1 /* 2 * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "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* 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 } 250 251 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 return; 270 } 271 } 272 273 274 } 275 276 277 void Canonicalizer::do_NegateOp(NegateOp* x) { 278 ValueType* t = x->x()->type(); 279 if (t->is_constant()) { 280 switch (t->tag()) { 281 case intTag : set_constant(-t->as_IntConstant ()->value()); return; 282 case longTag : set_constant(-t->as_LongConstant ()->value()); return; 283 case floatTag : set_constant(-t->as_FloatConstant ()->value()); return; 284 case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return; 285 default : ShouldNotReachHere(); 286 } 287 } 288 } 289 290 291 void Canonicalizer::do_ArithmeticOp (ArithmeticOp* x) { do_Op2(x); } 292 293 294 void Canonicalizer::do_ShiftOp (ShiftOp* x) { 295 ValueType* t = x->x()->type(); 296 ValueType* t2 = x->y()->type(); 297 if (t->is_constant()) { 298 switch (t->tag()) { 299 case intTag : if (t->as_IntConstant()->value() == 0) { set_constant(0); return; } break; 300 case longTag : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break; 301 default : ShouldNotReachHere(); 302 } 303 if (t2->is_constant()) { 304 if (t->tag() == intTag) { 305 int value = t->as_IntConstant()->value(); 306 int shift = t2->as_IntConstant()->value() & 31; 307 jint mask = ~(~0 << (32 - shift)); 308 if (shift == 0) mask = ~0; 309 switch (x->op()) { 310 case Bytecodes::_ishl: set_constant(value << shift); return; 311 case Bytecodes::_ishr: set_constant(value >> shift); return; 312 case Bytecodes::_iushr: set_constant((value >> shift) & mask); return; 313 } 314 } else if (t->tag() == longTag) { 315 jlong value = t->as_LongConstant()->value(); 316 int shift = t2->as_IntConstant()->value() & 63; 317 jlong mask = ~(~jlong_cast(0) << (64 - shift)); 318 if (shift == 0) mask = ~jlong_cast(0); 319 switch (x->op()) { 320 case Bytecodes::_lshl: set_constant(value << shift); return; 321 case Bytecodes::_lshr: set_constant(value >> shift); return; 322 case Bytecodes::_lushr: set_constant((value >> shift) & mask); return; 323 } 324 } 325 } 326 } 327 if (t2->is_constant()) { 328 switch (t2->tag()) { 329 case intTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return; 330 case longTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return; 331 default : ShouldNotReachHere(); 332 } 333 } 334 } 335 336 337 void Canonicalizer::do_LogicOp (LogicOp* x) { do_Op2(x); } 338 void Canonicalizer::do_CompareOp (CompareOp* x) { 339 if (x->x() == x->y()) { 340 switch (x->x()->type()->tag()) { 341 case longTag: set_constant(0); break; 342 case floatTag: { 343 FloatConstant* fc = x->x()->type()->as_FloatConstant(); 344 if (fc) { 345 if (g_isnan(fc->value())) { 346 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1); 347 } else { 348 set_constant(0); 349 } 350 } 351 break; 352 } 353 case doubleTag: { 354 DoubleConstant* dc = x->x()->type()->as_DoubleConstant(); 355 if (dc) { 356 if (g_isnan(dc->value())) { 357 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1); 358 } else { 359 set_constant(0); 360 } 361 } 362 break; 363 } 364 } 365 } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) { 366 switch (x->x()->type()->tag()) { 367 case longTag: { 368 jlong vx = x->x()->type()->as_LongConstant()->value(); 369 jlong vy = x->y()->type()->as_LongConstant()->value(); 370 if (vx == vy) 371 set_constant(0); 372 else if (vx < vy) 373 set_constant(-1); 374 else 375 set_constant(1); 376 break; 377 } 378 379 case floatTag: { 380 float vx = x->x()->type()->as_FloatConstant()->value(); 381 float vy = x->y()->type()->as_FloatConstant()->value(); 382 if (g_isnan(vx) || g_isnan(vy)) 383 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1); 384 else if (vx == vy) 385 set_constant(0); 386 else if (vx < vy) 387 set_constant(-1); 388 else 389 set_constant(1); 390 break; 391 } 392 393 case doubleTag: { 394 double vx = x->x()->type()->as_DoubleConstant()->value(); 395 double vy = x->y()->type()->as_DoubleConstant()->value(); 396 if (g_isnan(vx) || g_isnan(vy)) 397 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1); 398 else if (vx == vy) 399 set_constant(0); 400 else if (vx < vy) 401 set_constant(-1); 402 else 403 set_constant(1); 404 break; 405 } 406 } 407 408 } 409 } 410 411 412 void Canonicalizer::do_IfInstanceOf(IfInstanceOf* x) {} 413 414 void Canonicalizer::do_IfOp(IfOp* x) { 415 // Caution: do not use do_Op2(x) here for now since 416 // we map the condition to the op for now! 417 move_const_to_right(x); 418 } 419 420 421 void Canonicalizer::do_Intrinsic (Intrinsic* x) { 422 switch (x->id()) { 423 case vmIntrinsics::_floatToRawIntBits : { 424 FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant(); 425 if (c != NULL) { 426 JavaValue v; 427 v.set_jfloat(c->value()); 428 set_constant(v.get_jint()); 429 } 430 break; 431 } 432 case vmIntrinsics::_intBitsToFloat : { 433 IntConstant* c = x->argument_at(0)->type()->as_IntConstant(); 434 if (c != NULL) { 435 JavaValue v; 436 v.set_jint(c->value()); 437 set_constant(v.get_jfloat()); 438 } 439 break; 440 } 441 case vmIntrinsics::_doubleToRawLongBits : { 442 DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant(); 443 if (c != NULL) { 444 JavaValue v; 445 v.set_jdouble(c->value()); 446 set_constant(v.get_jlong()); 447 } 448 break; 449 } 450 case vmIntrinsics::_longBitsToDouble : { 451 LongConstant* c = x->argument_at(0)->type()->as_LongConstant(); 452 if (c != NULL) { 453 JavaValue v; 454 v.set_jlong(c->value()); 455 set_constant(v.get_jdouble()); 456 } 457 break; 458 } 459 case vmIntrinsics::_isInstance : { 460 assert(x->number_of_arguments() == 2, "wrong type"); 461 462 InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant(); 463 if (c != NULL && !c->value()->is_null_object()) { 464 // ciInstance::java_mirror_type() returns non-NULL only for Java mirrors 465 ciType* t = c->value()->as_instance()->java_mirror_type(); 466 if (t->is_klass()) { 467 // substitute cls.isInstance(obj) of a constant Class into 468 // an InstantOf instruction 469 InstanceOf* i = new InstanceOf(t->as_klass(), x->argument_at(1), x->state_before()); 470 set_canonical(i); 471 // and try to canonicalize even further 472 do_InstanceOf(i); 473 } else { 474 assert(t->is_primitive_type(), "should be a primitive type"); 475 // cls.isInstance(obj) always returns false for primitive classes 476 set_constant(0); 477 } 478 } 479 break; 480 } 481 } 482 } 483 484 void Canonicalizer::do_Convert (Convert* x) { 485 if (x->value()->type()->is_constant()) { 486 switch (x->op()) { 487 case Bytecodes::_i2b: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break; 488 case Bytecodes::_i2s: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break; 489 case Bytecodes::_i2c: set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break; 490 case Bytecodes::_i2l: set_constant((jlong)(x->value()->type()->as_IntConstant()->value())); break; 491 case Bytecodes::_i2f: set_constant((float)(x->value()->type()->as_IntConstant()->value())); break; 492 case Bytecodes::_i2d: set_constant((double)(x->value()->type()->as_IntConstant()->value())); break; 493 case Bytecodes::_l2i: set_constant((int)(x->value()->type()->as_LongConstant()->value())); break; 494 case Bytecodes::_l2f: set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break; 495 case Bytecodes::_l2d: set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break; 496 case Bytecodes::_f2d: set_constant((double)(x->value()->type()->as_FloatConstant()->value())); break; 497 case Bytecodes::_f2i: set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break; 498 case Bytecodes::_f2l: set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break; 499 case Bytecodes::_d2f: set_constant((float)(x->value()->type()->as_DoubleConstant()->value())); break; 500 case Bytecodes::_d2i: set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break; 501 case Bytecodes::_d2l: set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break; 502 default: 503 ShouldNotReachHere(); 504 } 505 } 506 507 Value value = x->value(); 508 BasicType type = T_ILLEGAL; 509 LoadField* lf = value->as_LoadField(); 510 if (lf) { 511 type = lf->field_type(); 512 } else { 513 LoadIndexed* li = value->as_LoadIndexed(); 514 if (li) { 515 type = li->elt_type(); 516 } else { 517 Convert* conv = value->as_Convert(); 518 if (conv) { 519 switch (conv->op()) { 520 case Bytecodes::_i2b: type = T_BYTE; break; 521 case Bytecodes::_i2s: type = T_SHORT; break; 522 case Bytecodes::_i2c: type = T_CHAR; break; 523 } 524 } 525 } 526 } 527 if (type != T_ILLEGAL) { 528 switch (x->op()) { 529 case Bytecodes::_i2b: if (type == T_BYTE) set_canonical(x->value()); break; 530 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break; 531 case Bytecodes::_i2c: if (type == T_CHAR) set_canonical(x->value()); break; 532 } 533 } else { 534 Op2* op2 = x->value()->as_Op2(); 535 if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) { 536 jint safebits = 0; 537 jint mask = op2->y()->type()->as_IntConstant()->value(); 538 switch (x->op()) { 539 case Bytecodes::_i2b: safebits = 0x7f; break; 540 case Bytecodes::_i2s: safebits = 0x7fff; break; 541 case Bytecodes::_i2c: safebits = 0xffff; break; 542 } 543 // When casting a masked integer to a smaller signed type, if 544 // the mask doesn't include the sign bit the cast isn't needed. 545 if (safebits && (mask & ~safebits) == 0) { 546 set_canonical(x->value()); 547 } 548 } 549 } 550 551 } 552 553 void Canonicalizer::do_NullCheck (NullCheck* x) { 554 if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) { 555 set_canonical(x->obj()); 556 } else { 557 Constant* con = x->obj()->as_Constant(); 558 if (con) { 559 ObjectType* c = con->type()->as_ObjectType(); 560 if (c && c->is_loaded()) { 561 ObjectConstant* oc = c->as_ObjectConstant(); 562 if (!oc || !oc->value()->is_null_object()) { 563 set_canonical(con); 564 } 565 } 566 } 567 } 568 } 569 570 void Canonicalizer::do_TypeCast (TypeCast* x) {} 571 void Canonicalizer::do_Invoke (Invoke* x) {} 572 void Canonicalizer::do_NewInstance (NewInstance* x) {} 573 void Canonicalizer::do_NewTypeArray (NewTypeArray* x) {} 574 void Canonicalizer::do_NewObjectArray (NewObjectArray* x) {} 575 void Canonicalizer::do_NewMultiArray (NewMultiArray* x) {} 576 void Canonicalizer::do_CheckCast (CheckCast* x) { 577 if (x->klass()->is_loaded()) { 578 Value obj = x->obj(); 579 ciType* klass = obj->exact_type(); 580 if (klass == NULL) klass = obj->declared_type(); 581 if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) { 582 set_canonical(obj); 583 return; 584 } 585 // checkcast of null returns null 586 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) { 587 set_canonical(obj); 588 } 589 } 590 } 591 void Canonicalizer::do_InstanceOf (InstanceOf* x) { 592 if (x->klass()->is_loaded()) { 593 Value obj = x->obj(); 594 ciType* exact = obj->exact_type(); 595 if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) { 596 set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0); 597 return; 598 } 599 // instanceof null returns false 600 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) { 601 set_constant(0); 602 } 603 } 604 605 } 606 void Canonicalizer::do_MonitorEnter (MonitorEnter* x) {} 607 void Canonicalizer::do_MonitorExit (MonitorExit* x) {} 608 void Canonicalizer::do_BlockBegin (BlockBegin* x) {} 609 void Canonicalizer::do_Goto (Goto* x) {} 610 611 612 static bool is_true(jlong x, If::Condition cond, jlong y) { 613 switch (cond) { 614 case If::eql: return x == y; 615 case If::neq: return x != y; 616 case If::lss: return x < y; 617 case If::leq: return x <= y; 618 case If::gtr: return x > y; 619 case If::geq: return x >= y; 620 } 621 ShouldNotReachHere(); 622 return false; 623 } 624 625 static bool is_safepoint(BlockEnd* x, BlockBegin* sux) { 626 // An Instruction with multiple successors, x, is replaced by a Goto 627 // to a single successor, sux. Is a safepoint check needed = was the 628 // instruction being replaced a safepoint and the single remaining 629 // successor a back branch? 630 return x->is_safepoint() && (sux->bci() < x->state_before()->bci()); 631 } 632 633 void Canonicalizer::do_If(If* x) { 634 // move const to right 635 if (x->x()->type()->is_constant()) x->swap_operands(); 636 // simplify 637 const Value l = x->x(); ValueType* lt = l->type(); 638 const Value r = x->y(); ValueType* rt = r->type(); 639 640 if (l == r && !lt->is_float_kind()) { 641 // pattern: If (a cond a) => simplify to Goto 642 BlockBegin* sux; 643 switch (x->cond()) { 644 case If::eql: sux = x->sux_for(true); break; 645 case If::neq: sux = x->sux_for(false); break; 646 case If::lss: sux = x->sux_for(false); break; 647 case If::leq: sux = x->sux_for(true); break; 648 case If::gtr: sux = x->sux_for(false); break; 649 case If::geq: sux = x->sux_for(true); break; 650 } 651 // If is a safepoint then the debug information should come from the state_before of the If. 652 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 653 return; 654 } 655 656 if (lt->is_constant() && rt->is_constant()) { 657 if (x->x()->as_Constant() != NULL) { 658 // pattern: If (lc cond rc) => simplify to: Goto 659 BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(), 660 x->sux_for(true), 661 x->sux_for(false)); 662 if (sux != NULL) { 663 // If is a safepoint then the debug information should come from the state_before of the If. 664 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 665 } 666 } 667 } else if (rt->as_IntConstant() != NULL) { 668 // pattern: If (l cond rc) => investigate further 669 const jint rc = rt->as_IntConstant()->value(); 670 if (l->as_CompareOp() != NULL) { 671 // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto 672 CompareOp* cmp = l->as_CompareOp(); 673 bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl; 674 BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b 675 BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b 676 BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b 677 BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered 678 // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are 679 // equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either 680 // lss_sux or gtr_sux. 681 if (lss_sux == eql_sux && eql_sux == gtr_sux) { 682 // all successors identical => simplify to: Goto 683 set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint())); 684 } else { 685 // two successors differ and two successors are the same => simplify to: If (x cmp y) 686 // determine new condition & successors 687 If::Condition cond; 688 BlockBegin* tsux = NULL; 689 BlockBegin* fsux = NULL; 690 if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; } 691 else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; } 692 else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; } 693 else { ShouldNotReachHere(); } 694 If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint()); 695 if (cmp->x() == cmp->y()) { 696 do_If(canon); 697 } else { 698 if (compilation()->profile_branches()) { 699 // TODO: If profiling, leave floating point comparisons unoptimized. 700 // We currently do not support profiling of the unordered case. 701 switch(cmp->op()) { 702 case Bytecodes::_fcmpl: case Bytecodes::_fcmpg: 703 case Bytecodes::_dcmpl: case Bytecodes::_dcmpg: 704 set_canonical(x); 705 return; 706 } 707 } 708 set_bci(cmp->state_before()->bci()); 709 set_canonical(canon); 710 } 711 } 712 } else if (l->as_InstanceOf() != NULL) { 713 // NOTE: Code permanently disabled for now since it leaves the old InstanceOf 714 // instruction in the graph (it is pinned). Need to fix this at some point. 715 // It should also be left in the graph when generating a profiled method version or Goto 716 // has to know that it was an InstanceOf. 717 return; 718 // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto 719 InstanceOf* inst = l->as_InstanceOf(); 720 BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1 721 BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0 722 if (is_inst_sux == no_inst_sux && inst->is_loaded()) { 723 // both successors identical and klass is loaded => simplify to: Goto 724 set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint())); 725 } else { 726 // successors differ => simplify to: IfInstanceOf 727 set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->state_before()->bci(), is_inst_sux, no_inst_sux)); 728 } 729 } 730 } else if (rt == objectNull && (l->as_NewInstance() || l->as_NewArray())) { 731 if (x->cond() == Instruction::eql) { 732 BlockBegin* sux = x->fsux(); 733 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 734 } else { 735 assert(x->cond() == Instruction::neq, "only other valid case"); 736 BlockBegin* sux = x->tsux(); 737 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 738 } 739 } 740 } 741 742 743 void Canonicalizer::do_TableSwitch(TableSwitch* x) { 744 if (x->tag()->type()->is_constant()) { 745 int v = x->tag()->type()->as_IntConstant()->value(); 746 BlockBegin* sux = x->default_sux(); 747 if (v >= x->lo_key() && v <= x->hi_key()) { 748 sux = x->sux_at(v - x->lo_key()); 749 } 750 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 751 } else if (x->number_of_sux() == 1) { 752 // NOTE: Code permanently disabled for now since the switch statement's 753 // tag expression may produce side-effects in which case it must 754 // be executed. 755 return; 756 // simplify to Goto 757 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint())); 758 } else if (x->number_of_sux() == 2) { 759 // NOTE: Code permanently disabled for now since it produces two new nodes 760 // (Constant & If) and the Canonicalizer cannot return them correctly 761 // yet. For now we copied the corresponding code directly into the 762 // GraphBuilder (i.e., we should never reach here). 763 return; 764 // simplify to If 765 assert(x->lo_key() == x->hi_key(), "keys must be the same"); 766 Constant* key = new Constant(new IntConstant(x->lo_key())); 767 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint())); 768 } 769 } 770 771 772 void Canonicalizer::do_LookupSwitch(LookupSwitch* x) { 773 if (x->tag()->type()->is_constant()) { 774 int v = x->tag()->type()->as_IntConstant()->value(); 775 BlockBegin* sux = x->default_sux(); 776 for (int i = 0; i < x->length(); i++) { 777 if (v == x->key_at(i)) { 778 sux = x->sux_at(i); 779 } 780 } 781 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 782 } else if (x->number_of_sux() == 1) { 783 // NOTE: Code permanently disabled for now since the switch statement's 784 // tag expression may produce side-effects in which case it must 785 // be executed. 786 return; 787 // simplify to Goto 788 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint())); 789 } else if (x->number_of_sux() == 2) { 790 // NOTE: Code permanently disabled for now since it produces two new nodes 791 // (Constant & If) and the Canonicalizer cannot return them correctly 792 // yet. For now we copied the corresponding code directly into the 793 // GraphBuilder (i.e., we should never reach here). 794 return; 795 // simplify to If 796 assert(x->length() == 1, "length must be the same"); 797 Constant* key = new Constant(new IntConstant(x->key_at(0))); 798 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint())); 799 } 800 } 801 802 803 void Canonicalizer::do_Return (Return* x) {} 804 void Canonicalizer::do_Throw (Throw* x) {} 805 void Canonicalizer::do_Base (Base* x) {} 806 void Canonicalizer::do_OsrEntry (OsrEntry* x) {} 807 void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {} 808 809 static bool match_index_and_scale(Instruction* instr, 810 Instruction** index, 811 int* log2_scale, 812 Instruction** instr_to_unpin) { 813 *instr_to_unpin = NULL; 814 815 // Skip conversion ops 816 Convert* convert = instr->as_Convert(); 817 if (convert != NULL) { 818 instr = convert->value(); 819 } 820 821 ShiftOp* shift = instr->as_ShiftOp(); 822 if (shift != NULL) { 823 if (shift->is_pinned()) { 824 *instr_to_unpin = shift; 825 } 826 // Constant shift value? 827 Constant* con = shift->y()->as_Constant(); 828 if (con == NULL) return false; 829 // Well-known type and value? 830 IntConstant* val = con->type()->as_IntConstant(); 831 if (val == NULL) return false; 832 if (shift->x()->type() != intType) return false; 833 *index = shift->x(); 834 int tmp_scale = val->value(); 835 if (tmp_scale >= 0 && tmp_scale < 4) { 836 *log2_scale = tmp_scale; 837 return true; 838 } else { 839 return false; 840 } 841 } 842 843 ArithmeticOp* arith = instr->as_ArithmeticOp(); 844 if (arith != NULL) { 845 if (arith->is_pinned()) { 846 *instr_to_unpin = arith; 847 } 848 // Check for integer multiply 849 if (arith->op() == Bytecodes::_imul) { 850 // See if either arg is a known constant 851 Constant* con = arith->x()->as_Constant(); 852 if (con != NULL) { 853 *index = arith->y(); 854 } else { 855 con = arith->y()->as_Constant(); 856 if (con == NULL) return false; 857 *index = arith->x(); 858 } 859 if ((*index)->type() != intType) return false; 860 // Well-known type and value? 861 IntConstant* val = con->type()->as_IntConstant(); 862 if (val == NULL) return false; 863 switch (val->value()) { 864 case 1: *log2_scale = 0; return true; 865 case 2: *log2_scale = 1; return true; 866 case 4: *log2_scale = 2; return true; 867 case 8: *log2_scale = 3; return true; 868 default: return false; 869 } 870 } 871 } 872 873 // Unknown instruction sequence; don't touch it 874 return false; 875 } 876 877 878 static bool match(UnsafeRawOp* x, 879 Instruction** base, 880 Instruction** index, 881 int* log2_scale) { 882 Instruction* instr_to_unpin = NULL; 883 ArithmeticOp* root = x->base()->as_ArithmeticOp(); 884 if (root == NULL) return false; 885 // Limit ourselves to addition for now 886 if (root->op() != Bytecodes::_ladd) return false; 887 // Try to find shift or scale op 888 if (match_index_and_scale(root->y(), index, log2_scale, &instr_to_unpin)) { 889 *base = root->x(); 890 } else if (match_index_and_scale(root->x(), index, log2_scale, &instr_to_unpin)) { 891 *base = root->y(); 892 } else if (root->y()->as_Convert() != NULL) { 893 Convert* convert = root->y()->as_Convert(); 894 if (convert->op() == Bytecodes::_i2l && convert->value()->type() == intType) { 895 // pick base and index, setting scale at 1 896 *base = root->x(); 897 *index = convert->value(); 898 *log2_scale = 0; 899 } else { 900 return false; 901 } 902 } else { 903 // doesn't match any expected sequences 904 return false; 905 } 906 907 // If the value is pinned then it will be always be computed so 908 // there's no profit to reshaping the expression. 909 return !root->is_pinned(); 910 } 911 912 913 void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) { 914 Instruction* base = NULL; 915 Instruction* index = NULL; 916 int log2_scale; 917 918 if (match(x, &base, &index, &log2_scale)) { 919 x->set_base(base); 920 x->set_index(index); 921 x->set_log2_scale(log2_scale); 922 if (PrintUnsafeOptimization) { 923 tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d", 924 x->id(), x->base()->id(), x->index()->id(), x->log2_scale()); 925 } 926 } 927 } 928 929 void Canonicalizer::do_RoundFP(RoundFP* x) {} 930 void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); } 931 void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); } 932 void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {} 933 void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {} 934 void Canonicalizer::do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) {} 935 void Canonicalizer::do_UnsafePrefetchRead (UnsafePrefetchRead* x) {} 936 void Canonicalizer::do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) {} 937 void Canonicalizer::do_ProfileCall(ProfileCall* x) {} 938 void Canonicalizer::do_ProfileInvoke(ProfileInvoke* x) {} 939 void Canonicalizer::do_RuntimeCall(RuntimeCall* x) {} 940 void Canonicalizer::do_RangeCheckPredicate(RangeCheckPredicate* x) {} 941 void Canonicalizer::do_Assert(Assert* x) {} 942 void Canonicalizer::do_MemBar(MemBar* x) {}