const TypeLong* t2 = phase->type(in(2))->is_long();
1365
1366 // Can we determine maximum statically?
1367 if (t1->_lo >= t2->_hi) {
1368 return in(1);
1369 } else if (t2->_lo >= t1->_hi) {
1370 return in(2);
1371 }
1372
1373 return MaxNode::Identity(phase);
1374 }
1375
1376 Node* MaxLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1377 Node* n = AddNode::Ideal(phase, can_reshape);
1378 if (n != nullptr) {
1379 return n;
1380 }
1381 if (can_reshape) {
1382 return fold_subI_no_underflow_pattern(this, phase);
1383 }
1384 return nullptr;
1385 }
1386
1387 const Type* MinLNode::add_ring(const Type* t0, const Type* t1) const {
1388 const TypeLong* r0 = t0->is_long();
1389 const TypeLong* r1 = t1->is_long();
1390
1391 return TypeLong::make(MIN2(r0->_lo, r1->_lo), MIN2(r0->_hi, r1->_hi), MIN2(r0->_widen, r1->_widen));
1392 }
1393
1394 Node* MinLNode::Identity(PhaseGVN* phase) {
1395 const TypeLong* t1 = phase->type(in(1))->is_long();
1396 const TypeLong* t2 = phase->type(in(2))->is_long();
1397
1398 // Can we determine minimum statically?
1399 if (t1->_lo >= t2->_hi) {
1400 return in(2);
1401 } else if (t2->_lo >= t1->_hi) {
1402 return in(1);
1403 }
1404
1405 return MaxNode::Identity(phase);
1406 }
1407
1408 Node* MinLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1409 Node* n = AddNode::Ideal(phase, can_reshape);
1410 if (n != nullptr) {
1411 return n;
1412 }
1413 if (can_reshape) {
1414 return fold_subI_no_underflow_pattern(this, phase);
1415 }
1416 return nullptr;
1417 }
1418
1419 //------------------------------add_ring---------------------------------------
1420 const Type* MinFNode::add_ring(const Type* t0, const Type* t1 ) const {
1421 const TypeF* r0 = t0->isa_float_constant();
1422 const TypeF* r1 = t1->isa_float_constant();
1423 if (r0 == nullptr || r1 == nullptr) {
1424 return bottom_type();
1425 }
1426
1427 if (r0->is_nan()) {
1428 return r0;
1429 }
1430 if (r1->is_nan()) {
1431 return r1;
1432 }
1433
1434 float f0 = r0->getf();
1435 float f1 = r1->getf();
1436 if (f0 != 0.0f || f1 != 0.0f) {
1437 return f0 < f1 ? r0 : r1;
1438 }
1439
1440 // handle min of 0.0, -0.0 case.
1441 return (jint_cast(f0) < jint_cast(f1)) ? r0 : r1;
1442 }
1443
1444 //------------------------------add_ring---------------------------------------
1445 const Type* MinDNode::add_ring(const Type* t0, const Type* t1) const {
1446 const TypeD* r0 = t0->isa_double_constant();
1447 const TypeD* r1 = t1->isa_double_constant();
1448 if (r0 == nullptr || r1 == nullptr) {
1449 return bottom_type();
1450 }
1451
1452 if (r0->is_nan()) {
1453 return r0;
1454 }
1455 if (r1->is_nan()) {
1456 return r1;
1457 }
1458
1459 double d0 = r0->getd();
1460 double d1 = r1->getd();
1461 if (d0 != 0.0 || d1 != 0.0) {
1462 return d0 < d1 ? r0 : r1;
1463 }
1464
1465 // handle min of 0.0, -0.0 case.
1466 return (jlong_cast(d0) < jlong_cast(d1)) ? r0 : r1;
1467 }
1468
1469 //------------------------------add_ring---------------------------------------
1470 const Type* MaxFNode::add_ring(const Type* t0, const Type* t1) const {
1471 const TypeF* r0 = t0->isa_float_constant();
1472 const TypeF* r1 = t1->isa_float_constant();
1473 if (r0 == nullptr || r1 == nullptr) {
1474 return bottom_type();
1475 }
1476
1477 if (r0->is_nan()) {
1478 return r0;
1479 }
1480 if (r1->is_nan()) {
1481 return r1;
1482 }
1483
1484 float f0 = r0->getf();
1485 float f1 = r1->getf();
1486 if (f0 != 0.0f || f1 != 0.0f) {
1487 return f0 > f1 ? r0 : r1;
1488 }
1489
1490 // handle max of 0.0,-0.0 case.
1491 return (jint_cast(f0) > jint_cast(f1)) ? r0 : r1;
1492 }
1493
1494 //------------------------------add_ring---------------------------------------
1495 const Type* MaxDNode::add_ring(const Type* t0, const Type* t1) const {
1496 const TypeD* r0 = t0->isa_double_constant();
1497 const TypeD* r1 = t1->isa_double_constant();
1498 if (r0 == nullptr || r1 == nullptr) {
1499 return bottom_type();
1500 }
1501
1502 if (r0->is_nan()) {
1503 return r0;
1504 }
1505 if (r1->is_nan()) {
1506 return r1;
1507 }
1508
1509 double d0 = r0->getd();
1510 double d1 = r1->getd();
1511 if (d0 != 0.0 || d1 != 0.0) {
1512 return d0 > d1 ? r0 : r1;
1513 }
1514
1515 // handle max of 0.0, -0.0 case.
1516 return (jlong_cast(d0) > jlong_cast(d1)) ? r0 : r1;
1517 }