1 /*
2 * Copyright (c) 1997, 2023, 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 ) return Type::TOP;
222 if( t2 == Type::TOP ) return Type::TOP;
223
224 // Either input is BOTTOM ==> the result is the local BOTTOM
225 const Type *bot = bottom_type();
226 if( (t1 == bot) || (t2 == bot) ||
227 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
228 return bot;
229
230 // Check for an addition involving the additive identity
231 const Type *tadd = add_of_identity( t1, t2 );
232 if( tadd ) return tadd;
233
234 return add_ring(t1,t2); // Local flavor of type addition
235 }
236
237 //------------------------------add_identity-----------------------------------
238 // Check for addition of the identity
239 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
240 const Type *zero = add_id(); // The additive identity
241 if( t1->higher_equal( zero ) ) return t2;
242 if( t2->higher_equal( zero ) ) return t1;
243
244 return nullptr;
245 }
246
247 AddNode* AddNode::make(Node* in1, Node* in2, BasicType bt) {
248 switch (bt) {
249 case T_INT:
250 return new AddINode(in1, in2);
251 case T_LONG:
252 return new AddLNode(in1, in2);
253 default:
254 fatal("Not implemented for %s", type2name(bt));
255 }
256 return nullptr;
257 }
258
259 //=============================================================================
260 //------------------------------Idealize---------------------------------------
261 Node* AddNode::IdealIL(PhaseGVN* phase, bool can_reshape, BasicType bt) {
262 Node* in1 = in(1);
263 Node* in2 = in(2);
264 int op1 = in1->Opcode();
265 int op2 = in2->Opcode();
266 // Fold (con1-x)+con2 into (con1+con2)-x
267 if (op1 == Op_Add(bt) && op2 == Op_Sub(bt)) {
268 // Swap edges to try optimizations below
269 in1 = in2;
270 in2 = in(1);
271 op1 = op2;
272 op2 = in2->Opcode();
273 }
274 if (op1 == Op_Sub(bt)) {
275 const Type* t_sub1 = phase->type(in1->in(1));
276 const Type* t_2 = phase->type(in2 );
277 if (t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP) {
278 return SubNode::make(phase->makecon(add_ring(t_sub1, t_2)), in1->in(2), bt);
279 }
280 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
281 if (op2 == Op_Sub(bt)) {
282 // Check for dead cycle: d = (a-b)+(c-d)
283 assert( in1->in(2) != this && in2->in(2) != this,
284 "dead loop in AddINode::Ideal" );
285 Node* sub = SubNode::make(nullptr, nullptr, bt);
286 sub->init_req(1, phase->transform(AddNode::make(in1->in(1), in2->in(1), bt)));
287 sub->init_req(2, phase->transform(AddNode::make(in1->in(2), in2->in(2), bt)));
288 return sub;
289 }
290 // Convert "(a-b)+(b+c)" into "(a+c)"
291 if (op2 == Op_Add(bt) && in1->in(2) == in2->in(1)) {
292 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal/AddLNode::Ideal");
293 return AddNode::make(in1->in(1), in2->in(2), bt);
294 }
295 // Convert "(a-b)+(c+b)" into "(a+c)"
296 if (op2 == Op_Add(bt) && in1->in(2) == in2->in(2)) {
297 assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal/AddLNode::Ideal");
298 return AddNode::make(in1->in(1), in2->in(1), bt);
299 }
300 }
301
302 // Convert (con - y) + x into "(x - y) + con"
303 if (op1 == Op_Sub(bt) && in1->in(1)->Opcode() == Op_ConIL(bt)
304 && in1 != in1->in(2) && !(in1->in(2)->is_Phi() && in1->in(2)->as_Phi()->is_tripcount(bt))) {
305 return AddNode::make(phase->transform(SubNode::make(in2, in1->in(2), bt)), in1->in(1), bt);
306 }
307
308 // Convert x + (con - y) into "(x - y) + con"
309 if (op2 == Op_Sub(bt) && in2->in(1)->Opcode() == Op_ConIL(bt)
310 && in2 != in2->in(2) && !(in2->in(2)->is_Phi() && in2->in(2)->as_Phi()->is_tripcount(bt))) {
311 return AddNode::make(phase->transform(SubNode::make(in1, in2->in(2), bt)), in2->in(1), bt);
312 }
313
314 // Associative
315 if (op1 == Op_Mul(bt) && op2 == Op_Mul(bt)) {
316 Node* add_in1 = nullptr;
317 Node* add_in2 = nullptr;
318 Node* mul_in = nullptr;
319
320 if (in1->in(1) == in2->in(1)) {
321 // Convert "a*b+a*c into a*(b+c)
322 add_in1 = in1->in(2);
323 add_in2 = in2->in(2);
324 mul_in = in1->in(1);
325 } else if (in1->in(2) == in2->in(1)) {
326 // Convert a*b+b*c into b*(a+c)
327 add_in1 = in1->in(1);
328 add_in2 = in2->in(2);
329 mul_in = in1->in(2);
330 } else if (in1->in(2) == in2->in(2)) {
331 // Convert a*c+b*c into (a+b)*c
332 add_in1 = in1->in(1);
333 add_in2 = in2->in(1);
334 mul_in = in1->in(2);
335 } else if (in1->in(1) == in2->in(2)) {
336 // Convert a*b+c*a into a*(b+c)
337 add_in1 = in1->in(2);
338 add_in2 = in2->in(1);
339 mul_in = in1->in(1);
340 }
341
342 if (mul_in != nullptr) {
343 Node* add = phase->transform(AddNode::make(add_in1, add_in2, bt));
344 return MulNode::make(mul_in, add, bt);
345 }
346 }
347
348 // Convert (x >>> rshift) + (x << lshift) into RotateRight(x, rshift)
349 if (Matcher::match_rule_supported(Op_RotateRight) &&
350 ((op1 == Op_URShift(bt) && op2 == Op_LShift(bt)) || (op1 == Op_LShift(bt) && op2 == Op_URShift(bt))) &&
351 in1->in(1) != nullptr && in1->in(1) == in2->in(1)) {
352 Node* rshift = op1 == Op_URShift(bt) ? in1->in(2) : in2->in(2);
353 Node* lshift = op1 == Op_URShift(bt) ? in2->in(2) : in1->in(2);
354 if (rshift != nullptr && lshift != nullptr) {
355 const TypeInt* rshift_t = phase->type(rshift)->isa_int();
356 const TypeInt* lshift_t = phase->type(lshift)->isa_int();
357 int bits = bt == T_INT ? 32 : 64;
358 int mask = bt == T_INT ? 0x1F : 0x3F;
359 if (lshift_t != nullptr && lshift_t->is_con() &&
360 rshift_t != nullptr && rshift_t->is_con() &&
361 ((lshift_t->get_con() & mask) == (bits - (rshift_t->get_con() & mask)))) {
362 return new RotateRightNode(in1->in(1), phase->intcon(rshift_t->get_con() & mask), TypeInteger::bottom(bt));
363 }
364 }
365 }
366
367 return AddNode::Ideal(phase, can_reshape);
368 }
369
370
371 Node* AddINode::Ideal(PhaseGVN* phase, bool can_reshape) {
372 Node* in1 = in(1);
373 Node* in2 = in(2);
374 int op1 = in1->Opcode();
375 int op2 = in2->Opcode();
376
377 // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
378 // Helps with array allocation math constant folding
379 // See 4790063:
380 // Unrestricted transformation is unsafe for some runtime values of 'x'
381 // ( x == 0, z == 1, y == -1 ) fails
382 // ( x == -5, z == 1, y == 1 ) fails
383 // Transform works for small z and small negative y when the addition
384 // (x + (y << z)) does not cross zero.
385 // Implement support for negative y and (x >= -(y << z))
386 // Have not observed cases where type information exists to support
387 // positive y and (x <= -(y << z))
388 if (op1 == Op_URShiftI && op2 == Op_ConI &&
389 in1->in(2)->Opcode() == Op_ConI) {
390 jint z = phase->type(in1->in(2))->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
391 jint y = phase->type(in2)->is_int()->get_con();
392
393 if (z < 5 && -5 < y && y < 0) {
394 const Type* t_in11 = phase->type(in1->in(1));
395 if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z))) {
396 Node* a = phase->transform(new AddINode( in1->in(1), phase->intcon(y<<z)));
397 return new URShiftINode(a, in1->in(2));
398 }
399 }
400 }
401
402 return AddNode::IdealIL(phase, can_reshape, T_INT);
403 }
404
405
406 //------------------------------Identity---------------------------------------
407 // Fold (x-y)+y OR y+(x-y) into x
408 Node* AddINode::Identity(PhaseGVN* phase) {
409 if (in(1)->Opcode() == Op_SubI && in(1)->in(2) == in(2)) {
410 return in(1)->in(1);
411 } else if (in(2)->Opcode() == Op_SubI && in(2)->in(2) == in(1)) {
412 return in(2)->in(1);
413 }
414 return AddNode::Identity(phase);
415 }
416
417
418 //------------------------------add_ring---------------------------------------
419 // Supplied function returns the sum of the inputs. Guaranteed never
420 // to be passed a TOP or BOTTOM type, these are filtered out by
421 // pre-check.
422 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
423 const TypeInt *r0 = t0->is_int(); // Handy access
424 const TypeInt *r1 = t1->is_int();
425 int lo = java_add(r0->_lo, r1->_lo);
426 int hi = java_add(r0->_hi, r1->_hi);
427 if( !(r0->is_con() && r1->is_con()) ) {
428 // Not both constants, compute approximate result
429 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
430 lo = min_jint; hi = max_jint; // Underflow on the low side
431 }
432 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
433 lo = min_jint; hi = max_jint; // Overflow on the high side
434 }
435 if( lo > hi ) { // Handle overflow
436 lo = min_jint; hi = max_jint;
437 }
438 } else {
439 // both constants, compute precise result using 'lo' and 'hi'
440 // Semantics define overflow and underflow for integer addition
441 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
442 }
443 return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
444 }
445
446
447 //=============================================================================
448 //------------------------------Idealize---------------------------------------
449 Node* AddLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
450 return AddNode::IdealIL(phase, can_reshape, T_LONG);
451 }
452
453
454 //------------------------------Identity---------------------------------------
455 // Fold (x-y)+y OR y+(x-y) into x
456 Node* AddLNode::Identity(PhaseGVN* phase) {
457 if (in(1)->Opcode() == Op_SubL && in(1)->in(2) == in(2)) {
458 return in(1)->in(1);
459 } else if (in(2)->Opcode() == Op_SubL && in(2)->in(2) == in(1)) {
460 return in(2)->in(1);
461 }
462 return AddNode::Identity(phase);
463 }
464
465
466 //------------------------------add_ring---------------------------------------
467 // Supplied function returns the sum of the inputs. Guaranteed never
468 // to be passed a TOP or BOTTOM type, these are filtered out by
469 // pre-check.
470 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
471 const TypeLong *r0 = t0->is_long(); // Handy access
472 const TypeLong *r1 = t1->is_long();
473 jlong lo = java_add(r0->_lo, r1->_lo);
474 jlong hi = java_add(r0->_hi, r1->_hi);
475 if( !(r0->is_con() && r1->is_con()) ) {
476 // Not both constants, compute approximate result
477 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
478 lo =min_jlong; hi = max_jlong; // Underflow on the low side
479 }
480 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
481 lo = min_jlong; hi = max_jlong; // Overflow on the high side
482 }
483 if( lo > hi ) { // Handle overflow
484 lo = min_jlong; hi = max_jlong;
485 }
486 } else {
487 // both constants, compute precise result using 'lo' and 'hi'
488 // Semantics define overflow and underflow for integer addition
489 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
490 }
491 return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
492 }
493
494
495 //=============================================================================
496 //------------------------------add_of_identity--------------------------------
497 // Check for addition of the identity
498 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
499 // x ADD 0 should return x unless 'x' is a -zero
500 //
501 // const Type *zero = add_id(); // The additive identity
502 // jfloat f1 = t1->getf();
503 // jfloat f2 = t2->getf();
504 //
505 // if( t1->higher_equal( zero ) ) return t2;
506 // if( t2->higher_equal( zero ) ) return t1;
507
508 return nullptr;
509 }
510
511 //------------------------------add_ring---------------------------------------
512 // Supplied function returns the sum of the inputs.
513 // This also type-checks the inputs for sanity. Guaranteed never to
514 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
515 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
516 // We must be adding 2 float constants.
517 return TypeF::make( t0->getf() + t1->getf() );
518 }
519
520 //------------------------------Ideal------------------------------------------
521 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
522 // Floating point additions are not associative because of boundary conditions (infinity)
523 return commute(phase, this) ? this : nullptr;
524 }
525
526
527 //=============================================================================
528 //------------------------------add_of_identity--------------------------------
529 // Check for addition of the identity
530 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
531 // x ADD 0 should return x unless 'x' is a -zero
532 //
533 // const Type *zero = add_id(); // The additive identity
534 // jfloat f1 = t1->getf();
535 // jfloat f2 = t2->getf();
536 //
537 // if( t1->higher_equal( zero ) ) return t2;
538 // if( t2->higher_equal( zero ) ) return t1;
539
540 return nullptr;
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 *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
547 // We must be adding 2 double constants.
548 return TypeD::make( t0->getd() + t1->getd() );
549 }
550
551 //------------------------------Ideal------------------------------------------
552 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
553 // Floating point additions are not associative because of boundary conditions (infinity)
554 return commute(phase, this) ? this : nullptr;
555 }
556
557
558 //=============================================================================
559 //------------------------------Identity---------------------------------------
560 // If one input is a constant 0, return the other input.
561 Node* AddPNode::Identity(PhaseGVN* phase) {
562 return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
563 }
564
565 //------------------------------Idealize---------------------------------------
566 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
567 // Bail out if dead inputs
568 if( phase->type( in(Address) ) == Type::TOP ) return nullptr;
569
570 // If the left input is an add of a constant, flatten the expression tree.
571 const Node *n = in(Address);
572 if (n->is_AddP() && n->in(Base) == in(Base)) {
573 const AddPNode *addp = n->as_AddP(); // Left input is an AddP
574 assert( !addp->in(Address)->is_AddP() ||
575 addp->in(Address)->as_AddP() != addp,
576 "dead loop in AddPNode::Ideal" );
577 // Type of left input's right input
578 const Type *t = phase->type( addp->in(Offset) );
579 if( t == Type::TOP ) return nullptr;
580 const TypeX *t12 = t->is_intptr_t();
581 if( t12->is_con() ) { // Left input is an add of a constant?
582 // If the right input is a constant, combine constants
583 const Type *temp_t2 = phase->type( in(Offset) );
584 if( temp_t2 == Type::TOP ) return nullptr;
585 const TypeX *t2 = temp_t2->is_intptr_t();
586 Node* address;
587 Node* offset;
588 if( t2->is_con() ) {
589 // The Add of the flattened expression
590 address = addp->in(Address);
591 offset = phase->MakeConX(t2->get_con() + t12->get_con());
592 } else {
593 // Else move the constant to the right. ((A+con)+B) into ((A+B)+con)
594 address = phase->transform(new AddPNode(in(Base),addp->in(Address),in(Offset)));
595 offset = addp->in(Offset);
596 }
597 set_req_X(Address, address, phase);
598 set_req_X(Offset, offset, phase);
599 return this;
600 }
601 }
602
603 // Raw pointers?
604 if( in(Base)->bottom_type() == Type::TOP ) {
605 // If this is a null+long form (from unsafe accesses), switch to a rawptr.
606 if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
607 Node* offset = in(Offset);
608 return new CastX2PNode(offset);
609 }
610 }
611
612 // If the right is an add of a constant, push the offset down.
613 // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
614 // The idea is to merge array_base+scaled_index groups together,
615 // and only have different constant offsets from the same base.
616 const Node *add = in(Offset);
617 if( add->Opcode() == Op_AddX && add->in(1) != add ) {
618 const Type *t22 = phase->type( add->in(2) );
619 if( t22->singleton() && (t22 != Type::TOP) ) { // Right input is an add of a constant?
620 set_req(Address, phase->transform(new AddPNode(in(Base),in(Address),add->in(1))));
621 set_req_X(Offset, add->in(2), phase); // puts add on igvn worklist if needed
622 return this; // Made progress
623 }
624 }
625
626 return nullptr; // No progress
627 }
628
629 //------------------------------bottom_type------------------------------------
630 // Bottom-type is the pointer-type with unknown offset.
631 const Type *AddPNode::bottom_type() const {
632 if (in(Address) == nullptr) return TypePtr::BOTTOM;
633 const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
634 if( !tp ) return Type::TOP; // TOP input means TOP output
635 assert( in(Offset)->Opcode() != Op_ConP, "" );
636 const Type *t = in(Offset)->bottom_type();
637 if( t == Type::TOP )
638 return tp->add_offset(Type::OffsetTop);
639 const TypeX *tx = t->is_intptr_t();
640 intptr_t txoffset = Type::OffsetBot;
641 if (tx->is_con()) { // Left input is an add of a constant?
642 txoffset = tx->get_con();
643 }
644 return tp->add_offset(txoffset);
645 }
646
647 //------------------------------Value------------------------------------------
648 const Type* AddPNode::Value(PhaseGVN* phase) const {
649 // Either input is TOP ==> the result is TOP
650 const Type *t1 = phase->type( in(Address) );
651 const Type *t2 = phase->type( in(Offset) );
652 if( t1 == Type::TOP ) return Type::TOP;
653 if( t2 == Type::TOP ) return Type::TOP;
654
655 // Left input is a pointer
656 const TypePtr *p1 = t1->isa_ptr();
657 // Right input is an int
658 const TypeX *p2 = t2->is_intptr_t();
659 // Add 'em
660 intptr_t p2offset = Type::OffsetBot;
661 if (p2->is_con()) { // Left input is an add of a constant?
662 p2offset = p2->get_con();
663 }
664 return p1->add_offset(p2offset);
665 }
666
667 //------------------------Ideal_base_and_offset--------------------------------
668 // Split an oop pointer into a base and offset.
669 // (The offset might be Type::OffsetBot in the case of an array.)
670 // Return the base, or null if failure.
671 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseValues* phase,
672 // second return value:
673 intptr_t& offset) {
674 if (ptr->is_AddP()) {
675 Node* base = ptr->in(AddPNode::Base);
676 Node* addr = ptr->in(AddPNode::Address);
677 Node* offs = ptr->in(AddPNode::Offset);
678 if (base == addr || base->is_top()) {
679 offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
680 if (offset != Type::OffsetBot) {
681 return addr;
682 }
683 }
684 }
685 offset = Type::OffsetBot;
686 return nullptr;
687 }
688
689 //------------------------------unpack_offsets----------------------------------
690 // Collect the AddP offset values into the elements array, giving up
691 // if there are more than length.
692 int AddPNode::unpack_offsets(Node* elements[], int length) {
693 int count = 0;
694 Node* addr = this;
695 Node* base = addr->in(AddPNode::Base);
696 while (addr->is_AddP()) {
697 if (addr->in(AddPNode::Base) != base) {
698 // give up
699 return -1;
700 }
701 elements[count++] = addr->in(AddPNode::Offset);
702 if (count == length) {
703 // give up
704 return -1;
705 }
706 addr = addr->in(AddPNode::Address);
707 }
708 if (addr != base) {
709 return -1;
710 }
711 return count;
712 }
713
714 //------------------------------match_edge-------------------------------------
715 // Do we Match on this edge index or not? Do not match base pointer edge
716 uint AddPNode::match_edge(uint idx) const {
717 return idx > Base;
718 }
719
720 //=============================================================================
721 //------------------------------Identity---------------------------------------
722 Node* OrINode::Identity(PhaseGVN* phase) {
723 // x | x => x
724 if (in(1) == in(2)) {
725 return in(1);
726 }
727
728 return AddNode::Identity(phase);
729 }
730
731 // Find shift value for Integer or Long OR.
732 Node* rotate_shift(PhaseGVN* phase, Node* lshift, Node* rshift, int mask) {
733 // val << norm_con_shift | val >> ({32|64} - norm_con_shift) => rotate_left val, norm_con_shift
734 const TypeInt* lshift_t = phase->type(lshift)->isa_int();
735 const TypeInt* rshift_t = phase->type(rshift)->isa_int();
736 if (lshift_t != nullptr && lshift_t->is_con() &&
737 rshift_t != nullptr && rshift_t->is_con() &&
738 ((lshift_t->get_con() & mask) == ((mask + 1) - (rshift_t->get_con() & mask)))) {
739 return phase->intcon(lshift_t->get_con() & mask);
740 }
741 // val << var_shift | val >> ({0|32|64} - var_shift) => rotate_left val, var_shift
742 if (rshift->Opcode() == Op_SubI && rshift->in(2) == lshift && rshift->in(1)->is_Con()){
743 const TypeInt* shift_t = phase->type(rshift->in(1))->isa_int();
744 if (shift_t != nullptr && shift_t->is_con() &&
745 (shift_t->get_con() == 0 || shift_t->get_con() == (mask + 1))) {
746 return lshift;
747 }
748 }
749 return nullptr;
750 }
751
752 Node* OrINode::Ideal(PhaseGVN* phase, bool can_reshape) {
753 int lopcode = in(1)->Opcode();
754 int ropcode = in(2)->Opcode();
755 if (Matcher::match_rule_supported(Op_RotateLeft) &&
756 lopcode == Op_LShiftI && ropcode == Op_URShiftI && in(1)->in(1) == in(2)->in(1)) {
757 Node* lshift = in(1)->in(2);
758 Node* rshift = in(2)->in(2);
759 Node* shift = rotate_shift(phase, lshift, rshift, 0x1F);
760 if (shift != nullptr) {
761 return new RotateLeftNode(in(1)->in(1), shift, TypeInt::INT);
762 }
763 return nullptr;
764 }
765 if (Matcher::match_rule_supported(Op_RotateRight) &&
766 lopcode == Op_URShiftI && ropcode == Op_LShiftI && in(1)->in(1) == in(2)->in(1)) {
767 Node* rshift = in(1)->in(2);
768 Node* lshift = in(2)->in(2);
769 Node* shift = rotate_shift(phase, rshift, lshift, 0x1F);
770 if (shift != nullptr) {
771 return new RotateRightNode(in(1)->in(1), shift, TypeInt::INT);
772 }
773 }
774 return nullptr;
775 }
776
777 //------------------------------add_ring---------------------------------------
778 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
779 // the logical operations the ring's ADD is really a logical OR function.
780 // This also type-checks the inputs for sanity. Guaranteed never to
781 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
782 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
783 const TypeInt *r0 = t0->is_int(); // Handy access
784 const TypeInt *r1 = t1->is_int();
785
786 // If both args are bool, can figure out better types
787 if ( r0 == TypeInt::BOOL ) {
788 if ( r1 == TypeInt::ONE) {
789 return TypeInt::ONE;
790 } else if ( r1 == TypeInt::BOOL ) {
791 return TypeInt::BOOL;
792 }
793 } else if ( r0 == TypeInt::ONE ) {
794 if ( r1 == TypeInt::BOOL ) {
795 return TypeInt::ONE;
796 }
797 }
798
799 // If either input is not a constant, just return all integers.
800 if( !r0->is_con() || !r1->is_con() )
801 return TypeInt::INT; // Any integer, but still no symbols.
802
803 // Otherwise just OR them bits.
804 return TypeInt::make( r0->get_con() | r1->get_con() );
805 }
806
807 //=============================================================================
808 //------------------------------Identity---------------------------------------
809 Node* OrLNode::Identity(PhaseGVN* phase) {
810 // x | x => x
811 if (in(1) == in(2)) {
812 return in(1);
813 }
814
815 return AddNode::Identity(phase);
816 }
817
818 Node* OrLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
819 int lopcode = in(1)->Opcode();
820 int ropcode = in(2)->Opcode();
821 if (Matcher::match_rule_supported(Op_RotateLeft) &&
822 lopcode == Op_LShiftL && ropcode == Op_URShiftL && in(1)->in(1) == in(2)->in(1)) {
823 Node* lshift = in(1)->in(2);
824 Node* rshift = in(2)->in(2);
825 Node* shift = rotate_shift(phase, lshift, rshift, 0x3F);
826 if (shift != nullptr) {
827 return new RotateLeftNode(in(1)->in(1), shift, TypeLong::LONG);
828 }
829 return nullptr;
830 }
831 if (Matcher::match_rule_supported(Op_RotateRight) &&
832 lopcode == Op_URShiftL && ropcode == Op_LShiftL && in(1)->in(1) == in(2)->in(1)) {
833 Node* rshift = in(1)->in(2);
834 Node* lshift = in(2)->in(2);
835 Node* shift = rotate_shift(phase, rshift, lshift, 0x3F);
836 if (shift != nullptr) {
837 return new RotateRightNode(in(1)->in(1), shift, TypeLong::LONG);
838 }
839 }
840 return nullptr;
841 }
842
843 //------------------------------add_ring---------------------------------------
844 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
845 const TypeLong *r0 = t0->is_long(); // Handy access
846 const TypeLong *r1 = t1->is_long();
847
848 // If either input is not a constant, just return all integers.
849 if( !r0->is_con() || !r1->is_con() )
850 return TypeLong::LONG; // Any integer, but still no symbols.
851
852 // Otherwise just OR them bits.
853 return TypeLong::make( r0->get_con() | r1->get_con() );
854 }
855
856 //---------------------------Helper -------------------------------------------
857 /* Decide if the given node is used only in arithmetic expressions(add or sub).
858 */
859 static bool is_used_in_only_arithmetic(Node* n, BasicType bt) {
860 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
861 Node* u = n->fast_out(i);
862 if (u->Opcode() != Op_Add(bt) && u->Opcode() != Op_Sub(bt)) {
863 return false;
864 }
865 }
866 return true;
867 }
868
869 //=============================================================================
870 //------------------------------Idealize---------------------------------------
871 Node* XorINode::Ideal(PhaseGVN* phase, bool can_reshape) {
872 Node* in1 = in(1);
873 Node* in2 = in(2);
874
875 // Convert ~x into -1-x when ~x is used in an arithmetic expression
876 // or x itself is an expression.
877 if (phase->type(in2) == TypeInt::MINUS_1) { // follows LHS^(-1), i.e., ~LHS
878 if (phase->is_IterGVN()) {
879 if (is_used_in_only_arithmetic(this, T_INT)
880 // LHS is arithmetic
881 || (in1->Opcode() == Op_AddI || in1->Opcode() == Op_SubI)) {
882 return new SubINode(in2, in1);
883 }
884 } else {
885 // graph could be incomplete in GVN so we postpone to IGVN
886 phase->record_for_igvn(this);
887 }
888 }
889
890 // Propagate xor through constant cmoves. This pattern can occur after expansion of Conv2B nodes.
891 const TypeInt* in2_type = phase->type(in2)->isa_int();
892 if (in1->Opcode() == Op_CMoveI && in2_type != nullptr && in2_type->is_con()) {
893 int in2_val = in2_type->get_con();
894
895 // Get types of both sides of the CMove
896 const TypeInt* left = phase->type(in1->in(CMoveNode::IfFalse))->isa_int();
897 const TypeInt* right = phase->type(in1->in(CMoveNode::IfTrue))->isa_int();
898
899 // Ensure that both sides are int constants
900 if (left != nullptr && right != nullptr && left->is_con() && right->is_con()) {
901 Node* cond = in1->in(CMoveNode::Condition);
902
903 // Check that the comparison is a bool and that the cmp node type is correct
904 if (cond->is_Bool()) {
905 int cmp_op = cond->in(1)->Opcode();
906
907 if (cmp_op == Op_CmpI || cmp_op == Op_CmpP) {
908 int l_val = left->get_con();
909 int r_val = right->get_con();
910
911 return new CMoveINode(cond, phase->intcon(l_val ^ in2_val), phase->intcon(r_val ^ in2_val), TypeInt::INT);
912 }
913 }
914 }
915 }
916
917 return AddNode::Ideal(phase, can_reshape);
918 }
919
920 const Type* XorINode::Value(PhaseGVN* phase) const {
921 Node* in1 = in(1);
922 Node* in2 = in(2);
923 const Type* t1 = phase->type(in1);
924 const Type* t2 = phase->type(in2);
925 if (t1 == Type::TOP || t2 == Type::TOP) {
926 return Type::TOP;
927 }
928 // x ^ x ==> 0
929 if (in1->eqv_uncast(in2)) {
930 return add_id();
931 }
932 // result of xor can only have bits sets where any of the
933 // inputs have bits set. lo can always become 0.
934 const TypeInt* t1i = t1->is_int();
935 const TypeInt* t2i = t2->is_int();
936 if ((t1i->_lo >= 0) &&
937 (t1i->_hi > 0) &&
938 (t2i->_lo >= 0) &&
939 (t2i->_hi > 0)) {
940 // hi - set all bits below the highest bit. Using round_down to avoid overflow.
941 const TypeInt* t1x = TypeInt::make(0, round_down_power_of_2(t1i->_hi) + (round_down_power_of_2(t1i->_hi) - 1), t1i->_widen);
942 const TypeInt* t2x = TypeInt::make(0, round_down_power_of_2(t2i->_hi) + (round_down_power_of_2(t2i->_hi) - 1), t2i->_widen);
943 return t1x->meet(t2x);
944 }
945 return AddNode::Value(phase);
946 }
947
948
949 //------------------------------add_ring---------------------------------------
950 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
951 // the logical operations the ring's ADD is really a logical OR function.
952 // This also type-checks the inputs for sanity. Guaranteed never to
953 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
954 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
955 const TypeInt *r0 = t0->is_int(); // Handy access
956 const TypeInt *r1 = t1->is_int();
957
958 // Complementing a boolean?
959 if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
960 || r1 == TypeInt::BOOL))
961 return TypeInt::BOOL;
962
963 if( !r0->is_con() || !r1->is_con() ) // Not constants
964 return TypeInt::INT; // Any integer, but still no symbols.
965
966 // Otherwise just XOR them bits.
967 return TypeInt::make( r0->get_con() ^ r1->get_con() );
968 }
969
970 //=============================================================================
971 //------------------------------add_ring---------------------------------------
972 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
973 const TypeLong *r0 = t0->is_long(); // Handy access
974 const TypeLong *r1 = t1->is_long();
975
976 // If either input is not a constant, just return all integers.
977 if( !r0->is_con() || !r1->is_con() )
978 return TypeLong::LONG; // Any integer, but still no symbols.
979
980 // Otherwise just OR them bits.
981 return TypeLong::make( r0->get_con() ^ r1->get_con() );
982 }
983
984 Node* XorLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
985 Node* in1 = in(1);
986 Node* in2 = in(2);
987
988 // Convert ~x into -1-x when ~x is used in an arithmetic expression
989 // or x itself is an arithmetic expression.
990 if (phase->type(in2) == TypeLong::MINUS_1) { // follows LHS^(-1), i.e., ~LHS
991 if (phase->is_IterGVN()) {
992 if (is_used_in_only_arithmetic(this, T_LONG)
993 // LHS is arithmetic
994 || (in1->Opcode() == Op_AddL || in1->Opcode() == Op_SubL)) {
995 return new SubLNode(in2, in1);
996 }
997 } else {
998 // graph could be incomplete in GVN so we postpone to IGVN
999 phase->record_for_igvn(this);
1000 }
1001 }
1002 return AddNode::Ideal(phase, can_reshape);
1003 }
1004
1005 const Type* XorLNode::Value(PhaseGVN* phase) const {
1006 Node* in1 = in(1);
1007 Node* in2 = in(2);
1008 const Type* t1 = phase->type(in1);
1009 const Type* t2 = phase->type(in2);
1010 if (t1 == Type::TOP || t2 == Type::TOP) {
1011 return Type::TOP;
1012 }
1013 // x ^ x ==> 0
1014 if (in1->eqv_uncast(in2)) {
1015 return add_id();
1016 }
1017 // result of xor can only have bits sets where any of the
1018 // inputs have bits set. lo can always become 0.
1019 const TypeLong* t1l = t1->is_long();
1020 const TypeLong* t2l = t2->is_long();
1021 if ((t1l->_lo >= 0) &&
1022 (t1l->_hi > 0) &&
1023 (t2l->_lo >= 0) &&
1024 (t2l->_hi > 0)) {
1025 // hi - set all bits below the highest bit. Using round_down to avoid overflow.
1026 const TypeLong* t1x = TypeLong::make(0, round_down_power_of_2(t1l->_hi) + (round_down_power_of_2(t1l->_hi) - 1), t1l->_widen);
1027 const TypeLong* t2x = TypeLong::make(0, round_down_power_of_2(t2l->_hi) + (round_down_power_of_2(t2l->_hi) - 1), t2l->_widen);
1028 return t1x->meet(t2x);
1029 }
1030 return AddNode::Value(phase);
1031 }
1032
1033 Node* build_min_max_int(Node* a, Node* b, bool is_max) {
1034 if (is_max) {
1035 return new MaxINode(a, b);
1036 } else {
1037 return new MinINode(a, b);
1038 }
1039 }
1040
1041 Node* MaxNode::build_min_max(Node* a, Node* b, bool is_max, bool is_unsigned, const Type* t, PhaseGVN& gvn) {
1042 bool is_int = gvn.type(a)->isa_int();
1043 assert(is_int || gvn.type(a)->isa_long(), "int or long inputs");
1044 assert(is_int == (gvn.type(b)->isa_int() != nullptr), "inconsistent inputs");
1045 BasicType bt = is_int ? T_INT: T_LONG;
1046 Node* hook = nullptr;
1047 if (gvn.is_IterGVN()) {
1048 // Make sure a and b are not destroyed
1049 hook = new Node(2);
1050 hook->init_req(0, a);
1051 hook->init_req(1, b);
1052 }
1053 Node* res = nullptr;
1054 if (is_int && !is_unsigned) {
1055 res = gvn.transform(build_min_max_int(a, b, is_max));
1056 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");
1057 } else {
1058 Node* cmp = nullptr;
1059 if (is_max) {
1060 cmp = gvn.transform(CmpNode::make(a, b, bt, is_unsigned));
1061 } else {
1062 cmp = gvn.transform(CmpNode::make(b, a, bt, is_unsigned));
1063 }
1064 Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::lt));
1065 res = gvn.transform(CMoveNode::make(nullptr, bol, a, b, t));
1066 }
1067 if (hook != nullptr) {
1068 hook->destruct(&gvn);
1069 }
1070 return res;
1071 }
1072
1073 Node* MaxNode::build_min_max_diff_with_zero(Node* a, Node* b, bool is_max, const Type* t, PhaseGVN& gvn) {
1074 bool is_int = gvn.type(a)->isa_int();
1075 assert(is_int || gvn.type(a)->isa_long(), "int or long inputs");
1076 assert(is_int == (gvn.type(b)->isa_int() != nullptr), "inconsistent inputs");
1077 BasicType bt = is_int ? T_INT: T_LONG;
1078 Node* zero = gvn.integercon(0, bt);
1079 Node* hook = nullptr;
1080 if (gvn.is_IterGVN()) {
1081 // Make sure a and b are not destroyed
1082 hook = new Node(2);
1083 hook->init_req(0, a);
1084 hook->init_req(1, b);
1085 }
1086 Node* cmp = nullptr;
1087 if (is_max) {
1088 cmp = gvn.transform(CmpNode::make(a, b, bt, false));
1089 } else {
1090 cmp = gvn.transform(CmpNode::make(b, a, bt, false));
1091 }
1092 Node* sub = gvn.transform(SubNode::make(a, b, bt));
1093 Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::lt));
1094 Node* res = gvn.transform(CMoveNode::make(nullptr, bol, sub, zero, t));
1095 if (hook != nullptr) {
1096 hook->destruct(&gvn);
1097 }
1098 return res;
1099 }
1100
1101 // Check if addition of an integer with type 't' and a constant 'c' can overflow.
1102 static bool can_overflow(const TypeInt* t, jint c) {
1103 jint t_lo = t->_lo;
1104 jint t_hi = t->_hi;
1105 return ((c < 0 && (java_add(t_lo, c) > t_lo)) ||
1106 (c > 0 && (java_add(t_hi, c) < t_hi)));
1107 }
1108
1109 // Let <x, x_off> = x_operands and <y, y_off> = y_operands.
1110 // If x == y and neither add(x, x_off) nor add(y, y_off) overflow, return
1111 // add(x, op(x_off, y_off)). Otherwise, return nullptr.
1112 Node* MaxNode::extract_add(PhaseGVN* phase, ConstAddOperands x_operands, ConstAddOperands y_operands) {
1113 Node* x = x_operands.first;
1114 Node* y = y_operands.first;
1115 int opcode = Opcode();
1116 assert(opcode == Op_MaxI || opcode == Op_MinI, "Unexpected opcode");
1117 const TypeInt* tx = phase->type(x)->isa_int();
1118 jint x_off = x_operands.second;
1119 jint y_off = y_operands.second;
1120 if (x == y && tx != nullptr &&
1121 !can_overflow(tx, x_off) &&
1122 !can_overflow(tx, y_off)) {
1123 jint c = opcode == Op_MinI ? MIN2(x_off, y_off) : MAX2(x_off, y_off);
1124 return new AddINode(x, phase->intcon(c));
1125 }
1126 return nullptr;
1127 }
1128
1129 // Try to cast n as an integer addition with a constant. Return:
1130 // <x, C>, if n == add(x, C), where 'C' is a non-TOP constant;
1131 // <nullptr, 0>, if n == add(x, C), where 'C' is a TOP constant; or
1132 // <n, 0>, otherwise.
1133 static ConstAddOperands as_add_with_constant(Node* n) {
1134 if (n->Opcode() != Op_AddI) {
1135 return ConstAddOperands(n, 0);
1136 }
1137 Node* x = n->in(1);
1138 Node* c = n->in(2);
1139 if (!c->is_Con()) {
1140 return ConstAddOperands(n, 0);
1141 }
1142 const Type* c_type = c->bottom_type();
1143 if (c_type == Type::TOP) {
1144 return ConstAddOperands(nullptr, 0);
1145 }
1146 return ConstAddOperands(x, c_type->is_int()->get_con());
1147 }
1148
1149 Node* MaxNode::IdealI(PhaseGVN* phase, bool can_reshape) {
1150 int opcode = Opcode();
1151 assert(opcode == Op_MinI || opcode == Op_MaxI, "Unexpected opcode");
1152 // Try to transform the following pattern, in any of its four possible
1153 // permutations induced by op's commutativity:
1154 // op(op(add(inner, inner_off), inner_other), add(outer, outer_off))
1155 // into
1156 // op(add(inner, op(inner_off, outer_off)), inner_other),
1157 // where:
1158 // op is either MinI or MaxI, and
1159 // inner == outer, and
1160 // the additions cannot overflow.
1161 for (uint inner_op_index = 1; inner_op_index <= 2; inner_op_index++) {
1162 if (in(inner_op_index)->Opcode() != opcode) {
1163 continue;
1164 }
1165 Node* outer_add = in(inner_op_index == 1 ? 2 : 1);
1166 ConstAddOperands outer_add_operands = as_add_with_constant(outer_add);
1167 if (outer_add_operands.first == nullptr) {
1168 return nullptr; // outer_add has a TOP input, no need to continue.
1169 }
1170 // One operand is a MinI/MaxI and the other is an integer addition with
1171 // constant. Test the operands of the inner MinI/MaxI.
1172 for (uint inner_add_index = 1; inner_add_index <= 2; inner_add_index++) {
1173 Node* inner_op = in(inner_op_index);
1174 Node* inner_add = inner_op->in(inner_add_index);
1175 ConstAddOperands inner_add_operands = as_add_with_constant(inner_add);
1176 if (inner_add_operands.first == nullptr) {
1177 return nullptr; // inner_add has a TOP input, no need to continue.
1178 }
1179 // Try to extract the inner add.
1180 Node* add_extracted = extract_add(phase, inner_add_operands, outer_add_operands);
1181 if (add_extracted == nullptr) {
1182 continue;
1183 }
1184 Node* add_transformed = phase->transform(add_extracted);
1185 Node* inner_other = inner_op->in(inner_add_index == 1 ? 2 : 1);
1186 return build_min_max_int(add_transformed, inner_other, opcode == Op_MaxI);
1187 }
1188 }
1189 // Try to transform
1190 // op(add(x, x_off), add(y, y_off))
1191 // into
1192 // add(x, op(x_off, y_off)),
1193 // where:
1194 // op is either MinI or MaxI, and
1195 // inner == outer, and
1196 // the additions cannot overflow.
1197 ConstAddOperands xC = as_add_with_constant(in(1));
1198 ConstAddOperands yC = as_add_with_constant(in(2));
1199 if (xC.first == nullptr || yC.first == nullptr) return nullptr;
1200 return extract_add(phase, xC, yC);
1201 }
1202
1203 // Ideal transformations for MaxINode
1204 Node* MaxINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1205 return IdealI(phase, can_reshape);
1206 }
1207
1208 //=============================================================================
1209 //------------------------------add_ring---------------------------------------
1210 // Supplied function returns the sum of the inputs.
1211 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
1212 const TypeInt *r0 = t0->is_int(); // Handy access
1213 const TypeInt *r1 = t1->is_int();
1214
1215 // Otherwise just MAX them bits.
1216 return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
1217 }
1218
1219 //=============================================================================
1220 //------------------------------Idealize---------------------------------------
1221 // MINs show up in range-check loop limit calculations. Look for
1222 // "MIN2(x+c0,MIN2(y,x+c1))". Pick the smaller constant: "MIN2(x+c0,y)"
1223 Node* MinINode::Ideal(PhaseGVN* phase, bool can_reshape) {
1224 return IdealI(phase, can_reshape);
1225 }
1226
1227 //------------------------------add_ring---------------------------------------
1228 // Supplied function returns the sum of the inputs.
1229 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
1230 const TypeInt *r0 = t0->is_int(); // Handy access
1231 const TypeInt *r1 = t1->is_int();
1232
1233 // Otherwise just MIN them bits.
1234 return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
1235 }
1236
1237 // Collapse the "addition with overflow-protection" pattern, and the symmetrical
1238 // "subtraction with underflow-protection" pattern. These are created during the
1239 // unrolling, when we have to adjust the limit by subtracting the stride, but want
1240 // to protect against underflow: MaxL(SubL(limit, stride), min_jint).
1241 // If we have more than one of those in a sequence:
1242 //
1243 // x con2
1244 // | |
1245 // AddL clamp2
1246 // | |
1247 // Max/MinL con1
1248 // | |
1249 // AddL clamp1
1250 // | |
1251 // Max/MinL (n)
1252 //
1253 // We want to collapse it to:
1254 //
1255 // x con1 con2
1256 // | | |
1257 // | AddLNode (new_con)
1258 // | |
1259 // AddLNode clamp1
1260 // | |
1261 // Max/MinL (n)
1262 //
1263 // Note: we assume that SubL was already replaced by an AddL, and that the stride
1264 // has its sign flipped: SubL(limit, stride) -> AddL(limit, -stride).
1265 Node* fold_subI_no_underflow_pattern(Node* n, PhaseGVN* phase) {
1266 assert(n->Opcode() == Op_MaxL || n->Opcode() == Op_MinL, "sanity");
1267 // Check that the two clamps have the correct values.
1268 jlong clamp = (n->Opcode() == Op_MaxL) ? min_jint : max_jint;
1269 auto is_clamp = [&](Node* c) {
1270 const TypeLong* t = phase->type(c)->isa_long();
1271 return t != nullptr && t->is_con() &&
1272 t->get_con() == clamp;
1273 };
1274 // Check that the constants are negative if MaxL, and positive if MinL.
1275 auto is_sub_con = [&](Node* c) {
1276 const TypeLong* t = phase->type(c)->isa_long();
1277 return t != nullptr && t->is_con() &&
1278 t->get_con() < max_jint && t->get_con() > min_jint &&
1279 (t->get_con() < 0) == (n->Opcode() == Op_MaxL);
1280 };
1281 // Verify the graph level by level:
1282 Node* add1 = n->in(1);
1283 Node* clamp1 = n->in(2);
1284 if (add1->Opcode() == Op_AddL && is_clamp(clamp1)) {
1285 Node* max2 = add1->in(1);
1286 Node* con1 = add1->in(2);
1287 if (max2->Opcode() == n->Opcode() && is_sub_con(con1)) {
1288 Node* add2 = max2->in(1);
1289 Node* clamp2 = max2->in(2);
1290 if (add2->Opcode() == Op_AddL && is_clamp(clamp2)) {
1291 Node* x = add2->in(1);
1292 Node* con2 = add2->in(2);
1293 if (is_sub_con(con2)) {
1294 Node* new_con = phase->transform(new AddLNode(con1, con2));
1295 Node* new_sub = phase->transform(new AddLNode(x, new_con));
1296 n->set_req_X(1, new_sub, phase);
1297 return n;
1298 }
1299 }
1300 }
1301 }
1302 return nullptr;
1303 }
1304
1305 const Type* MaxLNode::add_ring(const Type* t0, const Type* t1) const {
1306 const TypeLong* r0 = t0->is_long();
1307 const TypeLong* r1 = t1->is_long();
1308
1309 return TypeLong::make(MAX2(r0->_lo, r1->_lo), MAX2(r0->_hi, r1->_hi), MAX2(r0->_widen, r1->_widen));
1310 }
1311
1312 Node* MaxLNode::Identity(PhaseGVN* phase) {
1313 const TypeLong* t1 = phase->type(in(1))->is_long();
1314 const TypeLong* t2 = phase->type(in(2))->is_long();
1315
1316 // Can we determine maximum statically?
1317 if (t1->_lo >= t2->_hi) {
1318 return in(1);
1319 } else if (t2->_lo >= t1->_hi) {
1320 return in(2);
1321 }
1322
1323 return MaxNode::Identity(phase);
1324 }
1325
1326 Node* MaxLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1327 Node* n = AddNode::Ideal(phase, can_reshape);
1328 if (n != nullptr) {
1329 return n;
1330 }
1331 if (can_reshape) {
1332 return fold_subI_no_underflow_pattern(this, phase);
1333 }
1334 return nullptr;
1335 }
1336
1337 const Type* MinLNode::add_ring(const Type* t0, const Type* t1) const {
1338 const TypeLong* r0 = t0->is_long();
1339 const TypeLong* r1 = t1->is_long();
1340
1341 return TypeLong::make(MIN2(r0->_lo, r1->_lo), MIN2(r0->_hi, r1->_hi), MIN2(r0->_widen, r1->_widen));
1342 }
1343
1344 Node* MinLNode::Identity(PhaseGVN* phase) {
1345 const TypeLong* t1 = phase->type(in(1))->is_long();
1346 const TypeLong* t2 = phase->type(in(2))->is_long();
1347
1348 // Can we determine minimum statically?
1349 if (t1->_lo >= t2->_hi) {
1350 return in(2);
1351 } else if (t2->_lo >= t1->_hi) {
1352 return in(1);
1353 }
1354
1355 return MaxNode::Identity(phase);
1356 }
1357
1358 Node* MinLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1359 Node* n = AddNode::Ideal(phase, can_reshape);
1360 if (n != nullptr) {
1361 return n;
1362 }
1363 if (can_reshape) {
1364 return fold_subI_no_underflow_pattern(this, phase);
1365 }
1366 return nullptr;
1367 }
1368
1369 //------------------------------add_ring---------------------------------------
1370 const Type *MinFNode::add_ring( const Type *t0, const Type *t1 ) const {
1371 const TypeF *r0 = t0->is_float_constant();
1372 const TypeF *r1 = t1->is_float_constant();
1373
1374 if (r0->is_nan()) {
1375 return r0;
1376 }
1377 if (r1->is_nan()) {
1378 return r1;
1379 }
1380
1381 float f0 = r0->getf();
1382 float f1 = r1->getf();
1383 if (f0 != 0.0f || f1 != 0.0f) {
1384 return f0 < f1 ? r0 : r1;
1385 }
1386
1387 // handle min of 0.0, -0.0 case.
1388 return (jint_cast(f0) < jint_cast(f1)) ? r0 : r1;
1389 }
1390
1391 //------------------------------add_ring---------------------------------------
1392 const Type *MinDNode::add_ring( const Type *t0, const Type *t1 ) const {
1393 const TypeD *r0 = t0->is_double_constant();
1394 const TypeD *r1 = t1->is_double_constant();
1395
1396 if (r0->is_nan()) {
1397 return r0;
1398 }
1399 if (r1->is_nan()) {
1400 return r1;
1401 }
1402
1403 double d0 = r0->getd();
1404 double d1 = r1->getd();
1405 if (d0 != 0.0 || d1 != 0.0) {
1406 return d0 < d1 ? r0 : r1;
1407 }
1408
1409 // handle min of 0.0, -0.0 case.
1410 return (jlong_cast(d0) < jlong_cast(d1)) ? r0 : r1;
1411 }
1412
1413 //------------------------------add_ring---------------------------------------
1414 const Type *MaxFNode::add_ring( const Type *t0, const Type *t1 ) const {
1415 const TypeF *r0 = t0->is_float_constant();
1416 const TypeF *r1 = t1->is_float_constant();
1417
1418 if (r0->is_nan()) {
1419 return r0;
1420 }
1421 if (r1->is_nan()) {
1422 return r1;
1423 }
1424
1425 float f0 = r0->getf();
1426 float f1 = r1->getf();
1427 if (f0 != 0.0f || f1 != 0.0f) {
1428 return f0 > f1 ? r0 : r1;
1429 }
1430
1431 // handle max of 0.0,-0.0 case.
1432 return (jint_cast(f0) > jint_cast(f1)) ? r0 : r1;
1433 }
1434
1435 //------------------------------add_ring---------------------------------------
1436 const Type *MaxDNode::add_ring( const Type *t0, const Type *t1 ) const {
1437 const TypeD *r0 = t0->is_double_constant();
1438 const TypeD *r1 = t1->is_double_constant();
1439
1440 if (r0->is_nan()) {
1441 return r0;
1442 }
1443 if (r1->is_nan()) {
1444 return r1;
1445 }
1446
1447 double d0 = r0->getd();
1448 double d1 = r1->getd();
1449 if (d0 != 0.0 || d1 != 0.0) {
1450 return d0 > d1 ? r0 : r1;
1451 }
1452
1453 // handle max of 0.0, -0.0 case.
1454 return (jlong_cast(d0) > jlong_cast(d1)) ? r0 : r1;
1455 }