1 /* 2 * Copyright (c) 1997, 2023, 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 "memory/allocation.inline.hpp" 27 #include "opto/addnode.hpp" 28 #include "opto/connode.hpp" 29 #include "opto/convertnode.hpp" 30 #include "opto/divnode.hpp" 31 #include "opto/machnode.hpp" 32 #include "opto/movenode.hpp" 33 #include "opto/matcher.hpp" 34 #include "opto/mulnode.hpp" 35 #include "opto/phaseX.hpp" 36 #include "opto/subnode.hpp" 37 #include "utilities/powerOfTwo.hpp" 38 39 // Portions of code courtesy of Clifford Click 40 41 // Optimization - Graph Style 42 43 #include <math.h> 44 45 //----------------------magic_int_divide_constants----------------------------- 46 // Compute magic multiplier and shift constant for converting a 32 bit divide 47 // by constant into a multiply/shift/add series. Return false if calculations 48 // fail. 49 // 50 // Borrowed almost verbatim from Hacker's Delight by Henry S. Warren, Jr. with 51 // minor type name and parameter changes. 52 static bool magic_int_divide_constants(jint d, jint &M, jint &s) { 53 int32_t p; 54 uint32_t ad, anc, delta, q1, r1, q2, r2, t; 55 const uint32_t two31 = 0x80000000L; // 2**31. 56 57 ad = ABS(d); 58 if (d == 0 || d == 1) return false; 59 t = two31 + ((uint32_t)d >> 31); 60 anc = t - 1 - t%ad; // Absolute value of nc. 61 p = 31; // Init. p. 62 q1 = two31/anc; // Init. q1 = 2**p/|nc|. 63 r1 = two31 - q1*anc; // Init. r1 = rem(2**p, |nc|). 64 q2 = two31/ad; // Init. q2 = 2**p/|d|. 65 r2 = two31 - q2*ad; // Init. r2 = rem(2**p, |d|). 66 do { 67 p = p + 1; 68 q1 = 2*q1; // Update q1 = 2**p/|nc|. 69 r1 = 2*r1; // Update r1 = rem(2**p, |nc|). 70 if (r1 >= anc) { // (Must be an unsigned 71 q1 = q1 + 1; // comparison here). 72 r1 = r1 - anc; 73 } 74 q2 = 2*q2; // Update q2 = 2**p/|d|. 75 r2 = 2*r2; // Update r2 = rem(2**p, |d|). 76 if (r2 >= ad) { // (Must be an unsigned 77 q2 = q2 + 1; // comparison here). 78 r2 = r2 - ad; 79 } 80 delta = ad - r2; 81 } while (q1 < delta || (q1 == delta && r1 == 0)); 82 83 M = q2 + 1; 84 if (d < 0) M = -M; // Magic number and 85 s = p - 32; // shift amount to return. 86 87 return true; 88 } 89 90 //--------------------------transform_int_divide------------------------------- 91 // Convert a division by constant divisor into an alternate Ideal graph. 92 // Return null if no transformation occurs. 93 static Node *transform_int_divide( PhaseGVN *phase, Node *dividend, jint divisor ) { 94 95 // Check for invalid divisors 96 assert( divisor != 0 && divisor != min_jint, 97 "bad divisor for transforming to long multiply" ); 98 99 bool d_pos = divisor >= 0; 100 jint d = d_pos ? divisor : -divisor; 101 const int N = 32; 102 103 // Result 104 Node *q = nullptr; 105 106 if (d == 1) { 107 // division by +/- 1 108 if (!d_pos) { 109 // Just negate the value 110 q = new SubINode(phase->intcon(0), dividend); 111 } 112 } else if ( is_power_of_2(d) ) { 113 // division by +/- a power of 2 114 115 // See if we can simply do a shift without rounding 116 bool needs_rounding = true; 117 const Type *dt = phase->type(dividend); 118 const TypeInt *dti = dt->isa_int(); 119 if (dti && dti->_lo >= 0) { 120 // we don't need to round a positive dividend 121 needs_rounding = false; 122 } else if( dividend->Opcode() == Op_AndI ) { 123 // An AND mask of sufficient size clears the low bits and 124 // I can avoid rounding. 125 const TypeInt *andconi_t = phase->type( dividend->in(2) )->isa_int(); 126 if( andconi_t && andconi_t->is_con() ) { 127 jint andconi = andconi_t->get_con(); 128 if( andconi < 0 && is_power_of_2(-andconi) && (-andconi) >= d ) { 129 if( (-andconi) == d ) // Remove AND if it clears bits which will be shifted 130 dividend = dividend->in(1); 131 needs_rounding = false; 132 } 133 } 134 } 135 136 // Add rounding to the shift to handle the sign bit 137 int l = log2i_graceful(d - 1) + 1; 138 if (needs_rounding) { 139 // Divide-by-power-of-2 can be made into a shift, but you have to do 140 // more math for the rounding. You need to add 0 for positive 141 // numbers, and "i-1" for negative numbers. Example: i=4, so the 142 // shift is by 2. You need to add 3 to negative dividends and 0 to 143 // positive ones. So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1, 144 // (-2+3)>>2 becomes 0, etc. 145 146 // Compute 0 or -1, based on sign bit 147 Node *sign = phase->transform(new RShiftINode(dividend, phase->intcon(N - 1))); 148 // Mask sign bit to the low sign bits 149 Node *round = phase->transform(new URShiftINode(sign, phase->intcon(N - l))); 150 // Round up before shifting 151 dividend = phase->transform(new AddINode(dividend, round)); 152 } 153 154 // Shift for division 155 q = new RShiftINode(dividend, phase->intcon(l)); 156 157 if (!d_pos) { 158 q = new SubINode(phase->intcon(0), phase->transform(q)); 159 } 160 } else { 161 // Attempt the jint constant divide -> multiply transform found in 162 // "Division by Invariant Integers using Multiplication" 163 // by Granlund and Montgomery 164 // See also "Hacker's Delight", chapter 10 by Warren. 165 166 jint magic_const; 167 jint shift_const; 168 if (magic_int_divide_constants(d, magic_const, shift_const)) { 169 Node *magic = phase->longcon(magic_const); 170 Node *dividend_long = phase->transform(new ConvI2LNode(dividend)); 171 172 // Compute the high half of the dividend x magic multiplication 173 Node *mul_hi = phase->transform(new MulLNode(dividend_long, magic)); 174 175 if (magic_const < 0) { 176 mul_hi = phase->transform(new RShiftLNode(mul_hi, phase->intcon(N))); 177 mul_hi = phase->transform(new ConvL2INode(mul_hi)); 178 179 // The magic multiplier is too large for a 32 bit constant. We've adjusted 180 // it down by 2^32, but have to add 1 dividend back in after the multiplication. 181 // This handles the "overflow" case described by Granlund and Montgomery. 182 mul_hi = phase->transform(new AddINode(dividend, mul_hi)); 183 184 // Shift over the (adjusted) mulhi 185 if (shift_const != 0) { 186 mul_hi = phase->transform(new RShiftINode(mul_hi, phase->intcon(shift_const))); 187 } 188 } else { 189 // No add is required, we can merge the shifts together. 190 mul_hi = phase->transform(new RShiftLNode(mul_hi, phase->intcon(N + shift_const))); 191 mul_hi = phase->transform(new ConvL2INode(mul_hi)); 192 } 193 194 // Get a 0 or -1 from the sign of the dividend. 195 Node *addend0 = mul_hi; 196 Node *addend1 = phase->transform(new RShiftINode(dividend, phase->intcon(N-1))); 197 198 // If the divisor is negative, swap the order of the input addends; 199 // this has the effect of negating the quotient. 200 if (!d_pos) { 201 Node *temp = addend0; addend0 = addend1; addend1 = temp; 202 } 203 204 // Adjust the final quotient by subtracting -1 (adding 1) 205 // from the mul_hi. 206 q = new SubINode(addend0, addend1); 207 } 208 } 209 210 return q; 211 } 212 213 //---------------------magic_long_divide_constants----------------------------- 214 // Compute magic multiplier and shift constant for converting a 64 bit divide 215 // by constant into a multiply/shift/add series. Return false if calculations 216 // fail. 217 // 218 // Borrowed almost verbatim from Hacker's Delight by Henry S. Warren, Jr. with 219 // minor type name and parameter changes. Adjusted to 64 bit word width. 220 static bool magic_long_divide_constants(jlong d, jlong &M, jint &s) { 221 int64_t p; 222 uint64_t ad, anc, delta, q1, r1, q2, r2, t; 223 const uint64_t two63 = UCONST64(0x8000000000000000); // 2**63. 224 225 ad = ABS(d); 226 if (d == 0 || d == 1) return false; 227 t = two63 + ((uint64_t)d >> 63); 228 anc = t - 1 - t%ad; // Absolute value of nc. 229 p = 63; // Init. p. 230 q1 = two63/anc; // Init. q1 = 2**p/|nc|. 231 r1 = two63 - q1*anc; // Init. r1 = rem(2**p, |nc|). 232 q2 = two63/ad; // Init. q2 = 2**p/|d|. 233 r2 = two63 - q2*ad; // Init. r2 = rem(2**p, |d|). 234 do { 235 p = p + 1; 236 q1 = 2*q1; // Update q1 = 2**p/|nc|. 237 r1 = 2*r1; // Update r1 = rem(2**p, |nc|). 238 if (r1 >= anc) { // (Must be an unsigned 239 q1 = q1 + 1; // comparison here). 240 r1 = r1 - anc; 241 } 242 q2 = 2*q2; // Update q2 = 2**p/|d|. 243 r2 = 2*r2; // Update r2 = rem(2**p, |d|). 244 if (r2 >= ad) { // (Must be an unsigned 245 q2 = q2 + 1; // comparison here). 246 r2 = r2 - ad; 247 } 248 delta = ad - r2; 249 } while (q1 < delta || (q1 == delta && r1 == 0)); 250 251 M = q2 + 1; 252 if (d < 0) M = -M; // Magic number and 253 s = p - 64; // shift amount to return. 254 255 return true; 256 } 257 258 //---------------------long_by_long_mulhi-------------------------------------- 259 // Generate ideal node graph for upper half of a 64 bit x 64 bit multiplication 260 static Node* long_by_long_mulhi(PhaseGVN* phase, Node* dividend, jlong magic_const) { 261 // If the architecture supports a 64x64 mulhi, there is 262 // no need to synthesize it in ideal nodes. 263 if (Matcher::has_match_rule(Op_MulHiL)) { 264 Node* v = phase->longcon(magic_const); 265 return new MulHiLNode(dividend, v); 266 } 267 268 // Taken from Hacker's Delight, Fig. 8-2. Multiply high signed. 269 // 270 // int mulhs(int u, int v) { 271 // unsigned u0, v0, w0; 272 // int u1, v1, w1, w2, t; 273 // 274 // u0 = u & 0xFFFF; u1 = u >> 16; 275 // v0 = v & 0xFFFF; v1 = v >> 16; 276 // w0 = u0*v0; 277 // t = u1*v0 + (w0 >> 16); 278 // w1 = t & 0xFFFF; 279 // w2 = t >> 16; 280 // w1 = u0*v1 + w1; 281 // return u1*v1 + w2 + (w1 >> 16); 282 // } 283 // 284 // Note: The version above is for 32x32 multiplications, while the 285 // following inline comments are adapted to 64x64. 286 287 const int N = 64; 288 289 // Dummy node to keep intermediate nodes alive during construction 290 Node* hook = new Node(4); 291 292 // u0 = u & 0xFFFFFFFF; u1 = u >> 32; 293 Node* u0 = phase->transform(new AndLNode(dividend, phase->longcon(0xFFFFFFFF))); 294 Node* u1 = phase->transform(new RShiftLNode(dividend, phase->intcon(N / 2))); 295 hook->init_req(0, u0); 296 hook->init_req(1, u1); 297 298 // v0 = v & 0xFFFFFFFF; v1 = v >> 32; 299 Node* v0 = phase->longcon(magic_const & 0xFFFFFFFF); 300 Node* v1 = phase->longcon(magic_const >> (N / 2)); 301 302 // w0 = u0*v0; 303 Node* w0 = phase->transform(new MulLNode(u0, v0)); 304 305 // t = u1*v0 + (w0 >> 32); 306 Node* u1v0 = phase->transform(new MulLNode(u1, v0)); 307 Node* temp = phase->transform(new URShiftLNode(w0, phase->intcon(N / 2))); 308 Node* t = phase->transform(new AddLNode(u1v0, temp)); 309 hook->init_req(2, t); 310 311 // w1 = t & 0xFFFFFFFF; 312 Node* w1 = phase->transform(new AndLNode(t, phase->longcon(0xFFFFFFFF))); 313 hook->init_req(3, w1); 314 315 // w2 = t >> 32; 316 Node* w2 = phase->transform(new RShiftLNode(t, phase->intcon(N / 2))); 317 318 // w1 = u0*v1 + w1; 319 Node* u0v1 = phase->transform(new MulLNode(u0, v1)); 320 w1 = phase->transform(new AddLNode(u0v1, w1)); 321 322 // return u1*v1 + w2 + (w1 >> 32); 323 Node* u1v1 = phase->transform(new MulLNode(u1, v1)); 324 Node* temp1 = phase->transform(new AddLNode(u1v1, w2)); 325 Node* temp2 = phase->transform(new RShiftLNode(w1, phase->intcon(N / 2))); 326 327 // Remove the bogus extra edges used to keep things alive 328 hook->destruct(phase); 329 330 return new AddLNode(temp1, temp2); 331 } 332 333 334 //--------------------------transform_long_divide------------------------------ 335 // Convert a division by constant divisor into an alternate Ideal graph. 336 // Return null if no transformation occurs. 337 static Node *transform_long_divide( PhaseGVN *phase, Node *dividend, jlong divisor ) { 338 // Check for invalid divisors 339 assert( divisor != 0L && divisor != min_jlong, 340 "bad divisor for transforming to long multiply" ); 341 342 bool d_pos = divisor >= 0; 343 jlong d = d_pos ? divisor : -divisor; 344 const int N = 64; 345 346 // Result 347 Node *q = nullptr; 348 349 if (d == 1) { 350 // division by +/- 1 351 if (!d_pos) { 352 // Just negate the value 353 q = new SubLNode(phase->longcon(0), dividend); 354 } 355 } else if ( is_power_of_2(d) ) { 356 357 // division by +/- a power of 2 358 359 // See if we can simply do a shift without rounding 360 bool needs_rounding = true; 361 const Type *dt = phase->type(dividend); 362 const TypeLong *dtl = dt->isa_long(); 363 364 if (dtl && dtl->_lo > 0) { 365 // we don't need to round a positive dividend 366 needs_rounding = false; 367 } else if( dividend->Opcode() == Op_AndL ) { 368 // An AND mask of sufficient size clears the low bits and 369 // I can avoid rounding. 370 const TypeLong *andconl_t = phase->type( dividend->in(2) )->isa_long(); 371 if( andconl_t && andconl_t->is_con() ) { 372 jlong andconl = andconl_t->get_con(); 373 if( andconl < 0 && is_power_of_2(-andconl) && (-andconl) >= d ) { 374 if( (-andconl) == d ) // Remove AND if it clears bits which will be shifted 375 dividend = dividend->in(1); 376 needs_rounding = false; 377 } 378 } 379 } 380 381 // Add rounding to the shift to handle the sign bit 382 int l = log2i_graceful(d - 1) + 1; 383 if (needs_rounding) { 384 // Divide-by-power-of-2 can be made into a shift, but you have to do 385 // more math for the rounding. You need to add 0 for positive 386 // numbers, and "i-1" for negative numbers. Example: i=4, so the 387 // shift is by 2. You need to add 3 to negative dividends and 0 to 388 // positive ones. So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1, 389 // (-2+3)>>2 becomes 0, etc. 390 391 // Compute 0 or -1, based on sign bit 392 Node *sign = phase->transform(new RShiftLNode(dividend, phase->intcon(N - 1))); 393 // Mask sign bit to the low sign bits 394 Node *round = phase->transform(new URShiftLNode(sign, phase->intcon(N - l))); 395 // Round up before shifting 396 dividend = phase->transform(new AddLNode(dividend, round)); 397 } 398 399 // Shift for division 400 q = new RShiftLNode(dividend, phase->intcon(l)); 401 402 if (!d_pos) { 403 q = new SubLNode(phase->longcon(0), phase->transform(q)); 404 } 405 } else if ( !Matcher::use_asm_for_ldiv_by_con(d) ) { // Use hardware DIV instruction when 406 // it is faster than code generated below. 407 // Attempt the jlong constant divide -> multiply transform found in 408 // "Division by Invariant Integers using Multiplication" 409 // by Granlund and Montgomery 410 // See also "Hacker's Delight", chapter 10 by Warren. 411 412 jlong magic_const; 413 jint shift_const; 414 if (magic_long_divide_constants(d, magic_const, shift_const)) { 415 // Compute the high half of the dividend x magic multiplication 416 Node *mul_hi = phase->transform(long_by_long_mulhi(phase, dividend, magic_const)); 417 418 // The high half of the 128-bit multiply is computed. 419 if (magic_const < 0) { 420 // The magic multiplier is too large for a 64 bit constant. We've adjusted 421 // it down by 2^64, but have to add 1 dividend back in after the multiplication. 422 // This handles the "overflow" case described by Granlund and Montgomery. 423 mul_hi = phase->transform(new AddLNode(dividend, mul_hi)); 424 } 425 426 // Shift over the (adjusted) mulhi 427 if (shift_const != 0) { 428 mul_hi = phase->transform(new RShiftLNode(mul_hi, phase->intcon(shift_const))); 429 } 430 431 // Get a 0 or -1 from the sign of the dividend. 432 Node *addend0 = mul_hi; 433 Node *addend1 = phase->transform(new RShiftLNode(dividend, phase->intcon(N-1))); 434 435 // If the divisor is negative, swap the order of the input addends; 436 // this has the effect of negating the quotient. 437 if (!d_pos) { 438 Node *temp = addend0; addend0 = addend1; addend1 = temp; 439 } 440 441 // Adjust the final quotient by subtracting -1 (adding 1) 442 // from the mul_hi. 443 q = new SubLNode(addend0, addend1); 444 } 445 } 446 447 return q; 448 } 449 450 //============================================================================= 451 //------------------------------Identity--------------------------------------- 452 // If the divisor is 1, we are an identity on the dividend. 453 Node* DivINode::Identity(PhaseGVN* phase) { 454 return (phase->type( in(2) )->higher_equal(TypeInt::ONE)) ? in(1) : this; 455 } 456 457 //------------------------------Idealize--------------------------------------- 458 // Divides can be changed to multiplies and/or shifts 459 Node *DivINode::Ideal(PhaseGVN *phase, bool can_reshape) { 460 if (in(0) && remove_dead_region(phase, can_reshape)) return this; 461 // Don't bother trying to transform a dead node 462 if( in(0) && in(0)->is_top() ) return nullptr; 463 464 const Type *t = phase->type( in(2) ); 465 if( t == TypeInt::ONE ) // Identity? 466 return nullptr; // Skip it 467 468 const TypeInt *ti = t->isa_int(); 469 if( !ti ) return nullptr; 470 471 // Check for useless control input 472 // Check for excluding div-zero case 473 if (in(0) && (ti->_hi < 0 || ti->_lo > 0)) { 474 set_req(0, nullptr); // Yank control input 475 return this; 476 } 477 478 if( !ti->is_con() ) return nullptr; 479 jint i = ti->get_con(); // Get divisor 480 481 if (i == 0) return nullptr; // Dividing by zero constant does not idealize 482 483 // Dividing by MININT does not optimize as a power-of-2 shift. 484 if( i == min_jint ) return nullptr; 485 486 return transform_int_divide( phase, in(1), i ); 487 } 488 489 //------------------------------Value------------------------------------------ 490 // A DivINode divides its inputs. The third input is a Control input, used to 491 // prevent hoisting the divide above an unsafe test. 492 const Type* DivINode::Value(PhaseGVN* phase) const { 493 // Either input is TOP ==> the result is TOP 494 const Type *t1 = phase->type( in(1) ); 495 const Type *t2 = phase->type( in(2) ); 496 if( t1 == Type::TOP ) return Type::TOP; 497 if( t2 == Type::TOP ) return Type::TOP; 498 499 // x/x == 1 since we always generate the dynamic divisor check for 0. 500 if (in(1) == in(2)) { 501 return TypeInt::ONE; 502 } 503 504 // Either input is BOTTOM ==> the result is the local BOTTOM 505 const Type *bot = bottom_type(); 506 if( (t1 == bot) || (t2 == bot) || 507 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 508 return bot; 509 510 // Divide the two numbers. We approximate. 511 // If divisor is a constant and not zero 512 const TypeInt *i1 = t1->is_int(); 513 const TypeInt *i2 = t2->is_int(); 514 int widen = MAX2(i1->_widen, i2->_widen); 515 516 if( i2->is_con() && i2->get_con() != 0 ) { 517 int32_t d = i2->get_con(); // Divisor 518 jint lo, hi; 519 if( d >= 0 ) { 520 lo = i1->_lo/d; 521 hi = i1->_hi/d; 522 } else { 523 if( d == -1 && i1->_lo == min_jint ) { 524 // 'min_jint/-1' throws arithmetic exception during compilation 525 lo = min_jint; 526 // do not support holes, 'hi' must go to either min_jint or max_jint: 527 // [min_jint, -10]/[-1,-1] ==> [min_jint] UNION [10,max_jint] 528 hi = i1->_hi == min_jint ? min_jint : max_jint; 529 } else { 530 lo = i1->_hi/d; 531 hi = i1->_lo/d; 532 } 533 } 534 return TypeInt::make(lo, hi, widen); 535 } 536 537 // If the dividend is a constant 538 if( i1->is_con() ) { 539 int32_t d = i1->get_con(); 540 if( d < 0 ) { 541 if( d == min_jint ) { 542 // (-min_jint) == min_jint == (min_jint / -1) 543 return TypeInt::make(min_jint, max_jint/2 + 1, widen); 544 } else { 545 return TypeInt::make(d, -d, widen); 546 } 547 } 548 return TypeInt::make(-d, d, widen); 549 } 550 551 // Otherwise we give up all hope 552 return TypeInt::INT; 553 } 554 555 556 //============================================================================= 557 //------------------------------Identity--------------------------------------- 558 // If the divisor is 1, we are an identity on the dividend. 559 Node* DivLNode::Identity(PhaseGVN* phase) { 560 return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : this; 561 } 562 563 //------------------------------Idealize--------------------------------------- 564 // Dividing by a power of 2 is a shift. 565 Node *DivLNode::Ideal( PhaseGVN *phase, bool can_reshape) { 566 if (in(0) && remove_dead_region(phase, can_reshape)) return this; 567 // Don't bother trying to transform a dead node 568 if( in(0) && in(0)->is_top() ) return nullptr; 569 570 const Type *t = phase->type( in(2) ); 571 if( t == TypeLong::ONE ) // Identity? 572 return nullptr; // Skip it 573 574 const TypeLong *tl = t->isa_long(); 575 if( !tl ) return nullptr; 576 577 // Check for useless control input 578 // Check for excluding div-zero case 579 if (in(0) && (tl->_hi < 0 || tl->_lo > 0)) { 580 set_req(0, nullptr); // Yank control input 581 return this; 582 } 583 584 if( !tl->is_con() ) return nullptr; 585 jlong l = tl->get_con(); // Get divisor 586 587 if (l == 0) return nullptr; // Dividing by zero constant does not idealize 588 589 // Dividing by MINLONG does not optimize as a power-of-2 shift. 590 if( l == min_jlong ) return nullptr; 591 592 return transform_long_divide( phase, in(1), l ); 593 } 594 595 //------------------------------Value------------------------------------------ 596 // A DivLNode divides its inputs. The third input is a Control input, used to 597 // prevent hoisting the divide above an unsafe test. 598 const Type* DivLNode::Value(PhaseGVN* phase) const { 599 // Either input is TOP ==> the result is TOP 600 const Type *t1 = phase->type( in(1) ); 601 const Type *t2 = phase->type( in(2) ); 602 if( t1 == Type::TOP ) return Type::TOP; 603 if( t2 == Type::TOP ) return Type::TOP; 604 605 // x/x == 1 since we always generate the dynamic divisor check for 0. 606 if (in(1) == in(2)) { 607 return TypeLong::ONE; 608 } 609 610 // Either input is BOTTOM ==> the result is the local BOTTOM 611 const Type *bot = bottom_type(); 612 if( (t1 == bot) || (t2 == bot) || 613 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 614 return bot; 615 616 // Divide the two numbers. We approximate. 617 // If divisor is a constant and not zero 618 const TypeLong *i1 = t1->is_long(); 619 const TypeLong *i2 = t2->is_long(); 620 int widen = MAX2(i1->_widen, i2->_widen); 621 622 if( i2->is_con() && i2->get_con() != 0 ) { 623 jlong d = i2->get_con(); // Divisor 624 jlong lo, hi; 625 if( d >= 0 ) { 626 lo = i1->_lo/d; 627 hi = i1->_hi/d; 628 } else { 629 if( d == CONST64(-1) && i1->_lo == min_jlong ) { 630 // 'min_jlong/-1' throws arithmetic exception during compilation 631 lo = min_jlong; 632 // do not support holes, 'hi' must go to either min_jlong or max_jlong: 633 // [min_jlong, -10]/[-1,-1] ==> [min_jlong] UNION [10,max_jlong] 634 hi = i1->_hi == min_jlong ? min_jlong : max_jlong; 635 } else { 636 lo = i1->_hi/d; 637 hi = i1->_lo/d; 638 } 639 } 640 return TypeLong::make(lo, hi, widen); 641 } 642 643 // If the dividend is a constant 644 if( i1->is_con() ) { 645 jlong d = i1->get_con(); 646 if( d < 0 ) { 647 if( d == min_jlong ) { 648 // (-min_jlong) == min_jlong == (min_jlong / -1) 649 return TypeLong::make(min_jlong, max_jlong/2 + 1, widen); 650 } else { 651 return TypeLong::make(d, -d, widen); 652 } 653 } 654 return TypeLong::make(-d, d, widen); 655 } 656 657 // Otherwise we give up all hope 658 return TypeLong::LONG; 659 } 660 661 662 //============================================================================= 663 //------------------------------Value------------------------------------------ 664 // An DivFNode divides its inputs. The third input is a Control input, used to 665 // prevent hoisting the divide above an unsafe test. 666 const Type* DivFNode::Value(PhaseGVN* phase) const { 667 // Either input is TOP ==> the result is TOP 668 const Type *t1 = phase->type( in(1) ); 669 const Type *t2 = phase->type( in(2) ); 670 if( t1 == Type::TOP ) return Type::TOP; 671 if( t2 == Type::TOP ) return Type::TOP; 672 673 // Either input is BOTTOM ==> the result is the local BOTTOM 674 const Type *bot = bottom_type(); 675 if( (t1 == bot) || (t2 == bot) || 676 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 677 return bot; 678 679 // x/x == 1, we ignore 0/0. 680 // Note: if t1 and t2 are zero then result is NaN (JVMS page 213) 681 // Does not work for variables because of NaN's 682 if (in(1) == in(2) && t1->base() == Type::FloatCon && 683 !g_isnan(t1->getf()) && g_isfinite(t1->getf()) && t1->getf() != 0.0) { // could be negative ZERO or NaN 684 return TypeF::ONE; 685 } 686 687 if( t2 == TypeF::ONE ) 688 return t1; 689 690 // If divisor is a constant and not zero, divide them numbers 691 if( t1->base() == Type::FloatCon && 692 t2->base() == Type::FloatCon && 693 t2->getf() != 0.0 ) // could be negative zero 694 return TypeF::make( t1->getf()/t2->getf() ); 695 696 // If the dividend is a constant zero 697 // Note: if t1 and t2 are zero then result is NaN (JVMS page 213) 698 // Test TypeF::ZERO is not sufficient as it could be negative zero 699 700 if( t1 == TypeF::ZERO && !g_isnan(t2->getf()) && t2->getf() != 0.0 ) 701 return TypeF::ZERO; 702 703 // Otherwise we give up all hope 704 return Type::FLOAT; 705 } 706 707 //------------------------------isA_Copy--------------------------------------- 708 // Dividing by self is 1. 709 // If the divisor is 1, we are an identity on the dividend. 710 Node* DivFNode::Identity(PhaseGVN* phase) { 711 return (phase->type( in(2) ) == TypeF::ONE) ? in(1) : this; 712 } 713 714 715 //------------------------------Idealize--------------------------------------- 716 Node *DivFNode::Ideal(PhaseGVN *phase, bool can_reshape) { 717 if (in(0) && remove_dead_region(phase, can_reshape)) return this; 718 // Don't bother trying to transform a dead node 719 if( in(0) && in(0)->is_top() ) return nullptr; 720 721 const Type *t2 = phase->type( in(2) ); 722 if( t2 == TypeF::ONE ) // Identity? 723 return nullptr; // Skip it 724 725 const TypeF *tf = t2->isa_float_constant(); 726 if( !tf ) return nullptr; 727 if( tf->base() != Type::FloatCon ) return nullptr; 728 729 // Check for out of range values 730 if( tf->is_nan() || !tf->is_finite() ) return nullptr; 731 732 // Get the value 733 float f = tf->getf(); 734 int exp; 735 736 // Only for special case of dividing by a power of 2 737 if( frexp((double)f, &exp) != 0.5 ) return nullptr; 738 739 // Limit the range of acceptable exponents 740 if( exp < -126 || exp > 126 ) return nullptr; 741 742 // Compute the reciprocal 743 float reciprocal = ((float)1.0) / f; 744 745 assert( frexp((double)reciprocal, &exp) == 0.5, "reciprocal should be power of 2" ); 746 747 // return multiplication by the reciprocal 748 return (new MulFNode(in(1), phase->makecon(TypeF::make(reciprocal)))); 749 } 750 751 //============================================================================= 752 //------------------------------Value------------------------------------------ 753 // An DivDNode divides its inputs. The third input is a Control input, used to 754 // prevent hoisting the divide above an unsafe test. 755 const Type* DivDNode::Value(PhaseGVN* phase) const { 756 // Either input is TOP ==> the result is TOP 757 const Type *t1 = phase->type( in(1) ); 758 const Type *t2 = phase->type( in(2) ); 759 if( t1 == Type::TOP ) return Type::TOP; 760 if( t2 == Type::TOP ) return Type::TOP; 761 762 // Either input is BOTTOM ==> the result is the local BOTTOM 763 const Type *bot = bottom_type(); 764 if( (t1 == bot) || (t2 == bot) || 765 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 766 return bot; 767 768 // x/x == 1, we ignore 0/0. 769 // Note: if t1 and t2 are zero then result is NaN (JVMS page 213) 770 // Does not work for variables because of NaN's 771 if (in(1) == in(2) && t1->base() == Type::DoubleCon && 772 !g_isnan(t1->getd()) && g_isfinite(t1->getd()) && t1->getd() != 0.0) { // could be negative ZERO or NaN 773 return TypeD::ONE; 774 } 775 776 if( t2 == TypeD::ONE ) 777 return t1; 778 779 // IA32 would only execute this for non-strict FP, which is never the 780 // case now. 781 #if ! defined(IA32) 782 // If divisor is a constant and not zero, divide them numbers 783 if( t1->base() == Type::DoubleCon && 784 t2->base() == Type::DoubleCon && 785 t2->getd() != 0.0 ) // could be negative zero 786 return TypeD::make( t1->getd()/t2->getd() ); 787 #endif 788 789 // If the dividend is a constant zero 790 // Note: if t1 and t2 are zero then result is NaN (JVMS page 213) 791 // Test TypeF::ZERO is not sufficient as it could be negative zero 792 if( t1 == TypeD::ZERO && !g_isnan(t2->getd()) && t2->getd() != 0.0 ) 793 return TypeD::ZERO; 794 795 // Otherwise we give up all hope 796 return Type::DOUBLE; 797 } 798 799 800 //------------------------------isA_Copy--------------------------------------- 801 // Dividing by self is 1. 802 // If the divisor is 1, we are an identity on the dividend. 803 Node* DivDNode::Identity(PhaseGVN* phase) { 804 return (phase->type( in(2) ) == TypeD::ONE) ? in(1) : this; 805 } 806 807 //------------------------------Idealize--------------------------------------- 808 Node *DivDNode::Ideal(PhaseGVN *phase, bool can_reshape) { 809 if (in(0) && remove_dead_region(phase, can_reshape)) return this; 810 // Don't bother trying to transform a dead node 811 if( in(0) && in(0)->is_top() ) return nullptr; 812 813 const Type *t2 = phase->type( in(2) ); 814 if( t2 == TypeD::ONE ) // Identity? 815 return nullptr; // Skip it 816 817 const TypeD *td = t2->isa_double_constant(); 818 if( !td ) return nullptr; 819 if( td->base() != Type::DoubleCon ) return nullptr; 820 821 // Check for out of range values 822 if( td->is_nan() || !td->is_finite() ) return nullptr; 823 824 // Get the value 825 double d = td->getd(); 826 int exp; 827 828 // Only for special case of dividing by a power of 2 829 if( frexp(d, &exp) != 0.5 ) return nullptr; 830 831 // Limit the range of acceptable exponents 832 if( exp < -1021 || exp > 1022 ) return nullptr; 833 834 // Compute the reciprocal 835 double reciprocal = 1.0 / d; 836 837 assert( frexp(reciprocal, &exp) == 0.5, "reciprocal should be power of 2" ); 838 839 // return multiplication by the reciprocal 840 return (new MulDNode(in(1), phase->makecon(TypeD::make(reciprocal)))); 841 } 842 843 //============================================================================= 844 //------------------------------Identity--------------------------------------- 845 // If the divisor is 1, we are an identity on the dividend. 846 Node* UDivINode::Identity(PhaseGVN* phase) { 847 return (phase->type( in(2) )->higher_equal(TypeInt::ONE)) ? in(1) : this; 848 } 849 //------------------------------Value------------------------------------------ 850 // A UDivINode divides its inputs. The third input is a Control input, used to 851 // prevent hoisting the divide above an unsafe test. 852 const Type* UDivINode::Value(PhaseGVN* phase) const { 853 // Either input is TOP ==> the result is TOP 854 const Type *t1 = phase->type( in(1) ); 855 const Type *t2 = phase->type( in(2) ); 856 if( t1 == Type::TOP ) return Type::TOP; 857 if( t2 == Type::TOP ) return Type::TOP; 858 859 // x/x == 1 since we always generate the dynamic divisor check for 0. 860 if (in(1) == in(2)) { 861 return TypeInt::ONE; 862 } 863 864 // Either input is BOTTOM ==> the result is the local BOTTOM 865 const Type *bot = bottom_type(); 866 if( (t1 == bot) || (t2 == bot) || 867 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 868 return bot; 869 870 // Otherwise we give up all hope 871 return TypeInt::INT; 872 } 873 874 //------------------------------Idealize--------------------------------------- 875 Node *UDivINode::Ideal(PhaseGVN *phase, bool can_reshape) { 876 // Check for dead control input 877 if (in(0) && remove_dead_region(phase, can_reshape)) return this; 878 return nullptr; 879 } 880 881 882 //============================================================================= 883 //------------------------------Identity--------------------------------------- 884 // If the divisor is 1, we are an identity on the dividend. 885 Node* UDivLNode::Identity(PhaseGVN* phase) { 886 return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : this; 887 } 888 //------------------------------Value------------------------------------------ 889 // A UDivLNode divides its inputs. The third input is a Control input, used to 890 // prevent hoisting the divide above an unsafe test. 891 const Type* UDivLNode::Value(PhaseGVN* phase) const { 892 // Either input is TOP ==> the result is TOP 893 const Type *t1 = phase->type( in(1) ); 894 const Type *t2 = phase->type( in(2) ); 895 if( t1 == Type::TOP ) return Type::TOP; 896 if( t2 == Type::TOP ) return Type::TOP; 897 898 // x/x == 1 since we always generate the dynamic divisor check for 0. 899 if (in(1) == in(2)) { 900 return TypeLong::ONE; 901 } 902 903 // Either input is BOTTOM ==> the result is the local BOTTOM 904 const Type *bot = bottom_type(); 905 if( (t1 == bot) || (t2 == bot) || 906 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 907 return bot; 908 909 // Otherwise we give up all hope 910 return TypeLong::LONG; 911 } 912 913 //------------------------------Idealize--------------------------------------- 914 Node *UDivLNode::Ideal(PhaseGVN *phase, bool can_reshape) { 915 // Check for dead control input 916 if (in(0) && remove_dead_region(phase, can_reshape)) return this; 917 return nullptr; 918 } 919 920 921 //============================================================================= 922 //------------------------------Idealize--------------------------------------- 923 Node *ModINode::Ideal(PhaseGVN *phase, bool can_reshape) { 924 // Check for dead control input 925 if( in(0) && remove_dead_region(phase, can_reshape) ) return this; 926 // Don't bother trying to transform a dead node 927 if( in(0) && in(0)->is_top() ) return nullptr; 928 929 // Get the modulus 930 const Type *t = phase->type( in(2) ); 931 if( t == Type::TOP ) return nullptr; 932 const TypeInt *ti = t->is_int(); 933 934 // Check for useless control input 935 // Check for excluding mod-zero case 936 if (in(0) && (ti->_hi < 0 || ti->_lo > 0)) { 937 set_req(0, nullptr); // Yank control input 938 return this; 939 } 940 941 // See if we are MOD'ing by 2^k or 2^k-1. 942 if( !ti->is_con() ) return nullptr; 943 jint con = ti->get_con(); 944 945 Node *hook = new Node(1); 946 947 // First, special check for modulo 2^k-1 948 if( con >= 0 && con < max_jint && is_power_of_2(con+1) ) { 949 uint k = exact_log2(con+1); // Extract k 950 951 // Basic algorithm by David Detlefs. See fastmod_int.java for gory details. 952 static int unroll_factor[] = { 999, 999, 29, 14, 9, 7, 5, 4, 4, 3, 3, 2, 2, 2, 2, 2, 1 /*past here we assume 1 forever*/}; 953 int trip_count = 1; 954 if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k]; 955 956 // If the unroll factor is not too large, and if conditional moves are 957 // ok, then use this case 958 if( trip_count <= 5 && ConditionalMoveLimit != 0 ) { 959 Node *x = in(1); // Value being mod'd 960 Node *divisor = in(2); // Also is mask 961 962 hook->init_req(0, x); // Add a use to x to prevent him from dying 963 // Generate code to reduce X rapidly to nearly 2^k-1. 964 for( int i = 0; i < trip_count; i++ ) { 965 Node *xl = phase->transform( new AndINode(x,divisor) ); 966 Node *xh = phase->transform( new RShiftINode(x,phase->intcon(k)) ); // Must be signed 967 x = phase->transform( new AddINode(xh,xl) ); 968 hook->set_req(0, x); 969 } 970 971 // Generate sign-fixup code. Was original value positive? 972 // int hack_res = (i >= 0) ? divisor : 1; 973 Node *cmp1 = phase->transform( new CmpINode( in(1), phase->intcon(0) ) ); 974 Node *bol1 = phase->transform( new BoolNode( cmp1, BoolTest::ge ) ); 975 Node *cmov1= phase->transform( new CMoveINode(bol1, phase->intcon(1), divisor, TypeInt::POS) ); 976 // if( x >= hack_res ) x -= divisor; 977 Node *sub = phase->transform( new SubINode( x, divisor ) ); 978 Node *cmp2 = phase->transform( new CmpINode( x, cmov1 ) ); 979 Node *bol2 = phase->transform( new BoolNode( cmp2, BoolTest::ge ) ); 980 // Convention is to not transform the return value of an Ideal 981 // since Ideal is expected to return a modified 'this' or a new node. 982 Node *cmov2= new CMoveINode(bol2, x, sub, TypeInt::INT); 983 // cmov2 is now the mod 984 985 // Now remove the bogus extra edges used to keep things alive 986 hook->destruct(phase); 987 return cmov2; 988 } 989 } 990 991 // Fell thru, the unroll case is not appropriate. Transform the modulo 992 // into a long multiply/int multiply/subtract case 993 994 // Cannot handle mod 0, and min_jint isn't handled by the transform 995 if( con == 0 || con == min_jint ) return nullptr; 996 997 // Get the absolute value of the constant; at this point, we can use this 998 jint pos_con = (con >= 0) ? con : -con; 999 1000 // integer Mod 1 is always 0 1001 if( pos_con == 1 ) return new ConINode(TypeInt::ZERO); 1002 1003 int log2_con = -1; 1004 1005 // If this is a power of two, they maybe we can mask it 1006 if (is_power_of_2(pos_con)) { 1007 log2_con = log2i_exact(pos_con); 1008 1009 const Type *dt = phase->type(in(1)); 1010 const TypeInt *dti = dt->isa_int(); 1011 1012 // See if this can be masked, if the dividend is non-negative 1013 if( dti && dti->_lo >= 0 ) 1014 return ( new AndINode( in(1), phase->intcon( pos_con-1 ) ) ); 1015 } 1016 1017 // Save in(1) so that it cannot be changed or deleted 1018 hook->init_req(0, in(1)); 1019 1020 // Divide using the transform from DivI to MulL 1021 Node *result = transform_int_divide( phase, in(1), pos_con ); 1022 if (result != nullptr) { 1023 Node *divide = phase->transform(result); 1024 1025 // Re-multiply, using a shift if this is a power of two 1026 Node *mult = nullptr; 1027 1028 if( log2_con >= 0 ) 1029 mult = phase->transform( new LShiftINode( divide, phase->intcon( log2_con ) ) ); 1030 else 1031 mult = phase->transform( new MulINode( divide, phase->intcon( pos_con ) ) ); 1032 1033 // Finally, subtract the multiplied divided value from the original 1034 result = new SubINode( in(1), mult ); 1035 } 1036 1037 // Now remove the bogus extra edges used to keep things alive 1038 hook->destruct(phase); 1039 1040 // return the value 1041 return result; 1042 } 1043 1044 //------------------------------Value------------------------------------------ 1045 const Type* ModINode::Value(PhaseGVN* phase) const { 1046 // Either input is TOP ==> the result is TOP 1047 const Type *t1 = phase->type( in(1) ); 1048 const Type *t2 = phase->type( in(2) ); 1049 if( t1 == Type::TOP ) return Type::TOP; 1050 if( t2 == Type::TOP ) return Type::TOP; 1051 1052 // We always generate the dynamic check for 0. 1053 // 0 MOD X is 0 1054 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO; 1055 // X MOD X is 0 1056 if (in(1) == in(2)) { 1057 return TypeInt::ZERO; 1058 } 1059 1060 // Either input is BOTTOM ==> the result is the local BOTTOM 1061 const Type *bot = bottom_type(); 1062 if( (t1 == bot) || (t2 == bot) || 1063 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 1064 return bot; 1065 1066 const TypeInt *i1 = t1->is_int(); 1067 const TypeInt *i2 = t2->is_int(); 1068 if( !i1->is_con() || !i2->is_con() ) { 1069 if( i1->_lo >= 0 && i2->_lo >= 0 ) 1070 return TypeInt::POS; 1071 // If both numbers are not constants, we know little. 1072 return TypeInt::INT; 1073 } 1074 // Mod by zero? Throw exception at runtime! 1075 if( !i2->get_con() ) return TypeInt::POS; 1076 1077 // We must be modulo'ing 2 float constants. 1078 // Check for min_jint % '-1', result is defined to be '0'. 1079 if( i1->get_con() == min_jint && i2->get_con() == -1 ) 1080 return TypeInt::ZERO; 1081 1082 return TypeInt::make( i1->get_con() % i2->get_con() ); 1083 } 1084 1085 //============================================================================= 1086 //------------------------------Idealize--------------------------------------- 1087 Node *UModINode::Ideal(PhaseGVN *phase, bool can_reshape) { 1088 // Check for dead control input 1089 if( in(0) && remove_dead_region(phase, can_reshape) ) return this; 1090 return nullptr; 1091 } 1092 1093 //============================================================================= 1094 //------------------------------Idealize--------------------------------------- 1095 Node *ModLNode::Ideal(PhaseGVN *phase, bool can_reshape) { 1096 // Check for dead control input 1097 if( in(0) && remove_dead_region(phase, can_reshape) ) return this; 1098 // Don't bother trying to transform a dead node 1099 if( in(0) && in(0)->is_top() ) return nullptr; 1100 1101 // Get the modulus 1102 const Type *t = phase->type( in(2) ); 1103 if( t == Type::TOP ) return nullptr; 1104 const TypeLong *tl = t->is_long(); 1105 1106 // Check for useless control input 1107 // Check for excluding mod-zero case 1108 if (in(0) && (tl->_hi < 0 || tl->_lo > 0)) { 1109 set_req(0, nullptr); // Yank control input 1110 return this; 1111 } 1112 1113 // See if we are MOD'ing by 2^k or 2^k-1. 1114 if( !tl->is_con() ) return nullptr; 1115 jlong con = tl->get_con(); 1116 1117 Node *hook = new Node(1); 1118 1119 // Expand mod 1120 if(con >= 0 && con < max_jlong && is_power_of_2(con + 1)) { 1121 uint k = log2i_exact(con + 1); // Extract k 1122 1123 // Basic algorithm by David Detlefs. See fastmod_long.java for gory details. 1124 // Used to help a popular random number generator which does a long-mod 1125 // of 2^31-1 and shows up in SpecJBB and SciMark. 1126 static int unroll_factor[] = { 999, 999, 61, 30, 20, 15, 12, 10, 8, 7, 6, 6, 5, 5, 4, 4, 4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1 /*past here we assume 1 forever*/}; 1127 int trip_count = 1; 1128 if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k]; 1129 1130 // If the unroll factor is not too large, and if conditional moves are 1131 // ok, then use this case 1132 if( trip_count <= 5 && ConditionalMoveLimit != 0 ) { 1133 Node *x = in(1); // Value being mod'd 1134 Node *divisor = in(2); // Also is mask 1135 1136 hook->init_req(0, x); // Add a use to x to prevent him from dying 1137 // Generate code to reduce X rapidly to nearly 2^k-1. 1138 for( int i = 0; i < trip_count; i++ ) { 1139 Node *xl = phase->transform( new AndLNode(x,divisor) ); 1140 Node *xh = phase->transform( new RShiftLNode(x,phase->intcon(k)) ); // Must be signed 1141 x = phase->transform( new AddLNode(xh,xl) ); 1142 hook->set_req(0, x); // Add a use to x to prevent him from dying 1143 } 1144 1145 // Generate sign-fixup code. Was original value positive? 1146 // long hack_res = (i >= 0) ? divisor : CONST64(1); 1147 Node *cmp1 = phase->transform( new CmpLNode( in(1), phase->longcon(0) ) ); 1148 Node *bol1 = phase->transform( new BoolNode( cmp1, BoolTest::ge ) ); 1149 Node *cmov1= phase->transform( new CMoveLNode(bol1, phase->longcon(1), divisor, TypeLong::LONG) ); 1150 // if( x >= hack_res ) x -= divisor; 1151 Node *sub = phase->transform( new SubLNode( x, divisor ) ); 1152 Node *cmp2 = phase->transform( new CmpLNode( x, cmov1 ) ); 1153 Node *bol2 = phase->transform( new BoolNode( cmp2, BoolTest::ge ) ); 1154 // Convention is to not transform the return value of an Ideal 1155 // since Ideal is expected to return a modified 'this' or a new node. 1156 Node *cmov2= new CMoveLNode(bol2, x, sub, TypeLong::LONG); 1157 // cmov2 is now the mod 1158 1159 // Now remove the bogus extra edges used to keep things alive 1160 hook->destruct(phase); 1161 return cmov2; 1162 } 1163 } 1164 1165 // Fell thru, the unroll case is not appropriate. Transform the modulo 1166 // into a long multiply/int multiply/subtract case 1167 1168 // Cannot handle mod 0, and min_jlong isn't handled by the transform 1169 if( con == 0 || con == min_jlong ) return nullptr; 1170 1171 // Get the absolute value of the constant; at this point, we can use this 1172 jlong pos_con = (con >= 0) ? con : -con; 1173 1174 // integer Mod 1 is always 0 1175 if( pos_con == 1 ) return new ConLNode(TypeLong::ZERO); 1176 1177 int log2_con = -1; 1178 1179 // If this is a power of two, then maybe we can mask it 1180 if (is_power_of_2(pos_con)) { 1181 log2_con = log2i_exact(pos_con); 1182 1183 const Type *dt = phase->type(in(1)); 1184 const TypeLong *dtl = dt->isa_long(); 1185 1186 // See if this can be masked, if the dividend is non-negative 1187 if( dtl && dtl->_lo >= 0 ) 1188 return ( new AndLNode( in(1), phase->longcon( pos_con-1 ) ) ); 1189 } 1190 1191 // Save in(1) so that it cannot be changed or deleted 1192 hook->init_req(0, in(1)); 1193 1194 // Divide using the transform from DivL to MulL 1195 Node *result = transform_long_divide( phase, in(1), pos_con ); 1196 if (result != nullptr) { 1197 Node *divide = phase->transform(result); 1198 1199 // Re-multiply, using a shift if this is a power of two 1200 Node *mult = nullptr; 1201 1202 if( log2_con >= 0 ) 1203 mult = phase->transform( new LShiftLNode( divide, phase->intcon( log2_con ) ) ); 1204 else 1205 mult = phase->transform( new MulLNode( divide, phase->longcon( pos_con ) ) ); 1206 1207 // Finally, subtract the multiplied divided value from the original 1208 result = new SubLNode( in(1), mult ); 1209 } 1210 1211 // Now remove the bogus extra edges used to keep things alive 1212 hook->destruct(phase); 1213 1214 // return the value 1215 return result; 1216 } 1217 1218 //------------------------------Value------------------------------------------ 1219 const Type* ModLNode::Value(PhaseGVN* phase) const { 1220 // Either input is TOP ==> the result is TOP 1221 const Type *t1 = phase->type( in(1) ); 1222 const Type *t2 = phase->type( in(2) ); 1223 if( t1 == Type::TOP ) return Type::TOP; 1224 if( t2 == Type::TOP ) return Type::TOP; 1225 1226 // We always generate the dynamic check for 0. 1227 // 0 MOD X is 0 1228 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO; 1229 // X MOD X is 0 1230 if (in(1) == in(2)) { 1231 return TypeLong::ZERO; 1232 } 1233 1234 // Either input is BOTTOM ==> the result is the local BOTTOM 1235 const Type *bot = bottom_type(); 1236 if( (t1 == bot) || (t2 == bot) || 1237 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 1238 return bot; 1239 1240 const TypeLong *i1 = t1->is_long(); 1241 const TypeLong *i2 = t2->is_long(); 1242 if( !i1->is_con() || !i2->is_con() ) { 1243 if( i1->_lo >= CONST64(0) && i2->_lo >= CONST64(0) ) 1244 return TypeLong::POS; 1245 // If both numbers are not constants, we know little. 1246 return TypeLong::LONG; 1247 } 1248 // Mod by zero? Throw exception at runtime! 1249 if( !i2->get_con() ) return TypeLong::POS; 1250 1251 // We must be modulo'ing 2 float constants. 1252 // Check for min_jint % '-1', result is defined to be '0'. 1253 if( i1->get_con() == min_jlong && i2->get_con() == -1 ) 1254 return TypeLong::ZERO; 1255 1256 return TypeLong::make( i1->get_con() % i2->get_con() ); 1257 } 1258 1259 1260 //============================================================================= 1261 //------------------------------Value------------------------------------------ 1262 const Type* ModFNode::Value(PhaseGVN* phase) const { 1263 // Either input is TOP ==> the result is TOP 1264 const Type *t1 = phase->type( in(1) ); 1265 const Type *t2 = phase->type( in(2) ); 1266 if( t1 == Type::TOP ) return Type::TOP; 1267 if( t2 == Type::TOP ) return Type::TOP; 1268 1269 // Either input is BOTTOM ==> the result is the local BOTTOM 1270 const Type *bot = bottom_type(); 1271 if( (t1 == bot) || (t2 == bot) || 1272 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 1273 return bot; 1274 1275 // If either number is not a constant, we know nothing. 1276 if ((t1->base() != Type::FloatCon) || (t2->base() != Type::FloatCon)) { 1277 return Type::FLOAT; // note: x%x can be either NaN or 0 1278 } 1279 1280 float f1 = t1->getf(); 1281 float f2 = t2->getf(); 1282 jint x1 = jint_cast(f1); // note: *(int*)&f1, not just (int)f1 1283 jint x2 = jint_cast(f2); 1284 1285 // If either is a NaN, return an input NaN 1286 if (g_isnan(f1)) return t1; 1287 if (g_isnan(f2)) return t2; 1288 1289 // If an operand is infinity or the divisor is +/- zero, punt. 1290 if (!g_isfinite(f1) || !g_isfinite(f2) || x2 == 0 || x2 == min_jint) 1291 return Type::FLOAT; 1292 1293 // We must be modulo'ing 2 float constants. 1294 // Make sure that the sign of the fmod is equal to the sign of the dividend 1295 jint xr = jint_cast(fmod(f1, f2)); 1296 if ((x1 ^ xr) < 0) { 1297 xr ^= min_jint; 1298 } 1299 1300 return TypeF::make(jfloat_cast(xr)); 1301 } 1302 1303 //============================================================================= 1304 //------------------------------Idealize--------------------------------------- 1305 Node *UModLNode::Ideal(PhaseGVN *phase, bool can_reshape) { 1306 // Check for dead control input 1307 if( in(0) && remove_dead_region(phase, can_reshape) ) return this; 1308 return nullptr; 1309 } 1310 1311 1312 //============================================================================= 1313 //------------------------------Value------------------------------------------ 1314 const Type* ModDNode::Value(PhaseGVN* phase) const { 1315 // Either input is TOP ==> the result is TOP 1316 const Type *t1 = phase->type( in(1) ); 1317 const Type *t2 = phase->type( in(2) ); 1318 if( t1 == Type::TOP ) return Type::TOP; 1319 if( t2 == Type::TOP ) return Type::TOP; 1320 1321 // Either input is BOTTOM ==> the result is the local BOTTOM 1322 const Type *bot = bottom_type(); 1323 if( (t1 == bot) || (t2 == bot) || 1324 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 1325 return bot; 1326 1327 // If either number is not a constant, we know nothing. 1328 if ((t1->base() != Type::DoubleCon) || (t2->base() != Type::DoubleCon)) { 1329 return Type::DOUBLE; // note: x%x can be either NaN or 0 1330 } 1331 1332 double f1 = t1->getd(); 1333 double f2 = t2->getd(); 1334 jlong x1 = jlong_cast(f1); // note: *(long*)&f1, not just (long)f1 1335 jlong x2 = jlong_cast(f2); 1336 1337 // If either is a NaN, return an input NaN 1338 if (g_isnan(f1)) return t1; 1339 if (g_isnan(f2)) return t2; 1340 1341 // If an operand is infinity or the divisor is +/- zero, punt. 1342 if (!g_isfinite(f1) || !g_isfinite(f2) || x2 == 0 || x2 == min_jlong) 1343 return Type::DOUBLE; 1344 1345 // We must be modulo'ing 2 double constants. 1346 // Make sure that the sign of the fmod is equal to the sign of the dividend 1347 jlong xr = jlong_cast(fmod(f1, f2)); 1348 if ((x1 ^ xr) < 0) { 1349 xr ^= min_jlong; 1350 } 1351 1352 return TypeD::make(jdouble_cast(xr)); 1353 } 1354 1355 //============================================================================= 1356 1357 DivModNode::DivModNode( Node *c, Node *dividend, Node *divisor ) : MultiNode(3) { 1358 init_req(0, c); 1359 init_req(1, dividend); 1360 init_req(2, divisor); 1361 } 1362 1363 DivModNode* DivModNode::make(Node* div_or_mod, BasicType bt, bool is_unsigned) { 1364 assert(bt == T_INT || bt == T_LONG, "only int or long input pattern accepted"); 1365 1366 if (bt == T_INT) { 1367 if (is_unsigned) { 1368 return UDivModINode::make(div_or_mod); 1369 } else { 1370 return DivModINode::make(div_or_mod); 1371 } 1372 } else { 1373 if (is_unsigned) { 1374 return UDivModLNode::make(div_or_mod); 1375 } else { 1376 return DivModLNode::make(div_or_mod); 1377 } 1378 } 1379 } 1380 1381 //------------------------------make------------------------------------------ 1382 DivModINode* DivModINode::make(Node* div_or_mod) { 1383 Node* n = div_or_mod; 1384 assert(n->Opcode() == Op_DivI || n->Opcode() == Op_ModI, 1385 "only div or mod input pattern accepted"); 1386 1387 DivModINode* divmod = new DivModINode(n->in(0), n->in(1), n->in(2)); 1388 Node* dproj = new ProjNode(divmod, DivModNode::div_proj_num); 1389 Node* mproj = new ProjNode(divmod, DivModNode::mod_proj_num); 1390 return divmod; 1391 } 1392 1393 //------------------------------make------------------------------------------ 1394 DivModLNode* DivModLNode::make(Node* div_or_mod) { 1395 Node* n = div_or_mod; 1396 assert(n->Opcode() == Op_DivL || n->Opcode() == Op_ModL, 1397 "only div or mod input pattern accepted"); 1398 1399 DivModLNode* divmod = new DivModLNode(n->in(0), n->in(1), n->in(2)); 1400 Node* dproj = new ProjNode(divmod, DivModNode::div_proj_num); 1401 Node* mproj = new ProjNode(divmod, DivModNode::mod_proj_num); 1402 return divmod; 1403 } 1404 1405 //------------------------------match------------------------------------------ 1406 // return result(s) along with their RegMask info 1407 Node *DivModINode::match( const ProjNode *proj, const Matcher *match ) { 1408 uint ideal_reg = proj->ideal_reg(); 1409 RegMask rm; 1410 if (proj->_con == div_proj_num) { 1411 rm = match->divI_proj_mask(); 1412 } else { 1413 assert(proj->_con == mod_proj_num, "must be div or mod projection"); 1414 rm = match->modI_proj_mask(); 1415 } 1416 return new MachProjNode(this, proj->_con, rm, ideal_reg); 1417 } 1418 1419 1420 //------------------------------match------------------------------------------ 1421 // return result(s) along with their RegMask info 1422 Node *DivModLNode::match( const ProjNode *proj, const Matcher *match ) { 1423 uint ideal_reg = proj->ideal_reg(); 1424 RegMask rm; 1425 if (proj->_con == div_proj_num) { 1426 rm = match->divL_proj_mask(); 1427 } else { 1428 assert(proj->_con == mod_proj_num, "must be div or mod projection"); 1429 rm = match->modL_proj_mask(); 1430 } 1431 return new MachProjNode(this, proj->_con, rm, ideal_reg); 1432 } 1433 1434 //------------------------------make------------------------------------------ 1435 UDivModINode* UDivModINode::make(Node* div_or_mod) { 1436 Node* n = div_or_mod; 1437 assert(n->Opcode() == Op_UDivI || n->Opcode() == Op_UModI, 1438 "only div or mod input pattern accepted"); 1439 1440 UDivModINode* divmod = new UDivModINode(n->in(0), n->in(1), n->in(2)); 1441 Node* dproj = new ProjNode(divmod, DivModNode::div_proj_num); 1442 Node* mproj = new ProjNode(divmod, DivModNode::mod_proj_num); 1443 return divmod; 1444 } 1445 1446 //------------------------------make------------------------------------------ 1447 UDivModLNode* UDivModLNode::make(Node* div_or_mod) { 1448 Node* n = div_or_mod; 1449 assert(n->Opcode() == Op_UDivL || n->Opcode() == Op_UModL, 1450 "only div or mod input pattern accepted"); 1451 1452 UDivModLNode* divmod = new UDivModLNode(n->in(0), n->in(1), n->in(2)); 1453 Node* dproj = new ProjNode(divmod, DivModNode::div_proj_num); 1454 Node* mproj = new ProjNode(divmod, DivModNode::mod_proj_num); 1455 return divmod; 1456 } 1457 1458 //------------------------------match------------------------------------------ 1459 // return result(s) along with their RegMask info 1460 Node* UDivModINode::match( const ProjNode *proj, const Matcher *match ) { 1461 uint ideal_reg = proj->ideal_reg(); 1462 RegMask rm; 1463 if (proj->_con == div_proj_num) { 1464 rm = match->divI_proj_mask(); 1465 } else { 1466 assert(proj->_con == mod_proj_num, "must be div or mod projection"); 1467 rm = match->modI_proj_mask(); 1468 } 1469 return new MachProjNode(this, proj->_con, rm, ideal_reg); 1470 } 1471 1472 1473 //------------------------------match------------------------------------------ 1474 // return result(s) along with their RegMask info 1475 Node* UDivModLNode::match( const ProjNode *proj, const Matcher *match ) { 1476 uint ideal_reg = proj->ideal_reg(); 1477 RegMask rm; 1478 if (proj->_con == div_proj_num) { 1479 rm = match->divL_proj_mask(); 1480 } else { 1481 assert(proj->_con == mod_proj_num, "must be div or mod projection"); 1482 rm = match->modL_proj_mask(); 1483 } 1484 return new MachProjNode(this, proj->_con, rm, ideal_reg); 1485 } --- EOF ---