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/cfgnode.hpp"
29 #include "opto/connode.hpp"
30 #include "opto/machnode.hpp"
31 #include "opto/mulnode.hpp"
32 #include "opto/phaseX.hpp"
33 #include "opto/subnode.hpp"
34 #if INCLUDE_ALL_GCS
35 #include "gc_implementation/shenandoah/c2/shenandoahSupport.hpp"
36 #endif
37
38 // Portions of code courtesy of Clifford Click
39
40 // Classic Add functionality. This covers all the usual 'add' behaviors for
41 // an algebraic ring. Add-integer, add-float, add-double, and binary-or are
42 // all inherited from this class. The various identity values are supplied
43 // by virtual functions.
44
45
46 //=============================================================================
47 //------------------------------hash-------------------------------------------
48 // Hash function over AddNodes. Needs to be commutative; i.e., I swap
49 // (commute) inputs to AddNodes willy-nilly so the hash function must return
50 // the same value in the presence of edge swapping.
51 uint AddNode::hash() const {
52 return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
53 }
54
55 //------------------------------Identity---------------------------------------
56 // If either input is a constant 0, return the other input.
57 Node *AddNode::Identity( PhaseTransform *phase ) {
58 const Type *zero = add_id(); // The additive identity
59 if( phase->type( in(1) )->higher_equal( zero ) ) return in(2);
60 if( phase->type( in(2) )->higher_equal( zero ) ) return in(1);
61 return this;
62 }
63
64 //------------------------------commute----------------------------------------
65 // Commute operands to move loads and constants to the right.
66 static bool commute( Node *add, int con_left, int con_right ) {
67 Node *in1 = add->in(1);
68 Node *in2 = add->in(2);
69
70 // Convert "1+x" into "x+1".
71 // Right is a constant; leave it
72 if( con_right ) return false;
73 // Left is a constant; move it right.
74 if( con_left ) {
75 add->swap_edges(1, 2);
76 return true;
77 }
78
79 // Convert "Load+x" into "x+Load".
80 // Now check for loads
81 if (in2->is_Load()) {
82 if (!in1->is_Load()) {
83 // already x+Load to return
84 return false;
85 }
86 // both are loads, so fall through to sort inputs by idx
87 } else if( in1->is_Load() ) {
88 // Left is a Load and Right is not; move it right.
89 add->swap_edges(1, 2);
90 return true;
91 }
92
93 PhiNode *phi;
94 // Check for tight loop increments: Loop-phi of Add of loop-phi
95 if( in1->is_Phi() && (phi = in1->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add)
96 return false;
97 if( in2->is_Phi() && (phi = in2->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add){
98 add->swap_edges(1, 2);
99 return true;
100 }
101
102 // Otherwise, sort inputs (commutativity) to help value numbering.
103 if( in1->_idx > in2->_idx ) {
104 add->swap_edges(1, 2);
105 return true;
106 }
107 return false;
108 }
109
110 //------------------------------Idealize---------------------------------------
111 // If we get here, we assume we are associative!
112 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
113 const Type *t1 = phase->type( in(1) );
114 const Type *t2 = phase->type( in(2) );
115 int con_left = t1->singleton();
116 int con_right = t2->singleton();
117
118 // Check for commutative operation desired
119 if( commute(this,con_left,con_right) ) return this;
120
121 AddNode *progress = NULL; // Progress flag
122
123 // Convert "(x+1)+2" into "x+(1+2)". If the right input is a
124 // constant, and the left input is an add of a constant, flatten the
125 // expression tree.
126 Node *add1 = in(1);
127 Node *add2 = in(2);
128 int add1_op = add1->Opcode();
129 int this_op = Opcode();
130 if( con_right && t2 != Type::TOP && // Right input is a constant?
131 add1_op == this_op ) { // Left input is an Add?
132
133 // Type of left _in right input
134 const Type *t12 = phase->type( add1->in(2) );
135 if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
136 // Check for rare case of closed data cycle which can happen inside
137 // unreachable loops. In these cases the computation is undefined.
138 #ifdef ASSERT
139 Node *add11 = add1->in(1);
140 int add11_op = add11->Opcode();
141 if( (add1 == add1->in(1))
142 || (add11_op == this_op && add11->in(1) == add1) ) {
143 assert(false, "dead loop in AddNode::Ideal");
144 }
145 #endif
146 // The Add of the flattened expression
147 Node *x1 = add1->in(1);
148 Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 ));
149 PhaseIterGVN *igvn = phase->is_IterGVN();
150 if( igvn ) {
151 set_req_X(2,x2,igvn);
152 set_req_X(1,x1,igvn);
153 } else {
154 set_req(2,x2);
155 set_req(1,x1);
156 }
157 progress = this; // Made progress
158 add1 = in(1);
159 add1_op = add1->Opcode();
160 }
161 }
162
163 // Convert "(x+1)+y" into "(x+y)+1". Push constants down the expression tree.
164 if( add1_op == this_op && !con_right ) {
165 Node *a12 = add1->in(2);
166 const Type *t12 = phase->type( a12 );
167 if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) &&
168 !(add1->in(1)->is_Phi() && add1->in(1)->as_Phi()->is_tripcount()) ) {
169 assert(add1->in(1) != this, "dead loop in AddNode::Ideal");
170 add2 = add1->clone();
171 add2->set_req(2, in(2));
172 add2 = phase->transform(add2);
173 set_req(1, add2);
174 set_req(2, a12);
175 progress = this;
176 add2 = a12;
177 }
178 }
179
180 // Convert "x+(y+1)" into "(x+y)+1". Push constants down the expression tree.
181 int add2_op = add2->Opcode();
182 if( add2_op == this_op && !con_left ) {
183 Node *a22 = add2->in(2);
184 const Type *t22 = phase->type( a22 );
185 if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) &&
186 !(add2->in(1)->is_Phi() && add2->in(1)->as_Phi()->is_tripcount()) ) {
187 assert(add2->in(1) != this, "dead loop in AddNode::Ideal");
188 Node *addx = add2->clone();
189 addx->set_req(1, in(1));
190 addx->set_req(2, add2->in(1));
191 addx = phase->transform(addx);
192 set_req(1, addx);
193 set_req(2, a22);
194 progress = this;
195 PhaseIterGVN *igvn = phase->is_IterGVN();
196 if (add2->outcnt() == 0 && igvn) {
197 // add disconnected.
198 igvn->_worklist.push(add2);
199 }
200 }
201 }
202
203 return progress;
204 }
205
206 //------------------------------Value-----------------------------------------
207 // An add node sums it's two _in. If one input is an RSD, we must mixin
208 // the other input's symbols.
209 const Type *AddNode::Value( PhaseTransform *phase ) const {
210 // Either input is TOP ==> the result is TOP
211 const Type *t1 = phase->type( in(1) );
212 const Type *t2 = phase->type( in(2) );
213 if( t1 == Type::TOP ) return Type::TOP;
214 if( t2 == Type::TOP ) return Type::TOP;
215
216 // Either input is BOTTOM ==> the result is the local BOTTOM
217 const Type *bot = bottom_type();
218 if( (t1 == bot) || (t2 == bot) ||
219 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
220 return bot;
221
222 // Check for an addition involving the additive identity
223 const Type *tadd = add_of_identity( t1, t2 );
224 if( tadd ) return tadd;
225
226 return add_ring(t1,t2); // Local flavor of type addition
227 }
228
229 //------------------------------add_identity-----------------------------------
230 // Check for addition of the identity
231 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
232 const Type *zero = add_id(); // The additive identity
233 if( t1->higher_equal( zero ) ) return t2;
234 if( t2->higher_equal( zero ) ) return t1;
235
236 return NULL;
237 }
238
239
240 //=============================================================================
241 //------------------------------Idealize---------------------------------------
242 Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) {
243 Node* in1 = in(1);
244 Node* in2 = in(2);
245 int op1 = in1->Opcode();
246 int op2 = in2->Opcode();
247 // Fold (con1-x)+con2 into (con1+con2)-x
248 if ( op1 == Op_AddI && op2 == Op_SubI ) {
249 // Swap edges to try optimizations below
250 in1 = in2;
251 in2 = in(1);
252 op1 = op2;
253 op2 = in2->Opcode();
254 }
255 if( op1 == Op_SubI ) {
256 const Type *t_sub1 = phase->type( in1->in(1) );
257 const Type *t_2 = phase->type( in2 );
258 if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
259 return new (phase->C) SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ),
260 in1->in(2) );
261 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
262 if( op2 == Op_SubI ) {
263 // Check for dead cycle: d = (a-b)+(c-d)
264 assert( in1->in(2) != this && in2->in(2) != this,
265 "dead loop in AddINode::Ideal" );
266 Node *sub = new (phase->C) SubINode(NULL, NULL);
267 sub->init_req(1, phase->transform(new (phase->C) AddINode(in1->in(1), in2->in(1) ) ));
268 sub->init_req(2, phase->transform(new (phase->C) AddINode(in1->in(2), in2->in(2) ) ));
269 return sub;
270 }
271 // Convert "(a-b)+(b+c)" into "(a+c)"
272 if( op2 == Op_AddI && in1->in(2) == in2->in(1) ) {
273 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
274 return new (phase->C) AddINode(in1->in(1), in2->in(2));
275 }
276 // Convert "(a-b)+(c+b)" into "(a+c)"
277 if( op2 == Op_AddI && in1->in(2) == in2->in(2) ) {
278 assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
279 return new (phase->C) AddINode(in1->in(1), in2->in(1));
280 }
281 // Convert "(a-b)+(b-c)" into "(a-c)"
282 if( op2 == Op_SubI && in1->in(2) == in2->in(1) ) {
283 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
284 return new (phase->C) SubINode(in1->in(1), in2->in(2));
285 }
286 // Convert "(a-b)+(c-a)" into "(c-b)"
287 if( op2 == Op_SubI && in1->in(1) == in2->in(2) ) {
288 assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
289 return new (phase->C) SubINode(in2->in(1), in1->in(2));
290 }
291 }
292
293 // Convert "x+(0-y)" into "(x-y)"
294 if( op2 == Op_SubI && phase->type(in2->in(1)) == TypeInt::ZERO )
295 return new (phase->C) SubINode(in1, in2->in(2) );
296
297 // Convert "(0-y)+x" into "(x-y)"
298 if( op1 == Op_SubI && phase->type(in1->in(1)) == TypeInt::ZERO )
299 return new (phase->C) SubINode( in2, in1->in(2) );
300
301 // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
302 // Helps with array allocation math constant folding
303 // See 4790063:
304 // Unrestricted transformation is unsafe for some runtime values of 'x'
305 // ( x == 0, z == 1, y == -1 ) fails
306 // ( x == -5, z == 1, y == 1 ) fails
307 // Transform works for small z and small negative y when the addition
308 // (x + (y << z)) does not cross zero.
309 // Implement support for negative y and (x >= -(y << z))
310 // Have not observed cases where type information exists to support
311 // positive y and (x <= -(y << z))
312 if( op1 == Op_URShiftI && op2 == Op_ConI &&
313 in1->in(2)->Opcode() == Op_ConI ) {
314 jint z = phase->type( in1->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
315 jint y = phase->type( in2 )->is_int()->get_con();
316
317 if( z < 5 && -5 < y && y < 0 ) {
318 const Type *t_in11 = phase->type(in1->in(1));
319 if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) {
320 Node *a = phase->transform( new (phase->C) AddINode( in1->in(1), phase->intcon(y<<z) ) );
321 return new (phase->C) URShiftINode( a, in1->in(2) );
322 }
323 }
324 }
325
326 return AddNode::Ideal(phase, can_reshape);
327 }
328
329
330 //------------------------------Identity---------------------------------------
331 // Fold (x-y)+y OR y+(x-y) into x
332 Node *AddINode::Identity( PhaseTransform *phase ) {
333 if( in(1)->Opcode() == Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) {
334 return in(1)->in(1);
335 }
336 else if( in(2)->Opcode() == Op_SubI && phase->eqv(in(2)->in(2),in(1)) ) {
337 return in(2)->in(1);
338 }
339 return AddNode::Identity(phase);
340 }
341
342
343 //------------------------------add_ring---------------------------------------
344 // Supplied function returns the sum of the inputs. Guaranteed never
345 // to be passed a TOP or BOTTOM type, these are filtered out by
346 // pre-check.
347 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
348 const TypeInt *r0 = t0->is_int(); // Handy access
349 const TypeInt *r1 = t1->is_int();
350 int lo = java_add(r0->_lo, r1->_lo);
351 int hi = java_add(r0->_hi, r1->_hi);
352 if( !(r0->is_con() && r1->is_con()) ) {
353 // Not both constants, compute approximate result
354 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
355 lo = min_jint; hi = max_jint; // Underflow on the low side
356 }
357 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
358 lo = min_jint; hi = max_jint; // Overflow on the high side
359 }
360 if( lo > hi ) { // Handle overflow
361 lo = min_jint; hi = max_jint;
362 }
363 } else {
364 // both constants, compute precise result using 'lo' and 'hi'
365 // Semantics define overflow and underflow for integer addition
366 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
367 }
368 return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
369 }
370
371
372 //=============================================================================
373 //------------------------------Idealize---------------------------------------
374 Node *AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
375 Node* in1 = in(1);
376 Node* in2 = in(2);
377 int op1 = in1->Opcode();
378 int op2 = in2->Opcode();
379 // Fold (con1-x)+con2 into (con1+con2)-x
380 if ( op1 == Op_AddL && op2 == Op_SubL ) {
381 // Swap edges to try optimizations below
382 in1 = in2;
383 in2 = in(1);
384 op1 = op2;
385 op2 = in2->Opcode();
386 }
387 // Fold (con1-x)+con2 into (con1+con2)-x
388 if( op1 == Op_SubL ) {
389 const Type *t_sub1 = phase->type( in1->in(1) );
390 const Type *t_2 = phase->type( in2 );
391 if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
392 return new (phase->C) SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ),
393 in1->in(2) );
394 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
395 if( op2 == Op_SubL ) {
396 // Check for dead cycle: d = (a-b)+(c-d)
397 assert( in1->in(2) != this && in2->in(2) != this,
398 "dead loop in AddLNode::Ideal" );
399 Node *sub = new (phase->C) SubLNode(NULL, NULL);
400 sub->init_req(1, phase->transform(new (phase->C) AddLNode(in1->in(1), in2->in(1) ) ));
401 sub->init_req(2, phase->transform(new (phase->C) AddLNode(in1->in(2), in2->in(2) ) ));
402 return sub;
403 }
404 // Convert "(a-b)+(b+c)" into "(a+c)"
405 if( op2 == Op_AddL && in1->in(2) == in2->in(1) ) {
406 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
407 return new (phase->C) AddLNode(in1->in(1), in2->in(2));
408 }
409 // Convert "(a-b)+(c+b)" into "(a+c)"
410 if( op2 == Op_AddL && in1->in(2) == in2->in(2) ) {
411 assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
412 return new (phase->C) AddLNode(in1->in(1), in2->in(1));
413 }
414 // Convert "(a-b)+(b-c)" into "(a-c)"
415 if( op2 == Op_SubL && in1->in(2) == in2->in(1) ) {
416 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
417 return new (phase->C) SubLNode(in1->in(1), in2->in(2));
418 }
419 // Convert "(a-b)+(c-a)" into "(c-b)"
420 if( op2 == Op_SubL && in1->in(1) == in1->in(2) ) {
421 assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
422 return new (phase->C) SubLNode(in2->in(1), in1->in(2));
423 }
424 }
425
426 // Convert "x+(0-y)" into "(x-y)"
427 if( op2 == Op_SubL && phase->type(in2->in(1)) == TypeLong::ZERO )
428 return new (phase->C) SubLNode( in1, in2->in(2) );
429
430 // Convert "(0-y)+x" into "(x-y)"
431 if( op1 == Op_SubL && phase->type(in1->in(1)) == TypeInt::ZERO )
432 return new (phase->C) SubLNode( in2, in1->in(2) );
433
434 // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)"
435 // into "(X<<1)+Y" and let shift-folding happen.
436 if( op2 == Op_AddL &&
437 in2->in(1) == in1 &&
438 op1 != Op_ConL &&
439 0 ) {
440 Node *shift = phase->transform(new (phase->C) LShiftLNode(in1,phase->intcon(1)));
441 return new (phase->C) AddLNode(shift,in2->in(2));
442 }
443
444 return AddNode::Ideal(phase, can_reshape);
445 }
446
447
448 //------------------------------Identity---------------------------------------
449 // Fold (x-y)+y OR y+(x-y) into x
450 Node *AddLNode::Identity( PhaseTransform *phase ) {
451 if( in(1)->Opcode() == Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) {
452 return in(1)->in(1);
453 }
454 else if( in(2)->Opcode() == Op_SubL && phase->eqv(in(2)->in(2),in(1)) ) {
455 return in(2)->in(1);
456 }
457 return AddNode::Identity(phase);
458 }
459
460
461 //------------------------------add_ring---------------------------------------
462 // Supplied function returns the sum of the inputs. Guaranteed never
463 // to be passed a TOP or BOTTOM type, these are filtered out by
464 // pre-check.
465 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
466 const TypeLong *r0 = t0->is_long(); // Handy access
467 const TypeLong *r1 = t1->is_long();
468 jlong lo = java_add(r0->_lo, r1->_lo);
469 jlong hi = java_add(r0->_hi, r1->_hi);
470 if( !(r0->is_con() && r1->is_con()) ) {
471 // Not both constants, compute approximate result
472 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
473 lo =min_jlong; hi = max_jlong; // Underflow on the low side
474 }
475 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
476 lo = min_jlong; hi = max_jlong; // Overflow on the high side
477 }
478 if( lo > hi ) { // Handle overflow
479 lo = min_jlong; hi = max_jlong;
480 }
481 } else {
482 // both constants, compute precise result using 'lo' and 'hi'
483 // Semantics define overflow and underflow for integer addition
484 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0
485 }
486 return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
487 }
488
489
490 //=============================================================================
491 //------------------------------add_of_identity--------------------------------
492 // Check for addition of the identity
493 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
494 // x ADD 0 should return x unless 'x' is a -zero
495 //
496 // const Type *zero = add_id(); // The additive identity
497 // jfloat f1 = t1->getf();
498 // jfloat f2 = t2->getf();
499 //
500 // if( t1->higher_equal( zero ) ) return t2;
501 // if( t2->higher_equal( zero ) ) return t1;
502
503 return NULL;
504 }
505
506 //------------------------------add_ring---------------------------------------
507 // Supplied function returns the sum of the inputs.
508 // This also type-checks the inputs for sanity. Guaranteed never to
509 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
510 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
511 // We must be adding 2 float constants.
512 return TypeF::make( t0->getf() + t1->getf() );
513 }
514
515 //------------------------------Ideal------------------------------------------
516 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
517 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
518 return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
519 }
520
521 // Floating point additions are not associative because of boundary conditions (infinity)
522 return commute(this,
523 phase->type( in(1) )->singleton(),
524 phase->type( in(2) )->singleton() ) ? this : NULL;
525 }
526
527
528 //=============================================================================
529 //------------------------------add_of_identity--------------------------------
530 // Check for addition of the identity
531 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
532 // x ADD 0 should return x unless 'x' is a -zero
533 //
534 // const Type *zero = add_id(); // The additive identity
535 // jfloat f1 = t1->getf();
536 // jfloat f2 = t2->getf();
537 //
538 // if( t1->higher_equal( zero ) ) return t2;
539 // if( t2->higher_equal( zero ) ) return t1;
540
541 return NULL;
542 }
543 //------------------------------add_ring---------------------------------------
544 // Supplied function returns the sum of the inputs.
545 // This also type-checks the inputs for sanity. Guaranteed never to
546 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
547 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
548 // We must be adding 2 double constants.
549 return TypeD::make( t0->getd() + t1->getd() );
550 }
551
552 //------------------------------Ideal------------------------------------------
553 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
554 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
555 return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
556 }
557
558 // Floating point additions are not associative because of boundary conditions (infinity)
559 return commute(this,
560 phase->type( in(1) )->singleton(),
561 phase->type( in(2) )->singleton() ) ? this : NULL;
562 }
563
564
565 //=============================================================================
566 //------------------------------Identity---------------------------------------
567 // If one input is a constant 0, return the other input.
568 Node *AddPNode::Identity( PhaseTransform *phase ) {
569 return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
570 }
571
572 //------------------------------Idealize---------------------------------------
573 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
574 // Bail out if dead inputs
575 if( phase->type( in(Address) ) == Type::TOP ) return NULL;
576
577 // If the left input is an add of a constant, flatten the expression tree.
578 const Node *n = in(Address);
579 if (n->is_AddP() && n->in(Base) == in(Base)) {
580 const AddPNode *addp = n->as_AddP(); // Left input is an AddP
581 assert( !addp->in(Address)->is_AddP() ||
582 addp->in(Address)->as_AddP() != addp,
583 "dead loop in AddPNode::Ideal" );
584 // Type of left input's right input
585 const Type *t = phase->type( addp->in(Offset) );
586 if( t == Type::TOP ) return NULL;
587 const TypeX *t12 = t->is_intptr_t();
588 if( t12->is_con() ) { // Left input is an add of a constant?
589 // If the right input is a constant, combine constants
590 const Type *temp_t2 = phase->type( in(Offset) );
591 if( temp_t2 == Type::TOP ) return NULL;
592 const TypeX *t2 = temp_t2->is_intptr_t();
593 Node* address;
594 Node* offset;
595 if( t2->is_con() ) {
596 // The Add of the flattened expression
597 address = addp->in(Address);
598 offset = phase->MakeConX(t2->get_con() + t12->get_con());
599 } else {
600 // Else move the constant to the right. ((A+con)+B) into ((A+B)+con)
601 address = phase->transform(new (phase->C) AddPNode(in(Base),addp->in(Address),in(Offset)));
602 offset = addp->in(Offset);
603 }
604 PhaseIterGVN *igvn = phase->is_IterGVN();
605 if( igvn ) {
606 set_req_X(Address,address,igvn);
607 set_req_X(Offset,offset,igvn);
608 } else {
609 set_req(Address,address);
610 set_req(Offset,offset);
611 }
612 return this;
613 }
614 }
615
616 // Raw pointers?
617 if( in(Base)->bottom_type() == Type::TOP ) {
618 // If this is a NULL+long form (from unsafe accesses), switch to a rawptr.
619 if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
620 Node* offset = in(Offset);
621 return new (phase->C) CastX2PNode(offset);
622 }
623 }
624
625 // If the right is an add of a constant, push the offset down.
626 // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
627 // The idea is to merge array_base+scaled_index groups together,
628 // and only have different constant offsets from the same base.
629 const Node *add = in(Offset);
630 if( add->Opcode() == Op_AddX && add->in(1) != add ) {
631 const Type *t22 = phase->type( add->in(2) );
632 if( t22->singleton() && (t22 != Type::TOP) ) { // Right input is an add of a constant?
633 set_req(Address, phase->transform(new (phase->C) AddPNode(in(Base),in(Address),add->in(1))));
634 set_req(Offset, add->in(2));
635 PhaseIterGVN *igvn = phase->is_IterGVN();
636 if (add->outcnt() == 0 && igvn) {
637 // add disconnected.
638 igvn->_worklist.push((Node*)add);
639 }
640 return this; // Made progress
641 }
642 }
643
644 return NULL; // No progress
645 }
646
647 //------------------------------bottom_type------------------------------------
648 // Bottom-type is the pointer-type with unknown offset.
649 const Type *AddPNode::bottom_type() const {
650 if (in(Address) == NULL) return TypePtr::BOTTOM;
651 const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
652 if( !tp ) return Type::TOP; // TOP input means TOP output
653 assert( in(Offset)->Opcode() != Op_ConP, "" );
654 const Type *t = in(Offset)->bottom_type();
655 if( t == Type::TOP )
656 return tp->add_offset(Type::OffsetTop);
657 const TypeX *tx = t->is_intptr_t();
658 intptr_t txoffset = Type::OffsetBot;
659 if (tx->is_con()) { // Left input is an add of a constant?
660 txoffset = tx->get_con();
661 }
662 return tp->add_offset(txoffset);
663 }
664
665 //------------------------------Value------------------------------------------
666 const Type *AddPNode::Value( PhaseTransform *phase ) const {
667 // Either input is TOP ==> the result is TOP
668 const Type *t1 = phase->type( in(Address) );
669 const Type *t2 = phase->type( in(Offset) );
670 if( t1 == Type::TOP ) return Type::TOP;
671 if( t2 == Type::TOP ) return Type::TOP;
672
673 // Left input is a pointer
674 const TypePtr *p1 = t1->isa_ptr();
675 // Right input is an int
676 const TypeX *p2 = t2->is_intptr_t();
677 // Add 'em
678 intptr_t p2offset = Type::OffsetBot;
679 if (p2->is_con()) { // Left input is an add of a constant?
680 p2offset = p2->get_con();
681 }
682 return p1->add_offset(p2offset);
683 }
684
685 //------------------------Ideal_base_and_offset--------------------------------
686 // Split an oop pointer into a base and offset.
687 // (The offset might be Type::OffsetBot in the case of an array.)
688 // Return the base, or NULL if failure.
689 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseTransform* phase,
690 // second return value:
691 intptr_t& offset) {
692 if (ptr->is_AddP()) {
693 Node* base = ptr->in(AddPNode::Base);
694 Node* addr = ptr->in(AddPNode::Address);
695 Node* offs = ptr->in(AddPNode::Offset);
696 if (base == addr || base->is_top()) {
697 offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
698 if (offset != Type::OffsetBot) {
699 return addr;
700 }
701 }
702 }
703 offset = Type::OffsetBot;
704 return NULL;
705 }
706
707 //------------------------------unpack_offsets----------------------------------
708 // Collect the AddP offset values into the elements array, giving up
709 // if there are more than length.
710 int AddPNode::unpack_offsets(Node* elements[], int length) {
711 int count = 0;
712 Node* addr = this;
713 Node* base = addr->in(AddPNode::Base);
714 while (addr->is_AddP()) {
715 if (addr->in(AddPNode::Base) != base) {
716 // give up
717 return -1;
718 }
719 elements[count++] = addr->in(AddPNode::Offset);
720 if (count == length) {
721 // give up
722 return -1;
723 }
724 addr = addr->in(AddPNode::Address);
725 }
726 if (addr != base) {
727 return -1;
728 }
729 return count;
730 }
731
732 //------------------------------match_edge-------------------------------------
733 // Do we Match on this edge index or not? Do not match base pointer edge
734 uint AddPNode::match_edge(uint idx) const {
735 return idx > Base;
736 }
737
738 //=============================================================================
739 //------------------------------Identity---------------------------------------
740 Node *OrINode::Identity( PhaseTransform *phase ) {
741 // x | x => x
742 if (phase->eqv(in(1), in(2))) {
743 return in(1);
744 }
745
746 return AddNode::Identity(phase);
747 }
748
749 //------------------------------add_ring---------------------------------------
750 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
751 // the logical operations the ring's ADD is really a logical OR function.
752 // This also type-checks the inputs for sanity. Guaranteed never to
753 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
754 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
755 const TypeInt *r0 = t0->is_int(); // Handy access
756 const TypeInt *r1 = t1->is_int();
757
758 // If both args are bool, can figure out better types
759 if ( r0 == TypeInt::BOOL ) {
760 if ( r1 == TypeInt::ONE) {
761 return TypeInt::ONE;
762 } else if ( r1 == TypeInt::BOOL ) {
763 return TypeInt::BOOL;
764 }
765 } else if ( r0 == TypeInt::ONE ) {
766 if ( r1 == TypeInt::BOOL ) {
767 return TypeInt::ONE;
768 }
769 }
770
771 // If either input is not a constant, just return all integers.
772 if( !r0->is_con() || !r1->is_con() )
773 return TypeInt::INT; // Any integer, but still no symbols.
774
775 // Otherwise just OR them bits.
776 return TypeInt::make( r0->get_con() | r1->get_con() );
777 }
778
779 //=============================================================================
780 //------------------------------Identity---------------------------------------
781 Node *OrLNode::Identity( PhaseTransform *phase ) {
782 // x | x => x
783 if (phase->eqv(in(1), in(2))) {
784 return in(1);
785 }
786
787 return AddNode::Identity(phase);
788 }
789
790 //------------------------------add_ring---------------------------------------
791 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
792 const TypeLong *r0 = t0->is_long(); // Handy access
793 const TypeLong *r1 = t1->is_long();
794
795 // If either input is not a constant, just return all integers.
796 if( !r0->is_con() || !r1->is_con() )
797 return TypeLong::LONG; // Any integer, but still no symbols.
798
799 // Otherwise just OR them bits.
800 return TypeLong::make( r0->get_con() | r1->get_con() );
801 }
802
803 //=============================================================================
804 //------------------------------add_ring---------------------------------------
805 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For
806 // the logical operations the ring's ADD is really a logical OR function.
807 // This also type-checks the inputs for sanity. Guaranteed never to
808 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
809 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
810 const TypeInt *r0 = t0->is_int(); // Handy access
811 const TypeInt *r1 = t1->is_int();
812
813 // Complementing a boolean?
814 if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
815 || r1 == TypeInt::BOOL))
816 return TypeInt::BOOL;
817
818 if( !r0->is_con() || !r1->is_con() ) // Not constants
819 return TypeInt::INT; // Any integer, but still no symbols.
820
821 // Otherwise just XOR them bits.
822 return TypeInt::make( r0->get_con() ^ r1->get_con() );
823 }
824
825 //=============================================================================
826 //------------------------------add_ring---------------------------------------
827 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
828 const TypeLong *r0 = t0->is_long(); // Handy access
829 const TypeLong *r1 = t1->is_long();
830
831 // If either input is not a constant, just return all integers.
832 if( !r0->is_con() || !r1->is_con() )
833 return TypeLong::LONG; // Any integer, but still no symbols.
834
835 // Otherwise just OR them bits.
836 return TypeLong::make( r0->get_con() ^ r1->get_con() );
837 }
838
839 //=============================================================================
840 //------------------------------add_ring---------------------------------------
841 // Supplied function returns the sum of the inputs.
842 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
843 const TypeInt *r0 = t0->is_int(); // Handy access
844 const TypeInt *r1 = t1->is_int();
845
846 // Otherwise just MAX them bits.
847 return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
848 }
849
850 // Check if addition of an integer with type 't' and a constant 'c' can overflow
851 static bool can_overflow(const TypeInt* t, jint c) {
852 jint t_lo = t->_lo;
853 jint t_hi = t->_hi;
854 return ((c < 0 && (java_add(t_lo, c) > t_lo)) ||
855 (c > 0 && (java_add(t_hi, c) < t_hi)));
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 (phase->C) 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 jint 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 jint 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 const TypeInt* tx = phase->type(x)->isa_int();
906
907 if( r->Opcode() == Op_MinI ) {
908 assert( r != r->in(2), "dead loop in MinINode::Ideal" );
909 y = r->in(1);
910 // Check final part of MIN tree
911 if( y->Opcode() == Op_AddI &&// Check for "y+c1" and collect constant
912 y->in(2)->is_Con() ) {
913 const Type *t = y->in(2)->bottom_type();
914 if( t == Type::TOP ) return NULL; // No progress
915 y_off = t->is_int()->get_con();
916 y = y->in(1);
917 }
918
919 if( x->_idx > y->_idx )
920 return new (phase->C) MinINode(r->in(1),phase->transform(new (phase->C) MinINode(l,r->in(2))));
921
922 // Transform MIN2(x + c0, MIN2(x + c1, z)) into MIN2(x + MIN2(c0, c1), z)
923 // if x == y and the additions can't overflow.
924 if (phase->eqv(x,y) && tx != NULL &&
925 !can_overflow(tx, x_off) &&
926 !can_overflow(tx, y_off)) {
927 return new (phase->C) MinINode(phase->transform(new (phase->C) AddINode(x, phase->intcon(MIN2(x_off, y_off)))), r->in(2));
928 }
929 } else {
930 // Transform MIN2(x + c0, y + c1) into x + MIN2(c0, c1)
931 // if x == y and the additions can't overflow.
932 if (phase->eqv(x,y) && tx != NULL &&
933 !can_overflow(tx, x_off) &&
934 !can_overflow(tx, y_off)) {
935 return new (phase->C) AddINode(x,phase->intcon(MIN2(x_off,y_off)));
936 }
937 }
938 return NULL;
939 }
940
941 //------------------------------add_ring---------------------------------------
942 // Supplied function returns the sum of the inputs.
943 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
944 const TypeInt *r0 = t0->is_int(); // Handy access
945 const TypeInt *r1 = t1->is_int();
946
947 // Otherwise just MIN them bits.
948 return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
949 }