1 /*
2 * Copyright (c) 1997, 2012, 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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
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/mulnode.hpp"
33 #include "opto/phaseX.hpp"
34 #include "opto/subnode.hpp"
35
36 // Portions of code courtesy of Clifford Click
37
38 // Classic Add functionality. This covers all the usual 'add' behaviors for
39 // an algebraic ring. Add-integer, add-float, add-double, and binary-or are
40 // all inherited from this class. The various identity values are supplied
41 // by virtual functions.
42
43
44 //=============================================================================
45 //------------------------------hash-------------------------------------------
46 // Hash function over AddNodes. Needs to be commutative; i.e., I swap
47 // (commute) inputs to AddNodes willy-nilly so the hash function must return
48 // the same value in the presence of edge swapping.
49 uint AddNode::hash() const {
50 return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
51 }
52
53 //------------------------------Identity---------------------------------------
54 // If either input is a constant 0, return the other input.
55 Node* AddNode::Identity(PhaseGVN* phase) {
56 const Type *zero = add_id(); // The additive identity
57 if( phase->type( in(1) )->higher_equal( zero ) ) return in(2);
58 if( phase->type( in(2) )->higher_equal( zero ) ) return in(1);
59 return this;
60 }
61
62 //------------------------------commute----------------------------------------
63 // Commute operands to move loads and constants to the right.
64 static bool commute(Node *add, bool con_left, bool con_right) {
65 Node *in1 = add->in(1);
66 Node *in2 = add->in(2);
67
68 // Convert "1+x" into "x+1".
69 // Right is a constant; leave it
70 if( con_right ) return false;
71 // Left is a constant; move it right.
72 if( con_left ) {
73 add->swap_edges(1, 2);
74 return true;
75 }
76
77 // Convert "Load+x" into "x+Load".
78 // Now check for loads
79 if (in2->is_Load()) {
80 if (!in1->is_Load()) {
81 // already x+Load to return
82 return false;
83 }
84 // both are loads, so fall through to sort inputs by idx
85 } else if( in1->is_Load() ) {
86 // Left is a Load and Right is not; move it right.
87 add->swap_edges(1, 2);
88 return true;
89 }
90
91 PhiNode *phi;
92 // Check for tight loop increments: Loop-phi of Add of loop-phi
93 if( in1->is_Phi() && (phi = in1->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add)
94 return false;
95 if( in2->is_Phi() && (phi = in2->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add){
96 add->swap_edges(1, 2);
97 return true;
98 }
99
100 // Otherwise, sort inputs (commutativity) to help value numbering.
101 if( in1->_idx > in2->_idx ) {
102 add->swap_edges(1, 2);
103 return true;
104 }
105 return false;
106 }
107
108 //------------------------------Idealize---------------------------------------
109 // If we get here, we assume we are associative!
110 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
111 const Type *t1 = phase->type( in(1) );
112 const Type *t2 = phase->type( in(2) );
113 bool con_left = t1->singleton();
114 bool con_right = t2->singleton();
115
116 // Check for commutative operation desired
117 if( commute(this,con_left,con_right) ) return this;
118
119 AddNode *progress = NULL; // Progress flag
120
121 // Convert "(x+1)+2" into "x+(1+2)". If the right input is a
122 // constant, and the left input is an add of a constant, flatten the
123 // expression tree.
124 Node *add1 = in(1);
125 Node *add2 = in(2);
126 int add1_op = add1->Opcode();
127 int this_op = Opcode();
128 if( con_right && t2 != Type::TOP && // Right input is a constant?
129 add1_op == this_op ) { // Left input is an Add?
130
131 // Type of left _in right input
132 const Type *t12 = phase->type( add1->in(2) );
133 if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
134 // Check for rare case of closed data cycle which can happen inside
135 // unreachable loops. In these cases the computation is undefined.
136 #ifdef ASSERT
137 Node *add11 = add1->in(1);
138 int add11_op = add11->Opcode();
139 if( (add1 == add1->in(1))
140 || (add11_op == this_op && add11->in(1) == add1) ) {
141 assert(false, "dead loop in AddNode::Ideal");
142 }
143 #endif
144 // The Add of the flattened expression
145 Node *x1 = add1->in(1);
146 Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 ));
147 PhaseIterGVN *igvn = phase->is_IterGVN();
148 if( igvn ) {
149 set_req_X(2,x2,igvn);
150 set_req_X(1,x1,igvn);
151 } else {
152 set_req(2,x2);
153 set_req(1,x1);
154 }
155 progress = this; // Made progress
156 add1 = in(1);
157 add1_op = add1->Opcode();
158 }
159 }
160
161 // Convert "(x+1)+y" into "(x+y)+1". Push constants down the expression tree.
162 if( add1_op == this_op && !con_right ) {
163 Node *a12 = add1->in(2);
164 const Type *t12 = phase->type( a12 );
165 if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) &&
166 !(add1->in(1)->is_Phi() && add1->in(1)->as_Phi()->is_tripcount()) ) {
167 assert(add1->in(1) != this, "dead loop in AddNode::Ideal");
168 add2 = add1->clone();
169 add2->set_req(2, in(2));
170 add2 = phase->transform(add2);
171 set_req(1, add2);
172 set_req(2, a12);
173 progress = this;
174 add2 = a12;
175 }
176 }
177
178 // Convert "x+(y+1)" into "(x+y)+1". Push constants down the expression tree.
179 int add2_op = add2->Opcode();
180 if( add2_op == this_op && !con_left ) {
181 Node *a22 = add2->in(2);
182 const Type *t22 = phase->type( a22 );
183 if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) &&
184 !(add2->in(1)->is_Phi() && add2->in(1)->as_Phi()->is_tripcount()) ) {
185 assert(add2->in(1) != this, "dead loop in AddNode::Ideal");
186 Node *addx = add2->clone();
187 addx->set_req(1, in(1));
188 addx->set_req(2, add2->in(1));
189 addx = phase->transform(addx);
190 set_req(1, addx);
191 set_req(2, a22);
192 progress = this;
193 PhaseIterGVN *igvn = phase->is_IterGVN();
194 if (add2->outcnt() == 0 && igvn) {
195 // add disconnected.
196 igvn->_worklist.push(add2);
197 }
198 }
199 }
200
201 return progress;
202 }
203
204 //------------------------------Value-----------------------------------------
205 // An add node sums it's two _in. If one input is an RSD, we must mixin
206 // the other input's symbols.
207 const Type* AddNode::Value(PhaseGVN* phase) const {
208 // Either input is TOP ==> the result is TOP
209 const Type *t1 = phase->type( in(1) );
210 const Type *t2 = phase->type( in(2) );
211 if( t1 == Type::TOP ) return Type::TOP;
212 if( t2 == Type::TOP ) return Type::TOP;
213
214 // Either input is BOTTOM ==> the result is the local BOTTOM
215 const Type *bot = bottom_type();
216 if( (t1 == bot) || (t2 == bot) ||
217 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
218 return bot;
219
220 // Check for an addition involving the additive identity
221 const Type *tadd = add_of_identity( t1, t2 );
222 if( tadd ) return tadd;
223
224 return add_ring(t1,t2); // Local flavor of type addition
225 }
226
227 //------------------------------add_identity-----------------------------------
228 // Check for addition of the identity
229 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
230 const Type *zero = add_id(); // The additive identity
231 if( t1->higher_equal( zero ) ) return t2;
232 if( t2->higher_equal( zero ) ) return t1;
233
234 return NULL;
235 }
236
237
238 //=============================================================================
239 //------------------------------Idealize---------------------------------------
240 Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) {
241 Node* in1 = in(1);
242 Node* in2 = in(2);
243 int op1 = in1->Opcode();
244 int op2 = in2->Opcode();
245 // Fold (con1-x)+con2 into (con1+con2)-x
246 if ( op1 == Op_AddI && op2 == Op_SubI ) {
247 // Swap edges to try optimizations below
248 in1 = in2;
249 in2 = in(1);
250 op1 = op2;
251 op2 = in2->Opcode();
252 }
253 if( op1 == Op_SubI ) {
254 const Type *t_sub1 = phase->type( in1->in(1) );
255 const Type *t_2 = phase->type( in2 );
256 if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
257 return new SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ), in1->in(2) );
258 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
259 if( op2 == Op_SubI ) {
260 // Check for dead cycle: d = (a-b)+(c-d)
261 assert( in1->in(2) != this && in2->in(2) != this,
262 "dead loop in AddINode::Ideal" );
263 Node *sub = new SubINode(NULL, NULL);
264 sub->init_req(1, phase->transform(new AddINode(in1->in(1), in2->in(1) ) ));
265 sub->init_req(2, phase->transform(new AddINode(in1->in(2), in2->in(2) ) ));
266 return sub;
267 }
268 // Convert "(a-b)+(b+c)" into "(a+c)"
269 if( op2 == Op_AddI && in1->in(2) == in2->in(1) ) {
270 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
271 return new AddINode(in1->in(1), in2->in(2));
272 }
273 // Convert "(a-b)+(c+b)" into "(a+c)"
274 if( op2 == Op_AddI && in1->in(2) == in2->in(2) ) {
275 assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
276 return new AddINode(in1->in(1), in2->in(1));
277 }
278 // Convert "(a-b)+(b-c)" into "(a-c)"
279 if( op2 == Op_SubI && in1->in(2) == in2->in(1) ) {
280 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
281 return new SubINode(in1->in(1), in2->in(2));
282 }
283 // Convert "(a-b)+(c-a)" into "(c-b)"
284 if( op2 == Op_SubI && in1->in(1) == in2->in(2) ) {
285 assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
286 return new SubINode(in2->in(1), in1->in(2));
287 }
288 }
289
290 // Convert "x+(0-y)" into "(x-y)"
291 if( op2 == Op_SubI && phase->type(in2->in(1)) == TypeInt::ZERO )
292 return new SubINode(in1, in2->in(2) );
293
294 // Convert "(0-y)+x" into "(x-y)"
295 if( op1 == Op_SubI && phase->type(in1->in(1)) == TypeInt::ZERO )
296 return new SubINode( in2, in1->in(2) );
297
298 // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
299 // Helps with array allocation math constant folding
300 // See 4790063:
301 // Unrestricted transformation is unsafe for some runtime values of 'x'
302 // ( x == 0, z == 1, y == -1 ) fails
303 // ( x == -5, z == 1, y == 1 ) fails
304 // Transform works for small z and small negative y when the addition
305 // (x + (y << z)) does not cross zero.
306 // Implement support for negative y and (x >= -(y << z))
307 // Have not observed cases where type information exists to support
308 // positive y and (x <= -(y << z))
309 if( op1 == Op_URShiftI && op2 == Op_ConI &&
310 in1->in(2)->Opcode() == Op_ConI ) {
311 jint z = phase->type( in1->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
312 jint y = phase->type( in2 )->is_int()->get_con();
313
314 if( z < 5 && -5 < y && y < 0 ) {
315 const Type *t_in11 = phase->type(in1->in(1));
316 if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) {
317 Node *a = phase->transform( new AddINode( in1->in(1), phase->intcon(y<<z) ) );
318 return new URShiftINode( a, in1->in(2) );
319 }
320 }
321 }
322
323 return AddNode::Ideal(phase, can_reshape);
324 }
325
326
327 //------------------------------Identity---------------------------------------
328 // Fold (x-y)+y OR y+(x-y) into x
329 Node* AddINode::Identity(PhaseGVN* phase) {
330 if( in(1)->Opcode() == Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) {
331 return in(1)->in(1);
332 }
333 else if( in(2)->Opcode() == Op_SubI && phase->eqv(in(2)->in(2),in(1)) ) {
334 return in(2)->in(1);
335 }
336 return AddNode::Identity(phase);
337 }
338
339
340 //------------------------------add_ring---------------------------------------
341 // Supplied function returns the sum of the inputs. Guaranteed never
342 // to be passed a TOP or BOTTOM type, these are filtered out by
343 // pre-check.
344 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
345 const TypeInt *r0 = t0->is_int(); // Handy access
346 const TypeInt *r1 = t1->is_int();
347 int lo = java_add(r0->_lo, r1->_lo);
348 int hi = java_add(r0->_hi, r1->_hi);
349 if( !(r0->is_con() && r1->is_con()) ) {
350 // Not both constants, compute approximate result
351 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
352 lo = min_jint; hi = max_jint; // Underflow on the low side
353 }
354 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
355 lo = min_jint; hi = max_jint; // Overflow on the high side
356 }
357 if( lo > hi ) { // Handle overflow
358 lo = min_jint; hi = max_jint;
359 }
360 } else {
361 // both constants, compute precise result using 'lo' and 'hi'
362 // Semantics define overflow and underflow for integer addition
363 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
364 }
365 return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
366 }
367
368
369 //=============================================================================
370 //------------------------------Idealize---------------------------------------
371 Node *AddLNode::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 // Fold (con1-x)+con2 into (con1+con2)-x
377 if ( op1 == Op_AddL && op2 == Op_SubL ) {
378 // Swap edges to try optimizations below
379 in1 = in2;
380 in2 = in(1);
381 op1 = op2;
382 op2 = in2->Opcode();
383 }
384 // Fold (con1-x)+con2 into (con1+con2)-x
385 if( op1 == Op_SubL ) {
386 const Type *t_sub1 = phase->type( in1->in(1) );
387 const Type *t_2 = phase->type( in2 );
388 if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
389 return new SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ), in1->in(2) );
390 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
391 if( op2 == Op_SubL ) {
392 // Check for dead cycle: d = (a-b)+(c-d)
393 assert( in1->in(2) != this && in2->in(2) != this,
394 "dead loop in AddLNode::Ideal" );
395 Node *sub = new SubLNode(NULL, NULL);
396 sub->init_req(1, phase->transform(new AddLNode(in1->in(1), in2->in(1) ) ));
397 sub->init_req(2, phase->transform(new AddLNode(in1->in(2), in2->in(2) ) ));
398 return sub;
399 }
400 // Convert "(a-b)+(b+c)" into "(a+c)"
401 if( op2 == Op_AddL && in1->in(2) == in2->in(1) ) {
402 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
403 return new AddLNode(in1->in(1), in2->in(2));
404 }
405 // Convert "(a-b)+(c+b)" into "(a+c)"
406 if( op2 == Op_AddL && in1->in(2) == in2->in(2) ) {
407 assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
408 return new AddLNode(in1->in(1), in2->in(1));
409 }
410 // Convert "(a-b)+(b-c)" into "(a-c)"
411 if( op2 == Op_SubL && in1->in(2) == in2->in(1) ) {
412 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
413 return new SubLNode(in1->in(1), in2->in(2));
414 }
415 // Convert "(a-b)+(c-a)" into "(c-b)"
416 if( op2 == Op_SubL && in1->in(1) == in1->in(2) ) {
417 assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
418 return new SubLNode(in2->in(1), in1->in(2));
419 }
420 }
421
422 // Convert "x+(0-y)" into "(x-y)"
423 if( op2 == Op_SubL && phase->type(in2->in(1)) == TypeLong::ZERO )
424 return new SubLNode( in1, in2->in(2) );
425
426 // Convert "(0-y)+x" into "(x-y)"
427 if( op1 == Op_SubL && phase->type(in1->in(1)) == TypeInt::ZERO )
428 return new SubLNode( in2, in1->in(2) );
429
430 // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)"
431 // into "(X<<1)+Y" and let shift-folding happen.
432 if( op2 == Op_AddL &&
433 in2->in(1) == in1 &&
434 op1 != Op_ConL &&
435 0 ) {
436 Node *shift = phase->transform(new LShiftLNode(in1,phase->intcon(1)));
437 return new AddLNode(shift,in2->in(2));
438 }
439
440 return AddNode::Ideal(phase, can_reshape);
441 }
442
443
444 //------------------------------Identity---------------------------------------
445 // Fold (x-y)+y OR y+(x-y) into x
446 Node* AddLNode::Identity(PhaseGVN* phase) {
447 if( in(1)->Opcode() == Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) {
448 return in(1)->in(1);
449 }
450 else if( in(2)->Opcode() == Op_SubL && phase->eqv(in(2)->in(2),in(1)) ) {
451 return in(2)->in(1);
452 }
453 return AddNode::Identity(phase);
454 }
455
456
457 //------------------------------add_ring---------------------------------------
458 // Supplied function returns the sum of the inputs. Guaranteed never
459 // to be passed a TOP or BOTTOM type, these are filtered out by
460 // pre-check.
461 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
462 const TypeLong *r0 = t0->is_long(); // Handy access
463 const TypeLong *r1 = t1->is_long();
464 jlong lo = java_add(r0->_lo, r1->_lo);
465 jlong hi = java_add(r0->_hi, r1->_hi);
466 if( !(r0->is_con() && r1->is_con()) ) {
467 // Not both constants, compute approximate result
468 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
469 lo =min_jlong; hi = max_jlong; // Underflow on the low side
470 }
471 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
472 lo = min_jlong; hi = max_jlong; // Overflow on the high side
473 }
474 if( lo > hi ) { // Handle overflow
475 lo = min_jlong; hi = max_jlong;
476 }
477 } else {
478 // both constants, compute precise result using 'lo' and 'hi'
479 // Semantics define overflow and underflow for integer addition
480 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
481 }
482 return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
483 }
484
485
486 //=============================================================================
487 //------------------------------add_of_identity--------------------------------
488 // Check for addition of the identity
489 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
490 // x ADD 0 should return x unless 'x' is a -zero
491 //
492 // const Type *zero = add_id(); // The additive identity
493 // jfloat f1 = t1->getf();
494 // jfloat f2 = t2->getf();
495 //
496 // if( t1->higher_equal( zero ) ) return t2;
497 // if( t2->higher_equal( zero ) ) return t1;
498
499 return NULL;
500 }
501
502 //------------------------------add_ring---------------------------------------
503 // Supplied function returns the sum of the inputs.
504 // This also type-checks the inputs for sanity. Guaranteed never to
505 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
506 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
507 // We must be adding 2 float constants.
508 return TypeF::make( t0->getf() + t1->getf() );
509 }
510
511 //------------------------------Ideal------------------------------------------
512 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
513 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
514 return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
515 }
516
517 // Floating point additions are not associative because of boundary conditions (infinity)
518 return commute(this,
519 phase->type( in(1) )->singleton(),
520 phase->type( in(2) )->singleton() ) ? this : NULL;
521 }
522
523
524 //=============================================================================
525 //------------------------------add_of_identity--------------------------------
526 // Check for addition of the identity
527 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
528 // x ADD 0 should return x unless 'x' is a -zero
529 //
530 // const Type *zero = add_id(); // The additive identity
531 // jfloat f1 = t1->getf();
532 // jfloat f2 = t2->getf();
533 //
534 // if( t1->higher_equal( zero ) ) return t2;
535 // if( t2->higher_equal( zero ) ) return t1;
536
537 return NULL;
538 }
539 //------------------------------add_ring---------------------------------------
540 // Supplied function returns the sum of the inputs.
541 // This also type-checks the inputs for sanity. Guaranteed never to
542 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
543 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
544 // We must be adding 2 double constants.
545 return TypeD::make( t0->getd() + t1->getd() );
546 }
547
548 //------------------------------Ideal------------------------------------------
549 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
550 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
551 return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
552 }
553
554 // Floating point additions are not associative because of boundary conditions (infinity)
555 return commute(this,
556 phase->type( in(1) )->singleton(),
557 phase->type( in(2) )->singleton() ) ? this : NULL;
558 }
559
560
561 //=============================================================================
562 //------------------------------Identity---------------------------------------
563 // If one input is a constant 0, return the other input.
564 Node* AddPNode::Identity(PhaseGVN* phase) {
565 return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
566 }
567
568 //------------------------------Idealize---------------------------------------
569 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
570 // Bail out if dead inputs
571 if( phase->type( in(Address) ) == Type::TOP ) return NULL;
572
573 // If the left input is an add of a constant, flatten the expression tree.
574 const Node *n = in(Address);
575 if (n->is_AddP() && n->in(Base) == in(Base)) {
576 const AddPNode *addp = n->as_AddP(); // Left input is an AddP
577 assert( !addp->in(Address)->is_AddP() ||
578 addp->in(Address)->as_AddP() != addp,
579 "dead loop in AddPNode::Ideal" );
580 // Type of left input's right input
581 const Type *t = phase->type( addp->in(Offset) );
582 if( t == Type::TOP ) return NULL;
583 const TypeX *t12 = t->is_intptr_t();
584 if( t12->is_con() ) { // Left input is an add of a constant?
585 // If the right input is a constant, combine constants
586 const Type *temp_t2 = phase->type( in(Offset) );
587 if( temp_t2 == Type::TOP ) return NULL;
588 const TypeX *t2 = temp_t2->is_intptr_t();
589 Node* address;
590 Node* offset;
591 if( t2->is_con() ) {
592 // The Add of the flattened expression
593 address = addp->in(Address);
594 offset = phase->MakeConX(t2->get_con() + t12->get_con());
595 } else {
596 // Else move the constant to the right. ((A+con)+B) into ((A+B)+con)
597 address = phase->transform(new AddPNode(in(Base),addp->in(Address),in(Offset)));
598 offset = addp->in(Offset);
599 }
600 PhaseIterGVN *igvn = phase->is_IterGVN();
601 if( igvn ) {
602 set_req_X(Address,address,igvn);
603 set_req_X(Offset,offset,igvn);
604 } else {
605 set_req(Address,address);
606 set_req(Offset,offset);
607 }
608 return this;
609 }
610 }
611
612 // Raw pointers?
613 if( in(Base)->bottom_type() == Type::TOP ) {
614 // If this is a NULL+long form (from unsafe accesses), switch to a rawptr.
615 if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
616 Node* offset = in(Offset);
617 return new CastX2PNode(offset);
618 }
619 }
620
621 // If the right is an add of a constant, push the offset down.
622 // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
623 // The idea is to merge array_base+scaled_index groups together,
624 // and only have different constant offsets from the same base.
625 const Node *add = in(Offset);
626 if( add->Opcode() == Op_AddX && add->in(1) != add ) {
627 const Type *t22 = phase->type( add->in(2) );
628 if( t22->singleton() && (t22 != Type::TOP) ) { // Right input is an add of a constant?
629 set_req(Address, phase->transform(new AddPNode(in(Base),in(Address),add->in(1))));
630 set_req(Offset, add->in(2));
631 PhaseIterGVN *igvn = phase->is_IterGVN();
632 if (add->outcnt() == 0 && igvn) {
633 // add disconnected.
634 igvn->_worklist.push((Node*)add);
635 }
636 return this; // Made progress
637 }
638 }
639
640 return NULL; // No progress
641 }
642
643 //------------------------------bottom_type------------------------------------
644 // Bottom-type is the pointer-type with unknown offset.
645 const Type *AddPNode::bottom_type() const {
646 if (in(Address) == NULL) return TypePtr::BOTTOM;
647 const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
648 if( !tp ) return Type::TOP; // TOP input means TOP output
649 assert( in(Offset)->Opcode() != Op_ConP, "" );
650 const Type *t = in(Offset)->bottom_type();
651 if( t == Type::TOP )
652 return tp->add_offset(Type::OffsetTop);
653 const TypeX *tx = t->is_intptr_t();
654 intptr_t txoffset = Type::OffsetBot;
655 if (tx->is_con()) { // Left input is an add of a constant?
656 txoffset = tx->get_con();
657 }
658 if (tp->isa_aryptr()) {
659 // In the case of a flattened value type array, each field has its
660 // own slice so we need to extract the field being accessed from
661 // the address computation
662 return tp->is_aryptr()->add_field_offset_and_offset(txoffset);
663 }
664 return tp->add_offset(txoffset);
665 }
666
667 //------------------------------Value------------------------------------------
668 const Type* AddPNode::Value(PhaseGVN* phase) const {
669 // Either input is TOP ==> the result is TOP
670 const Type *t1 = phase->type( in(Address) );
671 const Type *t2 = phase->type( in(Offset) );
672 if( t1 == Type::TOP ) return Type::TOP;
673 if( t2 == Type::TOP ) return Type::TOP;
674
675 // Left input is a pointer
676 const TypePtr *p1 = t1->isa_ptr();
677 // Right input is an int
678 const TypeX *p2 = t2->is_intptr_t();
679 // Add 'em
680 intptr_t p2offset = Type::OffsetBot;
681 if (p2->is_con()) { // Left input is an add of a constant?
682 p2offset = p2->get_con();
683 }
684 if (p1->isa_aryptr()) {
685 // In the case of a flattened value type array, each field has its
686 // own slice so we need to extract the field being accessed from
687 // the address computation
688 return p1->is_aryptr()->add_field_offset_and_offset(p2offset);
689 }
690 return p1->add_offset(p2offset);
691 }
692
693 //------------------------Ideal_base_and_offset--------------------------------
694 // Split an oop pointer into a base and offset.
695 // (The offset might be Type::OffsetBot in the case of an array.)
696 // Return the base, or NULL if failure.
697 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseTransform* phase,
698 // second return value:
699 intptr_t& offset) {
700 if (ptr->is_AddP()) {
701 Node* base = ptr->in(AddPNode::Base);
702 Node* addr = ptr->in(AddPNode::Address);
703 Node* offs = ptr->in(AddPNode::Offset);
704 if (base == addr || base->is_top()) {
705 offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
706 if (offset != Type::OffsetBot) {
707 return addr;
708 }
709 }
710 }
711 offset = Type::OffsetBot;
712 return NULL;
713 }
714
715 //------------------------------unpack_offsets----------------------------------
716 // Collect the AddP offset values into the elements array, giving up
717 // if there are more than length.
718 int AddPNode::unpack_offsets(Node* elements[], int length) {
719 int count = 0;
720 Node* addr = this;
721 Node* base = addr->in(AddPNode::Base);
722 while (addr->is_AddP()) {
723 if (addr->in(AddPNode::Base) != base) {
724 // give up
725 return -1;
726 }
727 elements[count++] = addr->in(AddPNode::Offset);
728 if (count == length) {
729 // give up
730 return -1;
731 }
732 addr = addr->in(AddPNode::Address);
733 }
734 if (addr != base) {
735 return -1;
736 }
737 return count;
738 }
739
740 //------------------------------match_edge-------------------------------------
741 // Do we Match on this edge index or not? Do not match base pointer edge
742 uint AddPNode::match_edge(uint idx) const {
743 return idx > Base;
744 }
745
746 //=============================================================================
747 //------------------------------Identity---------------------------------------
748 Node* OrINode::Identity(PhaseGVN* phase) {
749 // x | x => x
750 if (phase->eqv(in(1), in(2))) {
751 return in(1);
752 }
753
754 return AddNode::Identity(phase);
755 }
756
757 //------------------------------add_ring---------------------------------------
758 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
759 // the logical operations the ring's ADD is really a logical OR function.
760 // This also type-checks the inputs for sanity. Guaranteed never to
761 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
762 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
763 const TypeInt *r0 = t0->is_int(); // Handy access
764 const TypeInt *r1 = t1->is_int();
765
766 // If both args are bool, can figure out better types
767 if ( r0 == TypeInt::BOOL ) {
768 if ( r1 == TypeInt::ONE) {
769 return TypeInt::ONE;
770 } else if ( r1 == TypeInt::BOOL ) {
771 return TypeInt::BOOL;
772 }
773 } else if ( r0 == TypeInt::ONE ) {
774 if ( r1 == TypeInt::BOOL ) {
775 return TypeInt::ONE;
776 }
777 }
778
779 // If either input is not a constant, just return all integers.
780 if( !r0->is_con() || !r1->is_con() )
781 return TypeInt::INT; // Any integer, but still no symbols.
782
783 // Otherwise just OR them bits.
784 return TypeInt::make( r0->get_con() | r1->get_con() );
785 }
786
787 //=============================================================================
788 //------------------------------Identity---------------------------------------
789 Node* OrLNode::Identity(PhaseGVN* phase) {
790 // x | x => x
791 if (phase->eqv(in(1), in(2))) {
792 return in(1);
793 }
794
795 return AddNode::Identity(phase);
796 }
797
798 //------------------------------add_ring---------------------------------------
799 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
800 const TypeLong *r0 = t0->is_long(); // Handy access
801 const TypeLong *r1 = t1->is_long();
802
803 // If either input is not a constant, just return all integers.
804 if( !r0->is_con() || !r1->is_con() )
805 return TypeLong::LONG; // Any integer, but still no symbols.
806
807 // Otherwise just OR them bits.
808 return TypeLong::make( r0->get_con() | r1->get_con() );
809 }
810
811 //=============================================================================
812 //------------------------------add_ring---------------------------------------
813 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
814 // the logical operations the ring's ADD is really a logical OR function.
815 // This also type-checks the inputs for sanity. Guaranteed never to
816 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
817 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
818 const TypeInt *r0 = t0->is_int(); // Handy access
819 const TypeInt *r1 = t1->is_int();
820
821 // Complementing a boolean?
822 if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
823 || r1 == TypeInt::BOOL))
824 return TypeInt::BOOL;
825
826 if( !r0->is_con() || !r1->is_con() ) // Not constants
827 return TypeInt::INT; // Any integer, but still no symbols.
828
829 // Otherwise just XOR them bits.
830 return TypeInt::make( r0->get_con() ^ r1->get_con() );
831 }
832
833 //=============================================================================
834 //------------------------------add_ring---------------------------------------
835 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
836 const TypeLong *r0 = t0->is_long(); // Handy access
837 const TypeLong *r1 = t1->is_long();
838
839 // If either input is not a constant, just return all integers.
840 if( !r0->is_con() || !r1->is_con() )
841 return TypeLong::LONG; // Any integer, but still no symbols.
842
843 // Otherwise just OR them bits.
844 return TypeLong::make( r0->get_con() ^ r1->get_con() );
845 }
846
847 //=============================================================================
848 //------------------------------add_ring---------------------------------------
849 // Supplied function returns the sum of the inputs.
850 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
851 const TypeInt *r0 = t0->is_int(); // Handy access
852 const TypeInt *r1 = t1->is_int();
853
854 // Otherwise just MAX them bits.
855 return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
856 }
857
858 //=============================================================================
859 //------------------------------Idealize---------------------------------------
860 // MINs show up in range-check loop limit calculations. Look for
861 // "MIN2(x+c0,MIN2(y,x+c1))". Pick the smaller constant: "MIN2(x+c0,y)"
862 Node *MinINode::Ideal(PhaseGVN *phase, bool can_reshape) {
863 Node *progress = NULL;
864 // Force a right-spline graph
865 Node *l = in(1);
866 Node *r = in(2);
867 // Transform MinI1( MinI2(a,b), c) into MinI1( a, MinI2(b,c) )
868 // to force a right-spline graph for the rest of MinINode::Ideal().
869 if( l->Opcode() == Op_MinI ) {
870 assert( l != l->in(1), "dead loop in MinINode::Ideal" );
871 r = phase->transform(new MinINode(l->in(2),r));
872 l = l->in(1);
873 set_req(1, l);
874 set_req(2, r);
875 return this;
876 }
877
878 // Get left input & constant
879 Node *x = l;
880 int x_off = 0;
881 if( x->Opcode() == Op_AddI && // Check for "x+c0" and collect constant
882 x->in(2)->is_Con() ) {
883 const Type *t = x->in(2)->bottom_type();
884 if( t == Type::TOP ) return NULL; // No progress
885 x_off = t->is_int()->get_con();
886 x = x->in(1);
887 }
888
889 // Scan a right-spline-tree for MINs
890 Node *y = r;
891 int y_off = 0;
892 // Check final part of MIN tree
893 if( y->Opcode() == Op_AddI && // Check for "y+c1" and collect constant
894 y->in(2)->is_Con() ) {
895 const Type *t = y->in(2)->bottom_type();
896 if( t == Type::TOP ) return NULL; // No progress
897 y_off = t->is_int()->get_con();
898 y = y->in(1);
899 }
900 if( x->_idx > y->_idx && r->Opcode() != Op_MinI ) {
901 swap_edges(1, 2);
902 return this;
903 }
904
905
906 if( r->Opcode() == Op_MinI ) {
907 assert( r != r->in(2), "dead loop in MinINode::Ideal" );
908 y = r->in(1);
909 // Check final part of MIN tree
910 if( y->Opcode() == Op_AddI &&// Check for "y+c1" and collect constant
911 y->in(2)->is_Con() ) {
912 const Type *t = y->in(2)->bottom_type();
913 if( t == Type::TOP ) return NULL; // No progress
914 y_off = t->is_int()->get_con();
915 y = y->in(1);
916 }
917
918 if( x->_idx > y->_idx )
919 return new MinINode(r->in(1),phase->transform(new MinINode(l,r->in(2))));
920
921 // See if covers: MIN2(x+c0,MIN2(y+c1,z))
922 if( !phase->eqv(x,y) ) return NULL;
923 // If (y == x) transform MIN2(x+c0, MIN2(x+c1,z)) into
924 // MIN2(x+c0 or x+c1 which less, z).
925 return new MinINode(phase->transform(new AddINode(x,phase->intcon(MIN2(x_off,y_off)))),r->in(2));
926 } else {
927 // See if covers: MIN2(x+c0,y+c1)
928 if( !phase->eqv(x,y) ) return NULL;
929 // If (y == x) transform MIN2(x+c0,x+c1) into x+c0 or x+c1 which less.
930 return new AddINode(x,phase->intcon(MIN2(x_off,y_off)));
931 }
932
933 }
934
935 //------------------------------add_ring---------------------------------------
936 // Supplied function returns the sum of the inputs.
937 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
938 const TypeInt *r0 = t0->is_int(); // Handy access
939 const TypeInt *r1 = t1->is_int();
940
941 // Otherwise just MIN them bits.
942 return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
943 }