1 /*
2 * Copyright (c) 1999, 2015, 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 "c1/c1_Canonicalizer.hpp"
27 #include "c1/c1_InstructionPrinter.hpp"
28 #include "c1/c1_ValueStack.hpp"
29 #include "ci/ciArray.hpp"
30 #include "runtime/sharedRuntime.hpp"
31
32
33 class PrintValueVisitor: public ValueVisitor {
34 void visit(Value* vp) {
35 (*vp)->print_line();
36 }
37 };
38
39 void Canonicalizer::set_canonical(Value x) {
40 assert(x != NULL, "value must exist");
41 // Note: we can not currently substitute root nodes which show up in
42 // the instruction stream (because the instruction list is embedded
43 // in the instructions).
44 if (canonical() != x) {
45 #ifndef PRODUCT
46 if (!x->has_printable_bci()) {
47 x->set_printable_bci(bci());
48 }
49 #endif
50 if (PrintCanonicalization) {
51 PrintValueVisitor do_print_value;
52 canonical()->input_values_do(&do_print_value);
53 canonical()->print_line();
54 tty->print_cr("canonicalized to:");
55 x->input_values_do(&do_print_value);
56 x->print_line();
57 tty->cr();
58 }
59 assert(_canonical->type()->tag() == x->type()->tag(), "types must match");
60 _canonical = x;
61 }
62 }
63
64
65 void Canonicalizer::move_const_to_right(Op2* x) {
66 if (x->x()->type()->is_constant() && x->is_commutative()) x->swap_operands();
67 }
68
69
70 void Canonicalizer::do_Op2(Op2* x) {
71 if (x->x() == x->y()) {
72 switch (x->op()) {
73 case Bytecodes::_isub: set_constant(0); return;
74 case Bytecodes::_lsub: set_constant(jlong_cast(0)); return;
75 case Bytecodes::_iand: // fall through
76 case Bytecodes::_land: // fall through
77 case Bytecodes::_ior: // fall through
78 case Bytecodes::_lor : set_canonical(x->x()); return;
79 case Bytecodes::_ixor: set_constant(0); return;
80 case Bytecodes::_lxor: set_constant(jlong_cast(0)); return;
81 }
82 }
83
84 if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
85 // do constant folding for selected operations
86 switch (x->type()->tag()) {
87 case intTag:
88 { jint a = x->x()->type()->as_IntConstant()->value();
89 jint b = x->y()->type()->as_IntConstant()->value();
90 switch (x->op()) {
91 case Bytecodes::_iadd: set_constant(a + b); return;
92 case Bytecodes::_isub: set_constant(a - b); return;
93 case Bytecodes::_imul: set_constant(a * b); return;
94 case Bytecodes::_idiv:
95 if (b != 0) {
96 if (a == min_jint && b == -1) {
97 set_constant(min_jint);
98 } else {
99 set_constant(a / b);
100 }
101 return;
102 }
103 break;
104 case Bytecodes::_irem:
105 if (b != 0) {
106 if (a == min_jint && b == -1) {
107 set_constant(0);
108 } else {
109 set_constant(a % b);
110 }
111 return;
112 }
113 break;
114 case Bytecodes::_iand: set_constant(a & b); return;
115 case Bytecodes::_ior : set_constant(a | b); return;
116 case Bytecodes::_ixor: set_constant(a ^ b); return;
117 }
118 }
119 break;
120 case longTag:
121 { jlong a = x->x()->type()->as_LongConstant()->value();
122 jlong b = x->y()->type()->as_LongConstant()->value();
123 switch (x->op()) {
124 case Bytecodes::_ladd: set_constant(a + b); return;
125 case Bytecodes::_lsub: set_constant(a - b); return;
126 case Bytecodes::_lmul: set_constant(a * b); return;
127 case Bytecodes::_ldiv:
128 if (b != 0) {
129 set_constant(SharedRuntime::ldiv(b, a));
130 return;
131 }
132 break;
133 case Bytecodes::_lrem:
134 if (b != 0) {
135 set_constant(SharedRuntime::lrem(b, a));
136 return;
137 }
138 break;
139 case Bytecodes::_land: set_constant(a & b); return;
140 case Bytecodes::_lor : set_constant(a | b); return;
141 case Bytecodes::_lxor: set_constant(a ^ b); return;
142 }
143 }
144 break;
145 // other cases not implemented (must be extremely careful with floats & doubles!)
146 }
147 }
148 // make sure constant is on the right side, if any
149 move_const_to_right(x);
150
151 if (x->y()->type()->is_constant()) {
152 // do constant folding for selected operations
153 switch (x->type()->tag()) {
154 case intTag:
155 if (x->y()->type()->as_IntConstant()->value() == 0) {
156 switch (x->op()) {
157 case Bytecodes::_iadd: set_canonical(x->x()); return;
158 case Bytecodes::_isub: set_canonical(x->x()); return;
159 case Bytecodes::_imul: set_constant(0); return;
160 // Note: for div and rem, make sure that C semantics
161 // corresponds to Java semantics!
162 case Bytecodes::_iand: set_constant(0); return;
163 case Bytecodes::_ior : set_canonical(x->x()); return;
164 }
165 }
166 break;
167 case longTag:
168 if (x->y()->type()->as_LongConstant()->value() == (jlong)0) {
169 switch (x->op()) {
170 case Bytecodes::_ladd: set_canonical(x->x()); return;
171 case Bytecodes::_lsub: set_canonical(x->x()); return;
172 case Bytecodes::_lmul: set_constant((jlong)0); return;
173 // Note: for div and rem, make sure that C semantics
174 // corresponds to Java semantics!
175 case Bytecodes::_land: set_constant((jlong)0); return;
176 case Bytecodes::_lor : set_canonical(x->x()); return;
177 }
178 }
179 break;
180 }
181 }
182 }
183
184
185 void Canonicalizer::do_Phi (Phi* x) {}
186 void Canonicalizer::do_Constant (Constant* x) {}
187 void Canonicalizer::do_Local (Local* x) {}
188 void Canonicalizer::do_LoadField (LoadField* x) {}
189
190 // checks if v is in the block that is currently processed by
191 // GraphBuilder. This is the only block that has not BlockEnd yet.
192 static bool in_current_block(Value v) {
193 int max_distance = 4;
194 while (max_distance > 0 && v != NULL && v->as_BlockEnd() == NULL) {
195 v = v->next();
196 max_distance--;
197 }
198 return v == NULL;
199 }
200
201 void Canonicalizer::do_StoreField (StoreField* x) {
202 // If a value is going to be stored into a field or array some of
203 // the conversions emitted by javac are unneeded because the fields
204 // are packed to their natural size.
205 Convert* conv = x->value()->as_Convert();
206 if (conv) {
207 Value value = NULL;
208 BasicType type = x->field()->type()->basic_type();
209 switch (conv->op()) {
210 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break;
211 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
212 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break;
213 }
214 // limit this optimization to current block
215 if (value != NULL && in_current_block(conv)) {
216 set_canonical(new StoreField(x->obj(), x->offset(), x->field(), value, x->is_static(),
217 x->state_before(), x->needs_patching()));
218 return;
219 }
220 }
221
222 }
223
224 void Canonicalizer::do_ArrayLength (ArrayLength* x) {
225 NewArray* na;
226 Constant* ct;
227 LoadField* lf;
228
229 if ((na = x->array()->as_NewArray()) != NULL) {
230 // New arrays might have the known length.
231 // Do not use the Constant itself, but create a new Constant
232 // with same value Otherwise a Constant is live over multiple
233 // blocks without being registered in a state array.
234 Constant* length;
235 if (na->length() != NULL &&
236 (length = na->length()->as_Constant()) != NULL) {
237 assert(length->type()->as_IntConstant() != NULL, "array length must be integer");
238 set_constant(length->type()->as_IntConstant()->value());
239 }
240
241 } else if ((ct = x->array()->as_Constant()) != NULL) {
242 // Constant arrays have constant lengths.
243 ArrayConstant* cnst = ct->type()->as_ArrayConstant();
244 if (cnst != NULL) {
245 set_constant(cnst->value()->length());
246 }
247
248 } else if ((lf = x->array()->as_LoadField()) != NULL) {
249 ciField* field = lf->field();
250 if (field->is_static_constant()) {
251 assert(PatchALot || ScavengeRootsInCode < 2, "Constant field loads are folded during parsing");
252 ciObject* c = field->constant_value().as_object();
253 if (!c->is_null_object()) {
254 set_constant(c->as_array()->length());
255 }
256 }
257 }
258 }
259
260 void Canonicalizer::do_LoadIndexed (LoadIndexed* x) {
261 StableArrayConstant* array = x->array()->type()->as_StableArrayConstant();
262 IntConstant* index = x->index()->type()->as_IntConstant();
263
264 assert(array == NULL || FoldStableValues, "not enabled");
265
266 // Constant fold loads from stable arrays.
267 if (array != NULL && index != NULL) {
268 jint idx = index->value();
269 if (idx < 0 || idx >= array->value()->length()) {
270 // Leave the load as is. The range check will handle it.
271 return;
272 }
273
274 ciConstant field_val = array->value()->element_value(idx);
275 if (!field_val.is_null_or_zero()) {
276 jint dimension = array->dimension();
277 assert(dimension <= array->value()->array_type()->dimension(), "inconsistent info");
278 ValueType* value = NULL;
279 if (dimension > 1) {
280 // Preserve information about the dimension for the element.
281 assert(field_val.as_object()->is_array(), "not an array");
282 value = new StableArrayConstant(field_val.as_object()->as_array(), dimension - 1);
283 } else {
284 assert(dimension == 1, "sanity");
285 value = as_ValueType(field_val);
286 }
287 set_canonical(new Constant(value));
288 }
289 }
290 }
291
292 void Canonicalizer::do_StoreIndexed (StoreIndexed* x) {
293 // If a value is going to be stored into a field or array some of
294 // the conversions emitted by javac are unneeded because the fields
295 // are packed to their natural size.
296 Convert* conv = x->value()->as_Convert();
297 if (conv) {
298 Value value = NULL;
299 BasicType type = x->elt_type();
300 switch (conv->op()) {
301 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break;
302 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
303 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break;
304 }
305 // limit this optimization to current block
306 if (value != NULL && in_current_block(conv)) {
307 set_canonical(new StoreIndexed(x->array(), x->index(), x->length(),
308 x->elt_type(), value, x->state_before(),
309 x->check_boolean()));
310 return;
311 }
312 }
313
314
315 }
316
317
318 void Canonicalizer::do_NegateOp(NegateOp* x) {
319 ValueType* t = x->x()->type();
320 if (t->is_constant()) {
321 switch (t->tag()) {
322 case intTag : set_constant(-t->as_IntConstant ()->value()); return;
323 case longTag : set_constant(-t->as_LongConstant ()->value()); return;
324 case floatTag : set_constant(-t->as_FloatConstant ()->value()); return;
325 case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return;
326 default : ShouldNotReachHere();
327 }
328 }
329 }
330
331
332 void Canonicalizer::do_ArithmeticOp (ArithmeticOp* x) { do_Op2(x); }
333
334
335 void Canonicalizer::do_ShiftOp (ShiftOp* x) {
336 ValueType* t = x->x()->type();
337 ValueType* t2 = x->y()->type();
338 if (t->is_constant()) {
339 switch (t->tag()) {
340 case intTag : if (t->as_IntConstant()->value() == 0) { set_constant(0); return; } break;
341 case longTag : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break;
342 default : ShouldNotReachHere();
343 }
344 if (t2->is_constant()) {
345 if (t->tag() == intTag) {
346 int value = t->as_IntConstant()->value();
347 int shift = t2->as_IntConstant()->value() & 31;
348 jint mask = ~(~0 << (32 - shift));
349 if (shift == 0) mask = ~0;
350 switch (x->op()) {
351 case Bytecodes::_ishl: set_constant(value << shift); return;
352 case Bytecodes::_ishr: set_constant(value >> shift); return;
353 case Bytecodes::_iushr: set_constant((value >> shift) & mask); return;
354 }
355 } else if (t->tag() == longTag) {
356 jlong value = t->as_LongConstant()->value();
357 int shift = t2->as_IntConstant()->value() & 63;
358 jlong mask = ~(~jlong_cast(0) << (64 - shift));
359 if (shift == 0) mask = ~jlong_cast(0);
360 switch (x->op()) {
361 case Bytecodes::_lshl: set_constant(value << shift); return;
362 case Bytecodes::_lshr: set_constant(value >> shift); return;
363 case Bytecodes::_lushr: set_constant((value >> shift) & mask); return;
364 }
365 }
366 }
367 }
368 if (t2->is_constant()) {
369 switch (t2->tag()) {
370 case intTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return;
371 case longTag : if (t2->as_LongConstant()->value() == (jlong)0) set_canonical(x->x()); return;
372 default : ShouldNotReachHere();
373 }
374 }
375 }
376
377
378 void Canonicalizer::do_LogicOp (LogicOp* x) { do_Op2(x); }
379 void Canonicalizer::do_CompareOp (CompareOp* x) {
380 if (x->x() == x->y()) {
381 switch (x->x()->type()->tag()) {
382 case longTag: set_constant(0); break;
383 case floatTag: {
384 FloatConstant* fc = x->x()->type()->as_FloatConstant();
385 if (fc) {
386 if (g_isnan(fc->value())) {
387 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
388 } else {
389 set_constant(0);
390 }
391 }
392 break;
393 }
394 case doubleTag: {
395 DoubleConstant* dc = x->x()->type()->as_DoubleConstant();
396 if (dc) {
397 if (g_isnan(dc->value())) {
398 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
399 } else {
400 set_constant(0);
401 }
402 }
403 break;
404 }
405 }
406 } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
407 switch (x->x()->type()->tag()) {
408 case longTag: {
409 jlong vx = x->x()->type()->as_LongConstant()->value();
410 jlong vy = x->y()->type()->as_LongConstant()->value();
411 if (vx == vy)
412 set_constant(0);
413 else if (vx < vy)
414 set_constant(-1);
415 else
416 set_constant(1);
417 break;
418 }
419
420 case floatTag: {
421 float vx = x->x()->type()->as_FloatConstant()->value();
422 float vy = x->y()->type()->as_FloatConstant()->value();
423 if (g_isnan(vx) || g_isnan(vy))
424 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
425 else if (vx == vy)
426 set_constant(0);
427 else if (vx < vy)
428 set_constant(-1);
429 else
430 set_constant(1);
431 break;
432 }
433
434 case doubleTag: {
435 double vx = x->x()->type()->as_DoubleConstant()->value();
436 double vy = x->y()->type()->as_DoubleConstant()->value();
437 if (g_isnan(vx) || g_isnan(vy))
438 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
439 else if (vx == vy)
440 set_constant(0);
441 else if (vx < vy)
442 set_constant(-1);
443 else
444 set_constant(1);
445 break;
446 }
447 }
448
449 }
450 }
451
452
453 void Canonicalizer::do_IfInstanceOf(IfInstanceOf* x) {}
454
455 void Canonicalizer::do_IfOp(IfOp* x) {
456 // Caution: do not use do_Op2(x) here for now since
457 // we map the condition to the op for now!
458 move_const_to_right(x);
459 }
460
461
462 void Canonicalizer::do_Intrinsic (Intrinsic* x) {
463 switch (x->id()) {
464 case vmIntrinsics::_floatToRawIntBits : {
465 FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant();
466 if (c != NULL) {
467 JavaValue v;
468 v.set_jfloat(c->value());
469 set_constant(v.get_jint());
470 }
471 break;
472 }
473 case vmIntrinsics::_intBitsToFloat : {
474 IntConstant* c = x->argument_at(0)->type()->as_IntConstant();
475 if (c != NULL) {
476 JavaValue v;
477 v.set_jint(c->value());
478 set_constant(v.get_jfloat());
479 }
480 break;
481 }
482 case vmIntrinsics::_doubleToRawLongBits : {
483 DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant();
484 if (c != NULL) {
485 JavaValue v;
486 v.set_jdouble(c->value());
487 set_constant(v.get_jlong());
488 }
489 break;
490 }
491 case vmIntrinsics::_longBitsToDouble : {
492 LongConstant* c = x->argument_at(0)->type()->as_LongConstant();
493 if (c != NULL) {
494 JavaValue v;
495 v.set_jlong(c->value());
496 set_constant(v.get_jdouble());
497 }
498 break;
499 }
500 case vmIntrinsics::_isInstance : {
501 assert(x->number_of_arguments() == 2, "wrong type");
502
503 InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant();
504 if (c != NULL && !c->value()->is_null_object()) {
505 // ciInstance::java_mirror_type() returns non-NULL only for Java mirrors
506 ciType* t = c->value()->java_mirror_type();
507 if (t->is_klass()) {
508 // substitute cls.isInstance(obj) of a constant Class into
509 // an InstantOf instruction
510 InstanceOf* i = new InstanceOf(t->as_klass(), x->argument_at(1), x->state_before());
511 set_canonical(i);
512 // and try to canonicalize even further
513 do_InstanceOf(i);
514 } else {
515 assert(t->is_primitive_type(), "should be a primitive type");
516 // cls.isInstance(obj) always returns false for primitive classes
517 set_constant(0);
518 }
519 }
520 break;
521 }
522 case vmIntrinsics::_isPrimitive : {
523 assert(x->number_of_arguments() == 1, "wrong type");
524
525 // Class.isPrimitive is known on constant classes:
526 InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant();
527 if (c != NULL && !c->value()->is_null_object()) {
528 ciType* t = c->value()->java_mirror_type();
529 set_constant(t->is_primitive_type());
530 }
531 break;
532 }
533 }
534 }
535
536 void Canonicalizer::do_Convert (Convert* x) {
537 if (x->value()->type()->is_constant()) {
538 switch (x->op()) {
539 case Bytecodes::_i2b: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break;
540 case Bytecodes::_i2s: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break;
541 case Bytecodes::_i2c: set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break;
542 case Bytecodes::_i2l: set_constant((jlong)(x->value()->type()->as_IntConstant()->value())); break;
543 case Bytecodes::_i2f: set_constant((float)(x->value()->type()->as_IntConstant()->value())); break;
544 case Bytecodes::_i2d: set_constant((double)(x->value()->type()->as_IntConstant()->value())); break;
545 case Bytecodes::_l2i: set_constant((int)(x->value()->type()->as_LongConstant()->value())); break;
546 case Bytecodes::_l2f: set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break;
547 case Bytecodes::_l2d: set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break;
548 case Bytecodes::_f2d: set_constant((double)(x->value()->type()->as_FloatConstant()->value())); break;
549 case Bytecodes::_f2i: set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break;
550 case Bytecodes::_f2l: set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break;
551 case Bytecodes::_d2f: set_constant((float)(x->value()->type()->as_DoubleConstant()->value())); break;
552 case Bytecodes::_d2i: set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break;
553 case Bytecodes::_d2l: set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break;
554 default:
555 ShouldNotReachHere();
556 }
557 }
558
559 Value value = x->value();
560 BasicType type = T_ILLEGAL;
561 LoadField* lf = value->as_LoadField();
562 if (lf) {
563 type = lf->field_type();
564 } else {
565 LoadIndexed* li = value->as_LoadIndexed();
566 if (li) {
567 type = li->elt_type();
568 } else {
569 Convert* conv = value->as_Convert();
570 if (conv) {
571 switch (conv->op()) {
572 case Bytecodes::_i2b: type = T_BYTE; break;
573 case Bytecodes::_i2s: type = T_SHORT; break;
574 case Bytecodes::_i2c: type = T_CHAR; break;
575 }
576 }
577 }
578 }
579 if (type != T_ILLEGAL) {
580 switch (x->op()) {
581 case Bytecodes::_i2b: if (type == T_BYTE) set_canonical(x->value()); break;
582 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break;
583 case Bytecodes::_i2c: if (type == T_CHAR) set_canonical(x->value()); break;
584 }
585 } else {
586 Op2* op2 = x->value()->as_Op2();
587 if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) {
588 jint safebits = 0;
589 jint mask = op2->y()->type()->as_IntConstant()->value();
590 switch (x->op()) {
591 case Bytecodes::_i2b: safebits = 0x7f; break;
592 case Bytecodes::_i2s: safebits = 0x7fff; break;
593 case Bytecodes::_i2c: safebits = 0xffff; break;
594 }
595 // When casting a masked integer to a smaller signed type, if
596 // the mask doesn't include the sign bit the cast isn't needed.
597 if (safebits && (mask & ~safebits) == 0) {
598 set_canonical(x->value());
599 }
600 }
601 }
602
603 }
604
605 void Canonicalizer::do_NullCheck (NullCheck* x) {
606 if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) {
607 set_canonical(x->obj());
608 } else {
609 Constant* con = x->obj()->as_Constant();
610 if (con) {
611 ObjectType* c = con->type()->as_ObjectType();
612 if (c && c->is_loaded()) {
613 ObjectConstant* oc = c->as_ObjectConstant();
614 if (!oc || !oc->value()->is_null_object()) {
615 set_canonical(con);
616 }
617 }
618 }
619 }
620 }
621
622 void Canonicalizer::do_TypeCast (TypeCast* x) {}
623 void Canonicalizer::do_Invoke (Invoke* x) {}
624 void Canonicalizer::do_NewInstance (NewInstance* x) {}
625 void Canonicalizer::do_NewTypeArray (NewTypeArray* x) {}
626 void Canonicalizer::do_NewObjectArray (NewObjectArray* x) {}
627 void Canonicalizer::do_NewMultiArray (NewMultiArray* x) {}
628 void Canonicalizer::do_CheckCast (CheckCast* x) {
629 if (x->klass()->is_loaded()) {
630 Value obj = x->obj();
631 ciType* klass = obj->exact_type();
632 if (klass == NULL) klass = obj->declared_type();
633 if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) {
634 set_canonical(obj);
635 return;
636 }
637 // checkcast of null returns null
638 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
639 set_canonical(obj);
640 }
641 }
642 }
643 void Canonicalizer::do_InstanceOf (InstanceOf* x) {
644 if (x->klass()->is_loaded()) {
645 Value obj = x->obj();
646 ciType* exact = obj->exact_type();
647 if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) {
648 set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0);
649 return;
650 }
651 // instanceof null returns false
652 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
653 set_constant(0);
654 }
655 }
656
657 }
658 void Canonicalizer::do_MonitorEnter (MonitorEnter* x) {}
659 void Canonicalizer::do_MonitorExit (MonitorExit* x) {}
660 void Canonicalizer::do_BlockBegin (BlockBegin* x) {}
661 void Canonicalizer::do_Goto (Goto* x) {}
662
663
664 static bool is_true(jlong x, If::Condition cond, jlong y) {
665 switch (cond) {
666 case If::eql: return x == y;
667 case If::neq: return x != y;
668 case If::lss: return x < y;
669 case If::leq: return x <= y;
670 case If::gtr: return x > y;
671 case If::geq: return x >= y;
672 }
673 ShouldNotReachHere();
674 return false;
675 }
676
677 static bool is_safepoint(BlockEnd* x, BlockBegin* sux) {
678 // An Instruction with multiple successors, x, is replaced by a Goto
679 // to a single successor, sux. Is a safepoint check needed = was the
680 // instruction being replaced a safepoint and the single remaining
681 // successor a back branch?
682 return x->is_safepoint() && (sux->bci() < x->state_before()->bci());
683 }
684
685 void Canonicalizer::do_If(If* x) {
686 // move const to right
687 if (x->x()->type()->is_constant()) x->swap_operands();
688 // simplify
689 const Value l = x->x(); ValueType* lt = l->type();
690 const Value r = x->y(); ValueType* rt = r->type();
691
692 if (l == r && !lt->is_float_kind()) {
693 // pattern: If (a cond a) => simplify to Goto
694 BlockBegin* sux = NULL;
695 switch (x->cond()) {
696 case If::eql: sux = x->sux_for(true); break;
697 case If::neq: sux = x->sux_for(false); break;
698 case If::lss: sux = x->sux_for(false); break;
699 case If::leq: sux = x->sux_for(true); break;
700 case If::gtr: sux = x->sux_for(false); break;
701 case If::geq: sux = x->sux_for(true); break;
702 default: ShouldNotReachHere();
703 }
704 // If is a safepoint then the debug information should come from the state_before of the If.
705 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
706 return;
707 }
708
709 if (lt->is_constant() && rt->is_constant()) {
710 if (x->x()->as_Constant() != NULL) {
711 // pattern: If (lc cond rc) => simplify to: Goto
712 BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(),
713 x->sux_for(true),
714 x->sux_for(false));
715 if (sux != NULL) {
716 // If is a safepoint then the debug information should come from the state_before of the If.
717 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
718 }
719 }
720 } else if (rt->as_IntConstant() != NULL) {
721 // pattern: If (l cond rc) => investigate further
722 const jint rc = rt->as_IntConstant()->value();
723 if (l->as_CompareOp() != NULL) {
724 // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto
725 CompareOp* cmp = l->as_CompareOp();
726 bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl;
727 BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b
728 BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b
729 BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b
730 BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered
731 // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are
732 // equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either
733 // lss_sux or gtr_sux.
734 if (lss_sux == eql_sux && eql_sux == gtr_sux) {
735 // all successors identical => simplify to: Goto
736 set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint()));
737 } else {
738 // two successors differ and two successors are the same => simplify to: If (x cmp y)
739 // determine new condition & successors
740 If::Condition cond = If::eql;
741 BlockBegin* tsux = NULL;
742 BlockBegin* fsux = NULL;
743 if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; }
744 else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; }
745 else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; }
746 else { ShouldNotReachHere(); }
747 If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint());
748 if (cmp->x() == cmp->y()) {
749 do_If(canon);
750 } else {
751 if (compilation()->profile_branches()) {
752 // TODO: If profiling, leave floating point comparisons unoptimized.
753 // We currently do not support profiling of the unordered case.
754 switch(cmp->op()) {
755 case Bytecodes::_fcmpl: case Bytecodes::_fcmpg:
756 case Bytecodes::_dcmpl: case Bytecodes::_dcmpg:
757 set_canonical(x);
758 return;
759 }
760 }
761 set_bci(cmp->state_before()->bci());
762 set_canonical(canon);
763 }
764 }
765 } else if (l->as_InstanceOf() != NULL) {
766 // NOTE: Code permanently disabled for now since it leaves the old InstanceOf
767 // instruction in the graph (it is pinned). Need to fix this at some point.
768 // It should also be left in the graph when generating a profiled method version or Goto
769 // has to know that it was an InstanceOf.
770 return;
771 // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto
772 InstanceOf* inst = l->as_InstanceOf();
773 BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1
774 BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0
775 if (is_inst_sux == no_inst_sux && inst->is_loaded()) {
776 // both successors identical and klass is loaded => simplify to: Goto
777 set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint()));
778 } else {
779 // successors differ => simplify to: IfInstanceOf
780 set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->state_before()->bci(), is_inst_sux, no_inst_sux));
781 }
782 }
783 } else if (rt == objectNull &&
784 (l->as_NewInstance() || l->as_NewArray() ||
785 (l->as_Local() && l->as_Local()->is_receiver()))) {
786 if (x->cond() == Instruction::eql) {
787 BlockBegin* sux = x->fsux();
788 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
789 } else {
790 assert(x->cond() == Instruction::neq, "only other valid case");
791 BlockBegin* sux = x->tsux();
792 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
793 }
794 }
795 }
796
797
798 void Canonicalizer::do_TableSwitch(TableSwitch* x) {
799 if (x->tag()->type()->is_constant()) {
800 int v = x->tag()->type()->as_IntConstant()->value();
801 BlockBegin* sux = x->default_sux();
802 if (v >= x->lo_key() && v <= x->hi_key()) {
803 sux = x->sux_at(v - x->lo_key());
804 }
805 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
806 } else if (x->number_of_sux() == 1) {
807 // NOTE: Code permanently disabled for now since the switch statement's
808 // tag expression may produce side-effects in which case it must
809 // be executed.
810 return;
811 // simplify to Goto
812 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
813 } else if (x->number_of_sux() == 2) {
814 // NOTE: Code permanently disabled for now since it produces two new nodes
815 // (Constant & If) and the Canonicalizer cannot return them correctly
816 // yet. For now we copied the corresponding code directly into the
817 // GraphBuilder (i.e., we should never reach here).
818 return;
819 // simplify to If
820 assert(x->lo_key() == x->hi_key(), "keys must be the same");
821 Constant* key = new Constant(new IntConstant(x->lo_key()));
822 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
823 }
824 }
825
826
827 void Canonicalizer::do_LookupSwitch(LookupSwitch* x) {
828 if (x->tag()->type()->is_constant()) {
829 int v = x->tag()->type()->as_IntConstant()->value();
830 BlockBegin* sux = x->default_sux();
831 for (int i = 0; i < x->length(); i++) {
832 if (v == x->key_at(i)) {
833 sux = x->sux_at(i);
834 }
835 }
836 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
837 } else if (x->number_of_sux() == 1) {
838 // NOTE: Code permanently disabled for now since the switch statement's
839 // tag expression may produce side-effects in which case it must
840 // be executed.
841 return;
842 // simplify to Goto
843 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
844 } else if (x->number_of_sux() == 2) {
845 // NOTE: Code permanently disabled for now since it produces two new nodes
846 // (Constant & If) and the Canonicalizer cannot return them correctly
847 // yet. For now we copied the corresponding code directly into the
848 // GraphBuilder (i.e., we should never reach here).
849 return;
850 // simplify to If
851 assert(x->length() == 1, "length must be the same");
852 Constant* key = new Constant(new IntConstant(x->key_at(0)));
853 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
854 }
855 }
856
857
858 void Canonicalizer::do_Return (Return* x) {}
859 void Canonicalizer::do_Throw (Throw* x) {}
860 void Canonicalizer::do_Base (Base* x) {}
861 void Canonicalizer::do_OsrEntry (OsrEntry* x) {}
862 void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {}
863
864 static bool match_index_and_scale(Instruction* instr,
865 Instruction** index,
866 int* log2_scale) {
867 // Skip conversion ops. This works only on 32bit because of the implicit l2i that the
868 // unsafe performs.
869 #ifndef _LP64
870 Convert* convert = instr->as_Convert();
871 if (convert != NULL && convert->op() == Bytecodes::_i2l) {
872 assert(convert->value()->type() == intType, "invalid input type");
873 instr = convert->value();
874 }
875 #endif
876
877 ShiftOp* shift = instr->as_ShiftOp();
878 if (shift != NULL) {
879 if (shift->op() == Bytecodes::_lshl) {
880 assert(shift->x()->type() == longType, "invalid input type");
881 } else {
882 #ifndef _LP64
883 if (shift->op() == Bytecodes::_ishl) {
884 assert(shift->x()->type() == intType, "invalid input type");
885 } else {
886 return false;
887 }
888 #else
889 return false;
890 #endif
891 }
892
893
894 // Constant shift value?
895 Constant* con = shift->y()->as_Constant();
896 if (con == NULL) return false;
897 // Well-known type and value?
898 IntConstant* val = con->type()->as_IntConstant();
899 assert(val != NULL, "Should be an int constant");
900
901 *index = shift->x();
902 int tmp_scale = val->value();
903 if (tmp_scale >= 0 && tmp_scale < 4) {
904 *log2_scale = tmp_scale;
905 return true;
906 } else {
907 return false;
908 }
909 }
910
911 ArithmeticOp* arith = instr->as_ArithmeticOp();
912 if (arith != NULL) {
913 // See if either arg is a known constant
914 Constant* con = arith->x()->as_Constant();
915 if (con != NULL) {
916 *index = arith->y();
917 } else {
918 con = arith->y()->as_Constant();
919 if (con == NULL) return false;
920 *index = arith->x();
921 }
922 long const_value;
923 // Check for integer multiply
924 if (arith->op() == Bytecodes::_lmul) {
925 assert((*index)->type() == longType, "invalid input type");
926 LongConstant* val = con->type()->as_LongConstant();
927 assert(val != NULL, "expecting a long constant");
928 const_value = val->value();
929 } else {
930 #ifndef _LP64
931 if (arith->op() == Bytecodes::_imul) {
932 assert((*index)->type() == intType, "invalid input type");
933 IntConstant* val = con->type()->as_IntConstant();
934 assert(val != NULL, "expecting an int constant");
935 const_value = val->value();
936 } else {
937 return false;
938 }
939 #else
940 return false;
941 #endif
942 }
943 switch (const_value) {
944 case 1: *log2_scale = 0; return true;
945 case 2: *log2_scale = 1; return true;
946 case 4: *log2_scale = 2; return true;
947 case 8: *log2_scale = 3; return true;
948 default: return false;
949 }
950 }
951
952 // Unknown instruction sequence; don't touch it
953 return false;
954 }
955
956
957 static bool match(UnsafeRawOp* x,
958 Instruction** base,
959 Instruction** index,
960 int* log2_scale) {
961 ArithmeticOp* root = x->base()->as_ArithmeticOp();
962 if (root == NULL) return false;
963 // Limit ourselves to addition for now
964 if (root->op() != Bytecodes::_ladd) return false;
965
966 bool match_found = false;
967 // Try to find shift or scale op
968 if (match_index_and_scale(root->y(), index, log2_scale)) {
969 *base = root->x();
970 match_found = true;
971 } else if (match_index_and_scale(root->x(), index, log2_scale)) {
972 *base = root->y();
973 match_found = true;
974 } else if (NOT_LP64(root->y()->as_Convert() != NULL) LP64_ONLY(false)) {
975 // Skipping i2l works only on 32bit because of the implicit l2i that the unsafe performs.
976 // 64bit needs a real sign-extending conversion.
977 Convert* convert = root->y()->as_Convert();
978 if (convert->op() == Bytecodes::_i2l) {
979 assert(convert->value()->type() == intType, "should be an int");
980 // pick base and index, setting scale at 1
981 *base = root->x();
982 *index = convert->value();
983 *log2_scale = 0;
984 match_found = true;
985 }
986 }
987 // The default solution
988 if (!match_found) {
989 *base = root->x();
990 *index = root->y();
991 *log2_scale = 0;
992 }
993
994 // If the value is pinned then it will be always be computed so
995 // there's no profit to reshaping the expression.
996 return !root->is_pinned();
997 }
998
999
1000 void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) {
1001 Instruction* base = NULL;
1002 Instruction* index = NULL;
1003 int log2_scale;
1004
1005 if (match(x, &base, &index, &log2_scale)) {
1006 x->set_base(base);
1007 x->set_index(index);
1008 x->set_log2_scale(log2_scale);
1009 if (PrintUnsafeOptimization) {
1010 tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d",
1011 x->id(), x->base()->id(), x->index()->id(), x->log2_scale());
1012 }
1013 }
1014 }
1015
1016 void Canonicalizer::do_RoundFP(RoundFP* x) {}
1017 void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
1018 void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
1019 void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {}
1020 void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {}
1021 void Canonicalizer::do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) {}
1022 void Canonicalizer::do_ProfileCall(ProfileCall* x) {}
1023 void Canonicalizer::do_ProfileReturnType(ProfileReturnType* x) {}
1024 void Canonicalizer::do_ProfileInvoke(ProfileInvoke* x) {}
1025 void Canonicalizer::do_RuntimeCall(RuntimeCall* x) {}
1026 void Canonicalizer::do_RangeCheckPredicate(RangeCheckPredicate* x) {}
1027 #ifdef ASSERT
1028 void Canonicalizer::do_Assert(Assert* x) {}
1029 #endif
1030 void Canonicalizer::do_MemBar(MemBar* x) {}