1 /*
2 * Copyright (c) 1997, 2017, 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/connode.hpp"
29 #include "opto/convertnode.hpp"
30 #include "opto/memnode.hpp"
31 #include "opto/mulnode.hpp"
32 #include "opto/phaseX.hpp"
33 #include "opto/subnode.hpp"
34
35 // Portions of code courtesy of Clifford Click
36
37
38 //=============================================================================
39 //------------------------------hash-------------------------------------------
40 // Hash function over MulNodes. Needs to be commutative; i.e., I swap
41 // (commute) inputs to MulNodes willy-nilly so the hash function must return
42 // the same value in the presence of edge swapping.
43 uint MulNode::hash() const {
44 return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
45 }
46
47 //------------------------------Identity---------------------------------------
48 // Multiplying a one preserves the other argument
49 Node* MulNode::Identity(PhaseGVN* phase) {
50 const Type *one = mul_id(); // The multiplicative identity
51 if( phase->type( in(1) )->higher_equal( one ) ) return in(2);
52 if( phase->type( in(2) )->higher_equal( one ) ) return in(1);
53
54 return this;
55 }
56
57 //------------------------------Ideal------------------------------------------
58 // We also canonicalize the Node, moving constants to the right input,
59 // and flatten expressions (so that 1+x+2 becomes x+3).
60 Node *MulNode::Ideal(PhaseGVN *phase, bool can_reshape) {
61 const Type *t1 = phase->type( in(1) );
62 const Type *t2 = phase->type( in(2) );
63 Node *progress = NULL; // Progress flag
64 // We are OK if right is a constant, or right is a load and
65 // left is a non-constant.
66 if( !(t2->singleton() ||
67 (in(2)->is_Load() && !(t1->singleton() || in(1)->is_Load())) ) ) {
68 if( t1->singleton() || // Left input is a constant?
69 // Otherwise, sort inputs (commutativity) to help value numbering.
70 (in(1)->_idx > in(2)->_idx) ) {
71 swap_edges(1, 2);
72 const Type *t = t1;
73 t1 = t2;
74 t2 = t;
75 progress = this; // Made progress
76 }
77 }
78
79 // If the right input is a constant, and the left input is a product of a
80 // constant, flatten the expression tree.
81 uint op = Opcode();
82 if( t2->singleton() && // Right input is a constant?
83 op != Op_MulF && // Float & double cannot reassociate
84 op != Op_MulD ) {
85 if( t2 == Type::TOP ) return NULL;
86 Node *mul1 = in(1);
87 #ifdef ASSERT
88 // Check for dead loop
89 int op1 = mul1->Opcode();
90 if( phase->eqv( mul1, this ) || phase->eqv( in(2), this ) ||
91 ( ( op1 == mul_opcode() || op1 == add_opcode() ) &&
92 ( phase->eqv( mul1->in(1), this ) || phase->eqv( mul1->in(2), this ) ||
93 phase->eqv( mul1->in(1), mul1 ) || phase->eqv( mul1->in(2), mul1 ) ) ) )
94 assert(false, "dead loop in MulNode::Ideal");
95 #endif
96
97 if( mul1->Opcode() == mul_opcode() ) { // Left input is a multiply?
98 // Mul of a constant?
99 const Type *t12 = phase->type( mul1->in(2) );
100 if( t12->singleton() && t12 != Type::TOP) { // Left input is an add of a constant?
101 // Compute new constant; check for overflow
102 const Type *tcon01 = ((MulNode*)mul1)->mul_ring(t2,t12);
103 if( tcon01->singleton() ) {
104 // The Mul of the flattened expression
105 set_req(1, mul1->in(1));
106 set_req(2, phase->makecon( tcon01 ));
107 t2 = tcon01;
108 progress = this; // Made progress
109 }
110 }
111 }
112 // If the right input is a constant, and the left input is an add of a
113 // constant, flatten the tree: (X+con1)*con0 ==> X*con0 + con1*con0
114 const Node *add1 = in(1);
115 if( add1->Opcode() == add_opcode() ) { // Left input is an add?
116 // Add of a constant?
117 const Type *t12 = phase->type( add1->in(2) );
118 if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
119 assert( add1->in(1) != add1, "dead loop in MulNode::Ideal" );
120 // Compute new constant; check for overflow
121 const Type *tcon01 = mul_ring(t2,t12);
122 if( tcon01->singleton() ) {
123
124 // Convert (X+con1)*con0 into X*con0
125 Node *mul = clone(); // mul = ()*con0
126 mul->set_req(1,add1->in(1)); // mul = X*con0
127 mul = phase->transform(mul);
128
129 Node *add2 = add1->clone();
130 add2->set_req(1, mul); // X*con0 + con0*con1
131 add2->set_req(2, phase->makecon(tcon01) );
132 progress = add2;
133 }
134 }
135 } // End of is left input an add
136 } // End of is right input a Mul
137
138 return progress;
139 }
140
141 //------------------------------Value-----------------------------------------
142 const Type* MulNode::Value(PhaseGVN* phase) const {
143 const Type *t1 = phase->type( in(1) );
144 const Type *t2 = phase->type( in(2) );
145 // Either input is TOP ==> the result is TOP
146 if( t1 == Type::TOP ) return Type::TOP;
147 if( t2 == Type::TOP ) return Type::TOP;
148
149 // Either input is ZERO ==> the result is ZERO.
150 // Not valid for floats or doubles since +0.0 * -0.0 --> +0.0
151 int op = Opcode();
152 if( op == Op_MulI || op == Op_AndI || op == Op_MulL || op == Op_AndL ) {
153 const Type *zero = add_id(); // The multiplicative zero
154 if( t1->higher_equal( zero ) ) return zero;
155 if( t2->higher_equal( zero ) ) return zero;
156 }
157
158 // Either input is BOTTOM ==> the result is the local BOTTOM
159 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
160 return bottom_type();
161
162 #if defined(IA32)
163 // Can't trust native compilers to properly fold strict double
164 // multiplication with round-to-zero on this platform.
165 if (op == Op_MulD && phase->C->method()->is_strict()) {
166 return TypeD::DOUBLE;
167 }
168 #endif
169
170 return mul_ring(t1,t2); // Local flavor of type multiplication
171 }
172
173
174 //=============================================================================
175 //------------------------------Ideal------------------------------------------
176 // Check for power-of-2 multiply, then try the regular MulNode::Ideal
177 Node *MulINode::Ideal(PhaseGVN *phase, bool can_reshape) {
178 // Swap constant to right
179 jint con;
180 if ((con = in(1)->find_int_con(0)) != 0) {
181 swap_edges(1, 2);
182 // Finish rest of method to use info in 'con'
183 } else if ((con = in(2)->find_int_con(0)) == 0) {
184 return MulNode::Ideal(phase, can_reshape);
185 }
186
187 // Now we have a constant Node on the right and the constant in con
188 if( con == 0 ) return NULL; // By zero is handled by Value call
189 if( con == 1 ) return NULL; // By one is handled by Identity call
190
191 // Check for negative constant; if so negate the final result
192 bool sign_flip = false;
193 if( con < 0 ) {
194 con = -con;
195 sign_flip = true;
196 }
197
198 // Get low bit; check for being the only bit
199 Node *res = NULL;
200 jint bit1 = con & -con; // Extract low bit
201 if( bit1 == con ) { // Found a power of 2?
202 res = new LShiftINode( in(1), phase->intcon(log2_intptr(bit1)) );
203 } else {
204
205 // Check for constant with 2 bits set
206 jint bit2 = con-bit1;
207 bit2 = bit2 & -bit2; // Extract 2nd bit
208 if( bit2 + bit1 == con ) { // Found all bits in con?
209 Node *n1 = phase->transform( new LShiftINode( in(1), phase->intcon(log2_intptr(bit1)) ) );
210 Node *n2 = phase->transform( new LShiftINode( in(1), phase->intcon(log2_intptr(bit2)) ) );
211 res = new AddINode( n2, n1 );
212
213 } else if (is_power_of_2(con+1)) {
214 // Sleezy: power-of-2 -1. Next time be generic.
215 jint temp = (jint) (con + 1);
216 Node *n1 = phase->transform( new LShiftINode( in(1), phase->intcon(log2_intptr(temp)) ) );
217 res = new SubINode( n1, in(1) );
218 } else {
219 return MulNode::Ideal(phase, can_reshape);
220 }
221 }
222
223 if( sign_flip ) { // Need to negate result?
224 res = phase->transform(res);// Transform, before making the zero con
225 res = new SubINode(phase->intcon(0),res);
226 }
227
228 return res; // Return final result
229 }
230
231 //------------------------------mul_ring---------------------------------------
232 // Compute the product type of two integer ranges into this node.
233 const Type *MulINode::mul_ring(const Type *t0, const Type *t1) const {
234 const TypeInt *r0 = t0->is_int(); // Handy access
235 const TypeInt *r1 = t1->is_int();
236
237 // Fetch endpoints of all ranges
238 jint lo0 = r0->_lo;
239 double a = (double)lo0;
240 jint hi0 = r0->_hi;
241 double b = (double)hi0;
242 jint lo1 = r1->_lo;
243 double c = (double)lo1;
244 jint hi1 = r1->_hi;
245 double d = (double)hi1;
246
247 // Compute all endpoints & check for overflow
248 int32_t A = java_multiply(lo0, lo1);
249 if( (double)A != a*c ) return TypeInt::INT; // Overflow?
250 int32_t B = java_multiply(lo0, hi1);
251 if( (double)B != a*d ) return TypeInt::INT; // Overflow?
252 int32_t C = java_multiply(hi0, lo1);
253 if( (double)C != b*c ) return TypeInt::INT; // Overflow?
254 int32_t D = java_multiply(hi0, hi1);
255 if( (double)D != b*d ) return TypeInt::INT; // Overflow?
256
257 if( A < B ) { lo0 = A; hi0 = B; } // Sort range endpoints
258 else { lo0 = B; hi0 = A; }
259 if( C < D ) {
260 if( C < lo0 ) lo0 = C;
261 if( D > hi0 ) hi0 = D;
262 } else {
263 if( D < lo0 ) lo0 = D;
264 if( C > hi0 ) hi0 = C;
265 }
266 return TypeInt::make(lo0, hi0, MAX2(r0->_widen,r1->_widen));
267 }
268
269
270 //=============================================================================
271 //------------------------------Ideal------------------------------------------
272 // Check for power-of-2 multiply, then try the regular MulNode::Ideal
273 Node *MulLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
274 // Swap constant to right
275 jlong con;
276 if ((con = in(1)->find_long_con(0)) != 0) {
277 swap_edges(1, 2);
278 // Finish rest of method to use info in 'con'
279 } else if ((con = in(2)->find_long_con(0)) == 0) {
280 return MulNode::Ideal(phase, can_reshape);
281 }
282
283 // Now we have a constant Node on the right and the constant in con
284 if( con == CONST64(0) ) return NULL; // By zero is handled by Value call
285 if( con == CONST64(1) ) return NULL; // By one is handled by Identity call
286
287 // Check for negative constant; if so negate the final result
288 bool sign_flip = false;
289 if( con < 0 ) {
290 con = -con;
291 sign_flip = true;
292 }
293
294 // Get low bit; check for being the only bit
295 Node *res = NULL;
296 jlong bit1 = con & -con; // Extract low bit
297 if( bit1 == con ) { // Found a power of 2?
298 res = new LShiftLNode( in(1), phase->intcon(log2_long(bit1)) );
299 } else {
300
301 // Check for constant with 2 bits set
302 jlong bit2 = con-bit1;
303 bit2 = bit2 & -bit2; // Extract 2nd bit
304 if( bit2 + bit1 == con ) { // Found all bits in con?
305 Node *n1 = phase->transform( new LShiftLNode( in(1), phase->intcon(log2_long(bit1)) ) );
306 Node *n2 = phase->transform( new LShiftLNode( in(1), phase->intcon(log2_long(bit2)) ) );
307 res = new AddLNode( n2, n1 );
308
309 } else if (is_power_of_2_long(con+1)) {
310 // Sleezy: power-of-2 -1. Next time be generic.
311 jlong temp = (jlong) (con + 1);
312 Node *n1 = phase->transform( new LShiftLNode( in(1), phase->intcon(log2_long(temp)) ) );
313 res = new SubLNode( n1, in(1) );
314 } else {
315 return MulNode::Ideal(phase, can_reshape);
316 }
317 }
318
319 if( sign_flip ) { // Need to negate result?
320 res = phase->transform(res);// Transform, before making the zero con
321 res = new SubLNode(phase->longcon(0),res);
322 }
323
324 return res; // Return final result
325 }
326
327 //------------------------------mul_ring---------------------------------------
328 // Compute the product type of two integer ranges into this node.
329 const Type *MulLNode::mul_ring(const Type *t0, const Type *t1) const {
330 const TypeLong *r0 = t0->is_long(); // Handy access
331 const TypeLong *r1 = t1->is_long();
332
333 // Fetch endpoints of all ranges
334 jlong lo0 = r0->_lo;
335 double a = (double)lo0;
336 jlong hi0 = r0->_hi;
337 double b = (double)hi0;
338 jlong lo1 = r1->_lo;
339 double c = (double)lo1;
340 jlong hi1 = r1->_hi;
341 double d = (double)hi1;
342
343 // Compute all endpoints & check for overflow
344 jlong A = java_multiply(lo0, lo1);
345 if( (double)A != a*c ) return TypeLong::LONG; // Overflow?
346 jlong B = java_multiply(lo0, hi1);
347 if( (double)B != a*d ) return TypeLong::LONG; // Overflow?
348 jlong C = java_multiply(hi0, lo1);
349 if( (double)C != b*c ) return TypeLong::LONG; // Overflow?
350 jlong D = java_multiply(hi0, hi1);
351 if( (double)D != b*d ) return TypeLong::LONG; // Overflow?
352
353 if( A < B ) { lo0 = A; hi0 = B; } // Sort range endpoints
354 else { lo0 = B; hi0 = A; }
355 if( C < D ) {
356 if( C < lo0 ) lo0 = C;
357 if( D > hi0 ) hi0 = D;
358 } else {
359 if( D < lo0 ) lo0 = D;
360 if( C > hi0 ) hi0 = C;
361 }
362 return TypeLong::make(lo0, hi0, MAX2(r0->_widen,r1->_widen));
363 }
364
365 //=============================================================================
366 //------------------------------mul_ring---------------------------------------
367 // Compute the product type of two double ranges into this node.
368 const Type *MulFNode::mul_ring(const Type *t0, const Type *t1) const {
369 if( t0 == Type::FLOAT || t1 == Type::FLOAT ) return Type::FLOAT;
370 return TypeF::make( t0->getf() * t1->getf() );
371 }
372
373 //=============================================================================
374 //------------------------------mul_ring---------------------------------------
375 // Compute the product type of two double ranges into this node.
376 const Type *MulDNode::mul_ring(const Type *t0, const Type *t1) const {
377 if( t0 == Type::DOUBLE || t1 == Type::DOUBLE ) return Type::DOUBLE;
378 // We must be multiplying 2 double constants.
379 return TypeD::make( t0->getd() * t1->getd() );
380 }
381
382 //=============================================================================
383 //------------------------------Value------------------------------------------
384 const Type* MulHiLNode::Value(PhaseGVN* phase) const {
385 // Either input is TOP ==> the result is TOP
386 const Type *t1 = phase->type( in(1) );
387 const Type *t2 = phase->type( in(2) );
388 if( t1 == Type::TOP ) return Type::TOP;
389 if( t2 == Type::TOP ) return Type::TOP;
390
391 // Either input is BOTTOM ==> the result is the local BOTTOM
392 const Type *bot = bottom_type();
393 if( (t1 == bot) || (t2 == bot) ||
394 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
395 return bot;
396
397 // It is not worth trying to constant fold this stuff!
398 return TypeLong::LONG;
399 }
400
401 //=============================================================================
402 //------------------------------mul_ring---------------------------------------
403 // Supplied function returns the product of the inputs IN THE CURRENT RING.
404 // For the logical operations the ring's MUL is really a logical AND function.
405 // This also type-checks the inputs for sanity. Guaranteed never to
406 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
407 const Type *AndINode::mul_ring( const Type *t0, const Type *t1 ) const {
408 const TypeInt *r0 = t0->is_int(); // Handy access
409 const TypeInt *r1 = t1->is_int();
410 int widen = MAX2(r0->_widen,r1->_widen);
411
412 // If either input is a constant, might be able to trim cases
413 if( !r0->is_con() && !r1->is_con() )
414 return TypeInt::INT; // No constants to be had
415
416 // Both constants? Return bits
417 if( r0->is_con() && r1->is_con() )
418 return TypeInt::make( r0->get_con() & r1->get_con() );
419
420 if( r0->is_con() && r0->get_con() > 0 )
421 return TypeInt::make(0, r0->get_con(), widen);
422
423 if( r1->is_con() && r1->get_con() > 0 )
424 return TypeInt::make(0, r1->get_con(), widen);
425
426 if( r0 == TypeInt::BOOL || r1 == TypeInt::BOOL ) {
427 return TypeInt::BOOL;
428 }
429
430 return TypeInt::INT; // No constants to be had
431 }
432
433 //------------------------------Identity---------------------------------------
434 // Masking off the high bits of an unsigned load is not required
435 Node* AndINode::Identity(PhaseGVN* phase) {
436
437 // x & x => x
438 if (phase->eqv(in(1), in(2))) return in(1);
439
440 Node* in1 = in(1);
441 uint op = in1->Opcode();
442 const TypeInt* t2 = phase->type(in(2))->isa_int();
443 if (t2 && t2->is_con()) {
444 int con = t2->get_con();
445 // Masking off high bits which are always zero is useless.
446 const TypeInt* t1 = phase->type( in(1) )->isa_int();
447 if (t1 != NULL && t1->_lo >= 0) {
448 jint t1_support = right_n_bits(1 + log2_intptr(t1->_hi));
449 if ((t1_support & con) == t1_support)
450 return in1;
451 }
452 // Masking off the high bits of a unsigned-shift-right is not
453 // needed either.
454 if (op == Op_URShiftI) {
455 const TypeInt* t12 = phase->type(in1->in(2))->isa_int();
456 if (t12 && t12->is_con()) { // Shift is by a constant
457 int shift = t12->get_con();
458 shift &= BitsPerJavaInteger - 1; // semantics of Java shifts
459 int mask = max_juint >> shift;
460 if ((mask & con) == mask) // If AND is useless, skip it
461 return in1;
462 }
463 }
464 }
465 return MulNode::Identity(phase);
466 }
467
468 //------------------------------Ideal------------------------------------------
469 Node *AndINode::Ideal(PhaseGVN *phase, bool can_reshape) {
470 // Special case constant AND mask
471 const TypeInt *t2 = phase->type( in(2) )->isa_int();
472 if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
473 const int mask = t2->get_con();
474 Node *load = in(1);
475 uint lop = load->Opcode();
476
477 // Masking bits off of a Character? Hi bits are already zero.
478 if( lop == Op_LoadUS &&
479 (mask & 0xFFFF0000) ) // Can we make a smaller mask?
480 return new AndINode(load,phase->intcon(mask&0xFFFF));
481
482 // Masking bits off of a Short? Loading a Character does some masking
483 if (can_reshape &&
484 load->outcnt() == 1 && load->unique_out() == this) {
485 if (lop == Op_LoadS && (mask & 0xFFFF0000) == 0 ) {
486 Node* ldus = load->as_Load()->convert_to_unsigned_load(*phase);
487 ldus = phase->transform(ldus);
488 return new AndINode(ldus, phase->intcon(mask & 0xFFFF));
489 }
490
491 // Masking sign bits off of a Byte? Do an unsigned byte load plus
492 // an and.
493 // Prevent transform if it feeds to CmpI. We have special matcher
494 // for LoadB+AndI+CmpI that generates a single instruction.
495 bool feeds_to_cmpi_zero = outcnt() == 1 &&
496 unique_out()->Opcode() == Op_CmpI &&
497 phase->type(unique_out()->in(2))->is_zero_type();
498 if (lop == Op_LoadB && (mask & 0xFFFFFF00) == 0 && !feeds_to_cmpi_zero) {
499 Node* ldub = load->as_Load()->convert_to_unsigned_load(*phase);
500 ldub = phase->transform(ldub);
501 return new AndINode(ldub, phase->intcon(mask));
502 }
503 }
504
505 // Masking off sign bits? Dont make them!
506 if( lop == Op_RShiftI ) {
507 const TypeInt *t12 = phase->type(load->in(2))->isa_int();
508 if( t12 && t12->is_con() ) { // Shift is by a constant
509 int shift = t12->get_con();
510 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
511 const int sign_bits_mask = ~right_n_bits(BitsPerJavaInteger - shift);
512 // If the AND'ing of the 2 masks has no bits, then only original shifted
513 // bits survive. NO sign-extension bits survive the maskings.
514 if( (sign_bits_mask & mask) == 0 ) {
515 // Use zero-fill shift instead
516 Node *zshift = phase->transform(new URShiftINode(load->in(1),load->in(2)));
517 return new AndINode( zshift, in(2) );
518 }
519 }
520 }
521
522 // Check for 'negate/and-1', a pattern emitted when someone asks for
523 // 'mod 2'. Negate leaves the low order bit unchanged (think: complement
524 // plus 1) and the mask is of the low order bit. Skip the negate.
525 if( lop == Op_SubI && mask == 1 && load->in(1) &&
526 phase->type(load->in(1)) == TypeInt::ZERO )
527 return new AndINode( load->in(2), in(2) );
528
529 return MulNode::Ideal(phase, can_reshape);
530 }
531
532 //=============================================================================
533 //------------------------------mul_ring---------------------------------------
534 // Supplied function returns the product of the inputs IN THE CURRENT RING.
535 // For the logical operations the ring's MUL is really a logical AND function.
536 // This also type-checks the inputs for sanity. Guaranteed never to
537 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
538 const Type *AndLNode::mul_ring( const Type *t0, const Type *t1 ) const {
539 const TypeLong *r0 = t0->is_long(); // Handy access
540 const TypeLong *r1 = t1->is_long();
541 int widen = MAX2(r0->_widen,r1->_widen);
542
543 // If either input is a constant, might be able to trim cases
544 if( !r0->is_con() && !r1->is_con() )
545 return TypeLong::LONG; // No constants to be had
546
547 // Both constants? Return bits
548 if( r0->is_con() && r1->is_con() )
549 return TypeLong::make( r0->get_con() & r1->get_con() );
550
551 if( r0->is_con() && r0->get_con() > 0 )
552 return TypeLong::make(CONST64(0), r0->get_con(), widen);
553
554 if( r1->is_con() && r1->get_con() > 0 )
555 return TypeLong::make(CONST64(0), r1->get_con(), widen);
556
557 return TypeLong::LONG; // No constants to be had
558 }
559
560 //------------------------------Identity---------------------------------------
561 // Masking off the high bits of an unsigned load is not required
562 Node* AndLNode::Identity(PhaseGVN* phase) {
563
564 // x & x => x
565 if (phase->eqv(in(1), in(2))) return in(1);
566
567 Node *usr = in(1);
568 const TypeLong *t2 = phase->type( in(2) )->isa_long();
569 if( t2 && t2->is_con() ) {
570 jlong con = t2->get_con();
571 // Masking off high bits which are always zero is useless.
572 const TypeLong* t1 = phase->type( in(1) )->isa_long();
573 if (t1 != NULL && t1->_lo >= 0) {
574 int bit_count = log2_long(t1->_hi) + 1;
575 jlong t1_support = jlong(max_julong >> (BitsPerJavaLong - bit_count));
576 if ((t1_support & con) == t1_support)
577 return usr;
578 }
579 uint lop = usr->Opcode();
580 // Masking off the high bits of a unsigned-shift-right is not
581 // needed either.
582 if( lop == Op_URShiftL ) {
583 const TypeInt *t12 = phase->type( usr->in(2) )->isa_int();
584 if( t12 && t12->is_con() ) { // Shift is by a constant
585 int shift = t12->get_con();
586 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
587 jlong mask = max_julong >> shift;
588 if( (mask&con) == mask ) // If AND is useless, skip it
589 return usr;
590 }
591 }
592 }
593 return MulNode::Identity(phase);
594 }
595
596 //------------------------------Ideal------------------------------------------
597 Node *AndLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
598 // Special case constant AND mask
599 const TypeLong *t2 = phase->type( in(2) )->isa_long();
600 if( !t2 || !t2->is_con() ) return MulNode::Ideal(phase, can_reshape);
601 const jlong mask = t2->get_con();
602
603 Node* in1 = in(1);
604 uint op = in1->Opcode();
605
606 // Are we masking a long that was converted from an int with a mask
607 // that fits in 32-bits? Commute them and use an AndINode. Don't
608 // convert masks which would cause a sign extension of the integer
609 // value. This check includes UI2L masks (0x00000000FFFFFFFF) which
610 // would be optimized away later in Identity.
611 if (op == Op_ConvI2L && (mask & UCONST64(0xFFFFFFFF80000000)) == 0) {
612 Node* andi = new AndINode(in1->in(1), phase->intcon(mask));
613 andi = phase->transform(andi);
614 return new ConvI2LNode(andi);
615 }
616
617 // Masking off sign bits? Dont make them!
618 if (op == Op_RShiftL) {
619 const TypeInt* t12 = phase->type(in1->in(2))->isa_int();
620 if( t12 && t12->is_con() ) { // Shift is by a constant
621 int shift = t12->get_con();
622 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
623 const jlong sign_bits_mask = ~(((jlong)CONST64(1) << (jlong)(BitsPerJavaLong - shift)) -1);
624 // If the AND'ing of the 2 masks has no bits, then only original shifted
625 // bits survive. NO sign-extension bits survive the maskings.
626 if( (sign_bits_mask & mask) == 0 ) {
627 // Use zero-fill shift instead
628 Node *zshift = phase->transform(new URShiftLNode(in1->in(1), in1->in(2)));
629 return new AndLNode(zshift, in(2));
630 }
631 }
632 }
633
634 return MulNode::Ideal(phase, can_reshape);
635 }
636
637 //=============================================================================
638
639 static int getShiftCon(PhaseGVN *phase, Node *shiftNode, int retVal) {
640 const Type *t = phase->type(shiftNode->in(2));
641 if (t == Type::TOP) return retVal; // Right input is dead.
642 const TypeInt *t2 = t->isa_int();
643 if (!t2 || !t2->is_con()) return retVal; // Right input is a constant.
644
645 return t2->get_con();
646 }
647
648 static int maskShiftAmount(PhaseGVN *phase, Node *shiftNode, int nBits) {
649 int shift = getShiftCon(phase, shiftNode, 0);
650 int maskedShift = shift & (nBits - 1);
651
652 if (maskedShift == 0) return 0; // Let Identity() handle 0 shift count.
653
654 if (shift != maskedShift) {
655 shiftNode->set_req(2, phase->intcon(maskedShift)); // Replace shift count with masked value.
656 phase->igvn_rehash_node_delayed(shiftNode);
657 }
658
659 return maskedShift;
660 }
661
662 //------------------------------Identity---------------------------------------
663 Node* LShiftINode::Identity(PhaseGVN* phase) {
664 return ((getShiftCon(phase, this, -1) & (BitsPerJavaInteger - 1)) == 0) ? in(1) : this;
665 }
666
667 //------------------------------Ideal------------------------------------------
668 // If the right input is a constant, and the left input is an add of a
669 // constant, flatten the tree: (X+con1)<<con0 ==> X<<con0 + con1<<con0
670 Node *LShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
671 int con = maskShiftAmount(phase, this, BitsPerJavaInteger);
672 if (con == 0) {
673 return NULL;
674 }
675
676 // Left input is an add of a constant?
677 Node *add1 = in(1);
678 int add1_op = add1->Opcode();
679 if( add1_op == Op_AddI ) { // Left input is an add?
680 assert( add1 != add1->in(1), "dead loop in LShiftINode::Ideal" );
681 const TypeInt *t12 = phase->type(add1->in(2))->isa_int();
682 if( t12 && t12->is_con() ){ // Left input is an add of a con?
683 // Transform is legal, but check for profit. Avoid breaking 'i2s'
684 // and 'i2b' patterns which typically fold into 'StoreC/StoreB'.
685 if( con < 16 ) {
686 // Compute X << con0
687 Node *lsh = phase->transform( new LShiftINode( add1->in(1), in(2) ) );
688 // Compute X<<con0 + (con1<<con0)
689 return new AddINode( lsh, phase->intcon(t12->get_con() << con));
690 }
691 }
692 }
693
694 // Check for "(x>>c0)<<c0" which just masks off low bits
695 if( (add1_op == Op_RShiftI || add1_op == Op_URShiftI ) &&
696 add1->in(2) == in(2) )
697 // Convert to "(x & -(1<<c0))"
698 return new AndINode(add1->in(1),phase->intcon( -(1<<con)));
699
700 // Check for "((x>>c0) & Y)<<c0" which just masks off more low bits
701 if( add1_op == Op_AndI ) {
702 Node *add2 = add1->in(1);
703 int add2_op = add2->Opcode();
704 if( (add2_op == Op_RShiftI || add2_op == Op_URShiftI ) &&
705 add2->in(2) == in(2) ) {
706 // Convert to "(x & (Y<<c0))"
707 Node *y_sh = phase->transform( new LShiftINode( add1->in(2), in(2) ) );
708 return new AndINode( add2->in(1), y_sh );
709 }
710 }
711
712 // Check for ((x & ((1<<(32-c0))-1)) << c0) which ANDs off high bits
713 // before shifting them away.
714 const jint bits_mask = right_n_bits(BitsPerJavaInteger-con);
715 if( add1_op == Op_AndI &&
716 phase->type(add1->in(2)) == TypeInt::make( bits_mask ) )
717 return new LShiftINode( add1->in(1), in(2) );
718
719 return NULL;
720 }
721
722 //------------------------------Value------------------------------------------
723 // A LShiftINode shifts its input2 left by input1 amount.
724 const Type* LShiftINode::Value(PhaseGVN* phase) const {
725 const Type *t1 = phase->type( in(1) );
726 const Type *t2 = phase->type( in(2) );
727 // Either input is TOP ==> the result is TOP
728 if( t1 == Type::TOP ) return Type::TOP;
729 if( t2 == Type::TOP ) return Type::TOP;
730
731 // Left input is ZERO ==> the result is ZERO.
732 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
733 // Shift by zero does nothing
734 if( t2 == TypeInt::ZERO ) return t1;
735
736 // Either input is BOTTOM ==> the result is BOTTOM
737 if( (t1 == TypeInt::INT) || (t2 == TypeInt::INT) ||
738 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
739 return TypeInt::INT;
740
741 const TypeInt *r1 = t1->is_int(); // Handy access
742 const TypeInt *r2 = t2->is_int(); // Handy access
743
744 if (!r2->is_con())
745 return TypeInt::INT;
746
747 uint shift = r2->get_con();
748 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
749 // Shift by a multiple of 32 does nothing:
750 if (shift == 0) return t1;
751
752 // If the shift is a constant, shift the bounds of the type,
753 // unless this could lead to an overflow.
754 if (!r1->is_con()) {
755 jint lo = r1->_lo, hi = r1->_hi;
756 if (((lo << shift) >> shift) == lo &&
757 ((hi << shift) >> shift) == hi) {
758 // No overflow. The range shifts up cleanly.
759 return TypeInt::make((jint)lo << (jint)shift,
760 (jint)hi << (jint)shift,
761 MAX2(r1->_widen,r2->_widen));
762 }
763 return TypeInt::INT;
764 }
765
766 return TypeInt::make( (jint)r1->get_con() << (jint)shift );
767 }
768
769 //=============================================================================
770 //------------------------------Identity---------------------------------------
771 Node* LShiftLNode::Identity(PhaseGVN* phase) {
772 return ((getShiftCon(phase, this, -1) & (BitsPerJavaLong - 1)) == 0) ? in(1) : this;
773 }
774
775 //------------------------------Ideal------------------------------------------
776 // If the right input is a constant, and the left input is an add of a
777 // constant, flatten the tree: (X+con1)<<con0 ==> X<<con0 + con1<<con0
778 Node *LShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
779 int con = maskShiftAmount(phase, this, BitsPerJavaLong);
780 if (con == 0) {
781 return NULL;
782 }
783
784 // Left input is an add of a constant?
785 Node *add1 = in(1);
786 int add1_op = add1->Opcode();
787 if( add1_op == Op_AddL ) { // Left input is an add?
788 // Avoid dead data cycles from dead loops
789 assert( add1 != add1->in(1), "dead loop in LShiftLNode::Ideal" );
790 const TypeLong *t12 = phase->type(add1->in(2))->isa_long();
791 if( t12 && t12->is_con() ){ // Left input is an add of a con?
792 // Compute X << con0
793 Node *lsh = phase->transform( new LShiftLNode( add1->in(1), in(2) ) );
794 // Compute X<<con0 + (con1<<con0)
795 return new AddLNode( lsh, phase->longcon(t12->get_con() << con));
796 }
797 }
798
799 // Check for "(x>>c0)<<c0" which just masks off low bits
800 if( (add1_op == Op_RShiftL || add1_op == Op_URShiftL ) &&
801 add1->in(2) == in(2) )
802 // Convert to "(x & -(1<<c0))"
803 return new AndLNode(add1->in(1),phase->longcon( -(CONST64(1)<<con)));
804
805 // Check for "((x>>c0) & Y)<<c0" which just masks off more low bits
806 if( add1_op == Op_AndL ) {
807 Node *add2 = add1->in(1);
808 int add2_op = add2->Opcode();
809 if( (add2_op == Op_RShiftL || add2_op == Op_URShiftL ) &&
810 add2->in(2) == in(2) ) {
811 // Convert to "(x & (Y<<c0))"
812 Node *y_sh = phase->transform( new LShiftLNode( add1->in(2), in(2) ) );
813 return new AndLNode( add2->in(1), y_sh );
814 }
815 }
816
817 // Check for ((x & ((CONST64(1)<<(64-c0))-1)) << c0) which ANDs off high bits
818 // before shifting them away.
819 const jlong bits_mask = jlong(max_julong >> con);
820 if( add1_op == Op_AndL &&
821 phase->type(add1->in(2)) == TypeLong::make( bits_mask ) )
822 return new LShiftLNode( add1->in(1), in(2) );
823
824 return NULL;
825 }
826
827 //------------------------------Value------------------------------------------
828 // A LShiftLNode shifts its input2 left by input1 amount.
829 const Type* LShiftLNode::Value(PhaseGVN* phase) const {
830 const Type *t1 = phase->type( in(1) );
831 const Type *t2 = phase->type( in(2) );
832 // Either input is TOP ==> the result is TOP
833 if( t1 == Type::TOP ) return Type::TOP;
834 if( t2 == Type::TOP ) return Type::TOP;
835
836 // Left input is ZERO ==> the result is ZERO.
837 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
838 // Shift by zero does nothing
839 if( t2 == TypeInt::ZERO ) return t1;
840
841 // Either input is BOTTOM ==> the result is BOTTOM
842 if( (t1 == TypeLong::LONG) || (t2 == TypeInt::INT) ||
843 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
844 return TypeLong::LONG;
845
846 const TypeLong *r1 = t1->is_long(); // Handy access
847 const TypeInt *r2 = t2->is_int(); // Handy access
848
849 if (!r2->is_con())
850 return TypeLong::LONG;
851
852 uint shift = r2->get_con();
853 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
854 // Shift by a multiple of 64 does nothing:
855 if (shift == 0) return t1;
856
857 // If the shift is a constant, shift the bounds of the type,
858 // unless this could lead to an overflow.
859 if (!r1->is_con()) {
860 jlong lo = r1->_lo, hi = r1->_hi;
861 if (((lo << shift) >> shift) == lo &&
862 ((hi << shift) >> shift) == hi) {
863 // No overflow. The range shifts up cleanly.
864 return TypeLong::make((jlong)lo << (jint)shift,
865 (jlong)hi << (jint)shift,
866 MAX2(r1->_widen,r2->_widen));
867 }
868 return TypeLong::LONG;
869 }
870
871 return TypeLong::make( (jlong)r1->get_con() << (jint)shift );
872 }
873
874 //=============================================================================
875 //------------------------------Identity---------------------------------------
876 Node* RShiftINode::Identity(PhaseGVN* phase) {
877 int shift = getShiftCon(phase, this, -1);
878 if (shift == -1) return this;
879 if ((shift & (BitsPerJavaInteger - 1)) == 0) return in(1);
880
881 // Check for useless sign-masking
882 if (in(1)->Opcode() == Op_LShiftI &&
883 in(1)->req() == 3 &&
884 in(1)->in(2) == in(2)) {
885 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
886 // Compute masks for which this shifting doesn't change
887 int lo = (-1 << (BitsPerJavaInteger - ((uint)shift)-1)); // FFFF8000
888 int hi = ~lo; // 00007FFF
889 const TypeInt *t11 = phase->type(in(1)->in(1))->isa_int();
890 if (!t11) return this;
891 // Does actual value fit inside of mask?
892 if (lo <= t11->_lo && t11->_hi <= hi) {
893 return in(1)->in(1); // Then shifting is a nop
894 }
895 }
896
897 return this;
898 }
899
900 //------------------------------Ideal------------------------------------------
901 Node *RShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
902 // Inputs may be TOP if they are dead.
903 const TypeInt *t1 = phase->type(in(1))->isa_int();
904 if (!t1) return NULL; // Left input is an integer
905 const TypeInt *t3; // type of in(1).in(2)
906 int shift = maskShiftAmount(phase, this, BitsPerJavaInteger);
907 if (shift == 0) {
908 return NULL;
909 }
910
911 // Check for (x & 0xFF000000) >> 24, whose mask can be made smaller.
912 // Such expressions arise normally from shift chains like (byte)(x >> 24).
913 const Node *mask = in(1);
914 if( mask->Opcode() == Op_AndI &&
915 (t3 = phase->type(mask->in(2))->isa_int()) &&
916 t3->is_con() ) {
917 Node *x = mask->in(1);
918 jint maskbits = t3->get_con();
919 // Convert to "(x >> shift) & (mask >> shift)"
920 Node *shr_nomask = phase->transform( new RShiftINode(mask->in(1), in(2)) );
921 return new AndINode(shr_nomask, phase->intcon( maskbits >> shift));
922 }
923
924 // Check for "(short[i] <<16)>>16" which simply sign-extends
925 const Node *shl = in(1);
926 if( shl->Opcode() != Op_LShiftI ) return NULL;
927
928 if( shift == 16 &&
929 (t3 = phase->type(shl->in(2))->isa_int()) &&
930 t3->is_con(16) ) {
931 Node *ld = shl->in(1);
932 if( ld->Opcode() == Op_LoadS ) {
933 // Sign extension is just useless here. Return a RShiftI of zero instead
934 // returning 'ld' directly. We cannot return an old Node directly as
935 // that is the job of 'Identity' calls and Identity calls only work on
936 // direct inputs ('ld' is an extra Node removed from 'this'). The
937 // combined optimization requires Identity only return direct inputs.
938 set_req(1, ld);
939 set_req(2, phase->intcon(0));
940 return this;
941 }
942 else if( can_reshape &&
943 ld->Opcode() == Op_LoadUS &&
944 ld->outcnt() == 1 && ld->unique_out() == shl)
945 // Replace zero-extension-load with sign-extension-load
946 return ld->as_Load()->convert_to_signed_load(*phase);
947 }
948
949 // Check for "(byte[i] <<24)>>24" which simply sign-extends
950 if( shift == 24 &&
951 (t3 = phase->type(shl->in(2))->isa_int()) &&
952 t3->is_con(24) ) {
953 Node *ld = shl->in(1);
954 if( ld->Opcode() == Op_LoadB ) {
955 // Sign extension is just useless here
956 set_req(1, ld);
957 set_req(2, phase->intcon(0));
958 return this;
959 }
960 }
961
962 return NULL;
963 }
964
965 //------------------------------Value------------------------------------------
966 // A RShiftINode shifts its input2 right by input1 amount.
967 const Type* RShiftINode::Value(PhaseGVN* phase) const {
968 const Type *t1 = phase->type( in(1) );
969 const Type *t2 = phase->type( in(2) );
970 // Either input is TOP ==> the result is TOP
971 if( t1 == Type::TOP ) return Type::TOP;
972 if( t2 == Type::TOP ) return Type::TOP;
973
974 // Left input is ZERO ==> the result is ZERO.
975 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
976 // Shift by zero does nothing
977 if( t2 == TypeInt::ZERO ) return t1;
978
979 // Either input is BOTTOM ==> the result is BOTTOM
980 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
981 return TypeInt::INT;
982
983 if (t2 == TypeInt::INT)
984 return TypeInt::INT;
985
986 const TypeInt *r1 = t1->is_int(); // Handy access
987 const TypeInt *r2 = t2->is_int(); // Handy access
988
989 // If the shift is a constant, just shift the bounds of the type.
990 // For example, if the shift is 31, we just propagate sign bits.
991 if (r2->is_con()) {
992 uint shift = r2->get_con();
993 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
994 // Shift by a multiple of 32 does nothing:
995 if (shift == 0) return t1;
996 // Calculate reasonably aggressive bounds for the result.
997 // This is necessary if we are to correctly type things
998 // like (x<<24>>24) == ((byte)x).
999 jint lo = (jint)r1->_lo >> (jint)shift;
1000 jint hi = (jint)r1->_hi >> (jint)shift;
1001 assert(lo <= hi, "must have valid bounds");
1002 const TypeInt* ti = TypeInt::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1003 #ifdef ASSERT
1004 // Make sure we get the sign-capture idiom correct.
1005 if (shift == BitsPerJavaInteger-1) {
1006 if (r1->_lo >= 0) assert(ti == TypeInt::ZERO, ">>31 of + is 0");
1007 if (r1->_hi < 0) assert(ti == TypeInt::MINUS_1, ">>31 of - is -1");
1008 }
1009 #endif
1010 return ti;
1011 }
1012
1013 if( !r1->is_con() || !r2->is_con() )
1014 return TypeInt::INT;
1015
1016 // Signed shift right
1017 return TypeInt::make( r1->get_con() >> (r2->get_con()&31) );
1018 }
1019
1020 //=============================================================================
1021 //------------------------------Identity---------------------------------------
1022 Node* RShiftLNode::Identity(PhaseGVN* phase) {
1023 const TypeInt *ti = phase->type(in(2))->isa_int(); // Shift count is an int.
1024 return (ti && ti->is_con() && (ti->get_con() & (BitsPerJavaLong - 1)) == 0) ? in(1) : this;
1025 }
1026
1027 //------------------------------Value------------------------------------------
1028 // A RShiftLNode shifts its input2 right by input1 amount.
1029 const Type* RShiftLNode::Value(PhaseGVN* phase) const {
1030 const Type *t1 = phase->type( in(1) );
1031 const Type *t2 = phase->type( in(2) );
1032 // Either input is TOP ==> the result is TOP
1033 if( t1 == Type::TOP ) return Type::TOP;
1034 if( t2 == Type::TOP ) return Type::TOP;
1035
1036 // Left input is ZERO ==> the result is ZERO.
1037 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
1038 // Shift by zero does nothing
1039 if( t2 == TypeInt::ZERO ) return t1;
1040
1041 // Either input is BOTTOM ==> the result is BOTTOM
1042 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1043 return TypeLong::LONG;
1044
1045 if (t2 == TypeInt::INT)
1046 return TypeLong::LONG;
1047
1048 const TypeLong *r1 = t1->is_long(); // Handy access
1049 const TypeInt *r2 = t2->is_int (); // Handy access
1050
1051 // If the shift is a constant, just shift the bounds of the type.
1052 // For example, if the shift is 63, we just propagate sign bits.
1053 if (r2->is_con()) {
1054 uint shift = r2->get_con();
1055 shift &= (2*BitsPerJavaInteger)-1; // semantics of Java shifts
1056 // Shift by a multiple of 64 does nothing:
1057 if (shift == 0) return t1;
1058 // Calculate reasonably aggressive bounds for the result.
1059 // This is necessary if we are to correctly type things
1060 // like (x<<24>>24) == ((byte)x).
1061 jlong lo = (jlong)r1->_lo >> (jlong)shift;
1062 jlong hi = (jlong)r1->_hi >> (jlong)shift;
1063 assert(lo <= hi, "must have valid bounds");
1064 const TypeLong* tl = TypeLong::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1065 #ifdef ASSERT
1066 // Make sure we get the sign-capture idiom correct.
1067 if (shift == (2*BitsPerJavaInteger)-1) {
1068 if (r1->_lo >= 0) assert(tl == TypeLong::ZERO, ">>63 of + is 0");
1069 if (r1->_hi < 0) assert(tl == TypeLong::MINUS_1, ">>63 of - is -1");
1070 }
1071 #endif
1072 return tl;
1073 }
1074
1075 return TypeLong::LONG; // Give up
1076 }
1077
1078 //=============================================================================
1079 //------------------------------Identity---------------------------------------
1080 Node* URShiftINode::Identity(PhaseGVN* phase) {
1081 int shift = getShiftCon(phase, this, -1);
1082 if ((shift & (BitsPerJavaInteger - 1)) == 0) return in(1);
1083
1084 // Check for "((x << LogBytesPerWord) + (wordSize-1)) >> LogBytesPerWord" which is just "x".
1085 // Happens during new-array length computation.
1086 // Safe if 'x' is in the range [0..(max_int>>LogBytesPerWord)]
1087 Node *add = in(1);
1088 if (add->Opcode() == Op_AddI) {
1089 const TypeInt *t2 = phase->type(add->in(2))->isa_int();
1090 if (t2 && t2->is_con(wordSize - 1) &&
1091 add->in(1)->Opcode() == Op_LShiftI) {
1092 // Check that shift_counts are LogBytesPerWord.
1093 Node *lshift_count = add->in(1)->in(2);
1094 const TypeInt *t_lshift_count = phase->type(lshift_count)->isa_int();
1095 if (t_lshift_count && t_lshift_count->is_con(LogBytesPerWord) &&
1096 t_lshift_count == phase->type(in(2))) {
1097 Node *x = add->in(1)->in(1);
1098 const TypeInt *t_x = phase->type(x)->isa_int();
1099 if (t_x != NULL && 0 <= t_x->_lo && t_x->_hi <= (max_jint>>LogBytesPerWord)) {
1100 return x;
1101 }
1102 }
1103 }
1104 }
1105
1106 return (phase->type(in(2))->higher_equal(TypeInt::ZERO)) ? in(1) : this;
1107 }
1108
1109 //------------------------------Ideal------------------------------------------
1110 Node *URShiftINode::Ideal(PhaseGVN *phase, bool can_reshape) {
1111 int con = maskShiftAmount(phase, this, BitsPerJavaInteger);
1112 if (con == 0) {
1113 return NULL;
1114 }
1115
1116 // We'll be wanting the right-shift amount as a mask of that many bits
1117 const int mask = right_n_bits(BitsPerJavaInteger - con);
1118
1119 int in1_op = in(1)->Opcode();
1120
1121 // Check for ((x>>>a)>>>b) and replace with (x>>>(a+b)) when a+b < 32
1122 if( in1_op == Op_URShiftI ) {
1123 const TypeInt *t12 = phase->type( in(1)->in(2) )->isa_int();
1124 if( t12 && t12->is_con() ) { // Right input is a constant
1125 assert( in(1) != in(1)->in(1), "dead loop in URShiftINode::Ideal" );
1126 const int con2 = t12->get_con() & 31; // Shift count is always masked
1127 const int con3 = con+con2;
1128 if( con3 < 32 ) // Only merge shifts if total is < 32
1129 return new URShiftINode( in(1)->in(1), phase->intcon(con3) );
1130 }
1131 }
1132
1133 // Check for ((x << z) + Y) >>> z. Replace with x + con>>>z
1134 // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
1135 // If Q is "X << z" the rounding is useless. Look for patterns like
1136 // ((X<<Z) + Y) >>> Z and replace with (X + Y>>>Z) & Z-mask.
1137 Node *add = in(1);
1138 const TypeInt *t2 = phase->type(in(2))->isa_int();
1139 if (in1_op == Op_AddI) {
1140 Node *lshl = add->in(1);
1141 if( lshl->Opcode() == Op_LShiftI &&
1142 phase->type(lshl->in(2)) == t2 ) {
1143 Node *y_z = phase->transform( new URShiftINode(add->in(2),in(2)) );
1144 Node *sum = phase->transform( new AddINode( lshl->in(1), y_z ) );
1145 return new AndINode( sum, phase->intcon(mask) );
1146 }
1147 }
1148
1149 // Check for (x & mask) >>> z. Replace with (x >>> z) & (mask >>> z)
1150 // This shortens the mask. Also, if we are extracting a high byte and
1151 // storing it to a buffer, the mask will be removed completely.
1152 Node *andi = in(1);
1153 if( in1_op == Op_AndI ) {
1154 const TypeInt *t3 = phase->type( andi->in(2) )->isa_int();
1155 if( t3 && t3->is_con() ) { // Right input is a constant
1156 jint mask2 = t3->get_con();
1157 mask2 >>= con; // *signed* shift downward (high-order zeroes do not help)
1158 Node *newshr = phase->transform( new URShiftINode(andi->in(1), in(2)) );
1159 return new AndINode(newshr, phase->intcon(mask2));
1160 // The negative values are easier to materialize than positive ones.
1161 // A typical case from address arithmetic is ((x & ~15) >> 4).
1162 // It's better to change that to ((x >> 4) & ~0) versus
1163 // ((x >> 4) & 0x0FFFFFFF). The difference is greatest in LP64.
1164 }
1165 }
1166
1167 // Check for "(X << z ) >>> z" which simply zero-extends
1168 Node *shl = in(1);
1169 if( in1_op == Op_LShiftI &&
1170 phase->type(shl->in(2)) == t2 )
1171 return new AndINode( shl->in(1), phase->intcon(mask) );
1172
1173 return NULL;
1174 }
1175
1176 //------------------------------Value------------------------------------------
1177 // A URShiftINode shifts its input2 right by input1 amount.
1178 const Type* URShiftINode::Value(PhaseGVN* phase) const {
1179 // (This is a near clone of RShiftINode::Value.)
1180 const Type *t1 = phase->type( in(1) );
1181 const Type *t2 = phase->type( in(2) );
1182 // Either input is TOP ==> the result is TOP
1183 if( t1 == Type::TOP ) return Type::TOP;
1184 if( t2 == Type::TOP ) return Type::TOP;
1185
1186 // Left input is ZERO ==> the result is ZERO.
1187 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
1188 // Shift by zero does nothing
1189 if( t2 == TypeInt::ZERO ) return t1;
1190
1191 // Either input is BOTTOM ==> the result is BOTTOM
1192 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1193 return TypeInt::INT;
1194
1195 if (t2 == TypeInt::INT)
1196 return TypeInt::INT;
1197
1198 const TypeInt *r1 = t1->is_int(); // Handy access
1199 const TypeInt *r2 = t2->is_int(); // Handy access
1200
1201 if (r2->is_con()) {
1202 uint shift = r2->get_con();
1203 shift &= BitsPerJavaInteger-1; // semantics of Java shifts
1204 // Shift by a multiple of 32 does nothing:
1205 if (shift == 0) return t1;
1206 // Calculate reasonably aggressive bounds for the result.
1207 jint lo = (juint)r1->_lo >> (juint)shift;
1208 jint hi = (juint)r1->_hi >> (juint)shift;
1209 if (r1->_hi >= 0 && r1->_lo < 0) {
1210 // If the type has both negative and positive values,
1211 // there are two separate sub-domains to worry about:
1212 // The positive half and the negative half.
1213 jint neg_lo = lo;
1214 jint neg_hi = (juint)-1 >> (juint)shift;
1215 jint pos_lo = (juint) 0 >> (juint)shift;
1216 jint pos_hi = hi;
1217 lo = MIN2(neg_lo, pos_lo); // == 0
1218 hi = MAX2(neg_hi, pos_hi); // == -1 >>> shift;
1219 }
1220 assert(lo <= hi, "must have valid bounds");
1221 const TypeInt* ti = TypeInt::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1222 #ifdef ASSERT
1223 // Make sure we get the sign-capture idiom correct.
1224 if (shift == BitsPerJavaInteger-1) {
1225 if (r1->_lo >= 0) assert(ti == TypeInt::ZERO, ">>>31 of + is 0");
1226 if (r1->_hi < 0) assert(ti == TypeInt::ONE, ">>>31 of - is +1");
1227 }
1228 #endif
1229 return ti;
1230 }
1231
1232 //
1233 // Do not support shifted oops in info for GC
1234 //
1235 // else if( t1->base() == Type::InstPtr ) {
1236 //
1237 // const TypeInstPtr *o = t1->is_instptr();
1238 // if( t1->singleton() )
1239 // return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift );
1240 // }
1241 // else if( t1->base() == Type::KlassPtr ) {
1242 // const TypeKlassPtr *o = t1->is_klassptr();
1243 // if( t1->singleton() )
1244 // return TypeInt::make( ((uint32_t)o->const_oop() + o->_offset) >> shift );
1245 // }
1246
1247 return TypeInt::INT;
1248 }
1249
1250 //=============================================================================
1251 //------------------------------Identity---------------------------------------
1252 Node* URShiftLNode::Identity(PhaseGVN* phase) {
1253 return ((getShiftCon(phase, this, -1) & (BitsPerJavaLong - 1)) == 0) ? in(1) : this;
1254 }
1255
1256 //------------------------------Ideal------------------------------------------
1257 Node *URShiftLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1258 int con = maskShiftAmount(phase, this, BitsPerJavaLong);
1259 if (con == 0) {
1260 return NULL;
1261 }
1262
1263 // We'll be wanting the right-shift amount as a mask of that many bits
1264 const jlong mask = jlong(max_julong >> con);
1265
1266 // Check for ((x << z) + Y) >>> z. Replace with x + con>>>z
1267 // The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
1268 // If Q is "X << z" the rounding is useless. Look for patterns like
1269 // ((X<<Z) + Y) >>> Z and replace with (X + Y>>>Z) & Z-mask.
1270 Node *add = in(1);
1271 const TypeInt *t2 = phase->type(in(2))->isa_int();
1272 if (add->Opcode() == Op_AddL) {
1273 Node *lshl = add->in(1);
1274 if( lshl->Opcode() == Op_LShiftL &&
1275 phase->type(lshl->in(2)) == t2 ) {
1276 Node *y_z = phase->transform( new URShiftLNode(add->in(2),in(2)) );
1277 Node *sum = phase->transform( new AddLNode( lshl->in(1), y_z ) );
1278 return new AndLNode( sum, phase->longcon(mask) );
1279 }
1280 }
1281
1282 // Check for (x & mask) >>> z. Replace with (x >>> z) & (mask >>> z)
1283 // This shortens the mask. Also, if we are extracting a high byte and
1284 // storing it to a buffer, the mask will be removed completely.
1285 Node *andi = in(1);
1286 if( andi->Opcode() == Op_AndL ) {
1287 const TypeLong *t3 = phase->type( andi->in(2) )->isa_long();
1288 if( t3 && t3->is_con() ) { // Right input is a constant
1289 jlong mask2 = t3->get_con();
1290 mask2 >>= con; // *signed* shift downward (high-order zeroes do not help)
1291 Node *newshr = phase->transform( new URShiftLNode(andi->in(1), in(2)) );
1292 return new AndLNode(newshr, phase->longcon(mask2));
1293 }
1294 }
1295
1296 // Check for "(X << z ) >>> z" which simply zero-extends
1297 Node *shl = in(1);
1298 if( shl->Opcode() == Op_LShiftL &&
1299 phase->type(shl->in(2)) == t2 )
1300 return new AndLNode( shl->in(1), phase->longcon(mask) );
1301
1302 return NULL;
1303 }
1304
1305 //------------------------------Value------------------------------------------
1306 // A URShiftINode shifts its input2 right by input1 amount.
1307 const Type* URShiftLNode::Value(PhaseGVN* phase) const {
1308 // (This is a near clone of RShiftLNode::Value.)
1309 const Type *t1 = phase->type( in(1) );
1310 const Type *t2 = phase->type( in(2) );
1311 // Either input is TOP ==> the result is TOP
1312 if( t1 == Type::TOP ) return Type::TOP;
1313 if( t2 == Type::TOP ) return Type::TOP;
1314
1315 // Left input is ZERO ==> the result is ZERO.
1316 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
1317 // Shift by zero does nothing
1318 if( t2 == TypeInt::ZERO ) return t1;
1319
1320 // Either input is BOTTOM ==> the result is BOTTOM
1321 if (t1 == Type::BOTTOM || t2 == Type::BOTTOM)
1322 return TypeLong::LONG;
1323
1324 if (t2 == TypeInt::INT)
1325 return TypeLong::LONG;
1326
1327 const TypeLong *r1 = t1->is_long(); // Handy access
1328 const TypeInt *r2 = t2->is_int (); // Handy access
1329
1330 if (r2->is_con()) {
1331 uint shift = r2->get_con();
1332 shift &= BitsPerJavaLong - 1; // semantics of Java shifts
1333 // Shift by a multiple of 64 does nothing:
1334 if (shift == 0) return t1;
1335 // Calculate reasonably aggressive bounds for the result.
1336 jlong lo = (julong)r1->_lo >> (juint)shift;
1337 jlong hi = (julong)r1->_hi >> (juint)shift;
1338 if (r1->_hi >= 0 && r1->_lo < 0) {
1339 // If the type has both negative and positive values,
1340 // there are two separate sub-domains to worry about:
1341 // The positive half and the negative half.
1342 jlong neg_lo = lo;
1343 jlong neg_hi = (julong)-1 >> (juint)shift;
1344 jlong pos_lo = (julong) 0 >> (juint)shift;
1345 jlong pos_hi = hi;
1346 //lo = MIN2(neg_lo, pos_lo); // == 0
1347 lo = neg_lo < pos_lo ? neg_lo : pos_lo;
1348 //hi = MAX2(neg_hi, pos_hi); // == -1 >>> shift;
1349 hi = neg_hi > pos_hi ? neg_hi : pos_hi;
1350 }
1351 assert(lo <= hi, "must have valid bounds");
1352 const TypeLong* tl = TypeLong::make(lo, hi, MAX2(r1->_widen,r2->_widen));
1353 #ifdef ASSERT
1354 // Make sure we get the sign-capture idiom correct.
1355 if (shift == BitsPerJavaLong - 1) {
1356 if (r1->_lo >= 0) assert(tl == TypeLong::ZERO, ">>>63 of + is 0");
1357 if (r1->_hi < 0) assert(tl == TypeLong::ONE, ">>>63 of - is +1");
1358 }
1359 #endif
1360 return tl;
1361 }
1362
1363 return TypeLong::LONG; // Give up
1364 }
1365
1366 //=============================================================================
1367 //------------------------------Value------------------------------------------
1368 const Type* FmaDNode::Value(PhaseGVN* phase) const {
1369 const Type *t1 = phase->type(in(1));
1370 if (t1 == Type::TOP) return Type::TOP;
1371 if (t1->base() != Type::DoubleCon) return Type::DOUBLE;
1372 const Type *t2 = phase->type(in(2));
1373 if (t2 == Type::TOP) return Type::TOP;
1374 if (t2->base() != Type::DoubleCon) return Type::DOUBLE;
1375 const Type *t3 = phase->type(in(3));
1376 if (t3 == Type::TOP) return Type::TOP;
1377 if (t3->base() != Type::DoubleCon) return Type::DOUBLE;
1378 #ifndef __STDC_IEC_559__
1379 return Type::DOUBLE;
1380 #else
1381 double d1 = t1->getd();
1382 double d2 = t2->getd();
1383 double d3 = t3->getd();
1384 return TypeD::make(fma(d1, d2, d3));
1385 #endif
1386 }
1387
1388 //=============================================================================
1389 //------------------------------Value------------------------------------------
1390 const Type* FmaFNode::Value(PhaseGVN* phase) const {
1391 const Type *t1 = phase->type(in(1));
1392 if (t1 == Type::TOP) return Type::TOP;
1393 if (t1->base() != Type::FloatCon) return Type::FLOAT;
1394 const Type *t2 = phase->type(in(2));
1395 if (t2 == Type::TOP) return Type::TOP;
1396 if (t2->base() != Type::FloatCon) return Type::FLOAT;
1397 const Type *t3 = phase->type(in(3));
1398 if (t3 == Type::TOP) return Type::TOP;
1399 if (t3->base() != Type::FloatCon) return Type::FLOAT;
1400 #ifndef __STDC_IEC_559__
1401 return Type::FLOAT;
1402 #else
1403 float f1 = t1->getf();
1404 float f2 = t2->getf();
1405 float f3 = t3->getf();
1406 return TypeF::make(fma(f1, f2, f3));
1407 #endif
1408 }