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src/share/vm/c1/c1_Canonicalizer.cpp@d109bda16490
src/share/vm/c1/c1_Canonicalizer.cpp
Tue, 05 Apr 2016 08:55:39 -0700
- author
- asaha
- date
- Tue, 05 Apr 2016 08:55:39 -0700
- changeset 8415
- d109bda16490
- parent 8316
- 626f594dffa6
- parent 8368
- 32b682649973
- child 8604
- 04d83ba48607
- permissions
- -rw-r--r--
Merge
1 /*
2 * Copyright (c) 1999, 2016, 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 */
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"
33 class PrintValueVisitor: public ValueVisitor {
34 void visit(Value* vp) {
35 (*vp)->print_line();
36 }
37 };
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 }
65 void Canonicalizer::move_const_to_right(Op2* x) {
66 if (x->x()->type()->is_constant() && x->is_commutative()) x->swap_operands();
67 }
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 }
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);
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 }
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) {}
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 }
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 }
222 }
224 void Canonicalizer::do_ArrayLength (ArrayLength* x) {
225 NewArray* array = x->array()->as_NewArray();
226 if (array != NULL && array->length() != NULL) {
227 Constant* length = array->length()->as_Constant();
228 if (length != NULL) {
229 // do not use the Constant itself, but create a new Constant
230 // with same value Otherwise a Constant is live over multiple
231 // blocks without being registered in a state array.
232 assert(length->type()->as_IntConstant() != NULL, "array length must be integer");
233 set_constant(length->type()->as_IntConstant()->value());
234 }
235 } else {
236 LoadField* lf = x->array()->as_LoadField();
237 if (lf != NULL) {
238 ciField* field = lf->field();
239 if (field->is_constant() && field->is_static()) {
240 // final static field
241 ciObject* c = field->constant_value().as_object();
242 if (c->is_array()) {
243 ciArray* array = (ciArray*) c;
244 set_constant(array->length());
245 }
246 }
247 }
248 }
249 }
251 void Canonicalizer::do_LoadIndexed (LoadIndexed* x) {}
252 void Canonicalizer::do_StoreIndexed (StoreIndexed* x) {
253 // If a value is going to be stored into a field or array some of
254 // the conversions emitted by javac are unneeded because the fields
255 // are packed to their natural size.
256 Convert* conv = x->value()->as_Convert();
257 if (conv) {
258 Value value = NULL;
259 BasicType type = x->elt_type();
260 switch (conv->op()) {
261 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break;
262 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
263 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break;
264 }
265 // limit this optimization to current block
266 if (value != NULL && in_current_block(conv)) {
267 set_canonical(new StoreIndexed(x->array(), x->index(), x->length(),
268 x->elt_type(), value, x->state_before(),
269 x->check_boolean()));
270 return;
271 }
272 }
275 }
278 void Canonicalizer::do_NegateOp(NegateOp* x) {
279 ValueType* t = x->x()->type();
280 if (t->is_constant()) {
281 switch (t->tag()) {
282 case intTag : set_constant(-t->as_IntConstant ()->value()); return;
283 case longTag : set_constant(-t->as_LongConstant ()->value()); return;
284 case floatTag : set_constant(-t->as_FloatConstant ()->value()); return;
285 case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return;
286 default : ShouldNotReachHere();
287 }
288 }
289 }
292 void Canonicalizer::do_ArithmeticOp (ArithmeticOp* x) { do_Op2(x); }
295 void Canonicalizer::do_ShiftOp (ShiftOp* x) {
296 ValueType* t = x->x()->type();
297 ValueType* t2 = x->y()->type();
298 if (t->is_constant()) {
299 switch (t->tag()) {
300 case intTag : if (t->as_IntConstant()->value() == 0) { set_constant(0); return; } break;
301 case longTag : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break;
302 default : ShouldNotReachHere();
303 }
304 if (t2->is_constant()) {
305 if (t->tag() == intTag) {
306 int value = t->as_IntConstant()->value();
307 int shift = t2->as_IntConstant()->value() & 31;
308 jint mask = ~(~0 << (32 - shift));
309 if (shift == 0) mask = ~0;
310 switch (x->op()) {
311 case Bytecodes::_ishl: set_constant(value << shift); return;
312 case Bytecodes::_ishr: set_constant(value >> shift); return;
313 case Bytecodes::_iushr: set_constant((value >> shift) & mask); return;
314 }
315 } else if (t->tag() == longTag) {
316 jlong value = t->as_LongConstant()->value();
317 int shift = t2->as_IntConstant()->value() & 63;
318 jlong mask = ~(~jlong_cast(0) << (64 - shift));
319 if (shift == 0) mask = ~jlong_cast(0);
320 switch (x->op()) {
321 case Bytecodes::_lshl: set_constant(value << shift); return;
322 case Bytecodes::_lshr: set_constant(value >> shift); return;
323 case Bytecodes::_lushr: set_constant((value >> shift) & mask); return;
324 }
325 }
326 }
327 }
328 if (t2->is_constant()) {
329 switch (t2->tag()) {
330 case intTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return;
331 case longTag : if (t2->as_LongConstant()->value() == (jlong)0) set_canonical(x->x()); return;
332 default : ShouldNotReachHere();
333 }
334 }
335 }
338 void Canonicalizer::do_LogicOp (LogicOp* x) { do_Op2(x); }
339 void Canonicalizer::do_CompareOp (CompareOp* x) {
340 if (x->x() == x->y()) {
341 switch (x->x()->type()->tag()) {
342 case longTag: set_constant(0); break;
343 case floatTag: {
344 FloatConstant* fc = x->x()->type()->as_FloatConstant();
345 if (fc) {
346 if (g_isnan(fc->value())) {
347 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
348 } else {
349 set_constant(0);
350 }
351 }
352 break;
353 }
354 case doubleTag: {
355 DoubleConstant* dc = x->x()->type()->as_DoubleConstant();
356 if (dc) {
357 if (g_isnan(dc->value())) {
358 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
359 } else {
360 set_constant(0);
361 }
362 }
363 break;
364 }
365 }
366 } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
367 switch (x->x()->type()->tag()) {
368 case longTag: {
369 jlong vx = x->x()->type()->as_LongConstant()->value();
370 jlong vy = x->y()->type()->as_LongConstant()->value();
371 if (vx == vy)
372 set_constant(0);
373 else if (vx < vy)
374 set_constant(-1);
375 else
376 set_constant(1);
377 break;
378 }
380 case floatTag: {
381 float vx = x->x()->type()->as_FloatConstant()->value();
382 float vy = x->y()->type()->as_FloatConstant()->value();
383 if (g_isnan(vx) || g_isnan(vy))
384 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
385 else if (vx == vy)
386 set_constant(0);
387 else if (vx < vy)
388 set_constant(-1);
389 else
390 set_constant(1);
391 break;
392 }
394 case doubleTag: {
395 double vx = x->x()->type()->as_DoubleConstant()->value();
396 double vy = x->y()->type()->as_DoubleConstant()->value();
397 if (g_isnan(vx) || g_isnan(vy))
398 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
399 else if (vx == vy)
400 set_constant(0);
401 else if (vx < vy)
402 set_constant(-1);
403 else
404 set_constant(1);
405 break;
406 }
407 }
409 }
410 }
413 void Canonicalizer::do_IfInstanceOf(IfInstanceOf* x) {}
415 void Canonicalizer::do_IfOp(IfOp* x) {
416 // Caution: do not use do_Op2(x) here for now since
417 // we map the condition to the op for now!
418 move_const_to_right(x);
419 }
422 void Canonicalizer::do_Intrinsic (Intrinsic* x) {
423 switch (x->id()) {
424 case vmIntrinsics::_floatToRawIntBits : {
425 FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant();
426 if (c != NULL) {
427 JavaValue v;
428 v.set_jfloat(c->value());
429 set_constant(v.get_jint());
430 }
431 break;
432 }
433 case vmIntrinsics::_intBitsToFloat : {
434 IntConstant* c = x->argument_at(0)->type()->as_IntConstant();
435 if (c != NULL) {
436 JavaValue v;
437 v.set_jint(c->value());
438 set_constant(v.get_jfloat());
439 }
440 break;
441 }
442 case vmIntrinsics::_doubleToRawLongBits : {
443 DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant();
444 if (c != NULL) {
445 JavaValue v;
446 v.set_jdouble(c->value());
447 set_constant(v.get_jlong());
448 }
449 break;
450 }
451 case vmIntrinsics::_longBitsToDouble : {
452 LongConstant* c = x->argument_at(0)->type()->as_LongConstant();
453 if (c != NULL) {
454 JavaValue v;
455 v.set_jlong(c->value());
456 set_constant(v.get_jdouble());
457 }
458 break;
459 }
460 case vmIntrinsics::_isInstance : {
461 assert(x->number_of_arguments() == 2, "wrong type");
463 InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant();
464 if (c != NULL && !c->value()->is_null_object()) {
465 // ciInstance::java_mirror_type() returns non-NULL only for Java mirrors
466 ciType* t = c->value()->as_instance()->java_mirror_type();
467 if (t->is_klass()) {
468 // substitute cls.isInstance(obj) of a constant Class into
469 // an InstantOf instruction
470 InstanceOf* i = new InstanceOf(t->as_klass(), x->argument_at(1), x->state_before());
471 set_canonical(i);
472 // and try to canonicalize even further
473 do_InstanceOf(i);
474 } else {
475 assert(t->is_primitive_type(), "should be a primitive type");
476 // cls.isInstance(obj) always returns false for primitive classes
477 set_constant(0);
478 }
479 }
480 break;
481 }
482 }
483 }
485 void Canonicalizer::do_Convert (Convert* x) {
486 if (x->value()->type()->is_constant()) {
487 switch (x->op()) {
488 case Bytecodes::_i2b: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break;
489 case Bytecodes::_i2s: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break;
490 case Bytecodes::_i2c: set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break;
491 case Bytecodes::_i2l: set_constant((jlong)(x->value()->type()->as_IntConstant()->value())); break;
492 case Bytecodes::_i2f: set_constant((float)(x->value()->type()->as_IntConstant()->value())); break;
493 case Bytecodes::_i2d: set_constant((double)(x->value()->type()->as_IntConstant()->value())); break;
494 case Bytecodes::_l2i: set_constant((int)(x->value()->type()->as_LongConstant()->value())); break;
495 case Bytecodes::_l2f: set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break;
496 case Bytecodes::_l2d: set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break;
497 case Bytecodes::_f2d: set_constant((double)(x->value()->type()->as_FloatConstant()->value())); break;
498 case Bytecodes::_f2i: set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break;
499 case Bytecodes::_f2l: set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break;
500 case Bytecodes::_d2f: set_constant((float)(x->value()->type()->as_DoubleConstant()->value())); break;
501 case Bytecodes::_d2i: set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break;
502 case Bytecodes::_d2l: set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break;
503 default:
504 ShouldNotReachHere();
505 }
506 }
508 Value value = x->value();
509 BasicType type = T_ILLEGAL;
510 LoadField* lf = value->as_LoadField();
511 if (lf) {
512 type = lf->field_type();
513 } else {
514 LoadIndexed* li = value->as_LoadIndexed();
515 if (li) {
516 type = li->elt_type();
517 } else {
518 Convert* conv = value->as_Convert();
519 if (conv) {
520 switch (conv->op()) {
521 case Bytecodes::_i2b: type = T_BYTE; break;
522 case Bytecodes::_i2s: type = T_SHORT; break;
523 case Bytecodes::_i2c: type = T_CHAR; break;
524 }
525 }
526 }
527 }
528 if (type != T_ILLEGAL) {
529 switch (x->op()) {
530 case Bytecodes::_i2b: if (type == T_BYTE) set_canonical(x->value()); break;
531 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break;
532 case Bytecodes::_i2c: if (type == T_CHAR) set_canonical(x->value()); break;
533 }
534 } else {
535 Op2* op2 = x->value()->as_Op2();
536 if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) {
537 jint safebits = 0;
538 jint mask = op2->y()->type()->as_IntConstant()->value();
539 switch (x->op()) {
540 case Bytecodes::_i2b: safebits = 0x7f; break;
541 case Bytecodes::_i2s: safebits = 0x7fff; break;
542 case Bytecodes::_i2c: safebits = 0xffff; break;
543 }
544 // When casting a masked integer to a smaller signed type, if
545 // the mask doesn't include the sign bit the cast isn't needed.
546 if (safebits && (mask & ~safebits) == 0) {
547 set_canonical(x->value());
548 }
549 }
550 }
552 }
554 void Canonicalizer::do_NullCheck (NullCheck* x) {
555 if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) {
556 set_canonical(x->obj());
557 } else {
558 Constant* con = x->obj()->as_Constant();
559 if (con) {
560 ObjectType* c = con->type()->as_ObjectType();
561 if (c && c->is_loaded()) {
562 ObjectConstant* oc = c->as_ObjectConstant();
563 if (!oc || !oc->value()->is_null_object()) {
564 set_canonical(con);
565 }
566 }
567 }
568 }
569 }
571 void Canonicalizer::do_TypeCast (TypeCast* x) {}
572 void Canonicalizer::do_Invoke (Invoke* x) {}
573 void Canonicalizer::do_NewInstance (NewInstance* x) {}
574 void Canonicalizer::do_NewTypeArray (NewTypeArray* x) {}
575 void Canonicalizer::do_NewObjectArray (NewObjectArray* x) {}
576 void Canonicalizer::do_NewMultiArray (NewMultiArray* x) {}
577 void Canonicalizer::do_CheckCast (CheckCast* x) {
578 if (x->klass()->is_loaded()) {
579 Value obj = x->obj();
580 ciType* klass = obj->exact_type();
581 if (klass == NULL) klass = obj->declared_type();
582 if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) {
583 set_canonical(obj);
584 return;
585 }
586 // checkcast of null returns null
587 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
588 set_canonical(obj);
589 }
590 }
591 }
592 void Canonicalizer::do_InstanceOf (InstanceOf* x) {
593 if (x->klass()->is_loaded()) {
594 Value obj = x->obj();
595 ciType* exact = obj->exact_type();
596 if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) {
597 set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0);
598 return;
599 }
600 // instanceof null returns false
601 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
602 set_constant(0);
603 }
604 }
606 }
607 void Canonicalizer::do_MonitorEnter (MonitorEnter* x) {}
608 void Canonicalizer::do_MonitorExit (MonitorExit* x) {}
609 void Canonicalizer::do_BlockBegin (BlockBegin* x) {}
610 void Canonicalizer::do_Goto (Goto* x) {}
613 static bool is_true(jlong x, If::Condition cond, jlong y) {
614 switch (cond) {
615 case If::eql: return x == y;
616 case If::neq: return x != y;
617 case If::lss: return x < y;
618 case If::leq: return x <= y;
619 case If::gtr: return x > y;
620 case If::geq: return x >= y;
621 }
622 ShouldNotReachHere();
623 return false;
624 }
626 static bool is_safepoint(BlockEnd* x, BlockBegin* sux) {
627 // An Instruction with multiple successors, x, is replaced by a Goto
628 // to a single successor, sux. Is a safepoint check needed = was the
629 // instruction being replaced a safepoint and the single remaining
630 // successor a back branch?
631 return x->is_safepoint() && (sux->bci() < x->state_before()->bci());
632 }
634 void Canonicalizer::do_If(If* x) {
635 // move const to right
636 if (x->x()->type()->is_constant()) x->swap_operands();
637 // simplify
638 const Value l = x->x(); ValueType* lt = l->type();
639 const Value r = x->y(); ValueType* rt = r->type();
641 if (l == r && !lt->is_float_kind()) {
642 // pattern: If (a cond a) => simplify to Goto
643 BlockBegin* sux = NULL;
644 switch (x->cond()) {
645 case If::eql: sux = x->sux_for(true); break;
646 case If::neq: sux = x->sux_for(false); break;
647 case If::lss: sux = x->sux_for(false); break;
648 case If::leq: sux = x->sux_for(true); break;
649 case If::gtr: sux = x->sux_for(false); break;
650 case If::geq: sux = x->sux_for(true); break;
651 default: ShouldNotReachHere();
652 }
653 // If is a safepoint then the debug information should come from the state_before of the If.
654 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
655 return;
656 }
658 if (lt->is_constant() && rt->is_constant()) {
659 if (x->x()->as_Constant() != NULL) {
660 // pattern: If (lc cond rc) => simplify to: Goto
661 BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(),
662 x->sux_for(true),
663 x->sux_for(false));
664 if (sux != NULL) {
665 // If is a safepoint then the debug information should come from the state_before of the If.
666 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
667 }
668 }
669 } else if (rt->as_IntConstant() != NULL) {
670 // pattern: If (l cond rc) => investigate further
671 const jint rc = rt->as_IntConstant()->value();
672 if (l->as_CompareOp() != NULL) {
673 // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto
674 CompareOp* cmp = l->as_CompareOp();
675 bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl;
676 BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b
677 BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b
678 BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b
679 BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered
680 // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are
681 // equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either
682 // lss_sux or gtr_sux.
683 if (lss_sux == eql_sux && eql_sux == gtr_sux) {
684 // all successors identical => simplify to: Goto
685 set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint()));
686 } else {
687 // two successors differ and two successors are the same => simplify to: If (x cmp y)
688 // determine new condition & successors
689 If::Condition cond = If::eql;
690 BlockBegin* tsux = NULL;
691 BlockBegin* fsux = NULL;
692 if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; }
693 else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; }
694 else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; }
695 else { ShouldNotReachHere(); }
696 If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint());
697 if (cmp->x() == cmp->y()) {
698 do_If(canon);
699 } else {
700 if (compilation()->profile_branches()) {
701 // TODO: If profiling, leave floating point comparisons unoptimized.
702 // We currently do not support profiling of the unordered case.
703 switch(cmp->op()) {
704 case Bytecodes::_fcmpl: case Bytecodes::_fcmpg:
705 case Bytecodes::_dcmpl: case Bytecodes::_dcmpg:
706 set_canonical(x);
707 return;
708 }
709 }
710 set_bci(cmp->state_before()->bci());
711 set_canonical(canon);
712 }
713 }
714 } else if (l->as_InstanceOf() != NULL) {
715 // NOTE: Code permanently disabled for now since it leaves the old InstanceOf
716 // instruction in the graph (it is pinned). Need to fix this at some point.
717 // It should also be left in the graph when generating a profiled method version or Goto
718 // has to know that it was an InstanceOf.
719 return;
720 // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto
721 InstanceOf* inst = l->as_InstanceOf();
722 BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1
723 BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0
724 if (is_inst_sux == no_inst_sux && inst->is_loaded()) {
725 // both successors identical and klass is loaded => simplify to: Goto
726 set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint()));
727 } else {
728 // successors differ => simplify to: IfInstanceOf
729 set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->state_before()->bci(), is_inst_sux, no_inst_sux));
730 }
731 }
732 } else if (rt == objectNull && (l->as_NewInstance() || l->as_NewArray())) {
733 if (x->cond() == Instruction::eql) {
734 BlockBegin* sux = x->fsux();
735 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
736 } else {
737 assert(x->cond() == Instruction::neq, "only other valid case");
738 BlockBegin* sux = x->tsux();
739 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
740 }
741 }
742 }
745 void Canonicalizer::do_TableSwitch(TableSwitch* x) {
746 if (x->tag()->type()->is_constant()) {
747 int v = x->tag()->type()->as_IntConstant()->value();
748 BlockBegin* sux = x->default_sux();
749 if (v >= x->lo_key() && v <= x->hi_key()) {
750 sux = x->sux_at(v - x->lo_key());
751 }
752 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
753 } else if (x->number_of_sux() == 1) {
754 // NOTE: Code permanently disabled for now since the switch statement's
755 // tag expression may produce side-effects in which case it must
756 // be executed.
757 return;
758 // simplify to Goto
759 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
760 } else if (x->number_of_sux() == 2) {
761 // NOTE: Code permanently disabled for now since it produces two new nodes
762 // (Constant & If) and the Canonicalizer cannot return them correctly
763 // yet. For now we copied the corresponding code directly into the
764 // GraphBuilder (i.e., we should never reach here).
765 return;
766 // simplify to If
767 assert(x->lo_key() == x->hi_key(), "keys must be the same");
768 Constant* key = new Constant(new IntConstant(x->lo_key()));
769 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
770 }
771 }
774 void Canonicalizer::do_LookupSwitch(LookupSwitch* x) {
775 if (x->tag()->type()->is_constant()) {
776 int v = x->tag()->type()->as_IntConstant()->value();
777 BlockBegin* sux = x->default_sux();
778 for (int i = 0; i < x->length(); i++) {
779 if (v == x->key_at(i)) {
780 sux = x->sux_at(i);
781 }
782 }
783 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux)));
784 } else if (x->number_of_sux() == 1) {
785 // NOTE: Code permanently disabled for now since the switch statement's
786 // tag expression may produce side-effects in which case it must
787 // be executed.
788 return;
789 // simplify to Goto
790 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
791 } else if (x->number_of_sux() == 2) {
792 // NOTE: Code permanently disabled for now since it produces two new nodes
793 // (Constant & If) and the Canonicalizer cannot return them correctly
794 // yet. For now we copied the corresponding code directly into the
795 // GraphBuilder (i.e., we should never reach here).
796 return;
797 // simplify to If
798 assert(x->length() == 1, "length must be the same");
799 Constant* key = new Constant(new IntConstant(x->key_at(0)));
800 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
801 }
802 }
805 void Canonicalizer::do_Return (Return* x) {}
806 void Canonicalizer::do_Throw (Throw* x) {}
807 void Canonicalizer::do_Base (Base* x) {}
808 void Canonicalizer::do_OsrEntry (OsrEntry* x) {}
809 void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {}
811 static bool match_index_and_scale(Instruction* instr,
812 Instruction** index,
813 int* log2_scale) {
814 // Skip conversion ops. This works only on 32bit because of the implicit l2i that the
815 // unsafe performs.
816 #ifndef _LP64
817 Convert* convert = instr->as_Convert();
818 if (convert != NULL && convert->op() == Bytecodes::_i2l) {
819 assert(convert->value()->type() == intType, "invalid input type");
820 instr = convert->value();
821 }
822 #endif
824 ShiftOp* shift = instr->as_ShiftOp();
825 if (shift != NULL) {
826 if (shift->op() == Bytecodes::_lshl) {
827 assert(shift->x()->type() == longType, "invalid input type");
828 } else {
829 #ifndef _LP64
830 if (shift->op() == Bytecodes::_ishl) {
831 assert(shift->x()->type() == intType, "invalid input type");
832 } else {
833 return false;
834 }
835 #else
836 return false;
837 #endif
838 }
841 // Constant shift value?
842 Constant* con = shift->y()->as_Constant();
843 if (con == NULL) return false;
844 // Well-known type and value?
845 IntConstant* val = con->type()->as_IntConstant();
846 assert(val != NULL, "Should be an int constant");
848 *index = shift->x();
849 int tmp_scale = val->value();
850 if (tmp_scale >= 0 && tmp_scale < 4) {
851 *log2_scale = tmp_scale;
852 return true;
853 } else {
854 return false;
855 }
856 }
858 ArithmeticOp* arith = instr->as_ArithmeticOp();
859 if (arith != NULL) {
860 // See if either arg is a known constant
861 Constant* con = arith->x()->as_Constant();
862 if (con != NULL) {
863 *index = arith->y();
864 } else {
865 con = arith->y()->as_Constant();
866 if (con == NULL) return false;
867 *index = arith->x();
868 }
869 long const_value;
870 // Check for integer multiply
871 if (arith->op() == Bytecodes::_lmul) {
872 assert((*index)->type() == longType, "invalid input type");
873 LongConstant* val = con->type()->as_LongConstant();
874 assert(val != NULL, "expecting a long constant");
875 const_value = val->value();
876 } else {
877 #ifndef _LP64
878 if (arith->op() == Bytecodes::_imul) {
879 assert((*index)->type() == intType, "invalid input type");
880 IntConstant* val = con->type()->as_IntConstant();
881 assert(val != NULL, "expecting an int constant");
882 const_value = val->value();
883 } else {
884 return false;
885 }
886 #else
887 return false;
888 #endif
889 }
890 switch (const_value) {
891 case 1: *log2_scale = 0; return true;
892 case 2: *log2_scale = 1; return true;
893 case 4: *log2_scale = 2; return true;
894 case 8: *log2_scale = 3; return true;
895 default: return false;
896 }
897 }
899 // Unknown instruction sequence; don't touch it
900 return false;
901 }
904 static bool match(UnsafeRawOp* x,
905 Instruction** base,
906 Instruction** index,
907 int* log2_scale) {
908 ArithmeticOp* root = x->base()->as_ArithmeticOp();
909 if (root == NULL) return false;
910 // Limit ourselves to addition for now
911 if (root->op() != Bytecodes::_ladd) return false;
913 bool match_found = false;
914 // Try to find shift or scale op
915 if (match_index_and_scale(root->y(), index, log2_scale)) {
916 *base = root->x();
917 match_found = true;
918 } else if (match_index_and_scale(root->x(), index, log2_scale)) {
919 *base = root->y();
920 match_found = true;
921 } else if (NOT_LP64(root->y()->as_Convert() != NULL) LP64_ONLY(false)) {
922 // Skipping i2l works only on 32bit because of the implicit l2i that the unsafe performs.
923 // 64bit needs a real sign-extending conversion.
924 Convert* convert = root->y()->as_Convert();
925 if (convert->op() == Bytecodes::_i2l) {
926 assert(convert->value()->type() == intType, "should be an int");
927 // pick base and index, setting scale at 1
928 *base = root->x();
929 *index = convert->value();
930 *log2_scale = 0;
931 match_found = true;
932 }
933 }
934 // The default solution
935 if (!match_found) {
936 *base = root->x();
937 *index = root->y();
938 *log2_scale = 0;
939 }
941 // If the value is pinned then it will be always be computed so
942 // there's no profit to reshaping the expression.
943 return !root->is_pinned();
944 }
947 void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) {
948 Instruction* base = NULL;
949 Instruction* index = NULL;
950 int log2_scale;
952 if (match(x, &base, &index, &log2_scale)) {
953 x->set_base(base);
954 x->set_index(index);
955 x->set_log2_scale(log2_scale);
956 if (PrintUnsafeOptimization) {
957 tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d",
958 x->id(), x->base()->id(), x->index()->id(), x->log2_scale());
959 }
960 }
961 }
963 void Canonicalizer::do_RoundFP(RoundFP* x) {}
964 void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
965 void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
966 void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {}
967 void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {}
968 void Canonicalizer::do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) {}
969 void Canonicalizer::do_UnsafePrefetchRead (UnsafePrefetchRead* x) {}
970 void Canonicalizer::do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) {}
971 void Canonicalizer::do_ProfileCall(ProfileCall* x) {}
972 void Canonicalizer::do_ProfileReturnType(ProfileReturnType* x) {}
973 void Canonicalizer::do_ProfileInvoke(ProfileInvoke* x) {}
974 void Canonicalizer::do_RuntimeCall(RuntimeCall* x) {}
975 void Canonicalizer::do_RangeCheckPredicate(RangeCheckPredicate* x) {}
976 #ifdef ASSERT
977 void Canonicalizer::do_Assert(Assert* x) {}
978 #endif
979 void Canonicalizer::do_MemBar(MemBar* x) {}
