1 /*
2 * Copyright 1999-2010 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_c1_Canonicalizer.cpp.incl"
27
28
29 static void do_print_value(Value* vp) {
30 (*vp)->print_line();
31 }
32
33 void Canonicalizer::set_canonical(Value x) {
34 assert(x != NULL, "value must exist");
35 // Note: we can not currently substitute root nodes which show up in
36 // the instruction stream (because the instruction list is embedded
37 // in the instructions).
38 if (canonical() != x) {
39 if (PrintCanonicalization) {
40 canonical()->input_values_do(do_print_value);
41 canonical()->print_line();
42 tty->print_cr("canonicalized to:");
43 x->input_values_do(do_print_value);
44 x->print_line();
45 tty->cr();
46 }
47 assert(_canonical->type()->tag() == x->type()->tag(), "types must match");
48 _canonical = x;
49 }
50 }
51
52
53 void Canonicalizer::move_const_to_right(Op2* x) {
54 if (x->x()->type()->is_constant() && x->is_commutative()) x->swap_operands();
55 }
56
57
58 void Canonicalizer::do_Op2(Op2* x) {
59 if (x->x() == x->y()) {
60 switch (x->op()) {
61 case Bytecodes::_isub: set_constant(0); return;
62 case Bytecodes::_lsub: set_constant(jlong_cast(0)); return;
63 case Bytecodes::_iand: // fall through
64 case Bytecodes::_land: // fall through
65 case Bytecodes::_ior: // fall through
66 case Bytecodes::_lor : set_canonical(x->x()); return;
67 case Bytecodes::_ixor: set_constant(0); return;
68 case Bytecodes::_lxor: set_constant(jlong_cast(0)); return;
69 }
70 }
71
72 if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
73 // do constant folding for selected operations
74 switch (x->type()->tag()) {
75 case intTag:
76 { jint a = x->x()->type()->as_IntConstant()->value();
77 jint b = x->y()->type()->as_IntConstant()->value();
78 switch (x->op()) {
79 case Bytecodes::_iadd: set_constant(a + b); return;
80 case Bytecodes::_isub: set_constant(a - b); return;
81 case Bytecodes::_imul: set_constant(a * b); return;
82 case Bytecodes::_idiv:
83 if (b != 0) {
84 if (a == min_jint && b == -1) {
85 set_constant(min_jint);
86 } else {
87 set_constant(a / b);
88 }
89 return;
90 }
91 break;
92 case Bytecodes::_irem:
93 if (b != 0) {
94 if (a == min_jint && b == -1) {
95 set_constant(0);
96 } else {
97 set_constant(a % b);
98 }
99 return;
100 }
101 break;
102 case Bytecodes::_iand: set_constant(a & b); return;
103 case Bytecodes::_ior : set_constant(a | b); return;
104 case Bytecodes::_ixor: set_constant(a ^ b); return;
105 }
106 }
107 break;
108 case longTag:
109 { jlong a = x->x()->type()->as_LongConstant()->value();
110 jlong b = x->y()->type()->as_LongConstant()->value();
111 switch (x->op()) {
112 case Bytecodes::_ladd: set_constant(a + b); return;
113 case Bytecodes::_lsub: set_constant(a - b); return;
114 case Bytecodes::_lmul: set_constant(a * b); return;
115 case Bytecodes::_ldiv:
116 if (b != 0) {
117 set_constant(SharedRuntime::ldiv(b, a));
118 return;
119 }
120 break;
121 case Bytecodes::_lrem:
122 if (b != 0) {
123 set_constant(SharedRuntime::lrem(b, a));
124 return;
125 }
126 break;
127 case Bytecodes::_land: set_constant(a & b); return;
128 case Bytecodes::_lor : set_constant(a | b); return;
129 case Bytecodes::_lxor: set_constant(a ^ b); return;
130 }
131 }
132 break;
133 // other cases not implemented (must be extremely careful with floats & doubles!)
134 }
135 }
136 // make sure constant is on the right side, if any
137 move_const_to_right(x);
138
139 if (x->y()->type()->is_constant()) {
140 // do constant folding for selected operations
141 switch (x->type()->tag()) {
142 case intTag:
143 if (x->y()->type()->as_IntConstant()->value() == 0) {
144 switch (x->op()) {
145 case Bytecodes::_iadd: set_canonical(x->x()); return;
146 case Bytecodes::_isub: set_canonical(x->x()); return;
147 case Bytecodes::_imul: set_constant(0); return;
148 // Note: for div and rem, make sure that C semantics
149 // corresponds to Java semantics!
150 case Bytecodes::_iand: set_constant(0); return;
151 case Bytecodes::_ior : set_canonical(x->x()); return;
152 }
153 }
154 break;
155 case longTag:
156 if (x->y()->type()->as_LongConstant()->value() == (jlong)0) {
157 switch (x->op()) {
158 case Bytecodes::_ladd: set_canonical(x->x()); return;
159 case Bytecodes::_lsub: set_canonical(x->x()); return;
160 case Bytecodes::_lmul: set_constant((jlong)0); return;
161 // Note: for div and rem, make sure that C semantics
162 // corresponds to Java semantics!
163 case Bytecodes::_land: set_constant((jlong)0); return;
164 case Bytecodes::_lor : set_canonical(x->x()); return;
165 }
166 }
167 break;
168 }
169 }
170 }
171
172
173 void Canonicalizer::do_Phi (Phi* x) {}
174 void Canonicalizer::do_Constant (Constant* x) {}
175 void Canonicalizer::do_Local (Local* x) {}
176 void Canonicalizer::do_LoadField (LoadField* x) {}
177
178 // checks if v is in the block that is currently processed by
179 // GraphBuilder. This is the only block that has not BlockEnd yet.
180 static bool in_current_block(Value v) {
181 int max_distance = 4;
182 while (max_distance > 0 && v != NULL && v->as_BlockEnd() == NULL) {
183 v = v->next();
184 max_distance--;
185 }
186 return v == NULL;
187 }
188
189 void Canonicalizer::do_StoreField (StoreField* x) {
190 // If a value is going to be stored into a field or array some of
191 // the conversions emitted by javac are unneeded because the fields
192 // are packed to their natural size.
193 Convert* conv = x->value()->as_Convert();
194 if (conv) {
195 Value value = NULL;
196 BasicType type = x->field()->type()->basic_type();
197 switch (conv->op()) {
198 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break;
199 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
200 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break;
201 }
202 // limit this optimization to current block
203 if (value != NULL && in_current_block(conv)) {
204 set_canonical(new StoreField(x->obj(), x->offset(), x->field(), value, x->is_static(),
205 x->lock_stack(), x->state_before(), x->is_loaded(), x->is_initialized()));
206 return;
207 }
208 }
209
210 }
211
212 void Canonicalizer::do_ArrayLength (ArrayLength* x) {
213 NewArray* array = x->array()->as_NewArray();
214 if (array != NULL && array->length() != NULL) {
215 Constant* length = array->length()->as_Constant();
216 if (length != NULL) {
217 // do not use the Constant itself, but create a new Constant
218 // with same value Otherwise a Constant is live over multiple
219 // blocks without being registered in a state array.
220 assert(length->type()->as_IntConstant() != NULL, "array length must be integer");
221 set_constant(length->type()->as_IntConstant()->value());
222 }
223 } else {
224 LoadField* lf = x->array()->as_LoadField();
225 if (lf != NULL) {
226 ciField* field = lf->field();
227 if (field->is_constant() && field->is_static()) {
228 // final static field
229 ciObject* c = field->constant_value().as_object();
230 if (c->is_array()) {
231 ciArray* array = (ciArray*) c;
232 set_constant(array->length());
233 }
234 }
235 }
236 }
237 }
238
239 void Canonicalizer::do_LoadIndexed (LoadIndexed* x) {}
240 void Canonicalizer::do_StoreIndexed (StoreIndexed* x) {
241 // If a value is going to be stored into a field or array some of
242 // the conversions emitted by javac are unneeded because the fields
243 // are packed to their natural size.
244 Convert* conv = x->value()->as_Convert();
245 if (conv) {
246 Value value = NULL;
247 BasicType type = x->elt_type();
248 switch (conv->op()) {
249 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break;
250 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break;
251 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break;
252 }
253 // limit this optimization to current block
254 if (value != NULL && in_current_block(conv)) {
255 set_canonical(new StoreIndexed(x->array(), x->index(), x->length(),
256 x->elt_type(), value, x->lock_stack()));
257 return;
258 }
259 }
260
261
262 }
263
264
265 void Canonicalizer::do_NegateOp(NegateOp* x) {
266 ValueType* t = x->x()->type();
267 if (t->is_constant()) {
268 switch (t->tag()) {
269 case intTag : set_constant(-t->as_IntConstant ()->value()); return;
270 case longTag : set_constant(-t->as_LongConstant ()->value()); return;
271 case floatTag : set_constant(-t->as_FloatConstant ()->value()); return;
272 case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return;
273 default : ShouldNotReachHere();
274 }
275 }
276 }
277
278
279 void Canonicalizer::do_ArithmeticOp (ArithmeticOp* x) { do_Op2(x); }
280
281
282 void Canonicalizer::do_ShiftOp (ShiftOp* x) {
283 ValueType* t = x->x()->type();
284 ValueType* t2 = x->y()->type();
285 if (t->is_constant()) {
286 switch (t->tag()) {
287 case intTag : if (t->as_IntConstant()->value() == 0) { set_constant(0); return; } break;
288 case longTag : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break;
289 default : ShouldNotReachHere();
290 }
291 if (t2->is_constant()) {
292 if (t->tag() == intTag) {
293 int value = t->as_IntConstant()->value();
294 int shift = t2->as_IntConstant()->value() & 31;
295 jint mask = ~(~0 << (32 - shift));
296 if (shift == 0) mask = ~0;
297 switch (x->op()) {
298 case Bytecodes::_ishl: set_constant(value << shift); return;
299 case Bytecodes::_ishr: set_constant(value >> shift); return;
300 case Bytecodes::_iushr: set_constant((value >> shift) & mask); return;
301 }
302 } else if (t->tag() == longTag) {
303 jlong value = t->as_LongConstant()->value();
304 int shift = t2->as_IntConstant()->value() & 63;
305 jlong mask = ~(~jlong_cast(0) << (64 - shift));
306 if (shift == 0) mask = ~jlong_cast(0);
307 switch (x->op()) {
308 case Bytecodes::_lshl: set_constant(value << shift); return;
309 case Bytecodes::_lshr: set_constant(value >> shift); return;
310 case Bytecodes::_lushr: set_constant((value >> shift) & mask); return;
311 }
312 }
313 }
314 }
315 if (t2->is_constant()) {
316 switch (t2->tag()) {
317 case intTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return;
318 case longTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return;
319 default : ShouldNotReachHere();
320 }
321 }
322 }
323
324
325 void Canonicalizer::do_LogicOp (LogicOp* x) { do_Op2(x); }
326 void Canonicalizer::do_CompareOp (CompareOp* x) {
327 if (x->x() == x->y()) {
328 switch (x->x()->type()->tag()) {
329 case longTag: set_constant(0); break;
330 case floatTag: {
331 FloatConstant* fc = x->x()->type()->as_FloatConstant();
332 if (fc) {
333 if (g_isnan(fc->value())) {
334 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
335 } else {
336 set_constant(0);
337 }
338 }
339 break;
340 }
341 case doubleTag: {
342 DoubleConstant* dc = x->x()->type()->as_DoubleConstant();
343 if (dc) {
344 if (g_isnan(dc->value())) {
345 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
346 } else {
347 set_constant(0);
348 }
349 }
350 break;
351 }
352 }
353 } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) {
354 switch (x->x()->type()->tag()) {
355 case longTag: {
356 jlong vx = x->x()->type()->as_LongConstant()->value();
357 jlong vy = x->y()->type()->as_LongConstant()->value();
358 if (vx == vy)
359 set_constant(0);
360 else if (vx < vy)
361 set_constant(-1);
362 else
363 set_constant(1);
364 break;
365 }
366
367 case floatTag: {
368 float vx = x->x()->type()->as_FloatConstant()->value();
369 float vy = x->y()->type()->as_FloatConstant()->value();
370 if (g_isnan(vx) || g_isnan(vy))
371 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1);
372 else if (vx == vy)
373 set_constant(0);
374 else if (vx < vy)
375 set_constant(-1);
376 else
377 set_constant(1);
378 break;
379 }
380
381 case doubleTag: {
382 double vx = x->x()->type()->as_DoubleConstant()->value();
383 double vy = x->y()->type()->as_DoubleConstant()->value();
384 if (g_isnan(vx) || g_isnan(vy))
385 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1);
386 else if (vx == vy)
387 set_constant(0);
388 else if (vx < vy)
389 set_constant(-1);
390 else
391 set_constant(1);
392 break;
393 }
394 }
395
396 }
397 }
398
399
400 void Canonicalizer::do_IfInstanceOf(IfInstanceOf* x) {}
401
402 void Canonicalizer::do_IfOp(IfOp* x) {
403 // Caution: do not use do_Op2(x) here for now since
404 // we map the condition to the op for now!
405 move_const_to_right(x);
406 }
407
408
409 void Canonicalizer::do_Intrinsic (Intrinsic* x) {
410 switch (x->id()) {
411 case vmIntrinsics::_floatToRawIntBits : {
412 FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant();
413 if (c != NULL) {
414 JavaValue v;
415 v.set_jfloat(c->value());
416 set_constant(v.get_jint());
417 }
418 break;
419 }
420 case vmIntrinsics::_intBitsToFloat : {
421 IntConstant* c = x->argument_at(0)->type()->as_IntConstant();
422 if (c != NULL) {
423 JavaValue v;
424 v.set_jint(c->value());
425 set_constant(v.get_jfloat());
426 }
427 break;
428 }
429 case vmIntrinsics::_doubleToRawLongBits : {
430 DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant();
431 if (c != NULL) {
432 JavaValue v;
433 v.set_jdouble(c->value());
434 set_constant(v.get_jlong());
435 }
436 break;
437 }
438 case vmIntrinsics::_longBitsToDouble : {
439 LongConstant* c = x->argument_at(0)->type()->as_LongConstant();
440 if (c != NULL) {
441 JavaValue v;
442 v.set_jlong(c->value());
443 set_constant(v.get_jdouble());
444 }
445 break;
446 }
447 }
448 }
449
450 void Canonicalizer::do_Convert (Convert* x) {
451 if (x->value()->type()->is_constant()) {
452 switch (x->op()) {
453 case Bytecodes::_i2b: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break;
454 case Bytecodes::_i2s: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break;
455 case Bytecodes::_i2c: set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break;
456 case Bytecodes::_i2l: set_constant((jlong)(x->value()->type()->as_IntConstant()->value())); break;
457 case Bytecodes::_i2f: set_constant((float)(x->value()->type()->as_IntConstant()->value())); break;
458 case Bytecodes::_i2d: set_constant((double)(x->value()->type()->as_IntConstant()->value())); break;
459 case Bytecodes::_l2i: set_constant((int)(x->value()->type()->as_LongConstant()->value())); break;
460 case Bytecodes::_l2f: set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break;
461 case Bytecodes::_l2d: set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break;
462 case Bytecodes::_f2d: set_constant((double)(x->value()->type()->as_FloatConstant()->value())); break;
463 case Bytecodes::_f2i: set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break;
464 case Bytecodes::_f2l: set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break;
465 case Bytecodes::_d2f: set_constant((float)(x->value()->type()->as_DoubleConstant()->value())); break;
466 case Bytecodes::_d2i: set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break;
467 case Bytecodes::_d2l: set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break;
468 default:
469 ShouldNotReachHere();
470 }
471 }
472
473 Value value = x->value();
474 BasicType type = T_ILLEGAL;
475 LoadField* lf = value->as_LoadField();
476 if (lf) {
477 type = lf->field_type();
478 } else {
479 LoadIndexed* li = value->as_LoadIndexed();
480 if (li) {
481 type = li->elt_type();
482 } else {
483 Convert* conv = value->as_Convert();
484 if (conv) {
485 switch (conv->op()) {
486 case Bytecodes::_i2b: type = T_BYTE; break;
487 case Bytecodes::_i2s: type = T_SHORT; break;
488 case Bytecodes::_i2c: type = T_CHAR; break;
489 }
490 }
491 }
492 }
493 if (type != T_ILLEGAL) {
494 switch (x->op()) {
495 case Bytecodes::_i2b: if (type == T_BYTE) set_canonical(x->value()); break;
496 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break;
497 case Bytecodes::_i2c: if (type == T_CHAR) set_canonical(x->value()); break;
498 }
499 } else {
500 Op2* op2 = x->value()->as_Op2();
501 if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) {
502 jint safebits = 0;
503 jint mask = op2->y()->type()->as_IntConstant()->value();
504 switch (x->op()) {
505 case Bytecodes::_i2b: safebits = 0x7f; break;
506 case Bytecodes::_i2s: safebits = 0x7fff; break;
507 case Bytecodes::_i2c: safebits = 0xffff; break;
508 }
509 // When casting a masked integer to a smaller signed type, if
510 // the mask doesn't include the sign bit the cast isn't needed.
511 if (safebits && (mask & ~safebits) == 0) {
512 set_canonical(x->value());
513 }
514 }
515 }
516
517 }
518
519 void Canonicalizer::do_NullCheck (NullCheck* x) {
520 if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) {
521 set_canonical(x->obj());
522 } else {
523 Constant* con = x->obj()->as_Constant();
524 if (con) {
525 ObjectType* c = con->type()->as_ObjectType();
526 if (c && c->is_loaded()) {
527 ObjectConstant* oc = c->as_ObjectConstant();
528 if (!oc || !oc->value()->is_null_object()) {
529 set_canonical(con);
530 }
531 }
532 }
533 }
534 }
535
536 void Canonicalizer::do_Invoke (Invoke* x) {}
537 void Canonicalizer::do_NewInstance (NewInstance* x) {}
538 void Canonicalizer::do_NewTypeArray (NewTypeArray* x) {}
539 void Canonicalizer::do_NewObjectArray (NewObjectArray* x) {}
540 void Canonicalizer::do_NewMultiArray (NewMultiArray* x) {}
541 void Canonicalizer::do_CheckCast (CheckCast* x) {
542 if (x->klass()->is_loaded()) {
543 Value obj = x->obj();
544 ciType* klass = obj->exact_type();
545 if (klass == NULL) klass = obj->declared_type();
546 if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) {
547 set_canonical(obj);
548 return;
549 }
550 // checkcast of null returns null
551 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
552 set_canonical(obj);
553 }
554 }
555 }
556 void Canonicalizer::do_InstanceOf (InstanceOf* x) {
557 if (x->klass()->is_loaded()) {
558 Value obj = x->obj();
559 ciType* exact = obj->exact_type();
560 if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) {
561 set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0);
562 return;
563 }
564 // instanceof null returns false
565 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) {
566 set_constant(0);
567 }
568 }
569
570 }
571 void Canonicalizer::do_MonitorEnter (MonitorEnter* x) {}
572 void Canonicalizer::do_MonitorExit (MonitorExit* x) {}
573 void Canonicalizer::do_BlockBegin (BlockBegin* x) {}
574 void Canonicalizer::do_Goto (Goto* x) {}
575
576
577 static bool is_true(jlong x, If::Condition cond, jlong y) {
578 switch (cond) {
579 case If::eql: return x == y;
580 case If::neq: return x != y;
581 case If::lss: return x < y;
582 case If::leq: return x <= y;
583 case If::gtr: return x > y;
584 case If::geq: return x >= y;
585 }
586 ShouldNotReachHere();
587 return false;
588 }
589
590
591 void Canonicalizer::do_If(If* x) {
592 // move const to right
593 if (x->x()->type()->is_constant()) x->swap_operands();
594 // simplify
595 const Value l = x->x(); ValueType* lt = l->type();
596 const Value r = x->y(); ValueType* rt = r->type();
597
598 if (l == r && !lt->is_float_kind()) {
599 // pattern: If (a cond a) => simplify to Goto
600 BlockBegin* sux;
601 switch (x->cond()) {
602 case If::eql: sux = x->sux_for(true); break;
603 case If::neq: sux = x->sux_for(false); break;
604 case If::lss: sux = x->sux_for(false); break;
605 case If::leq: sux = x->sux_for(true); break;
606 case If::gtr: sux = x->sux_for(false); break;
607 case If::geq: sux = x->sux_for(true); break;
608 }
609 // If is a safepoint then the debug information should come from the state_before of the If.
610 set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
611 return;
612 }
613
614 if (lt->is_constant() && rt->is_constant()) {
615 if (x->x()->as_Constant() != NULL) {
616 // pattern: If (lc cond rc) => simplify to: Goto
617 BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(),
618 x->sux_for(true),
619 x->sux_for(false));
620 if (sux != NULL) {
621 // If is a safepoint then the debug information should come from the state_before of the If.
622 set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
623 }
624 }
625 } else if (rt->as_IntConstant() != NULL) {
626 // pattern: If (l cond rc) => investigate further
627 const jint rc = rt->as_IntConstant()->value();
628 if (l->as_CompareOp() != NULL) {
629 // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto
630 CompareOp* cmp = l->as_CompareOp();
631 bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl;
632 BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b
633 BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b
634 BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b
635 BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered
636 // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are
637 // equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either
638 // lss_sux or gtr_sux.
639 if (lss_sux == eql_sux && eql_sux == gtr_sux) {
640 // all successors identical => simplify to: Goto
641 set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint()));
642 } else {
643 // two successors differ and two successors are the same => simplify to: If (x cmp y)
644 // determine new condition & successors
645 If::Condition cond;
646 BlockBegin* tsux = NULL;
647 BlockBegin* fsux = NULL;
648 if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; }
649 else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; }
650 else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; }
651 else { ShouldNotReachHere(); }
652 If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint());
653 if (cmp->x() == cmp->y()) {
654 do_If(canon);
655 } else {
656 set_canonical(canon);
657 set_bci(cmp->bci());
658 }
659 }
660 } else if (l->as_InstanceOf() != NULL) {
661 // NOTE: Code permanently disabled for now since it leaves the old InstanceOf
662 // instruction in the graph (it is pinned). Need to fix this at some point.
663 return;
664 // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto
665 InstanceOf* inst = l->as_InstanceOf();
666 BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1
667 BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0
668 if (is_inst_sux == no_inst_sux && inst->is_loaded()) {
669 // both successors identical and klass is loaded => simplify to: Goto
670 set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint()));
671 } else {
672 // successors differ => simplify to: IfInstanceOf
673 set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->bci(), is_inst_sux, no_inst_sux));
674 }
675 }
676 } else if (rt == objectNull && (l->as_NewInstance() || l->as_NewArray())) {
677 if (x->cond() == Instruction::eql) {
678 set_canonical(new Goto(x->fsux(), x->state_before(), x->is_safepoint()));
679 } else {
680 assert(x->cond() == Instruction::neq, "only other valid case");
681 set_canonical(new Goto(x->tsux(), x->state_before(), x->is_safepoint()));
682 }
683 }
684 }
685
686
687 void Canonicalizer::do_TableSwitch(TableSwitch* x) {
688 if (x->tag()->type()->is_constant()) {
689 int v = x->tag()->type()->as_IntConstant()->value();
690 BlockBegin* sux = x->default_sux();
691 if (v >= x->lo_key() && v <= x->hi_key()) {
692 sux = x->sux_at(v - x->lo_key());
693 }
694 set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
695 } else if (x->number_of_sux() == 1) {
696 // NOTE: Code permanently disabled for now since the switch statement's
697 // tag expression may produce side-effects in which case it must
698 // be executed.
699 return;
700 // simplify to Goto
701 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
702 } else if (x->number_of_sux() == 2) {
703 // NOTE: Code permanently disabled for now since it produces two new nodes
704 // (Constant & If) and the Canonicalizer cannot return them correctly
705 // yet. For now we copied the corresponding code directly into the
706 // GraphBuilder (i.e., we should never reach here).
707 return;
708 // simplify to If
709 assert(x->lo_key() == x->hi_key(), "keys must be the same");
710 Constant* key = new Constant(new IntConstant(x->lo_key()));
711 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
712 }
713 }
714
715
716 void Canonicalizer::do_LookupSwitch(LookupSwitch* x) {
717 if (x->tag()->type()->is_constant()) {
718 int v = x->tag()->type()->as_IntConstant()->value();
719 BlockBegin* sux = x->default_sux();
720 for (int i = 0; i < x->length(); i++) {
721 if (v == x->key_at(i)) {
722 sux = x->sux_at(i);
723 }
724 }
725 set_canonical(new Goto(sux, x->state_before(), x->is_safepoint()));
726 } else if (x->number_of_sux() == 1) {
727 // NOTE: Code permanently disabled for now since the switch statement's
728 // tag expression may produce side-effects in which case it must
729 // be executed.
730 return;
731 // simplify to Goto
732 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint()));
733 } else if (x->number_of_sux() == 2) {
734 // NOTE: Code permanently disabled for now since it produces two new nodes
735 // (Constant & If) and the Canonicalizer cannot return them correctly
736 // yet. For now we copied the corresponding code directly into the
737 // GraphBuilder (i.e., we should never reach here).
738 return;
739 // simplify to If
740 assert(x->length() == 1, "length must be the same");
741 Constant* key = new Constant(new IntConstant(x->key_at(0)));
742 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint()));
743 }
744 }
745
746
747 void Canonicalizer::do_Return (Return* x) {}
748 void Canonicalizer::do_Throw (Throw* x) {}
749 void Canonicalizer::do_Base (Base* x) {}
750 void Canonicalizer::do_OsrEntry (OsrEntry* x) {}
751 void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {}
752
753 static bool match_index_and_scale(Instruction* instr,
754 Instruction** index,
755 int* log2_scale,
756 Instruction** instr_to_unpin) {
757 *instr_to_unpin = NULL;
758
759 // Skip conversion ops
760 Convert* convert = instr->as_Convert();
761 if (convert != NULL) {
762 instr = convert->value();
763 }
764
765 ShiftOp* shift = instr->as_ShiftOp();
766 if (shift != NULL) {
767 if (shift->is_pinned()) {
768 *instr_to_unpin = shift;
769 }
770 // Constant shift value?
771 Constant* con = shift->y()->as_Constant();
772 if (con == NULL) return false;
773 // Well-known type and value?
774 IntConstant* val = con->type()->as_IntConstant();
775 if (val == NULL) return false;
776 if (shift->x()->type() != intType) return false;
777 *index = shift->x();
778 int tmp_scale = val->value();
779 if (tmp_scale >= 0 && tmp_scale < 4) {
780 *log2_scale = tmp_scale;
781 return true;
782 } else {
783 return false;
784 }
785 }
786
787 ArithmeticOp* arith = instr->as_ArithmeticOp();
788 if (arith != NULL) {
789 if (arith->is_pinned()) {
790 *instr_to_unpin = arith;
791 }
792 // Check for integer multiply
793 if (arith->op() == Bytecodes::_imul) {
794 // See if either arg is a known constant
795 Constant* con = arith->x()->as_Constant();
796 if (con != NULL) {
797 *index = arith->y();
798 } else {
799 con = arith->y()->as_Constant();
800 if (con == NULL) return false;
801 *index = arith->x();
802 }
803 if ((*index)->type() != intType) return false;
804 // Well-known type and value?
805 IntConstant* val = con->type()->as_IntConstant();
806 if (val == NULL) return false;
807 switch (val->value()) {
808 case 1: *log2_scale = 0; return true;
809 case 2: *log2_scale = 1; return true;
810 case 4: *log2_scale = 2; return true;
811 case 8: *log2_scale = 3; return true;
812 default: return false;
813 }
814 }
815 }
816
817 // Unknown instruction sequence; don't touch it
818 return false;
819 }
820
821
822 static bool match(UnsafeRawOp* x,
823 Instruction** base,
824 Instruction** index,
825 int* log2_scale) {
826 Instruction* instr_to_unpin = NULL;
827 ArithmeticOp* root = x->base()->as_ArithmeticOp();
828 if (root == NULL) return false;
829 // Limit ourselves to addition for now
830 if (root->op() != Bytecodes::_ladd) return false;
831 // Try to find shift or scale op
832 if (match_index_and_scale(root->y(), index, log2_scale, &instr_to_unpin)) {
833 *base = root->x();
834 } else if (match_index_and_scale(root->x(), index, log2_scale, &instr_to_unpin)) {
835 *base = root->y();
836 } else if (root->y()->as_Convert() != NULL) {
837 Convert* convert = root->y()->as_Convert();
838 if (convert->op() == Bytecodes::_i2l && convert->value()->type() == intType) {
839 // pick base and index, setting scale at 1
840 *base = root->x();
841 *index = convert->value();
842 *log2_scale = 0;
843 } else {
844 return false;
845 }
846 } else {
847 // doesn't match any expected sequences
848 return false;
849 }
850
851 // If the value is pinned then it will be always be computed so
852 // there's no profit to reshaping the expression.
853 return !root->is_pinned();
854 }
855
856
857 void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) {
858 Instruction* base = NULL;
859 Instruction* index = NULL;
860 int log2_scale;
861
862 if (match(x, &base, &index, &log2_scale)) {
863 x->set_base(base);
864 x->set_index(index);
865 x->set_log2_scale(log2_scale);
866 if (PrintUnsafeOptimization) {
867 tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d",
868 x->id(), x->base()->id(), x->index()->id(), x->log2_scale());
869 }
870 }
871 }
872
873 void Canonicalizer::do_RoundFP(RoundFP* x) {}
874 void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
875 void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); }
876 void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {}
877 void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {}
878 void Canonicalizer::do_UnsafePrefetchRead (UnsafePrefetchRead* x) {}
879 void Canonicalizer::do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) {}
880 void Canonicalizer::do_ProfileCall(ProfileCall* x) {}
881 void Canonicalizer::do_ProfileCounter(ProfileCounter* x) {}