1 /* 2 * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "c1/c1_Canonicalizer.hpp" 27 #include "c1/c1_InstructionPrinter.hpp" 28 #include "c1/c1_ValueStack.hpp" 29 #include "ci/ciArray.hpp" 30 #include "runtime/sharedRuntime.hpp" 31 32 33 class PrintValueVisitor: public ValueVisitor { 34 void visit(Value* vp) { 35 (*vp)->print_line(); 36 } 37 }; 38 39 void Canonicalizer::set_canonical(Value x) { 40 assert(x != NULL, "value must exist"); 41 // Note: we can not currently substitute root nodes which show up in 42 // the instruction stream (because the instruction list is embedded 43 // in the instructions). 44 if (canonical() != x) { 45 #ifndef PRODUCT 46 if (!x->has_printable_bci()) { 47 x->set_printable_bci(bci()); 48 } 49 #endif 50 if (PrintCanonicalization) { 51 PrintValueVisitor do_print_value; 52 canonical()->input_values_do(&do_print_value); 53 canonical()->print_line(); 54 tty->print_cr("canonicalized to:"); 55 x->input_values_do(&do_print_value); 56 x->print_line(); 57 tty->cr(); 58 } 59 assert(_canonical->type()->tag() == x->type()->tag(), "types must match"); 60 _canonical = x; 61 } 62 } 63 64 65 void Canonicalizer::move_const_to_right(Op2* x) { 66 if (x->x()->type()->is_constant() && x->is_commutative()) x->swap_operands(); 67 } 68 69 70 void Canonicalizer::do_Op2(Op2* x) { 71 if (x->x() == x->y()) { 72 switch (x->op()) { 73 case Bytecodes::_isub: set_constant(0); return; 74 case Bytecodes::_lsub: set_constant(jlong_cast(0)); return; 75 case Bytecodes::_iand: // fall through 76 case Bytecodes::_land: // fall through 77 case Bytecodes::_ior: // fall through 78 case Bytecodes::_lor : set_canonical(x->x()); return; 79 case Bytecodes::_ixor: set_constant(0); return; 80 case Bytecodes::_lxor: set_constant(jlong_cast(0)); return; 81 } 82 } 83 84 if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) { 85 // do constant folding for selected operations 86 switch (x->type()->tag()) { 87 case intTag: 88 { jint a = x->x()->type()->as_IntConstant()->value(); 89 jint b = x->y()->type()->as_IntConstant()->value(); 90 switch (x->op()) { 91 case Bytecodes::_iadd: set_constant(a + b); return; 92 case Bytecodes::_isub: set_constant(a - b); return; 93 case Bytecodes::_imul: set_constant(a * b); return; 94 case Bytecodes::_idiv: 95 if (b != 0) { 96 if (a == min_jint && b == -1) { 97 set_constant(min_jint); 98 } else { 99 set_constant(a / b); 100 } 101 return; 102 } 103 break; 104 case Bytecodes::_irem: 105 if (b != 0) { 106 if (a == min_jint && b == -1) { 107 set_constant(0); 108 } else { 109 set_constant(a % b); 110 } 111 return; 112 } 113 break; 114 case Bytecodes::_iand: set_constant(a & b); return; 115 case Bytecodes::_ior : set_constant(a | b); return; 116 case Bytecodes::_ixor: set_constant(a ^ b); return; 117 } 118 } 119 break; 120 case longTag: 121 { jlong a = x->x()->type()->as_LongConstant()->value(); 122 jlong b = x->y()->type()->as_LongConstant()->value(); 123 switch (x->op()) { 124 case Bytecodes::_ladd: set_constant(a + b); return; 125 case Bytecodes::_lsub: set_constant(a - b); return; 126 case Bytecodes::_lmul: set_constant(a * b); return; 127 case Bytecodes::_ldiv: 128 if (b != 0) { 129 set_constant(SharedRuntime::ldiv(b, a)); 130 return; 131 } 132 break; 133 case Bytecodes::_lrem: 134 if (b != 0) { 135 set_constant(SharedRuntime::lrem(b, a)); 136 return; 137 } 138 break; 139 case Bytecodes::_land: set_constant(a & b); return; 140 case Bytecodes::_lor : set_constant(a | b); return; 141 case Bytecodes::_lxor: set_constant(a ^ b); return; 142 } 143 } 144 break; 145 // other cases not implemented (must be extremely careful with floats & doubles!) 146 } 147 } 148 // make sure constant is on the right side, if any 149 move_const_to_right(x); 150 151 if (x->y()->type()->is_constant()) { 152 // do constant folding for selected operations 153 switch (x->type()->tag()) { 154 case intTag: 155 if (x->y()->type()->as_IntConstant()->value() == 0) { 156 switch (x->op()) { 157 case Bytecodes::_iadd: set_canonical(x->x()); return; 158 case Bytecodes::_isub: set_canonical(x->x()); return; 159 case Bytecodes::_imul: set_constant(0); return; 160 // Note: for div and rem, make sure that C semantics 161 // corresponds to Java semantics! 162 case Bytecodes::_iand: set_constant(0); return; 163 case Bytecodes::_ior : set_canonical(x->x()); return; 164 } 165 } 166 break; 167 case longTag: 168 if (x->y()->type()->as_LongConstant()->value() == (jlong)0) { 169 switch (x->op()) { 170 case Bytecodes::_ladd: set_canonical(x->x()); return; 171 case Bytecodes::_lsub: set_canonical(x->x()); return; 172 case Bytecodes::_lmul: set_constant((jlong)0); return; 173 // Note: for div and rem, make sure that C semantics 174 // corresponds to Java semantics! 175 case Bytecodes::_land: set_constant((jlong)0); return; 176 case Bytecodes::_lor : set_canonical(x->x()); return; 177 } 178 } 179 break; 180 } 181 } 182 } 183 184 185 void Canonicalizer::do_Phi (Phi* x) {} 186 void Canonicalizer::do_Constant (Constant* x) {} 187 void Canonicalizer::do_Local (Local* x) {} 188 void Canonicalizer::do_LoadField (LoadField* x) {} 189 190 // checks if v is in the block that is currently processed by 191 // GraphBuilder. This is the only block that has not BlockEnd yet. 192 static bool in_current_block(Value v) { 193 int max_distance = 4; 194 while (max_distance > 0 && v != NULL && v->as_BlockEnd() == NULL) { 195 v = v->next(); 196 max_distance--; 197 } 198 return v == NULL; 199 } 200 201 void Canonicalizer::do_StoreField (StoreField* x) { 202 // If a value is going to be stored into a field or array some of 203 // the conversions emitted by javac are unneeded because the fields 204 // are packed to their natural size. 205 Convert* conv = x->value()->as_Convert(); 206 if (conv) { 207 Value value = NULL; 208 BasicType type = x->field()->type()->basic_type(); 209 switch (conv->op()) { 210 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break; 211 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break; 212 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break; 213 } 214 // limit this optimization to current block 215 if (value != NULL && in_current_block(conv)) { 216 set_canonical(new StoreField(x->obj(), x->offset(), x->field(), value, x->is_static(), 217 x->state_before(), x->needs_patching())); 218 return; 219 } 220 } 221 222 } 223 224 void Canonicalizer::do_ArrayLength (ArrayLength* x) { 225 NewArray* na; 226 Constant* ct; 227 228 if ((na = x->array()->as_NewArray()) != NULL) { 229 // New arrays might have the known length. 230 // Do not use the Constant itself, but create a new Constant 231 // with same value Otherwise a Constant is live over multiple 232 // blocks without being registered in a state array. 233 Constant* length; 234 if (na->length() != NULL && 235 (length = na->length()->as_Constant()) != NULL) { 236 assert(length->type()->as_IntConstant() != NULL, "array length must be integer"); 237 set_constant(length->type()->as_IntConstant()->value()); 238 } 239 240 } else if ((ct = x->array()->as_Constant()) != NULL) { 241 // Constant arrays have constant lengths. 242 ArrayConstant* cnst = ct->type()->as_ArrayConstant(); 243 if (cnst != NULL) { 244 set_constant(cnst->value()->length()); 245 } 246 247 #ifdef ASSERT 248 } else { 249 LoadField* lf = x->array()->as_LoadField(); 250 bool is_static_constant = (lf != NULL) && lf->field()->is_constant() && lf->field()->is_static(); 251 assert(!is_static_constant, "Constant field loads are folded during parsing"); 252 #endif // ASSERT 253 } 254 } 255 256 void Canonicalizer::do_LoadIndexed (LoadIndexed* x) {} 257 void Canonicalizer::do_StoreIndexed (StoreIndexed* x) { 258 // If a value is going to be stored into a field or array some of 259 // the conversions emitted by javac are unneeded because the fields 260 // are packed to their natural size. 261 Convert* conv = x->value()->as_Convert(); 262 if (conv) { 263 Value value = NULL; 264 BasicType type = x->elt_type(); 265 switch (conv->op()) { 266 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break; 267 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break; 268 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break; 269 } 270 // limit this optimization to current block 271 if (value != NULL && in_current_block(conv)) { 272 set_canonical(new StoreIndexed(x->array(), x->index(), x->length(), 273 x->elt_type(), value, x->state_before())); 274 return; 275 } 276 } 277 278 279 } 280 281 282 void Canonicalizer::do_NegateOp(NegateOp* x) { 283 ValueType* t = x->x()->type(); 284 if (t->is_constant()) { 285 switch (t->tag()) { 286 case intTag : set_constant(-t->as_IntConstant ()->value()); return; 287 case longTag : set_constant(-t->as_LongConstant ()->value()); return; 288 case floatTag : set_constant(-t->as_FloatConstant ()->value()); return; 289 case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return; 290 default : ShouldNotReachHere(); 291 } 292 } 293 } 294 295 296 void Canonicalizer::do_ArithmeticOp (ArithmeticOp* x) { do_Op2(x); } 297 298 299 void Canonicalizer::do_ShiftOp (ShiftOp* x) { 300 ValueType* t = x->x()->type(); 301 ValueType* t2 = x->y()->type(); 302 if (t->is_constant()) { 303 switch (t->tag()) { 304 case intTag : if (t->as_IntConstant()->value() == 0) { set_constant(0); return; } break; 305 case longTag : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break; 306 default : ShouldNotReachHere(); 307 } 308 if (t2->is_constant()) { 309 if (t->tag() == intTag) { 310 int value = t->as_IntConstant()->value(); 311 int shift = t2->as_IntConstant()->value() & 31; 312 jint mask = ~(~0 << (32 - shift)); 313 if (shift == 0) mask = ~0; 314 switch (x->op()) { 315 case Bytecodes::_ishl: set_constant(value << shift); return; 316 case Bytecodes::_ishr: set_constant(value >> shift); return; 317 case Bytecodes::_iushr: set_constant((value >> shift) & mask); return; 318 } 319 } else if (t->tag() == longTag) { 320 jlong value = t->as_LongConstant()->value(); 321 int shift = t2->as_IntConstant()->value() & 63; 322 jlong mask = ~(~jlong_cast(0) << (64 - shift)); 323 if (shift == 0) mask = ~jlong_cast(0); 324 switch (x->op()) { 325 case Bytecodes::_lshl: set_constant(value << shift); return; 326 case Bytecodes::_lshr: set_constant(value >> shift); return; 327 case Bytecodes::_lushr: set_constant((value >> shift) & mask); return; 328 } 329 } 330 } 331 } 332 if (t2->is_constant()) { 333 switch (t2->tag()) { 334 case intTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return; 335 case longTag : if (t2->as_LongConstant()->value() == (jlong)0) set_canonical(x->x()); return; 336 default : ShouldNotReachHere(); 337 } 338 } 339 } 340 341 342 void Canonicalizer::do_LogicOp (LogicOp* x) { do_Op2(x); } 343 void Canonicalizer::do_CompareOp (CompareOp* x) { 344 if (x->x() == x->y()) { 345 switch (x->x()->type()->tag()) { 346 case longTag: set_constant(0); break; 347 case floatTag: { 348 FloatConstant* fc = x->x()->type()->as_FloatConstant(); 349 if (fc) { 350 if (g_isnan(fc->value())) { 351 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1); 352 } else { 353 set_constant(0); 354 } 355 } 356 break; 357 } 358 case doubleTag: { 359 DoubleConstant* dc = x->x()->type()->as_DoubleConstant(); 360 if (dc) { 361 if (g_isnan(dc->value())) { 362 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1); 363 } else { 364 set_constant(0); 365 } 366 } 367 break; 368 } 369 } 370 } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) { 371 switch (x->x()->type()->tag()) { 372 case longTag: { 373 jlong vx = x->x()->type()->as_LongConstant()->value(); 374 jlong vy = x->y()->type()->as_LongConstant()->value(); 375 if (vx == vy) 376 set_constant(0); 377 else if (vx < vy) 378 set_constant(-1); 379 else 380 set_constant(1); 381 break; 382 } 383 384 case floatTag: { 385 float vx = x->x()->type()->as_FloatConstant()->value(); 386 float vy = x->y()->type()->as_FloatConstant()->value(); 387 if (g_isnan(vx) || g_isnan(vy)) 388 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1); 389 else if (vx == vy) 390 set_constant(0); 391 else if (vx < vy) 392 set_constant(-1); 393 else 394 set_constant(1); 395 break; 396 } 397 398 case doubleTag: { 399 double vx = x->x()->type()->as_DoubleConstant()->value(); 400 double vy = x->y()->type()->as_DoubleConstant()->value(); 401 if (g_isnan(vx) || g_isnan(vy)) 402 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1); 403 else if (vx == vy) 404 set_constant(0); 405 else if (vx < vy) 406 set_constant(-1); 407 else 408 set_constant(1); 409 break; 410 } 411 } 412 413 } 414 } 415 416 417 void Canonicalizer::do_IfInstanceOf(IfInstanceOf* x) {} 418 419 void Canonicalizer::do_IfOp(IfOp* x) { 420 // Caution: do not use do_Op2(x) here for now since 421 // we map the condition to the op for now! 422 move_const_to_right(x); 423 } 424 425 426 void Canonicalizer::do_Intrinsic (Intrinsic* x) { 427 switch (x->id()) { 428 case vmIntrinsics::_floatToRawIntBits : { 429 FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant(); 430 if (c != NULL) { 431 JavaValue v; 432 v.set_jfloat(c->value()); 433 set_constant(v.get_jint()); 434 } 435 break; 436 } 437 case vmIntrinsics::_intBitsToFloat : { 438 IntConstant* c = x->argument_at(0)->type()->as_IntConstant(); 439 if (c != NULL) { 440 JavaValue v; 441 v.set_jint(c->value()); 442 set_constant(v.get_jfloat()); 443 } 444 break; 445 } 446 case vmIntrinsics::_doubleToRawLongBits : { 447 DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant(); 448 if (c != NULL) { 449 JavaValue v; 450 v.set_jdouble(c->value()); 451 set_constant(v.get_jlong()); 452 } 453 break; 454 } 455 case vmIntrinsics::_longBitsToDouble : { 456 LongConstant* c = x->argument_at(0)->type()->as_LongConstant(); 457 if (c != NULL) { 458 JavaValue v; 459 v.set_jlong(c->value()); 460 set_constant(v.get_jdouble()); 461 } 462 break; 463 } 464 case vmIntrinsics::_isInstance : { 465 assert(x->number_of_arguments() == 2, "wrong type"); 466 467 InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant(); 468 if (c != NULL && !c->value()->is_null_object()) { 469 // ciInstance::java_mirror_type() returns non-NULL only for Java mirrors 470 ciType* t = c->value()->as_instance()->java_mirror_type(); 471 if (t->is_klass()) { 472 // substitute cls.isInstance(obj) of a constant Class into 473 // an InstantOf instruction 474 InstanceOf* i = new InstanceOf(t->as_klass(), x->argument_at(1), x->state_before()); 475 set_canonical(i); 476 // and try to canonicalize even further 477 do_InstanceOf(i); 478 } else { 479 assert(t->is_primitive_type(), "should be a primitive type"); 480 // cls.isInstance(obj) always returns false for primitive classes 481 set_constant(0); 482 } 483 } 484 break; 485 } 486 } 487 } 488 489 void Canonicalizer::do_Convert (Convert* x) { 490 if (x->value()->type()->is_constant()) { 491 switch (x->op()) { 492 case Bytecodes::_i2b: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break; 493 case Bytecodes::_i2s: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break; 494 case Bytecodes::_i2c: set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break; 495 case Bytecodes::_i2l: set_constant((jlong)(x->value()->type()->as_IntConstant()->value())); break; 496 case Bytecodes::_i2f: set_constant((float)(x->value()->type()->as_IntConstant()->value())); break; 497 case Bytecodes::_i2d: set_constant((double)(x->value()->type()->as_IntConstant()->value())); break; 498 case Bytecodes::_l2i: set_constant((int)(x->value()->type()->as_LongConstant()->value())); break; 499 case Bytecodes::_l2f: set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break; 500 case Bytecodes::_l2d: set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break; 501 case Bytecodes::_f2d: set_constant((double)(x->value()->type()->as_FloatConstant()->value())); break; 502 case Bytecodes::_f2i: set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break; 503 case Bytecodes::_f2l: set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break; 504 case Bytecodes::_d2f: set_constant((float)(x->value()->type()->as_DoubleConstant()->value())); break; 505 case Bytecodes::_d2i: set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break; 506 case Bytecodes::_d2l: set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break; 507 default: 508 ShouldNotReachHere(); 509 } 510 } 511 512 Value value = x->value(); 513 BasicType type = T_ILLEGAL; 514 LoadField* lf = value->as_LoadField(); 515 if (lf) { 516 type = lf->field_type(); 517 } else { 518 LoadIndexed* li = value->as_LoadIndexed(); 519 if (li) { 520 type = li->elt_type(); 521 } else { 522 Convert* conv = value->as_Convert(); 523 if (conv) { 524 switch (conv->op()) { 525 case Bytecodes::_i2b: type = T_BYTE; break; 526 case Bytecodes::_i2s: type = T_SHORT; break; 527 case Bytecodes::_i2c: type = T_CHAR; break; 528 } 529 } 530 } 531 } 532 if (type != T_ILLEGAL) { 533 switch (x->op()) { 534 case Bytecodes::_i2b: if (type == T_BYTE) set_canonical(x->value()); break; 535 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break; 536 case Bytecodes::_i2c: if (type == T_CHAR) set_canonical(x->value()); break; 537 } 538 } else { 539 Op2* op2 = x->value()->as_Op2(); 540 if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) { 541 jint safebits = 0; 542 jint mask = op2->y()->type()->as_IntConstant()->value(); 543 switch (x->op()) { 544 case Bytecodes::_i2b: safebits = 0x7f; break; 545 case Bytecodes::_i2s: safebits = 0x7fff; break; 546 case Bytecodes::_i2c: safebits = 0xffff; break; 547 } 548 // When casting a masked integer to a smaller signed type, if 549 // the mask doesn't include the sign bit the cast isn't needed. 550 if (safebits && (mask & ~safebits) == 0) { 551 set_canonical(x->value()); 552 } 553 } 554 } 555 556 } 557 558 void Canonicalizer::do_NullCheck (NullCheck* x) { 559 if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) { 560 set_canonical(x->obj()); 561 } else { 562 Constant* con = x->obj()->as_Constant(); 563 if (con) { 564 ObjectType* c = con->type()->as_ObjectType(); 565 if (c && c->is_loaded()) { 566 ObjectConstant* oc = c->as_ObjectConstant(); 567 if (!oc || !oc->value()->is_null_object()) { 568 set_canonical(con); 569 } 570 } 571 } 572 } 573 } 574 575 void Canonicalizer::do_TypeCast (TypeCast* x) {} 576 void Canonicalizer::do_Invoke (Invoke* x) {} 577 void Canonicalizer::do_NewInstance (NewInstance* x) {} 578 void Canonicalizer::do_NewTypeArray (NewTypeArray* x) {} 579 void Canonicalizer::do_NewObjectArray (NewObjectArray* x) {} 580 void Canonicalizer::do_NewMultiArray (NewMultiArray* x) {} 581 void Canonicalizer::do_CheckCast (CheckCast* x) { 582 if (x->klass()->is_loaded()) { 583 Value obj = x->obj(); 584 ciType* klass = obj->exact_type(); 585 if (klass == NULL) klass = obj->declared_type(); 586 if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) { 587 set_canonical(obj); 588 return; 589 } 590 // checkcast of null returns null 591 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) { 592 set_canonical(obj); 593 } 594 } 595 } 596 void Canonicalizer::do_InstanceOf (InstanceOf* x) { 597 if (x->klass()->is_loaded()) { 598 Value obj = x->obj(); 599 ciType* exact = obj->exact_type(); 600 if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) { 601 set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0); 602 return; 603 } 604 // instanceof null returns false 605 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) { 606 set_constant(0); 607 } 608 } 609 610 } 611 void Canonicalizer::do_MonitorEnter (MonitorEnter* x) {} 612 void Canonicalizer::do_MonitorExit (MonitorExit* x) {} 613 void Canonicalizer::do_BlockBegin (BlockBegin* x) {} 614 void Canonicalizer::do_Goto (Goto* x) {} 615 616 617 static bool is_true(jlong x, If::Condition cond, jlong y) { 618 switch (cond) { 619 case If::eql: return x == y; 620 case If::neq: return x != y; 621 case If::lss: return x < y; 622 case If::leq: return x <= y; 623 case If::gtr: return x > y; 624 case If::geq: return x >= y; 625 } 626 ShouldNotReachHere(); 627 return false; 628 } 629 630 static bool is_safepoint(BlockEnd* x, BlockBegin* sux) { 631 // An Instruction with multiple successors, x, is replaced by a Goto 632 // to a single successor, sux. Is a safepoint check needed = was the 633 // instruction being replaced a safepoint and the single remaining 634 // successor a back branch? 635 return x->is_safepoint() && (sux->bci() < x->state_before()->bci()); 636 } 637 638 void Canonicalizer::do_If(If* x) { 639 // move const to right 640 if (x->x()->type()->is_constant()) x->swap_operands(); 641 // simplify 642 const Value l = x->x(); ValueType* lt = l->type(); 643 const Value r = x->y(); ValueType* rt = r->type(); 644 645 if (l == r && !lt->is_float_kind()) { 646 // pattern: If (a cond a) => simplify to Goto 647 BlockBegin* sux = NULL; 648 switch (x->cond()) { 649 case If::eql: sux = x->sux_for(true); break; 650 case If::neq: sux = x->sux_for(false); break; 651 case If::lss: sux = x->sux_for(false); break; 652 case If::leq: sux = x->sux_for(true); break; 653 case If::gtr: sux = x->sux_for(false); break; 654 case If::geq: sux = x->sux_for(true); break; 655 default: ShouldNotReachHere(); 656 } 657 // If is a safepoint then the debug information should come from the state_before of the If. 658 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 659 return; 660 } 661 662 if (lt->is_constant() && rt->is_constant()) { 663 if (x->x()->as_Constant() != NULL) { 664 // pattern: If (lc cond rc) => simplify to: Goto 665 BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(), 666 x->sux_for(true), 667 x->sux_for(false)); 668 if (sux != NULL) { 669 // If is a safepoint then the debug information should come from the state_before of the If. 670 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 671 } 672 } 673 } else if (rt->as_IntConstant() != NULL) { 674 // pattern: If (l cond rc) => investigate further 675 const jint rc = rt->as_IntConstant()->value(); 676 if (l->as_CompareOp() != NULL) { 677 // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto 678 CompareOp* cmp = l->as_CompareOp(); 679 bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl; 680 BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b 681 BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b 682 BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b 683 BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered 684 // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are 685 // equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either 686 // lss_sux or gtr_sux. 687 if (lss_sux == eql_sux && eql_sux == gtr_sux) { 688 // all successors identical => simplify to: Goto 689 set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint())); 690 } else { 691 // two successors differ and two successors are the same => simplify to: If (x cmp y) 692 // determine new condition & successors 693 If::Condition cond = If::eql; 694 BlockBegin* tsux = NULL; 695 BlockBegin* fsux = NULL; 696 if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; } 697 else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; } 698 else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; } 699 else { ShouldNotReachHere(); } 700 If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint()); 701 if (cmp->x() == cmp->y()) { 702 do_If(canon); 703 } else { 704 if (compilation()->profile_branches()) { 705 // TODO: If profiling, leave floating point comparisons unoptimized. 706 // We currently do not support profiling of the unordered case. 707 switch(cmp->op()) { 708 case Bytecodes::_fcmpl: case Bytecodes::_fcmpg: 709 case Bytecodes::_dcmpl: case Bytecodes::_dcmpg: 710 set_canonical(x); 711 return; 712 } 713 } 714 set_bci(cmp->state_before()->bci()); 715 set_canonical(canon); 716 } 717 } 718 } else if (l->as_InstanceOf() != NULL) { 719 // NOTE: Code permanently disabled for now since it leaves the old InstanceOf 720 // instruction in the graph (it is pinned). Need to fix this at some point. 721 // It should also be left in the graph when generating a profiled method version or Goto 722 // has to know that it was an InstanceOf. 723 return; 724 // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto 725 InstanceOf* inst = l->as_InstanceOf(); 726 BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1 727 BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0 728 if (is_inst_sux == no_inst_sux && inst->is_loaded()) { 729 // both successors identical and klass is loaded => simplify to: Goto 730 set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint())); 731 } else { 732 // successors differ => simplify to: IfInstanceOf 733 set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->state_before()->bci(), is_inst_sux, no_inst_sux)); 734 } 735 } 736 } else if (rt == objectNull && 737 (l->as_NewInstance() || l->as_NewArray() || 738 (l->as_Local() && l->as_Local()->is_receiver()))) { 739 if (x->cond() == Instruction::eql) { 740 BlockBegin* sux = x->fsux(); 741 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 742 } else { 743 assert(x->cond() == Instruction::neq, "only other valid case"); 744 BlockBegin* sux = x->tsux(); 745 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 746 } 747 } 748 } 749 750 751 void Canonicalizer::do_TableSwitch(TableSwitch* x) { 752 if (x->tag()->type()->is_constant()) { 753 int v = x->tag()->type()->as_IntConstant()->value(); 754 BlockBegin* sux = x->default_sux(); 755 if (v >= x->lo_key() && v <= x->hi_key()) { 756 sux = x->sux_at(v - x->lo_key()); 757 } 758 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 759 } else if (x->number_of_sux() == 1) { 760 // NOTE: Code permanently disabled for now since the switch statement's 761 // tag expression may produce side-effects in which case it must 762 // be executed. 763 return; 764 // simplify to Goto 765 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint())); 766 } else if (x->number_of_sux() == 2) { 767 // NOTE: Code permanently disabled for now since it produces two new nodes 768 // (Constant & If) and the Canonicalizer cannot return them correctly 769 // yet. For now we copied the corresponding code directly into the 770 // GraphBuilder (i.e., we should never reach here). 771 return; 772 // simplify to If 773 assert(x->lo_key() == x->hi_key(), "keys must be the same"); 774 Constant* key = new Constant(new IntConstant(x->lo_key())); 775 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint())); 776 } 777 } 778 779 780 void Canonicalizer::do_LookupSwitch(LookupSwitch* x) { 781 if (x->tag()->type()->is_constant()) { 782 int v = x->tag()->type()->as_IntConstant()->value(); 783 BlockBegin* sux = x->default_sux(); 784 for (int i = 0; i < x->length(); i++) { 785 if (v == x->key_at(i)) { 786 sux = x->sux_at(i); 787 } 788 } 789 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 790 } else if (x->number_of_sux() == 1) { 791 // NOTE: Code permanently disabled for now since the switch statement's 792 // tag expression may produce side-effects in which case it must 793 // be executed. 794 return; 795 // simplify to Goto 796 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint())); 797 } else if (x->number_of_sux() == 2) { 798 // NOTE: Code permanently disabled for now since it produces two new nodes 799 // (Constant & If) and the Canonicalizer cannot return them correctly 800 // yet. For now we copied the corresponding code directly into the 801 // GraphBuilder (i.e., we should never reach here). 802 return; 803 // simplify to If 804 assert(x->length() == 1, "length must be the same"); 805 Constant* key = new Constant(new IntConstant(x->key_at(0))); 806 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint())); 807 } 808 } 809 810 811 void Canonicalizer::do_Return (Return* x) {} 812 void Canonicalizer::do_Throw (Throw* x) {} 813 void Canonicalizer::do_Base (Base* x) {} 814 void Canonicalizer::do_OsrEntry (OsrEntry* x) {} 815 void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {} 816 817 static bool match_index_and_scale(Instruction* instr, 818 Instruction** index, 819 int* log2_scale) { 820 // Skip conversion ops. This works only on 32bit because of the implicit l2i that the 821 // unsafe performs. 822 #ifndef _LP64 823 Convert* convert = instr->as_Convert(); 824 if (convert != NULL && convert->op() == Bytecodes::_i2l) { 825 assert(convert->value()->type() == intType, "invalid input type"); 826 instr = convert->value(); 827 } 828 #endif 829 830 ShiftOp* shift = instr->as_ShiftOp(); 831 if (shift != NULL) { 832 if (shift->op() == Bytecodes::_lshl) { 833 assert(shift->x()->type() == longType, "invalid input type"); 834 } else { 835 #ifndef _LP64 836 if (shift->op() == Bytecodes::_ishl) { 837 assert(shift->x()->type() == intType, "invalid input type"); 838 } else { 839 return false; 840 } 841 #else 842 return false; 843 #endif 844 } 845 846 847 // Constant shift value? 848 Constant* con = shift->y()->as_Constant(); 849 if (con == NULL) return false; 850 // Well-known type and value? 851 IntConstant* val = con->type()->as_IntConstant(); 852 assert(val != NULL, "Should be an int constant"); 853 854 *index = shift->x(); 855 int tmp_scale = val->value(); 856 if (tmp_scale >= 0 && tmp_scale < 4) { 857 *log2_scale = tmp_scale; 858 return true; 859 } else { 860 return false; 861 } 862 } 863 864 ArithmeticOp* arith = instr->as_ArithmeticOp(); 865 if (arith != NULL) { 866 // See if either arg is a known constant 867 Constant* con = arith->x()->as_Constant(); 868 if (con != NULL) { 869 *index = arith->y(); 870 } else { 871 con = arith->y()->as_Constant(); 872 if (con == NULL) return false; 873 *index = arith->x(); 874 } 875 long const_value; 876 // Check for integer multiply 877 if (arith->op() == Bytecodes::_lmul) { 878 assert((*index)->type() == longType, "invalid input type"); 879 LongConstant* val = con->type()->as_LongConstant(); 880 assert(val != NULL, "expecting a long constant"); 881 const_value = val->value(); 882 } else { 883 #ifndef _LP64 884 if (arith->op() == Bytecodes::_imul) { 885 assert((*index)->type() == intType, "invalid input type"); 886 IntConstant* val = con->type()->as_IntConstant(); 887 assert(val != NULL, "expecting an int constant"); 888 const_value = val->value(); 889 } else { 890 return false; 891 } 892 #else 893 return false; 894 #endif 895 } 896 switch (const_value) { 897 case 1: *log2_scale = 0; return true; 898 case 2: *log2_scale = 1; return true; 899 case 4: *log2_scale = 2; return true; 900 case 8: *log2_scale = 3; return true; 901 default: return false; 902 } 903 } 904 905 // Unknown instruction sequence; don't touch it 906 return false; 907 } 908 909 910 static bool match(UnsafeRawOp* x, 911 Instruction** base, 912 Instruction** index, 913 int* log2_scale) { 914 ArithmeticOp* root = x->base()->as_ArithmeticOp(); 915 if (root == NULL) return false; 916 // Limit ourselves to addition for now 917 if (root->op() != Bytecodes::_ladd) return false; 918 919 bool match_found = false; 920 // Try to find shift or scale op 921 if (match_index_and_scale(root->y(), index, log2_scale)) { 922 *base = root->x(); 923 match_found = true; 924 } else if (match_index_and_scale(root->x(), index, log2_scale)) { 925 *base = root->y(); 926 match_found = true; 927 } else if (NOT_LP64(root->y()->as_Convert() != NULL) LP64_ONLY(false)) { 928 // Skipping i2l works only on 32bit because of the implicit l2i that the unsafe performs. 929 // 64bit needs a real sign-extending conversion. 930 Convert* convert = root->y()->as_Convert(); 931 if (convert->op() == Bytecodes::_i2l) { 932 assert(convert->value()->type() == intType, "should be an int"); 933 // pick base and index, setting scale at 1 934 *base = root->x(); 935 *index = convert->value(); 936 *log2_scale = 0; 937 match_found = true; 938 } 939 } 940 // The default solution 941 if (!match_found) { 942 *base = root->x(); 943 *index = root->y(); 944 *log2_scale = 0; 945 } 946 947 // If the value is pinned then it will be always be computed so 948 // there's no profit to reshaping the expression. 949 return !root->is_pinned(); 950 } 951 952 953 void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) { 954 Instruction* base = NULL; 955 Instruction* index = NULL; 956 int log2_scale; 957 958 if (match(x, &base, &index, &log2_scale)) { 959 x->set_base(base); 960 x->set_index(index); 961 x->set_log2_scale(log2_scale); 962 if (PrintUnsafeOptimization) { 963 tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d", 964 x->id(), x->base()->id(), x->index()->id(), x->log2_scale()); 965 } 966 } 967 } 968 969 void Canonicalizer::do_RoundFP(RoundFP* x) {} 970 void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); } 971 void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); } 972 void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {} 973 void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {} 974 void Canonicalizer::do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) {} 975 void Canonicalizer::do_ProfileCall(ProfileCall* x) {} 976 void Canonicalizer::do_ProfileReturnType(ProfileReturnType* x) {} 977 void Canonicalizer::do_ProfileInvoke(ProfileInvoke* x) {} 978 void Canonicalizer::do_RuntimeCall(RuntimeCall* x) {} 979 void Canonicalizer::do_RangeCheckPredicate(RangeCheckPredicate* x) {} 980 #ifdef ASSERT 981 void Canonicalizer::do_Assert(Assert* x) {} 982 #endif 983 void Canonicalizer::do_MemBar(MemBar* x) {}