c1_Canonicalizer.cpp revision 0:a61af66fc99e
1125410Sgrehan/* 2125410Sgrehan * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved. 3125410Sgrehan * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4125410Sgrehan * 5125410Sgrehan * This code is free software; you can redistribute it and/or modify it 6125410Sgrehan * under the terms of the GNU General Public License version 2 only, as 7125410Sgrehan * published by the Free Software Foundation. 8125410Sgrehan * 9125410Sgrehan * This code is distributed in the hope that it will be useful, but WITHOUT 10125410Sgrehan * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11125410Sgrehan * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12125410Sgrehan * version 2 for more details (a copy is included in the LICENSE file that 13125410Sgrehan * accompanied this code). 14125410Sgrehan * 15125410Sgrehan * You should have received a copy of the GNU General Public License version 16125410Sgrehan * 2 along with this work; if not, write to the Free Software Foundation, 17125410Sgrehan * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18125410Sgrehan * 19125410Sgrehan * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20125410Sgrehan * CA 95054 USA or visit www.sun.com if you need additional information or 21125410Sgrehan * have any questions. 22125410Sgrehan * 23125410Sgrehan */ 24125410Sgrehan 25125410Sgrehan#include "incls/_precompiled.incl" 26125410Sgrehan#include "incls/_c1_Canonicalizer.cpp.incl" 27125410Sgrehan 28125410Sgrehan 29125410Sgrehanstatic void do_print_value(Value* vp) { 30125410Sgrehan (*vp)->print_line(); 31125410Sgrehan} 32125410Sgrehan 33125410Sgrehanvoid Canonicalizer::set_canonical(Value x) { 34125410Sgrehan assert(x != NULL, "value must exist"); 35125410Sgrehan // Note: we can not currently substitute root nodes which show up in 36125410Sgrehan // the instruction stream (because the instruction list is embedded 37125410Sgrehan // in the instructions). 38125410Sgrehan if (canonical() != x) { 39125410Sgrehan if (PrintCanonicalization) { 40125410Sgrehan canonical()->input_values_do(do_print_value); 41125410Sgrehan canonical()->print_line(); 42125410Sgrehan tty->print_cr("canonicalized to:"); 43125410Sgrehan x->input_values_do(do_print_value); 44170088Sdougb x->print_line(); 45125410Sgrehan tty->cr(); 46125410Sgrehan } 47166250Smarcel assert(_canonical->type()->tag() == x->type()->tag(), "types must match"); 48166250Smarcel _canonical = x; 49166250Smarcel } 50166250Smarcel} 51125410Sgrehan 52125410Sgrehan 53125410Sgrehanvoid Canonicalizer::move_const_to_right(Op2* x) { 54125410Sgrehan if (x->x()->type()->is_constant() && x->is_commutative()) x->swap_operands(); 55125410Sgrehan} 56125410Sgrehan 57125410Sgrehan 58125410Sgrehanvoid Canonicalizer::do_Op2(Op2* x) { 59125410Sgrehan if (x->x() == x->y()) { 60125410Sgrehan switch (x->op()) { 61125410Sgrehan case Bytecodes::_isub: set_constant(0); return; 62125410Sgrehan case Bytecodes::_lsub: set_constant(jlong_cast(0)); return; 63125410Sgrehan case Bytecodes::_iand: // fall through 64125410Sgrehan case Bytecodes::_land: // fall through 65125410Sgrehan case Bytecodes::_ior: // fall through 66125410Sgrehan case Bytecodes::_lor : set_canonical(x->x()); return; 67125410Sgrehan case Bytecodes::_ixor: set_constant(0); return; 68125410Sgrehan case Bytecodes::_lxor: set_constant(jlong_cast(0)); return; 69125410Sgrehan } 70125410Sgrehan } 71125410Sgrehan 72125410Sgrehan if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) { 73125410Sgrehan // do constant folding for selected operations 74125410Sgrehan switch (x->type()->tag()) { 75125410Sgrehan case intTag: 76125410Sgrehan { jint a = x->x()->type()->as_IntConstant()->value(); 77125410Sgrehan jint b = x->y()->type()->as_IntConstant()->value(); 78125410Sgrehan switch (x->op()) { 79125410Sgrehan case Bytecodes::_iadd: set_constant(a + b); return; 80125410Sgrehan case Bytecodes::_isub: set_constant(a - b); return; 81125410Sgrehan case Bytecodes::_imul: set_constant(a * b); return; 82125410Sgrehan case Bytecodes::_idiv: 83125410Sgrehan if (b != 0) { 84125410Sgrehan if (a == min_jint && b == -1) { 85125410Sgrehan set_constant(min_jint); 86125410Sgrehan } else { 87125410Sgrehan set_constant(a / b); 88125410Sgrehan } 89125410Sgrehan return; 90125410Sgrehan } 91125410Sgrehan break; 92125410Sgrehan case Bytecodes::_irem: 93125410Sgrehan if (b != 0) { 94125410Sgrehan if (a == min_jint && b == -1) { 95125410Sgrehan set_constant(0); 96125410Sgrehan } else { 97125410Sgrehan set_constant(a % b); 98125410Sgrehan } 99125410Sgrehan return; 100125410Sgrehan } 101125410Sgrehan break; 102125410Sgrehan case Bytecodes::_iand: set_constant(a & b); return; 103125410Sgrehan case Bytecodes::_ior : set_constant(a | b); return; 104125410Sgrehan case Bytecodes::_ixor: set_constant(a ^ b); return; 105125410Sgrehan } 106125410Sgrehan } 107125410Sgrehan break; 108125410Sgrehan case longTag: 109125410Sgrehan { jlong a = x->x()->type()->as_LongConstant()->value(); 110125410Sgrehan jlong b = x->y()->type()->as_LongConstant()->value(); 111125410Sgrehan switch (x->op()) { 112125410Sgrehan case Bytecodes::_ladd: set_constant(a + b); return; 113125410Sgrehan case Bytecodes::_lsub: set_constant(a - b); return; 114125410Sgrehan case Bytecodes::_lmul: set_constant(a * b); return; 115125410Sgrehan case Bytecodes::_ldiv: 116125410Sgrehan if (b != 0) { 117125410Sgrehan set_constant(SharedRuntime::ldiv(b, a)); 118125410Sgrehan return; 119125410Sgrehan } 120125410Sgrehan break; 121125410Sgrehan case Bytecodes::_lrem: 122125410Sgrehan if (b != 0) { 123125410Sgrehan set_constant(SharedRuntime::lrem(b, a)); 124125410Sgrehan return; 125125410Sgrehan } 126125410Sgrehan break; 127125410Sgrehan case Bytecodes::_land: set_constant(a & b); return; 128125410Sgrehan case Bytecodes::_lor : set_constant(a | b); return; 129125410Sgrehan case Bytecodes::_lxor: set_constant(a ^ b); return; 130125410Sgrehan } 131125410Sgrehan } 132125410Sgrehan break; 133125410Sgrehan // other cases not implemented (must be extremely careful with floats & doubles!) 134125410Sgrehan } 135125410Sgrehan } 136125410Sgrehan // make sure constant is on the right side, if any 137125410Sgrehan move_const_to_right(x); 138125410Sgrehan 139125410Sgrehan if (x->y()->type()->is_constant()) { 140125410Sgrehan // do constant folding for selected operations 141125410Sgrehan switch (x->type()->tag()) { 142125410Sgrehan case intTag: 143125410Sgrehan if (x->y()->type()->as_IntConstant()->value() == 0) { 144125410Sgrehan switch (x->op()) { 145125410Sgrehan case Bytecodes::_iadd: set_canonical(x->x()); return; 146125410Sgrehan case Bytecodes::_isub: set_canonical(x->x()); return; 147125410Sgrehan case Bytecodes::_imul: set_constant(0); return; 148125410Sgrehan // Note: for div and rem, make sure that C semantics 149125410Sgrehan // corresponds to Java semantics! 150125410Sgrehan case Bytecodes::_iand: set_constant(0); return; 151125410Sgrehan case Bytecodes::_ior : set_canonical(x->x()); return; 152125410Sgrehan } 153125410Sgrehan } 154125410Sgrehan break; 155125410Sgrehan case longTag: 156125410Sgrehan if (x->y()->type()->as_LongConstant()->value() == (jlong)0) { 157125410Sgrehan switch (x->op()) { 158125410Sgrehan case Bytecodes::_ladd: set_canonical(x->x()); return; 159125410Sgrehan case Bytecodes::_lsub: set_canonical(x->x()); return; 160125410Sgrehan case Bytecodes::_lmul: set_constant((jlong)0); return; 161125410Sgrehan // Note: for div and rem, make sure that C semantics 162125410Sgrehan // corresponds to Java semantics! 163125410Sgrehan case Bytecodes::_land: set_constant((jlong)0); return; 164125410Sgrehan case Bytecodes::_lor : set_canonical(x->x()); return; 165125410Sgrehan } 166125410Sgrehan } 167125410Sgrehan break; 168125410Sgrehan } 169125410Sgrehan } 170125410Sgrehan} 171125410Sgrehan 172125410Sgrehan 173125410Sgrehanvoid Canonicalizer::do_Phi (Phi* x) {} 174125410Sgrehanvoid Canonicalizer::do_Constant (Constant* x) {} 175125410Sgrehanvoid Canonicalizer::do_Local (Local* x) {} 176125410Sgrehanvoid Canonicalizer::do_LoadField (LoadField* x) {} 177125410Sgrehan 178125410Sgrehan// checks if v is in the block that is currently processed by 179125410Sgrehan// GraphBuilder. This is the only block that has not BlockEnd yet. 180125410Sgrehanstatic bool in_current_block(Value v) { 181125410Sgrehan int max_distance = 4; 182125410Sgrehan while (max_distance > 0 && v != NULL && v->as_BlockEnd() == NULL) { 183125410Sgrehan v = v->next(); 184125410Sgrehan max_distance--; 185125410Sgrehan } 186125410Sgrehan return v == NULL; 187125410Sgrehan} 188125410Sgrehan 189125410Sgrehanvoid Canonicalizer::do_StoreField (StoreField* x) { 190125410Sgrehan // If a value is going to be stored into a field or array some of 191125410Sgrehan // the conversions emitted by javac are unneeded because the fields 192125410Sgrehan // are packed to their natural size. 193125410Sgrehan Convert* conv = x->value()->as_Convert(); 194125410Sgrehan if (conv) { 195125410Sgrehan Value value = NULL; 196125410Sgrehan BasicType type = x->field()->type()->basic_type(); 197125410Sgrehan switch (conv->op()) { 198125410Sgrehan case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break; 199125410Sgrehan case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break; 200125410Sgrehan case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break; 201125410Sgrehan } 202125410Sgrehan // limit this optimization to current block 203125410Sgrehan if (value != NULL && in_current_block(conv)) { 204125410Sgrehan set_canonical(new StoreField(x->obj(), x->offset(), x->field(), value, x->is_static(), 205125410Sgrehan x->lock_stack(), x->state_before(), x->is_loaded(), x->is_initialized())); 206125410Sgrehan return; 207125410Sgrehan } 208125410Sgrehan } 209125410Sgrehan 210125410Sgrehan} 211125410Sgrehan 212125410Sgrehanvoid Canonicalizer::do_ArrayLength (ArrayLength* x) { 213125410Sgrehan NewArray* array = x->array()->as_NewArray(); 214125410Sgrehan if (array != NULL && array->length() != NULL) { 215125410Sgrehan Constant* length = array->length()->as_Constant(); 216125410Sgrehan if (length != NULL) { 217125410Sgrehan // do not use the Constant itself, but create a new Constant 218125410Sgrehan // with same value Otherwise a Constant is live over multiple 219125410Sgrehan // blocks without being registered in a state array. 220125410Sgrehan assert(length->type()->as_IntConstant() != NULL, "array length must be integer"); 221125410Sgrehan set_constant(length->type()->as_IntConstant()->value()); 222125410Sgrehan } 223125410Sgrehan } else { 224125410Sgrehan LoadField* lf = x->array()->as_LoadField(); 225125410Sgrehan if (lf != NULL && lf->field()->is_constant()) { 226125410Sgrehan ciObject* c = lf->field()->constant_value().as_object(); 227125410Sgrehan if (c->is_array()) { 228125410Sgrehan ciArray* array = (ciArray*) c; 229125410Sgrehan set_constant(array->length()); 230125410Sgrehan } 231125410Sgrehan } 232125410Sgrehan } 233125410Sgrehan} 234125410Sgrehan 235125410Sgrehanvoid Canonicalizer::do_LoadIndexed (LoadIndexed* x) {} 236125410Sgrehanvoid Canonicalizer::do_StoreIndexed (StoreIndexed* x) { 237125410Sgrehan // If a value is going to be stored into a field or array some of 238125410Sgrehan // the conversions emitted by javac are unneeded because the fields 239125410Sgrehan // are packed to their natural size. 240125410Sgrehan Convert* conv = x->value()->as_Convert(); 241125410Sgrehan if (conv) { 242125410Sgrehan Value value = NULL; 243125410Sgrehan BasicType type = x->elt_type(); 244125410Sgrehan switch (conv->op()) { 245125410Sgrehan case Bytecodes::_i2b: if (type == T_BYTE) value = conv->value(); break; 246125410Sgrehan case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) value = conv->value(); break; 247125410Sgrehan case Bytecodes::_i2c: if (type == T_CHAR || type == T_BYTE) value = conv->value(); break; 248125410Sgrehan } 249125410Sgrehan // limit this optimization to current block 250125410Sgrehan if (value != NULL && in_current_block(conv)) { 251125410Sgrehan set_canonical(new StoreIndexed(x->array(), x->index(), x->length(), 252125410Sgrehan x->elt_type(), value, x->lock_stack())); 253125410Sgrehan return; 254125410Sgrehan } 255125410Sgrehan } 256125410Sgrehan 257125410Sgrehan 258125410Sgrehan} 259125410Sgrehan 260125410Sgrehan 261125410Sgrehanvoid Canonicalizer::do_NegateOp(NegateOp* x) { 262125410Sgrehan ValueType* t = x->x()->type(); 263125410Sgrehan if (t->is_constant()) { 264125410Sgrehan switch (t->tag()) { 265125410Sgrehan case intTag : set_constant(-t->as_IntConstant ()->value()); return; 266125410Sgrehan case longTag : set_constant(-t->as_LongConstant ()->value()); return; 267125410Sgrehan case floatTag : set_constant(-t->as_FloatConstant ()->value()); return; 268125410Sgrehan case doubleTag: set_constant(-t->as_DoubleConstant()->value()); return; 269125410Sgrehan default : ShouldNotReachHere(); 270125410Sgrehan } 271125410Sgrehan } 272125410Sgrehan} 273125410Sgrehan 274125410Sgrehan 275125410Sgrehanvoid Canonicalizer::do_ArithmeticOp (ArithmeticOp* x) { do_Op2(x); } 276125410Sgrehan 277125410Sgrehan 278125410Sgrehanvoid Canonicalizer::do_ShiftOp (ShiftOp* x) { 279125410Sgrehan ValueType* t = x->x()->type(); 280125410Sgrehan ValueType* t2 = x->y()->type(); 281125410Sgrehan if (t->is_constant()) { 282125410Sgrehan switch (t->tag()) { 283125410Sgrehan case intTag : if (t->as_IntConstant()->value() == 0) { set_constant(0); return; } break; 284125410Sgrehan case longTag : if (t->as_LongConstant()->value() == (jlong)0) { set_constant(jlong_cast(0)); return; } break; 285125410Sgrehan default : ShouldNotReachHere(); 286125410Sgrehan } 287125410Sgrehan if (t2->is_constant()) { 288125410Sgrehan if (t->tag() == intTag) { 289125410Sgrehan int value = t->as_IntConstant()->value(); 290125410Sgrehan int shift = t2->as_IntConstant()->value() & 31; 291125410Sgrehan jint mask = ~(~0 << (32 - shift)); 292125410Sgrehan if (shift == 0) mask = ~0; 293125410Sgrehan switch (x->op()) { 294125410Sgrehan case Bytecodes::_ishl: set_constant(value << shift); return; 295125410Sgrehan case Bytecodes::_ishr: set_constant(value >> shift); return; 296125410Sgrehan case Bytecodes::_iushr: set_constant((value >> shift) & mask); return; 297125410Sgrehan } 298125410Sgrehan } else if (t->tag() == longTag) { 299125410Sgrehan jlong value = t->as_LongConstant()->value(); 300125410Sgrehan int shift = t2->as_IntConstant()->value() & 63; 301125410Sgrehan jlong mask = ~(~jlong_cast(0) << (64 - shift)); 302125410Sgrehan if (shift == 0) mask = ~jlong_cast(0); 303125410Sgrehan switch (x->op()) { 304125410Sgrehan case Bytecodes::_lshl: set_constant(value << shift); return; 305125410Sgrehan case Bytecodes::_lshr: set_constant(value >> shift); return; 306125410Sgrehan case Bytecodes::_lushr: set_constant((value >> shift) & mask); return; 307125410Sgrehan } 308125410Sgrehan } 309125410Sgrehan } 310 } 311 if (t2->is_constant()) { 312 switch (t2->tag()) { 313 case intTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return; 314 case longTag : if (t2->as_IntConstant()->value() == 0) set_canonical(x->x()); return; 315 default : ShouldNotReachHere(); 316 } 317 } 318} 319 320 321void Canonicalizer::do_LogicOp (LogicOp* x) { do_Op2(x); } 322void Canonicalizer::do_CompareOp (CompareOp* x) { 323 if (x->x() == x->y()) { 324 switch (x->x()->type()->tag()) { 325 case longTag: set_constant(0); break; 326 case floatTag: { 327 FloatConstant* fc = x->x()->type()->as_FloatConstant(); 328 if (fc) { 329 if (g_isnan(fc->value())) { 330 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1); 331 } else { 332 set_constant(0); 333 } 334 } 335 break; 336 } 337 case doubleTag: { 338 DoubleConstant* dc = x->x()->type()->as_DoubleConstant(); 339 if (dc) { 340 if (g_isnan(dc->value())) { 341 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1); 342 } else { 343 set_constant(0); 344 } 345 } 346 break; 347 } 348 } 349 } else if (x->x()->type()->is_constant() && x->y()->type()->is_constant()) { 350 switch (x->x()->type()->tag()) { 351 case longTag: { 352 jlong vx = x->x()->type()->as_LongConstant()->value(); 353 jlong vy = x->y()->type()->as_LongConstant()->value(); 354 if (vx == vy) 355 set_constant(0); 356 else if (vx < vy) 357 set_constant(-1); 358 else 359 set_constant(1); 360 break; 361 } 362 363 case floatTag: { 364 float vx = x->x()->type()->as_FloatConstant()->value(); 365 float vy = x->y()->type()->as_FloatConstant()->value(); 366 if (g_isnan(vx) || g_isnan(vy)) 367 set_constant(x->op() == Bytecodes::_fcmpl ? -1 : 1); 368 else if (vx == vy) 369 set_constant(0); 370 else if (vx < vy) 371 set_constant(-1); 372 else 373 set_constant(1); 374 break; 375 } 376 377 case doubleTag: { 378 double vx = x->x()->type()->as_DoubleConstant()->value(); 379 double vy = x->y()->type()->as_DoubleConstant()->value(); 380 if (g_isnan(vx) || g_isnan(vy)) 381 set_constant(x->op() == Bytecodes::_dcmpl ? -1 : 1); 382 else if (vx == vy) 383 set_constant(0); 384 else if (vx < vy) 385 set_constant(-1); 386 else 387 set_constant(1); 388 break; 389 } 390 } 391 392 } 393} 394 395 396void Canonicalizer::do_IfInstanceOf(IfInstanceOf* x) {} 397 398void Canonicalizer::do_IfOp(IfOp* x) { 399 // Caution: do not use do_Op2(x) here for now since 400 // we map the condition to the op for now! 401 move_const_to_right(x); 402} 403 404 405void Canonicalizer::do_Intrinsic (Intrinsic* x) { 406 switch (x->id()) { 407 case vmIntrinsics::_floatToRawIntBits : { 408 FloatConstant* c = x->argument_at(0)->type()->as_FloatConstant(); 409 if (c != NULL) { 410 JavaValue v; 411 v.set_jfloat(c->value()); 412 set_constant(v.get_jint()); 413 } 414 break; 415 } 416 case vmIntrinsics::_intBitsToFloat : { 417 IntConstant* c = x->argument_at(0)->type()->as_IntConstant(); 418 if (c != NULL) { 419 JavaValue v; 420 v.set_jint(c->value()); 421 set_constant(v.get_jfloat()); 422 } 423 break; 424 } 425 case vmIntrinsics::_doubleToRawLongBits : { 426 DoubleConstant* c = x->argument_at(0)->type()->as_DoubleConstant(); 427 if (c != NULL) { 428 JavaValue v; 429 v.set_jdouble(c->value()); 430 set_constant(v.get_jlong()); 431 } 432 break; 433 } 434 case vmIntrinsics::_longBitsToDouble : { 435 LongConstant* c = x->argument_at(0)->type()->as_LongConstant(); 436 if (c != NULL) { 437 JavaValue v; 438 v.set_jlong(c->value()); 439 set_constant(v.get_jdouble()); 440 } 441 break; 442 } 443 } 444} 445 446void Canonicalizer::do_Convert (Convert* x) { 447 if (x->value()->type()->is_constant()) { 448 switch (x->op()) { 449 case Bytecodes::_i2b: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 24) >> 24)); break; 450 case Bytecodes::_i2s: set_constant((int)((x->value()->type()->as_IntConstant()->value() << 16) >> 16)); break; 451 case Bytecodes::_i2c: set_constant((int)(x->value()->type()->as_IntConstant()->value() & ((1<<16)-1))); break; 452 case Bytecodes::_i2l: set_constant((jlong)(x->value()->type()->as_IntConstant()->value())); break; 453 case Bytecodes::_i2f: set_constant((float)(x->value()->type()->as_IntConstant()->value())); break; 454 case Bytecodes::_i2d: set_constant((double)(x->value()->type()->as_IntConstant()->value())); break; 455 case Bytecodes::_l2i: set_constant((int)(x->value()->type()->as_LongConstant()->value())); break; 456 case Bytecodes::_l2f: set_constant(SharedRuntime::l2f(x->value()->type()->as_LongConstant()->value())); break; 457 case Bytecodes::_l2d: set_constant(SharedRuntime::l2d(x->value()->type()->as_LongConstant()->value())); break; 458 case Bytecodes::_f2d: set_constant((double)(x->value()->type()->as_FloatConstant()->value())); break; 459 case Bytecodes::_f2i: set_constant(SharedRuntime::f2i(x->value()->type()->as_FloatConstant()->value())); break; 460 case Bytecodes::_f2l: set_constant(SharedRuntime::f2l(x->value()->type()->as_FloatConstant()->value())); break; 461 case Bytecodes::_d2f: set_constant((float)(x->value()->type()->as_DoubleConstant()->value())); break; 462 case Bytecodes::_d2i: set_constant(SharedRuntime::d2i(x->value()->type()->as_DoubleConstant()->value())); break; 463 case Bytecodes::_d2l: set_constant(SharedRuntime::d2l(x->value()->type()->as_DoubleConstant()->value())); break; 464 default: 465 ShouldNotReachHere(); 466 } 467 } 468 469 Value value = x->value(); 470 BasicType type = T_ILLEGAL; 471 LoadField* lf = value->as_LoadField(); 472 if (lf) { 473 type = lf->field_type(); 474 } else { 475 LoadIndexed* li = value->as_LoadIndexed(); 476 if (li) { 477 type = li->elt_type(); 478 } else { 479 Convert* conv = value->as_Convert(); 480 if (conv) { 481 switch (conv->op()) { 482 case Bytecodes::_i2b: type = T_BYTE; break; 483 case Bytecodes::_i2s: type = T_SHORT; break; 484 case Bytecodes::_i2c: type = T_CHAR; break; 485 } 486 } 487 } 488 } 489 if (type != T_ILLEGAL) { 490 switch (x->op()) { 491 case Bytecodes::_i2b: if (type == T_BYTE) set_canonical(x->value()); break; 492 case Bytecodes::_i2s: if (type == T_SHORT || type == T_BYTE) set_canonical(x->value()); break; 493 case Bytecodes::_i2c: if (type == T_CHAR) set_canonical(x->value()); break; 494 } 495 } else { 496 Op2* op2 = x->value()->as_Op2(); 497 if (op2 && op2->op() == Bytecodes::_iand && op2->y()->type()->is_constant()) { 498 jint safebits = 0; 499 jint mask = op2->y()->type()->as_IntConstant()->value(); 500 switch (x->op()) { 501 case Bytecodes::_i2b: safebits = 0x7f; break; 502 case Bytecodes::_i2s: safebits = 0x7fff; break; 503 case Bytecodes::_i2c: safebits = 0xffff; break; 504 } 505 // When casting a masked integer to a smaller signed type, if 506 // the mask doesn't include the sign bit the cast isn't needed. 507 if (safebits && (mask & ~safebits) == 0) { 508 set_canonical(x->value()); 509 } 510 } 511 } 512 513} 514 515void Canonicalizer::do_NullCheck (NullCheck* x) { 516 if (x->obj()->as_NewArray() != NULL || x->obj()->as_NewInstance() != NULL) { 517 set_canonical(x->obj()); 518 } else { 519 Constant* con = x->obj()->as_Constant(); 520 if (con) { 521 ObjectType* c = con->type()->as_ObjectType(); 522 if (c && c->is_loaded()) { 523 ObjectConstant* oc = c->as_ObjectConstant(); 524 if (!oc || !oc->value()->is_null_object()) { 525 set_canonical(con); 526 } 527 } 528 } 529 } 530} 531 532void Canonicalizer::do_Invoke (Invoke* x) {} 533void Canonicalizer::do_NewInstance (NewInstance* x) {} 534void Canonicalizer::do_NewTypeArray (NewTypeArray* x) {} 535void Canonicalizer::do_NewObjectArray (NewObjectArray* x) {} 536void Canonicalizer::do_NewMultiArray (NewMultiArray* x) {} 537void Canonicalizer::do_CheckCast (CheckCast* x) { 538 if (x->klass()->is_loaded()) { 539 Value obj = x->obj(); 540 ciType* klass = obj->exact_type(); 541 if (klass == NULL) klass = obj->declared_type(); 542 if (klass != NULL && klass->is_loaded() && klass->is_subtype_of(x->klass())) { 543 set_canonical(obj); 544 return; 545 } 546 // checkcast of null returns null 547 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) { 548 set_canonical(obj); 549 } 550 } 551} 552void Canonicalizer::do_InstanceOf (InstanceOf* x) { 553 if (x->klass()->is_loaded()) { 554 Value obj = x->obj(); 555 ciType* exact = obj->exact_type(); 556 if (exact != NULL && exact->is_loaded() && (obj->as_NewInstance() || obj->as_NewArray())) { 557 set_constant(exact->is_subtype_of(x->klass()) ? 1 : 0); 558 return; 559 } 560 // instanceof null returns false 561 if (obj->as_Constant() && obj->type()->as_ObjectType()->constant_value()->is_null_object()) { 562 set_constant(0); 563 } 564 } 565 566} 567void Canonicalizer::do_MonitorEnter (MonitorEnter* x) {} 568void Canonicalizer::do_MonitorExit (MonitorExit* x) {} 569void Canonicalizer::do_BlockBegin (BlockBegin* x) {} 570void Canonicalizer::do_Goto (Goto* x) {} 571 572 573static bool is_true(jlong x, If::Condition cond, jlong y) { 574 switch (cond) { 575 case If::eql: return x == y; 576 case If::neq: return x != y; 577 case If::lss: return x < y; 578 case If::leq: return x <= y; 579 case If::gtr: return x > y; 580 case If::geq: return x >= y; 581 } 582 ShouldNotReachHere(); 583 return false; 584} 585 586 587void Canonicalizer::do_If(If* x) { 588 // move const to right 589 if (x->x()->type()->is_constant()) x->swap_operands(); 590 // simplify 591 const Value l = x->x(); ValueType* lt = l->type(); 592 const Value r = x->y(); ValueType* rt = r->type(); 593 594 if (l == r && !lt->is_float_kind()) { 595 // pattern: If (a cond a) => simplify to Goto 596 BlockBegin* sux; 597 switch (x->cond()) { 598 case If::eql: sux = x->sux_for(true); break; 599 case If::neq: sux = x->sux_for(false); break; 600 case If::lss: sux = x->sux_for(false); break; 601 case If::leq: sux = x->sux_for(true); break; 602 case If::gtr: sux = x->sux_for(false); break; 603 case If::geq: sux = x->sux_for(true); break; 604 } 605 // If is a safepoint then the debug information should come from the state_before of the If. 606 set_canonical(new Goto(sux, x->state_before(), x->is_safepoint())); 607 return; 608 } 609 610 if (lt->is_constant() && rt->is_constant()) { 611 if (x->x()->as_Constant() != NULL) { 612 // pattern: If (lc cond rc) => simplify to: Goto 613 BlockBegin* sux = x->x()->as_Constant()->compare(x->cond(), x->y(), 614 x->sux_for(true), 615 x->sux_for(false)); 616 if (sux != NULL) { 617 // If is a safepoint then the debug information should come from the state_before of the If. 618 set_canonical(new Goto(sux, x->state_before(), x->is_safepoint())); 619 } 620 } 621 } else if (rt->as_IntConstant() != NULL) { 622 // pattern: If (l cond rc) => investigate further 623 const jint rc = rt->as_IntConstant()->value(); 624 if (l->as_CompareOp() != NULL) { 625 // pattern: If ((a cmp b) cond rc) => simplify to: If (x cond y) or: Goto 626 CompareOp* cmp = l->as_CompareOp(); 627 bool unordered_is_less = cmp->op() == Bytecodes::_fcmpl || cmp->op() == Bytecodes::_dcmpl; 628 BlockBegin* lss_sux = x->sux_for(is_true(-1, x->cond(), rc)); // successor for a < b 629 BlockBegin* eql_sux = x->sux_for(is_true( 0, x->cond(), rc)); // successor for a = b 630 BlockBegin* gtr_sux = x->sux_for(is_true(+1, x->cond(), rc)); // successor for a > b 631 BlockBegin* nan_sux = unordered_is_less ? lss_sux : gtr_sux ; // successor for unordered 632 // Note: At this point all successors (lss_sux, eql_sux, gtr_sux, nan_sux) are 633 // equal to x->tsux() or x->fsux(). Furthermore, nan_sux equals either 634 // lss_sux or gtr_sux. 635 if (lss_sux == eql_sux && eql_sux == gtr_sux) { 636 // all successors identical => simplify to: Goto 637 set_canonical(new Goto(lss_sux, x->state_before(), x->is_safepoint())); 638 } else { 639 // two successors differ and two successors are the same => simplify to: If (x cmp y) 640 // determine new condition & successors 641 If::Condition cond; 642 BlockBegin* tsux = NULL; 643 BlockBegin* fsux = NULL; 644 if (lss_sux == eql_sux) { cond = If::leq; tsux = lss_sux; fsux = gtr_sux; } 645 else if (lss_sux == gtr_sux) { cond = If::neq; tsux = lss_sux; fsux = eql_sux; } 646 else if (eql_sux == gtr_sux) { cond = If::geq; tsux = eql_sux; fsux = lss_sux; } 647 else { ShouldNotReachHere(); } 648 If* canon = new If(cmp->x(), cond, nan_sux == tsux, cmp->y(), tsux, fsux, cmp->state_before(), x->is_safepoint()); 649 if (cmp->x() == cmp->y()) { 650 do_If(canon); 651 } else { 652 set_canonical(canon); 653 set_bci(cmp->bci()); 654 } 655 } 656 } else if (l->as_InstanceOf() != NULL) { 657 // NOTE: Code permanently disabled for now since it leaves the old InstanceOf 658 // instruction in the graph (it is pinned). Need to fix this at some point. 659 return; 660 // pattern: If ((obj instanceof klass) cond rc) => simplify to: IfInstanceOf or: Goto 661 InstanceOf* inst = l->as_InstanceOf(); 662 BlockBegin* is_inst_sux = x->sux_for(is_true(1, x->cond(), rc)); // successor for instanceof == 1 663 BlockBegin* no_inst_sux = x->sux_for(is_true(0, x->cond(), rc)); // successor for instanceof == 0 664 if (is_inst_sux == no_inst_sux && inst->is_loaded()) { 665 // both successors identical and klass is loaded => simplify to: Goto 666 set_canonical(new Goto(is_inst_sux, x->state_before(), x->is_safepoint())); 667 } else { 668 // successors differ => simplify to: IfInstanceOf 669 set_canonical(new IfInstanceOf(inst->klass(), inst->obj(), true, inst->bci(), is_inst_sux, no_inst_sux)); 670 } 671 } 672 } else if (rt == objectNull && (l->as_NewInstance() || l->as_NewArray())) { 673 if (x->cond() == Instruction::eql) { 674 set_canonical(new Goto(x->fsux(), x->state_before(), x->is_safepoint())); 675 } else { 676 assert(x->cond() == Instruction::neq, "only other valid case"); 677 set_canonical(new Goto(x->tsux(), x->state_before(), x->is_safepoint())); 678 } 679 } 680} 681 682 683void Canonicalizer::do_TableSwitch(TableSwitch* x) { 684 if (x->tag()->type()->is_constant()) { 685 int v = x->tag()->type()->as_IntConstant()->value(); 686 BlockBegin* sux = x->default_sux(); 687 if (v >= x->lo_key() && v <= x->hi_key()) { 688 sux = x->sux_at(v - x->lo_key()); 689 } 690 set_canonical(new Goto(sux, x->state_before(), x->is_safepoint())); 691 } else if (x->number_of_sux() == 1) { 692 // NOTE: Code permanently disabled for now since the switch statement's 693 // tag expression may produce side-effects in which case it must 694 // be executed. 695 return; 696 // simplify to Goto 697 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint())); 698 } else if (x->number_of_sux() == 2) { 699 // NOTE: Code permanently disabled for now since it produces two new nodes 700 // (Constant & If) and the Canonicalizer cannot return them correctly 701 // yet. For now we copied the corresponding code directly into the 702 // GraphBuilder (i.e., we should never reach here). 703 return; 704 // simplify to If 705 assert(x->lo_key() == x->hi_key(), "keys must be the same"); 706 Constant* key = new Constant(new IntConstant(x->lo_key())); 707 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint())); 708 } 709} 710 711 712void Canonicalizer::do_LookupSwitch(LookupSwitch* x) { 713 if (x->tag()->type()->is_constant()) { 714 int v = x->tag()->type()->as_IntConstant()->value(); 715 BlockBegin* sux = x->default_sux(); 716 for (int i = 0; i < x->length(); i++) { 717 if (v == x->key_at(i)) { 718 sux = x->sux_at(i); 719 } 720 } 721 set_canonical(new Goto(sux, x->state_before(), x->is_safepoint())); 722 } else if (x->number_of_sux() == 1) { 723 // NOTE: Code permanently disabled for now since the switch statement's 724 // tag expression may produce side-effects in which case it must 725 // be executed. 726 return; 727 // simplify to Goto 728 set_canonical(new Goto(x->default_sux(), x->state_before(), x->is_safepoint())); 729 } else if (x->number_of_sux() == 2) { 730 // NOTE: Code permanently disabled for now since it produces two new nodes 731 // (Constant & If) and the Canonicalizer cannot return them correctly 732 // yet. For now we copied the corresponding code directly into the 733 // GraphBuilder (i.e., we should never reach here). 734 return; 735 // simplify to If 736 assert(x->length() == 1, "length must be the same"); 737 Constant* key = new Constant(new IntConstant(x->key_at(0))); 738 set_canonical(new If(x->tag(), If::eql, true, key, x->sux_at(0), x->default_sux(), x->state_before(), x->is_safepoint())); 739 } 740} 741 742 743void Canonicalizer::do_Return (Return* x) {} 744void Canonicalizer::do_Throw (Throw* x) {} 745void Canonicalizer::do_Base (Base* x) {} 746void Canonicalizer::do_OsrEntry (OsrEntry* x) {} 747void Canonicalizer::do_ExceptionObject(ExceptionObject* x) {} 748 749static bool match_index_and_scale(Instruction* instr, 750 Instruction** index, 751 int* log2_scale, 752 Instruction** instr_to_unpin) { 753 *instr_to_unpin = NULL; 754 755 // Skip conversion ops 756 Convert* convert = instr->as_Convert(); 757 if (convert != NULL) { 758 instr = convert->value(); 759 } 760 761 ShiftOp* shift = instr->as_ShiftOp(); 762 if (shift != NULL) { 763 if (shift->is_pinned()) { 764 *instr_to_unpin = shift; 765 } 766 // Constant shift value? 767 Constant* con = shift->y()->as_Constant(); 768 if (con == NULL) return false; 769 // Well-known type and value? 770 IntConstant* val = con->type()->as_IntConstant(); 771 if (val == NULL) return false; 772 if (shift->x()->type() != intType) return false; 773 *index = shift->x(); 774 int tmp_scale = val->value(); 775 if (tmp_scale >= 0 && tmp_scale < 4) { 776 *log2_scale = tmp_scale; 777 return true; 778 } else { 779 return false; 780 } 781 } 782 783 ArithmeticOp* arith = instr->as_ArithmeticOp(); 784 if (arith != NULL) { 785 if (arith->is_pinned()) { 786 *instr_to_unpin = arith; 787 } 788 // Check for integer multiply 789 if (arith->op() == Bytecodes::_imul) { 790 // See if either arg is a known constant 791 Constant* con = arith->x()->as_Constant(); 792 if (con != NULL) { 793 *index = arith->y(); 794 } else { 795 con = arith->y()->as_Constant(); 796 if (con == NULL) return false; 797 *index = arith->x(); 798 } 799 if ((*index)->type() != intType) return false; 800 // Well-known type and value? 801 IntConstant* val = con->type()->as_IntConstant(); 802 if (val == NULL) return false; 803 switch (val->value()) { 804 case 1: *log2_scale = 0; return true; 805 case 2: *log2_scale = 1; return true; 806 case 4: *log2_scale = 2; return true; 807 case 8: *log2_scale = 3; return true; 808 default: return false; 809 } 810 } 811 } 812 813 // Unknown instruction sequence; don't touch it 814 return false; 815} 816 817 818static bool match(UnsafeRawOp* x, 819 Instruction** base, 820 Instruction** index, 821 int* log2_scale) { 822 Instruction* instr_to_unpin = NULL; 823 ArithmeticOp* root = x->base()->as_ArithmeticOp(); 824 if (root == NULL) return false; 825 // Limit ourselves to addition for now 826 if (root->op() != Bytecodes::_ladd) return false; 827 // Try to find shift or scale op 828 if (match_index_and_scale(root->y(), index, log2_scale, &instr_to_unpin)) { 829 *base = root->x(); 830 } else if (match_index_and_scale(root->x(), index, log2_scale, &instr_to_unpin)) { 831 *base = root->y(); 832 } else if (root->y()->as_Convert() != NULL) { 833 Convert* convert = root->y()->as_Convert(); 834 if (convert->op() == Bytecodes::_i2l && convert->value()->type() == intType) { 835 // pick base and index, setting scale at 1 836 *base = root->x(); 837 *index = convert->value(); 838 *log2_scale = 0; 839 } else { 840 return false; 841 } 842 } else { 843 // doesn't match any expected sequences 844 return false; 845 } 846 847 // If the value is pinned then it will be always be computed so 848 // there's no profit to reshaping the expression. 849 return !root->is_pinned(); 850} 851 852 853void Canonicalizer::do_UnsafeRawOp(UnsafeRawOp* x) { 854 Instruction* base = NULL; 855 Instruction* index = NULL; 856 int log2_scale; 857 858 if (match(x, &base, &index, &log2_scale)) { 859 x->set_base(base); 860 x->set_index(index); 861 x->set_log2_scale(log2_scale); 862 if (PrintUnsafeOptimization) { 863 tty->print_cr("Canonicalizer: UnsafeRawOp id %d: base = id %d, index = id %d, log2_scale = %d", 864 x->id(), x->base()->id(), x->index()->id(), x->log2_scale()); 865 } 866 } 867} 868 869void Canonicalizer::do_RoundFP(RoundFP* x) {} 870void Canonicalizer::do_UnsafeGetRaw(UnsafeGetRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); } 871void Canonicalizer::do_UnsafePutRaw(UnsafePutRaw* x) { if (OptimizeUnsafes) do_UnsafeRawOp(x); } 872void Canonicalizer::do_UnsafeGetObject(UnsafeGetObject* x) {} 873void Canonicalizer::do_UnsafePutObject(UnsafePutObject* x) {} 874void Canonicalizer::do_UnsafePrefetchRead (UnsafePrefetchRead* x) {} 875void Canonicalizer::do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) {} 876void Canonicalizer::do_ProfileCall(ProfileCall* x) {} 877void Canonicalizer::do_ProfileCounter(ProfileCounter* x) {} 878