1 /* 2 * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "c1/c1_Canonicalizer.hpp" 27 #include "c1/c1_InstructionPrinter.hpp" 28 #include "c1/c1_ValueStack.hpp" 29 #include "ci/ciArray.hpp" 30 #include "runtime/sharedRuntime.hpp" 31 32 33 class PrintValueVisitor: public ValueVisitor { 34 void visit(Value* vp) { 35 (*vp)->print_line(); 36 } 37 }; 38 39 void Canonicalizer::set_canonical(Value x) { 40 assert(x != NULL, "value must exist"); 41 // Note: we can not currently substitute root nodes which show up in 42 // the instruction stream (because the instruction list is embedded 43 // in the instructions). 44 if (canonical() != x) { 45 #ifndef PRODUCT 46 if (!x->has_printable_bci()) { 47 x->set_printable_bci(bci()); 48 } 49 #endif 50 if (PrintCanonicalization) { 51 PrintValueVisitor do_print_value; 52 canonical()->input_values_do(&do_print_value); 53 canonical()->print_line(); 54 tty->print_cr("canonicalized to:"); 55 x->input_values_do(&do_print_value); 56 x->print_line(); 57 tty->cr(); 58 } 59 assert(_canonical->type()->tag() == x->type()->tag(), "types must match"); 60 _canonical = x; 61 } 62 } 63 64 65 void Canonicalizer::move_const_to_right(Op2* x) { 66 if (x->x()->type()->is_constant() && x->is_commutative()) x->swap_operands(); 67 } 68 69 70 void Canonicalizer::do_Op2(Op2* x) { 71 if (x->x() == x->y()) { 72 switch (x->op()) { 73 case Bytecodes::_isub: set_constant(0); return; 74 case Bytecodes::_lsub: set_constant(jlong_cast(0)); return; 75 case Bytecodes::_iand: // fall through 76 case Bytecodes::_land: // fall through 77 case Bytecodes::_ior: // fall through 78 case Bytecodes::_lor : set_canonical(x->x()); return; 79 case Bytecodes::_ixor: set_constant(0); return; 80 case Bytecodes::_lxor: set_constant(jlong_cast(0)); return; 81 } 82 } 83 84 if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) { 85 // do constant folding for selected operations 86 switch (x->type()->tag()) { 87 case intTag: 88 { jint a = x->x()->type()->as_IntConstant()->value(); 89 jint b = x->y()->type()->as_IntConstant()->value(); 90 switch (x->op()) { 91 case Bytecodes::_iadd: set_constant(a + b); return; 92 case Bytecodes::_isub: set_constant(a - b); return; 93 case Bytecodes::_imul: set_constant(a * b); return; 94 case Bytecodes::_idiv: 95 if (b != 0) { 96 if (a == min_jint && b == -1) { 97 set_constant(min_jint); 98 } else { 99 set_constant(a / b); 100 } 101 return; 102 } 103 break; 104 case Bytecodes::_irem: 105 if (b != 0) { 106 if (a == min_jint && b == -1) { 107 set_constant(0); 108 } else { 109 set_constant(a % b); 110 } 111 return; 112 } 113 break; 114 case Bytecodes::_iand: set_constant(a & b); return; 115 case Bytecodes::_ior : set_constant(a | b); return; 116 case Bytecodes::_ixor: set_constant(a ^ b); return; 117 } 118 } 119 break; 120 case longTag: 121 { jlong a = x->x()->type()->as_LongConstant()->value(); 122 jlong b = x->y()->type()->as_LongConstant()->value(); 123 switch (x->op()) { 124 case Bytecodes::_ladd: set_constant(a + b); return; 125 case Bytecodes::_lsub: set_constant(a - b); return; 126 case Bytecodes::_lmul: set_constant(a * b); return; 127 case Bytecodes::_ldiv: 128 if (b != 0) { 129 set_constant(SharedRuntime::ldiv(b, a)); 130 return; 131 } 132 break; 133 case Bytecodes::_lrem: 134 if (b != 0) { 135 set_constant(SharedRuntime::lrem(b, a)); 136 return; 137 } 138 break; 139 case Bytecodes::_land: set_constant(a & b); return; 140 case Bytecodes::_lor : set_constant(a | b); return; 141 case Bytecodes::_lxor: set_constant(a ^ b); return; 142 } 143 } 144 break; 145 // other cases not implemented (must be extremely careful with floats & doubles!) 146 } 147 } 148 // make sure constant is on the right side, if any 149 move_const_to_right(x); 150 151 if (x->y()->type()->is_constant()) { 152 // do constant folding for selected operations 153 switch (x->type()->tag()) { 154 case intTag: 155 if (x->y()->type()->as_IntConstant()->value() == 0) { 156 switch (x->op()) { 157 case Bytecodes::_iadd: set_canonical(x->x()); return; 158 case Bytecodes::_isub: set_canonical(x->x()); return; 159 case Bytecodes::_imul: set_constant(0); return; 160 // Note: for div and rem, make sure that C semantics 161 // corresponds to Java semantics! 162 case Bytecodes::_iand: set_constant(0); return; 163 case Bytecodes::_ior : set_canonical(x->x()); return; 164 } 165 } 166 break; 167 case longTag: 168 if (x->y()->type()->as_LongConstant()->value() == (jlong)0) { 169 switch (x->op()) { 170 case Bytecodes::_ladd: set_canonical(x->x()); return; 171 case Bytecodes::_lsub: set_canonical(x->x()); return; 172 case Bytecodes::_lmul: set_constant((jlong)0); return; 173 // Note: for div and rem, make sure that C semantics 174 // corresponds to Java semantics! 175 case Bytecodes::_land: set_constant((jlong)0); return; 176 case Bytecodes::_lor : set_canonical(x->x()); return; 177 } 178 } 179 break; 180 } 181 } 182 } 183 184 185 void Canonicalizer::do_Phi (Phi* x) {} 186 void Canonicalizer::do_Constant (Constant* x) {} 187 void Canonicalizer::do_Local (Local* x) {} 188 void Canonicalizer::do_LoadField (LoadField* x) {} 189 190 // checks if v is in the block that is currently processed by 191 // GraphBuilder. This is the only block that has not BlockEnd yet. 192 static bool in_current_block(Value v) { 193 int max_distance = 4; 194 while (max_distance > 0 && v != NULL && v->as_BlockEnd() == NULL) { 195 v = v->next(); 196 max_distance--; 197 } 198 return v == NULL; 199 } 200 201 void Canonicalizer::do_StoreField (StoreField* x) { 202 // If a value is going to be stored into a field or array some of 203 // the conversions emitted by javac are unneeded because the fields 204 // are packed to their natural size. 205 Convert* conv = x->value()->as_Convert(); 206 if (conv) { 207 Value value = NULL; 208 BasicType type = x->field()->type()->basic_type(); 209 switch (conv->op()) { 210 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break; 211 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break; 212 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break; 213 } 214 // limit this optimization to current block 215 if (value != NULL && in_current_block(conv)) { 216 set_canonical(new StoreField(x->obj(), x->offset(), x->field(), value, x->is_static(), 217 x->state_before(), x->needs_patching())); 218 return; 219 } 220 } 221 222 } 223 224 void Canonicalizer::do_ArrayLength (ArrayLength* x) { 225 NewArray* na; 226 Constant* ct; 227 LoadField* lf; 228 229 if ((na = x->array()->as_NewArray()) != NULL) { 230 // New arrays might have the known length. 231 // Do not use the Constant itself, but create a new Constant 232 // with same value Otherwise a Constant is live over multiple 233 // blocks without being registered in a state array. 234 Constant* length; 235 if (na->length() != NULL && 236 (length = na->length()->as_Constant()) != NULL) { 237 assert(length->type()->as_IntConstant() != NULL, "array length must be integer"); 238 set_constant(length->type()->as_IntConstant()->value()); 239 } 240 241 } else if ((ct = x->array()->as_Constant()) != NULL) { 242 // Constant arrays have constant lengths. 243 ArrayConstant* cnst = ct->type()->as_ArrayConstant(); 244 if (cnst != NULL) { 245 set_constant(cnst->value()->length()); 246 } 247 248 } else if ((lf = x->array()->as_LoadField()) != NULL) { 249 ciField* field = lf->field(); 250 if (field->is_static_constant()) { 251 assert(PatchALot || ScavengeRootsInCode < 2, "Constant field loads are folded during parsing"); 252 ciObject* c = field->constant_value().as_object(); 253 if (!c->is_null_object()) { 254 set_constant(c->as_array()->length()); 255 } 256 } 257 } 258 } 259 260 void Canonicalizer::do_LoadIndexed (LoadIndexed* x) { 261 StableArrayConstant* array = x->array()->type()->as_StableArrayConstant(); 262 IntConstant* index = x->index()->type()->as_IntConstant(); 263 264 assert(array == NULL || FoldStableValues, "not enabled"); 265 266 // Constant fold loads from stable arrays. 267 if (array != NULL && index != NULL) { 268 jint idx = index->value(); 269 if (idx < 0 || idx >= array->value()->length()) { 270 // Leave the load as is. The range check will handle it. 271 return; 272 } 273 274 ciConstant field_val = array->value()->element_value(idx, x->elt_type()); 275 if (!field_val.is_null_or_zero()) { 276 jint dimension = array->dimension(); 277 assert(dimension <= array->value()->array_type()->dimension(), "inconsistent info"); 278 ValueType* value = NULL; 279 if (dimension > 1) { 280 // Preserve information about the dimension for the element. 281 assert(x->elt_type() == array->value()->element_basic_type(), "should not be mismatched"); 282 assert(field_val.as_object()->is_array(), "not an array"); 283 value = new StableArrayConstant(field_val.as_object()->as_array(), dimension - 1); 284 } else { 285 assert(dimension == 1, "sanity"); 286 value = as_ValueType(field_val); 287 } 288 set_canonical(new Constant(value)); 289 } 290 } 291 } 292 293 void Canonicalizer::do_StoreIndexed (StoreIndexed* x) { 294 // If a value is going to be stored into a field or array some of 295 // the conversions emitted by javac are unneeded because the fields 296 // are packed to their natural size. 297 Convert* conv = x->value()->as_Convert(); 298 if (conv) { 299 Value value = NULL; 300 BasicType type = x->elt_type(); 301 switch (conv->op()) { 302 case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break; 303 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break; 304 case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break; 305 } 306 // limit this optimization to current block 307 if (value != NULL && in_current_block(conv)) { 308 set_canonical(new StoreIndexed(x->array(), x->index(), x->length(), 309 x->elt_type(), value, x->state_before(), 310 x->check_boolean())); 311 return; 312 } 313 } 314 } 315 316 317 void Canonicalizer::do_NegateOp(NegateOp* x) { 318 ValueType* t = x->x()->type(); 319 if (t->is_constant()) { 320 switch (t->tag()) { 321 case intTag : set_constant(-t->as_IntConstant ()->value()); return; 322 case longTag : set_constant(-t->as_LongConstant ()->value()); return; 323 case floatTag : set_constant(-t->as_FloatConstant ()->value()); return; 324 case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return; 325 default : ShouldNotReachHere(); 326 } 327 } 328 } 329 330 331 void Canonicalizer::do_ArithmeticOp (ArithmeticOp* x) { do_Op2(x); } 332 333 334 void Canonicalizer::do_ShiftOp (ShiftOp* x) { 335 ValueType* t = x->x()->type(); 336 ValueType* t2 = x->y()->type(); 337 if (t->is_constant()) { 338 switch (t->tag()) { 339 case intTag : if (t->as_IntConstant()->value() == 0) { set_constant(0); return; } break; 340 case longTag : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break; 341 default : ShouldNotReachHere(); 342 } 343 if (t2->is_constant()) { 344 if (t->tag() == intTag) { 345 int value = t->as_IntConstant()->value(); 346 int shift = t2->as_IntConstant()->value() & 31; 347 jint mask = ~(~0 << (32 - shift)); 348 if (shift == 0) mask = ~0; 349 switch (x->op()) { 350 case Bytecodes::_ishl: set_constant(value << shift); return; 351 case Bytecodes::_ishr: set_constant(value >> shift); return; 352 case Bytecodes::_iushr: set_constant((value >> shift) & mask); return; 353 } 354 } else if (t->tag() == longTag) { 355 jlong value = t->as_LongConstant()->value(); 356 int shift = t2->as_IntConstant()->value() & 63; 357 jlong mask = ~(~jlong_cast(0) << (64 - shift)); 358 if (shift == 0) mask = ~jlong_cast(0); 359 switch (x->op()) { 360 case Bytecodes::_lshl: set_constant(value << shift); return; 361 case Bytecodes::_lshr: set_constant(value >> shift); return; 362 case Bytecodes::_lushr: set_constant((value >> shift) & mask); return; 363 } 364 } 365 } 366 } 367 if (t2->is_constant()) { 368 switch (t2->tag()) { 369 case intTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return; 370 case longTag : if (t2->as_LongConstant()->value() == (jlong)0) set_canonical(x->x()); return; 371 default : ShouldNotReachHere(); 372 } 373 } 374 } 375 376 377 void Canonicalizer::do_LogicOp (LogicOp* x) { do_Op2(x); } 378 void Canonicalizer::do_CompareOp (CompareOp* x) { 379 if (x->x() == x->y()) { 380 switch (x->x()->type()->tag()) { 381 case longTag: set_constant(0); break; 382 case floatTag: { 383 FloatConstant* fc = x->x()->type()->as_FloatConstant(); 384 if (fc) { 385 if (g_isnan(fc->value())) { 386 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1); 387 } else { 388 set_constant(0); 389 } 390 } 391 break; 392 } 393 case doubleTag: { 394 DoubleConstant* dc = x->x()->type()->as_DoubleConstant(); 395 if (dc) { 396 if (g_isnan(dc->value())) { 397 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1); 398 } else { 399 set_constant(0); 400 } 401 } 402 break; 403 } 404 } 405 } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) { 406 switch (x->x()->type()->tag()) { 407 case longTag: { 408 jlong vx = x->x()->type()->as_LongConstant()->value(); 409 jlong vy = x->y()->type()->as_LongConstant()->value(); 410 if (vx == vy) 411 set_constant(0); 412 else if (vx < vy) 413 set_constant(-1); 414 else 415 set_constant(1); 416 break; 417 } 418 419 case floatTag: { 420 float vx = x->x()->type()->as_FloatConstant()->value(); 421 float vy = x->y()->type()->as_FloatConstant()->value(); 422 if (g_isnan(vx) || g_isnan(vy)) 423 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1); 424 else if (vx == vy) 425 set_constant(0); 426 else if (vx < vy) 427 set_constant(-1); 428 else 429 set_constant(1); 430 break; 431 } 432 433 case doubleTag: { 434 double vx = x->x()->type()->as_DoubleConstant()->value(); 435 double vy = x->y()->type()->as_DoubleConstant()->value(); 436 if (g_isnan(vx) || g_isnan(vy)) 437 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1); 438 else if (vx == vy) 439 set_constant(0); 440 else if (vx < vy) 441 set_constant(-1); 442 else 443 set_constant(1); 444 break; 445 } 446 } 447 448 } 449 } 450 451 452 void Canonicalizer::do_IfInstanceOf(IfInstanceOf* x) {} 453 454 void Canonicalizer::do_IfOp(IfOp* x) { 455 // Caution: do not use do_Op2(x) here for now since 456 // we map the condition to the op for now! 457 move_const_to_right(x); 458 } 459 460 461 void Canonicalizer::do_Intrinsic (Intrinsic* x) { 462 switch (x->id()) { 463 case vmIntrinsics::_floatToRawIntBits : { 464 FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant(); 465 if (c != NULL) { 466 JavaValue v; 467 v.set_jfloat(c->value()); 468 set_constant(v.get_jint()); 469 } 470 break; 471 } 472 case vmIntrinsics::_intBitsToFloat : { 473 IntConstant* c = x->argument_at(0)->type()->as_IntConstant(); 474 if (c != NULL) { 475 JavaValue v; 476 v.set_jint(c->value()); 477 set_constant(v.get_jfloat()); 478 } 479 break; 480 } 481 case vmIntrinsics::_doubleToRawLongBits : { 482 DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant(); 483 if (c != NULL) { 484 JavaValue v; 485 v.set_jdouble(c->value()); 486 set_constant(v.get_jlong()); 487 } 488 break; 489 } 490 case vmIntrinsics::_longBitsToDouble : { 491 LongConstant* c = x->argument_at(0)->type()->as_LongConstant(); 492 if (c != NULL) { 493 JavaValue v; 494 v.set_jlong(c->value()); 495 set_constant(v.get_jdouble()); 496 } 497 break; 498 } 499 case vmIntrinsics::_isInstance : { 500 assert(x->number_of_arguments() == 2, "wrong type"); 501 502 InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant(); 503 if (c != NULL && !c->value()->is_null_object()) { 504 // ciInstance::java_mirror_type() returns non-NULL only for Java mirrors 505 ciType* t = c->value()->java_mirror_type(); 506 if (t->is_klass()) { 507 // substitute cls.isInstance(obj) of a constant Class into 508 // an InstantOf instruction 509 InstanceOf* i = new InstanceOf(t->as_klass(), x->argument_at(1), x->state_before()); 510 set_canonical(i); 511 // and try to canonicalize even further 512 do_InstanceOf(i); 513 } else { 514 assert(t->is_primitive_type(), "should be a primitive type"); 515 // cls.isInstance(obj) always returns false for primitive classes 516 set_constant(0); 517 } 518 } 519 break; 520 } 521 case vmIntrinsics::_isPrimitive : { 522 assert(x->number_of_arguments() == 1, "wrong type"); 523 524 // Class.isPrimitive is known on constant classes: 525 InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant(); 526 if (c != NULL && !c->value()->is_null_object()) { 527 ciType* t = c->value()->java_mirror_type(); 528 set_constant(t->is_primitive_type()); 529 } 530 break; 531 } 532 } 533 } 534 535 void Canonicalizer::do_Convert (Convert* x) { 536 if (x->value()->type()->is_constant()) { 537 switch (x->op()) { 538 case Bytecodes::_i2b: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break; 539 case Bytecodes::_i2s: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break; 540 case Bytecodes::_i2c: set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break; 541 case Bytecodes::_i2l: set_constant((jlong)(x->value()->type()->as_IntConstant()->value())); break; 542 case Bytecodes::_i2f: set_constant((float)(x->value()->type()->as_IntConstant()->value())); break; 543 case Bytecodes::_i2d: set_constant((double)(x->value()->type()->as_IntConstant()->value())); break; 544 case Bytecodes::_l2i: set_constant((int)(x->value()->type()->as_LongConstant()->value())); break; 545 case Bytecodes::_l2f: set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break; 546 case Bytecodes::_l2d: set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break; 547 case Bytecodes::_f2d: set_constant((double)(x->value()->type()->as_FloatConstant()->value())); break; 548 case Bytecodes::_f2i: set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break; 549 case Bytecodes::_f2l: set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break; 550 case Bytecodes::_d2f: set_constant((float)(x->value()->type()->as_DoubleConstant()->value())); break; 551 case Bytecodes::_d2i: set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break; 552 case Bytecodes::_d2l: set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break; 553 default: 554 ShouldNotReachHere(); 555 } 556 } 557 558 Value value = x->value(); 559 BasicType type = T_ILLEGAL; 560 LoadField* lf = value->as_LoadField(); 561 if (lf) { 562 type = lf->field_type(); 563 } else { 564 LoadIndexed* li = value->as_LoadIndexed(); 565 if (li) { 566 type = li->elt_type(); 567 } else { 568 Convert* conv = value->as_Convert(); 569 if (conv) { 570 switch (conv->op()) { 571 case Bytecodes::_i2b: type = T_BYTE; break; 572 case Bytecodes::_i2s: type = T_SHORT; break; 573 case Bytecodes::_i2c: type = T_CHAR; break; 574 } 575 } 576 } 577 } 578 if (type != T_ILLEGAL) { 579 switch (x->op()) { 580 case Bytecodes::_i2b: if (type == T_BYTE) set_canonical(x->value()); break; 581 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break; 582 case Bytecodes::_i2c: if (type == T_CHAR) set_canonical(x->value()); break; 583 } 584 } else { 585 Op2* op2 = x->value()->as_Op2(); 586 if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) { 587 jint safebits = 0; 588 jint mask = op2->y()->type()->as_IntConstant()->value(); 589 switch (x->op()) { 590 case Bytecodes::_i2b: safebits = 0x7f; break; 591 case Bytecodes::_i2s: safebits = 0x7fff; break; 592 case Bytecodes::_i2c: safebits = 0xffff; break; 593 } 594 // When casting a masked integer to a smaller signed type, if 595 // the mask doesn't include the sign bit the cast isn't needed. 596 if (safebits && (mask & ~safebits) == 0) { 597 set_canonical(x->value()); 598 } 599 } 600 } 601 602 } 603 604 void Canonicalizer::do_NullCheck (NullCheck* x) { 605 if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) { 606 set_canonical(x->obj()); 607 } else { 608 Constant* con = x->obj()->as_Constant(); 609 if (con) { 610 ObjectType* c = con->type()->as_ObjectType(); 611 if (c && c->is_loaded()) { 612 ObjectConstant* oc = c->as_ObjectConstant(); 613 if (!oc || !oc->value()->is_null_object()) { 614 set_canonical(con); 615 } 616 } 617 } 618 } 619 } 620 621 void Canonicalizer::do_TypeCast (TypeCast* x) {} 622 void Canonicalizer::do_Invoke (Invoke* x) {} 623 void Canonicalizer::do_NewInstance (NewInstance* x) {} 624 void Canonicalizer::do_NewTypeArray (NewTypeArray* x) {} 625 void Canonicalizer::do_NewObjectArray (NewObjectArray* x) {} 626 void Canonicalizer::do_NewMultiArray (NewMultiArray* x) {} 627 void Canonicalizer::do_CheckCast (CheckCast* x) { 628 if (x->klass()->is_loaded()) { 629 Value obj = x->obj(); 630 ciType* klass = obj->exact_type(); 631 if (klass == NULL) klass = obj->declared_type(); 632 if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) { 633 set_canonical(obj); 634 return; 635 } 636 // checkcast of null returns null 637 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) { 638 set_canonical(obj); 639 } 640 } 641 } 642 void Canonicalizer::do_InstanceOf (InstanceOf* x) { 643 if (x->klass()->is_loaded()) { 644 Value obj = x->obj(); 645 ciType* exact = obj->exact_type(); 646 if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) { 647 set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0); 648 return; 649 } 650 // instanceof null returns false 651 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) { 652 set_constant(0); 653 } 654 } 655 656 } 657 void Canonicalizer::do_MonitorEnter (MonitorEnter* x) {} 658 void Canonicalizer::do_MonitorExit (MonitorExit* x) {} 659 void Canonicalizer::do_BlockBegin (BlockBegin* x) {} 660 void Canonicalizer::do_Goto (Goto* x) {} 661 662 663 static bool is_true(jlong x, If::Condition cond, jlong y) { 664 switch (cond) { 665 case If::eql: return x == y; 666 case If::neq: return x != y; 667 case If::lss: return x < y; 668 case If::leq: return x <= y; 669 case If::gtr: return x > y; 670 case If::geq: return x >= y; 671 } 672 ShouldNotReachHere(); 673 return false; 674 } 675 676 static bool is_safepoint(BlockEnd* x, BlockBegin* sux) { 677 // An Instruction with multiple successors, x, is replaced by a Goto 678 // to a single successor, sux. Is a safepoint check needed = was the 679 // instruction being replaced a safepoint and the single remaining 680 // successor a back branch? 681 return x->is_safepoint() && (sux->bci() < x->state_before()->bci()); 682 } 683 684 void Canonicalizer::do_If(If* x) { 685 // move const to right 686 if (x->x()->type()->is_constant()) x->swap_operands(); 687 // simplify 688 const Value l = x->x(); ValueType* lt = l->type(); 689 const Value r = x->y(); ValueType* rt = r->type(); 690 691 if (l == r && !lt->is_float_kind()) { 692 // pattern: If (a cond a) => simplify to Goto 693 BlockBegin* sux = NULL; 694 switch (x->cond()) { 695 case If::eql: sux = x->sux_for(true); break; 696 case If::neq: sux = x->sux_for(false); break; 697 case If::lss: sux = x->sux_for(false); break; 698 case If::leq: sux = x->sux_for(true); break; 699 case If::gtr: sux = x->sux_for(false); break; 700 case If::geq: sux = x->sux_for(true); break; 701 default: ShouldNotReachHere(); 702 } 703 // If is a safepoint then the debug information should come from the state_before of the If. 704 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 705 return; 706 } 707 708 if (lt->is_constant() && rt->is_constant()) { 709 if (x->x()->as_Constant() != NULL) { 710 // pattern: If (lc cond rc) => simplify to: Goto 711 BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(), 712 x->sux_for(true), 713 x->sux_for(false)); 714 if (sux != NULL) { 715 // If is a safepoint then the debug information should come from the state_before of the If. 716 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 717 } 718 } 719 } else if (rt->as_IntConstant() != NULL) { 720 // pattern: If (l cond rc) => investigate further 721 const jint rc = rt->as_IntConstant()->value(); 722 if (l->as_CompareOp() != NULL) { 723 // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto 724 CompareOp* cmp = l->as_CompareOp(); 725 bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl; 726 BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b 727 BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b 728 BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b 729 BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered 730 // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are 731 // equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either 732 // lss_sux or gtr_sux. 733 if (lss_sux == eql_sux && eql_sux == gtr_sux) { 734 // all successors identical => simplify to: Goto 735 set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint())); 736 } else { 737 // two successors differ and two successors are the same => simplify to: If (x cmp y) 738 // determine new condition & successors 739 If::Condition cond = If::eql; 740 BlockBegin* tsux = NULL; 741 BlockBegin* fsux = NULL; 742 if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; } 743 else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; } 744 else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; } 745 else { ShouldNotReachHere(); } 746 If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint()); 747 if (cmp->x() == cmp->y()) { 748 do_If(canon); 749 } else { 750 if (compilation()->profile_branches()) { 751 // TODO: If profiling, leave floating point comparisons unoptimized. 752 // We currently do not support profiling of the unordered case. 753 switch(cmp->op()) { 754 case Bytecodes::_fcmpl: case Bytecodes::_fcmpg: 755 case Bytecodes::_dcmpl: case Bytecodes::_dcmpg: 756 set_canonical(x); 757 return; 758 } 759 } 760 set_bci(cmp->state_before()->bci()); 761 set_canonical(canon); 762 } 763 } 764 } else if (l->as_InstanceOf() != NULL) { 765 // NOTE: Code permanently disabled for now since it leaves the old InstanceOf 766 // instruction in the graph (it is pinned). Need to fix this at some point. 767 // It should also be left in the graph when generating a profiled method version or Goto 768 // has to know that it was an InstanceOf. 769 return; 770 // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto 771 InstanceOf* inst = l->as_InstanceOf(); 772 BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1 773 BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0 774 if (is_inst_sux == no_inst_sux && inst->is_loaded()) { 775 // both successors identical and klass is loaded => simplify to: Goto 776 set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint())); 777 } else { 778 // successors differ => simplify to: IfInstanceOf 779 set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->state_before()->bci(), is_inst_sux, no_inst_sux)); 780 } 781 } 782 } else if (rt == objectNull && 783 (l->as_NewInstance() || l->as_NewArray() || 784 (l->as_Local() && l->as_Local()->is_receiver()))) { 785 if (x->cond() == Instruction::eql) { 786 BlockBegin* sux = x->fsux(); 787 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 788 } else { 789 assert(x->cond() == Instruction::neq, "only other valid case"); 790 BlockBegin* sux = x->tsux(); 791 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 792 } 793 } 794 } 795 796 797 void Canonicalizer::do_TableSwitch(TableSwitch* x) { 798 if (x->tag()->type()->is_constant()) { 799 int v = x->tag()->type()->as_IntConstant()->value(); 800 BlockBegin* sux = x->default_sux(); 801 if (v >= x->lo_key() && v <= x->hi_key()) { 802 sux = x->sux_at(v - x->lo_key()); 803 } 804 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 805 } else if (x->number_of_sux() == 1) { 806 // NOTE: Code permanently disabled for now since the switch statement's 807 // tag expression may produce side-effects in which case it must 808 // be executed. 809 return; 810 // simplify to Goto 811 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint())); 812 } else if (x->number_of_sux() == 2) { 813 // NOTE: Code permanently disabled for now since it produces two new nodes 814 // (Constant & If) and the Canonicalizer cannot return them correctly 815 // yet. For now we copied the corresponding code directly into the 816 // GraphBuilder (i.e., we should never reach here). 817 return; 818 // simplify to If 819 assert(x->lo_key() == x->hi_key(), "keys must be the same"); 820 Constant* key = new Constant(new IntConstant(x->lo_key())); 821 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint())); 822 } 823 } 824 825 826 void Canonicalizer::do_LookupSwitch(LookupSwitch* x) { 827 if (x->tag()->type()->is_constant()) { 828 int v = x->tag()->type()->as_IntConstant()->value(); 829 BlockBegin* sux = x->default_sux(); 830 for (int i = 0; i < x->length(); i++) { 831 if (v == x->key_at(i)) { 832 sux = x->sux_at(i); 833 } 834 } 835 set_canonical(new Goto(sux, x->state_before(), is_safepoint(x, sux))); 836 } else if (x->number_of_sux() == 1) { 837 // NOTE: Code permanently disabled for now since the switch statement's 838 // tag expression may produce side-effects in which case it must 839 // be executed. 840 return; 841 // simplify to Goto 842 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint())); 843 } else if (x->number_of_sux() == 2) { 844 // NOTE: Code permanently disabled for now since it produces two new nodes 845 // (Constant & If) and the Canonicalizer cannot return them correctly 846 // yet. For now we copied the corresponding code directly into the 847 // GraphBuilder (i.e., we should never reach here). 848 return; 849 // simplify to If 850 assert(x->length() == 1, "length must be the same"); 851 Constant* key = new Constant(new IntConstant(x->key_at(0))); 852 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint())); 853 } 854 } 855 856 857 void Canonicalizer::do_Return (Return* x) {} 858 void Canonicalizer::do_Throw (Throw* x) {} 859 void Canonicalizer::do_Base (Base* x) {} 860 void Canonicalizer::do_OsrEntry (OsrEntry* x) {} 861 void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {} 862 863 static bool match_index_and_scale(Instruction* instr, 864 Instruction** index, 865 int* log2_scale) { 866 // Skip conversion ops. This works only on 32bit because of the implicit l2i that the 867 // unsafe performs. 868 #ifndef _LP64 869 Convert* convert = instr->as_Convert(); 870 if (convert != NULL && convert->op() == Bytecodes::_i2l) { 871 assert(convert->value()->type() == intType, "invalid input type"); 872 instr = convert->value(); 873 } 874 #endif 875 876 ShiftOp* shift = instr->as_ShiftOp(); 877 if (shift != NULL) { 878 if (shift->op() == Bytecodes::_lshl) { 879 assert(shift->x()->type() == longType, "invalid input type"); 880 } else { 881 #ifndef _LP64 882 if (shift->op() == Bytecodes::_ishl) { 883 assert(shift->x()->type() == intType, "invalid input type"); 884 } else { 885 return false; 886 } 887 #else 888 return false; 889 #endif 890 } 891 892 893 // Constant shift value? 894 Constant* con = shift->y()->as_Constant(); 895 if (con == NULL) return false; 896 // Well-known type and value? 897 IntConstant* val = con->type()->as_IntConstant(); 898 assert(val != NULL, "Should be an int constant"); 899 900 *index = shift->x(); 901 int tmp_scale = val->value(); 902 if (tmp_scale >= 0 && tmp_scale < 4) { 903 *log2_scale = tmp_scale; 904 return true; 905 } else { 906 return false; 907 } 908 } 909 910 ArithmeticOp* arith = instr->as_ArithmeticOp(); 911 if (arith != NULL) { 912 // See if either arg is a known constant 913 Constant* con = arith->x()->as_Constant(); 914 if (con != NULL) { 915 *index = arith->y(); 916 } else { 917 con = arith->y()->as_Constant(); 918 if (con == NULL) return false; 919 *index = arith->x(); 920 } 921 long const_value; 922 // Check for integer multiply 923 if (arith->op() == Bytecodes::_lmul) { 924 assert((*index)->type() == longType, "invalid input type"); 925 LongConstant* val = con->type()->as_LongConstant(); 926 assert(val != NULL, "expecting a long constant"); 927 const_value = val->value(); 928 } else { 929 #ifndef _LP64 930 if (arith->op() == Bytecodes::_imul) { 931 assert((*index)->type() == intType, "invalid input type"); 932 IntConstant* val = con->type()->as_IntConstant(); 933 assert(val != NULL, "expecting an int constant"); 934 const_value = val->value(); 935 } else { 936 return false; 937 } 938 #else 939 return false; 940 #endif 941 } 942 switch (const_value) { 943 case 1: *log2_scale = 0; return true; 944 case 2: *log2_scale = 1; return true; 945 case 4: *log2_scale = 2; return true; 946 case 8: *log2_scale = 3; return true; 947 default: return false; 948 } 949 } 950 951 // Unknown instruction sequence; don't touch it 952 return false; 953 } 954 955 956 static bool match(UnsafeRawOp* x, 957 Instruction** base, 958 Instruction** index, 959 int* log2_scale) { 960 ArithmeticOp* root = x->base()->as_ArithmeticOp(); 961 if (root == NULL) return false; 962 // Limit ourselves to addition for now 963 if (root->op() != Bytecodes::_ladd) return false; 964 965 bool match_found = false; 966 // Try to find shift or scale op 967 if (match_index_and_scale(root->y(), index, log2_scale)) { 968 *base = root->x(); 969 match_found = true; 970 } else if (match_index_and_scale(root->x(), index, log2_scale)) { 971 *base = root->y(); 972 match_found = true; 973 } else if (NOT_LP64(root->y()->as_Convert() != NULL) LP64_ONLY(false)) { 974 // Skipping i2l works only on 32bit because of the implicit l2i that the unsafe performs. 975 // 64bit needs a real sign-extending conversion. 976 Convert* convert = root->y()->as_Convert(); 977 if (convert->op() == Bytecodes::_i2l) { 978 assert(convert->value()->type() == intType, "should be an int"); 979 // pick base and index, setting scale at 1 980 *base = root->x(); 981 *index = convert->value(); 982 *log2_scale = 0; 983 match_found = true; 984 } 985 } 986 // The default solution 987 if (!match_found) { 988 *base = root->x(); 989 *index = root->y(); 990 *log2_scale = 0; 991 } 992 993 // If the value is pinned then it will be always be computed so 994 // there's no profit to reshaping the expression. 995 return !root->is_pinned(); 996 } 997 998 999 void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) { 1000 Instruction* base = NULL; 1001 Instruction* index = NULL; 1002 int log2_scale; 1003 1004 if (match(x, &base, &index, &log2_scale)) { 1005 x->set_base(base); 1006 x->set_index(index); 1007 x->set_log2_scale(log2_scale); 1008 if (PrintUnsafeOptimization) { 1009 tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d", 1010 x->id(), x->base()->id(), x->index()->id(), x->log2_scale()); 1011 } 1012 } 1013 } 1014 1015 void Canonicalizer::do_RoundFP(RoundFP* x) {} 1016 void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); } 1017 void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); } 1018 void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {} 1019 void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {} 1020 void Canonicalizer::do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) {} 1021 void Canonicalizer::do_ProfileCall(ProfileCall* x) {} 1022 void Canonicalizer::do_ProfileReturnType(ProfileReturnType* x) {} 1023 void Canonicalizer::do_ProfileInvoke(ProfileInvoke* x) {} 1024 void Canonicalizer::do_RuntimeCall(RuntimeCall* x) {} 1025 void Canonicalizer::do_RangeCheckPredicate(RangeCheckPredicate* x) {} 1026 #ifdef ASSERT 1027 void Canonicalizer::do_Assert(Assert* x) {} 1028 #endif 1029 void Canonicalizer::do_MemBar(MemBar* x) {}