src/share/vm/opto/divnode.cpp

Thu, 26 Jun 2008 13:34:00 -0700

author
kvn
date
Thu, 26 Jun 2008 13:34:00 -0700
changeset 658
1dd146f17531
parent 580
f3de1255b035
child 631
d1605aabd0a1
permissions
-rw-r--r--

6716441: error in meet with +DoEscapeAnalysis
Summary: Set instance_id to InstanceBot for InstPtr->meet(AryPtr) when types are not related.
Reviewed-by: jrose, never

duke@435 1 /*
duke@435 2 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 // Portions of code courtesy of Clifford Click
duke@435 26
duke@435 27 // Optimization - Graph Style
duke@435 28
duke@435 29 #include "incls/_precompiled.incl"
duke@435 30 #include "incls/_divnode.cpp.incl"
duke@435 31 #include <math.h>
duke@435 32
rasbold@580 33 //----------------------magic_int_divide_constants-----------------------------
rasbold@580 34 // Compute magic multiplier and shift constant for converting a 32 bit divide
rasbold@580 35 // by constant into a multiply/shift/add series. Return false if calculations
rasbold@580 36 // fail.
rasbold@580 37 //
rasbold@580 38 // Borrowed almost verbatum from Hacker's Delight by Henry S. Warren, Jr. with
rasbold@580 39 // minor type name and parameter changes.
rasbold@580 40 static bool magic_int_divide_constants(jint d, jint &M, jint &s) {
rasbold@580 41 int32_t p;
rasbold@580 42 uint32_t ad, anc, delta, q1, r1, q2, r2, t;
rasbold@580 43 const uint32_t two31 = 0x80000000L; // 2**31.
rasbold@580 44
rasbold@580 45 ad = ABS(d);
rasbold@580 46 if (d == 0 || d == 1) return false;
rasbold@580 47 t = two31 + ((uint32_t)d >> 31);
rasbold@580 48 anc = t - 1 - t%ad; // Absolute value of nc.
rasbold@580 49 p = 31; // Init. p.
rasbold@580 50 q1 = two31/anc; // Init. q1 = 2**p/|nc|.
rasbold@580 51 r1 = two31 - q1*anc; // Init. r1 = rem(2**p, |nc|).
rasbold@580 52 q2 = two31/ad; // Init. q2 = 2**p/|d|.
rasbold@580 53 r2 = two31 - q2*ad; // Init. r2 = rem(2**p, |d|).
rasbold@580 54 do {
rasbold@580 55 p = p + 1;
rasbold@580 56 q1 = 2*q1; // Update q1 = 2**p/|nc|.
rasbold@580 57 r1 = 2*r1; // Update r1 = rem(2**p, |nc|).
rasbold@580 58 if (r1 >= anc) { // (Must be an unsigned
rasbold@580 59 q1 = q1 + 1; // comparison here).
rasbold@580 60 r1 = r1 - anc;
rasbold@580 61 }
rasbold@580 62 q2 = 2*q2; // Update q2 = 2**p/|d|.
rasbold@580 63 r2 = 2*r2; // Update r2 = rem(2**p, |d|).
rasbold@580 64 if (r2 >= ad) { // (Must be an unsigned
rasbold@580 65 q2 = q2 + 1; // comparison here).
rasbold@580 66 r2 = r2 - ad;
rasbold@580 67 }
rasbold@580 68 delta = ad - r2;
rasbold@580 69 } while (q1 < delta || (q1 == delta && r1 == 0));
rasbold@580 70
rasbold@580 71 M = q2 + 1;
rasbold@580 72 if (d < 0) M = -M; // Magic number and
rasbold@580 73 s = p - 32; // shift amount to return.
rasbold@580 74
rasbold@580 75 return true;
rasbold@580 76 }
rasbold@580 77
rasbold@580 78 //--------------------------transform_int_divide-------------------------------
rasbold@580 79 // Convert a division by constant divisor into an alternate Ideal graph.
rasbold@580 80 // Return NULL if no transformation occurs.
rasbold@580 81 static Node *transform_int_divide( PhaseGVN *phase, Node *dividend, jint divisor ) {
duke@435 82
duke@435 83 // Check for invalid divisors
rasbold@580 84 assert( divisor != 0 && divisor != min_jint,
rasbold@580 85 "bad divisor for transforming to long multiply" );
duke@435 86
duke@435 87 bool d_pos = divisor >= 0;
rasbold@580 88 jint d = d_pos ? divisor : -divisor;
duke@435 89 const int N = 32;
duke@435 90
duke@435 91 // Result
rasbold@580 92 Node *q = NULL;
duke@435 93
duke@435 94 if (d == 1) {
rasbold@580 95 // division by +/- 1
rasbold@580 96 if (!d_pos) {
rasbold@580 97 // Just negate the value
duke@435 98 q = new (phase->C, 3) SubINode(phase->intcon(0), dividend);
duke@435 99 }
rasbold@580 100 } else if ( is_power_of_2(d) ) {
rasbold@580 101 // division by +/- a power of 2
duke@435 102
duke@435 103 // See if we can simply do a shift without rounding
duke@435 104 bool needs_rounding = true;
duke@435 105 const Type *dt = phase->type(dividend);
duke@435 106 const TypeInt *dti = dt->isa_int();
rasbold@580 107 if (dti && dti->_lo >= 0) {
rasbold@580 108 // we don't need to round a positive dividend
duke@435 109 needs_rounding = false;
rasbold@580 110 } else if( dividend->Opcode() == Op_AndI ) {
rasbold@580 111 // An AND mask of sufficient size clears the low bits and
rasbold@580 112 // I can avoid rounding.
duke@435 113 const TypeInt *andconi = phase->type( dividend->in(2) )->isa_int();
duke@435 114 if( andconi && andconi->is_con(-d) ) {
duke@435 115 dividend = dividend->in(1);
duke@435 116 needs_rounding = false;
duke@435 117 }
duke@435 118 }
duke@435 119
duke@435 120 // Add rounding to the shift to handle the sign bit
rasbold@580 121 int l = log2_intptr(d-1)+1;
rasbold@580 122 if (needs_rounding) {
rasbold@580 123 // Divide-by-power-of-2 can be made into a shift, but you have to do
rasbold@580 124 // more math for the rounding. You need to add 0 for positive
rasbold@580 125 // numbers, and "i-1" for negative numbers. Example: i=4, so the
rasbold@580 126 // shift is by 2. You need to add 3 to negative dividends and 0 to
rasbold@580 127 // positive ones. So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1,
rasbold@580 128 // (-2+3)>>2 becomes 0, etc.
rasbold@580 129
rasbold@580 130 // Compute 0 or -1, based on sign bit
rasbold@580 131 Node *sign = phase->transform(new (phase->C, 3) RShiftINode(dividend, phase->intcon(N - 1)));
rasbold@580 132 // Mask sign bit to the low sign bits
rasbold@580 133 Node *round = phase->transform(new (phase->C, 3) URShiftINode(sign, phase->intcon(N - l)));
rasbold@580 134 // Round up before shifting
rasbold@580 135 dividend = phase->transform(new (phase->C, 3) AddINode(dividend, round));
duke@435 136 }
duke@435 137
rasbold@580 138 // Shift for division
duke@435 139 q = new (phase->C, 3) RShiftINode(dividend, phase->intcon(l));
duke@435 140
rasbold@580 141 if (!d_pos) {
duke@435 142 q = new (phase->C, 3) SubINode(phase->intcon(0), phase->transform(q));
rasbold@580 143 }
rasbold@580 144 } else {
rasbold@580 145 // Attempt the jint constant divide -> multiply transform found in
rasbold@580 146 // "Division by Invariant Integers using Multiplication"
rasbold@580 147 // by Granlund and Montgomery
rasbold@580 148 // See also "Hacker's Delight", chapter 10 by Warren.
rasbold@580 149
rasbold@580 150 jint magic_const;
rasbold@580 151 jint shift_const;
rasbold@580 152 if (magic_int_divide_constants(d, magic_const, shift_const)) {
rasbold@580 153 Node *magic = phase->longcon(magic_const);
rasbold@580 154 Node *dividend_long = phase->transform(new (phase->C, 2) ConvI2LNode(dividend));
rasbold@580 155
rasbold@580 156 // Compute the high half of the dividend x magic multiplication
rasbold@580 157 Node *mul_hi = phase->transform(new (phase->C, 3) MulLNode(dividend_long, magic));
rasbold@580 158
rasbold@580 159 if (magic_const < 0) {
rasbold@580 160 mul_hi = phase->transform(new (phase->C, 3) RShiftLNode(mul_hi, phase->intcon(N)));
rasbold@580 161 mul_hi = phase->transform(new (phase->C, 2) ConvL2INode(mul_hi));
rasbold@580 162
rasbold@580 163 // The magic multiplier is too large for a 32 bit constant. We've adjusted
rasbold@580 164 // it down by 2^32, but have to add 1 dividend back in after the multiplication.
rasbold@580 165 // This handles the "overflow" case described by Granlund and Montgomery.
rasbold@580 166 mul_hi = phase->transform(new (phase->C, 3) AddINode(dividend, mul_hi));
rasbold@580 167
rasbold@580 168 // Shift over the (adjusted) mulhi
rasbold@580 169 if (shift_const != 0) {
rasbold@580 170 mul_hi = phase->transform(new (phase->C, 3) RShiftINode(mul_hi, phase->intcon(shift_const)));
rasbold@580 171 }
rasbold@580 172 } else {
rasbold@580 173 // No add is required, we can merge the shifts together.
rasbold@580 174 mul_hi = phase->transform(new (phase->C, 3) RShiftLNode(mul_hi, phase->intcon(N + shift_const)));
rasbold@580 175 mul_hi = phase->transform(new (phase->C, 2) ConvL2INode(mul_hi));
rasbold@580 176 }
rasbold@580 177
rasbold@580 178 // Get a 0 or -1 from the sign of the dividend.
rasbold@580 179 Node *addend0 = mul_hi;
rasbold@580 180 Node *addend1 = phase->transform(new (phase->C, 3) RShiftINode(dividend, phase->intcon(N-1)));
rasbold@580 181
rasbold@580 182 // If the divisor is negative, swap the order of the input addends;
rasbold@580 183 // this has the effect of negating the quotient.
rasbold@580 184 if (!d_pos) {
rasbold@580 185 Node *temp = addend0; addend0 = addend1; addend1 = temp;
rasbold@580 186 }
rasbold@580 187
rasbold@580 188 // Adjust the final quotient by subtracting -1 (adding 1)
rasbold@580 189 // from the mul_hi.
rasbold@580 190 q = new (phase->C, 3) SubINode(addend0, addend1);
rasbold@580 191 }
duke@435 192 }
duke@435 193
rasbold@580 194 return q;
rasbold@580 195 }
duke@435 196
rasbold@580 197 //---------------------magic_long_divide_constants-----------------------------
rasbold@580 198 // Compute magic multiplier and shift constant for converting a 64 bit divide
rasbold@580 199 // by constant into a multiply/shift/add series. Return false if calculations
rasbold@580 200 // fail.
rasbold@580 201 //
rasbold@580 202 // Borrowed almost verbatum from Hacker's Delight by Henry S. Warren, Jr. with
rasbold@580 203 // minor type name and parameter changes. Adjusted to 64 bit word width.
rasbold@580 204 static bool magic_long_divide_constants(jlong d, jlong &M, jint &s) {
rasbold@580 205 int64_t p;
rasbold@580 206 uint64_t ad, anc, delta, q1, r1, q2, r2, t;
rasbold@580 207 const uint64_t two63 = 0x8000000000000000LL; // 2**63.
rasbold@580 208
rasbold@580 209 ad = ABS(d);
rasbold@580 210 if (d == 0 || d == 1) return false;
rasbold@580 211 t = two63 + ((uint64_t)d >> 63);
rasbold@580 212 anc = t - 1 - t%ad; // Absolute value of nc.
rasbold@580 213 p = 63; // Init. p.
rasbold@580 214 q1 = two63/anc; // Init. q1 = 2**p/|nc|.
rasbold@580 215 r1 = two63 - q1*anc; // Init. r1 = rem(2**p, |nc|).
rasbold@580 216 q2 = two63/ad; // Init. q2 = 2**p/|d|.
rasbold@580 217 r2 = two63 - q2*ad; // Init. r2 = rem(2**p, |d|).
rasbold@580 218 do {
rasbold@580 219 p = p + 1;
rasbold@580 220 q1 = 2*q1; // Update q1 = 2**p/|nc|.
rasbold@580 221 r1 = 2*r1; // Update r1 = rem(2**p, |nc|).
rasbold@580 222 if (r1 >= anc) { // (Must be an unsigned
rasbold@580 223 q1 = q1 + 1; // comparison here).
rasbold@580 224 r1 = r1 - anc;
rasbold@580 225 }
rasbold@580 226 q2 = 2*q2; // Update q2 = 2**p/|d|.
rasbold@580 227 r2 = 2*r2; // Update r2 = rem(2**p, |d|).
rasbold@580 228 if (r2 >= ad) { // (Must be an unsigned
rasbold@580 229 q2 = q2 + 1; // comparison here).
rasbold@580 230 r2 = r2 - ad;
rasbold@580 231 }
rasbold@580 232 delta = ad - r2;
rasbold@580 233 } while (q1 < delta || (q1 == delta && r1 == 0));
rasbold@580 234
rasbold@580 235 M = q2 + 1;
rasbold@580 236 if (d < 0) M = -M; // Magic number and
rasbold@580 237 s = p - 64; // shift amount to return.
rasbold@580 238
rasbold@580 239 return true;
rasbold@580 240 }
rasbold@580 241
rasbold@580 242 //---------------------long_by_long_mulhi--------------------------------------
rasbold@580 243 // Generate ideal node graph for upper half of a 64 bit x 64 bit multiplication
rasbold@580 244 static Node *long_by_long_mulhi( PhaseGVN *phase, Node *dividend, jlong magic_const) {
rasbold@580 245 // If the architecture supports a 64x64 mulhi, there is
rasbold@580 246 // no need to synthesize it in ideal nodes.
rasbold@580 247 if (Matcher::has_match_rule(Op_MulHiL)) {
rasbold@580 248 Node *v = phase->longcon(magic_const);
rasbold@580 249 return new (phase->C, 3) MulHiLNode(dividend, v);
duke@435 250 }
duke@435 251
rasbold@580 252 const int N = 64;
duke@435 253
rasbold@580 254 Node *u_hi = phase->transform(new (phase->C, 3) RShiftLNode(dividend, phase->intcon(N / 2)));
rasbold@580 255 Node *u_lo = phase->transform(new (phase->C, 3) AndLNode(dividend, phase->longcon(0xFFFFFFFF)));
rasbold@580 256
rasbold@580 257 Node *v_hi = phase->longcon(magic_const >> N/2);
rasbold@580 258 Node *v_lo = phase->longcon(magic_const & 0XFFFFFFFF);
rasbold@580 259
rasbold@580 260 Node *hihi_product = phase->transform(new (phase->C, 3) MulLNode(u_hi, v_hi));
rasbold@580 261 Node *hilo_product = phase->transform(new (phase->C, 3) MulLNode(u_hi, v_lo));
rasbold@580 262 Node *lohi_product = phase->transform(new (phase->C, 3) MulLNode(u_lo, v_hi));
rasbold@580 263 Node *lolo_product = phase->transform(new (phase->C, 3) MulLNode(u_lo, v_lo));
rasbold@580 264
rasbold@580 265 Node *t1 = phase->transform(new (phase->C, 3) URShiftLNode(lolo_product, phase->intcon(N / 2)));
rasbold@580 266 Node *t2 = phase->transform(new (phase->C, 3) AddLNode(hilo_product, t1));
rasbold@580 267 Node *t3 = phase->transform(new (phase->C, 3) RShiftLNode(t2, phase->intcon(N / 2)));
rasbold@580 268 Node *t4 = phase->transform(new (phase->C, 3) AndLNode(t2, phase->longcon(0xFFFFFFFF)));
rasbold@580 269 Node *t5 = phase->transform(new (phase->C, 3) AddLNode(t4, lohi_product));
rasbold@580 270 Node *t6 = phase->transform(new (phase->C, 3) RShiftLNode(t5, phase->intcon(N / 2)));
rasbold@580 271 Node *t7 = phase->transform(new (phase->C, 3) AddLNode(t3, hihi_product));
rasbold@580 272
rasbold@580 273 return new (phase->C, 3) AddLNode(t7, t6);
rasbold@580 274 }
rasbold@580 275
rasbold@580 276
rasbold@580 277 //--------------------------transform_long_divide------------------------------
rasbold@580 278 // Convert a division by constant divisor into an alternate Ideal graph.
rasbold@580 279 // Return NULL if no transformation occurs.
rasbold@580 280 static Node *transform_long_divide( PhaseGVN *phase, Node *dividend, jlong divisor ) {
rasbold@580 281 // Check for invalid divisors
rasbold@580 282 assert( divisor != 0L && divisor != min_jlong,
rasbold@580 283 "bad divisor for transforming to long multiply" );
rasbold@580 284
rasbold@580 285 bool d_pos = divisor >= 0;
rasbold@580 286 jlong d = d_pos ? divisor : -divisor;
rasbold@580 287 const int N = 64;
rasbold@580 288
rasbold@580 289 // Result
rasbold@580 290 Node *q = NULL;
rasbold@580 291
rasbold@580 292 if (d == 1) {
rasbold@580 293 // division by +/- 1
rasbold@580 294 if (!d_pos) {
rasbold@580 295 // Just negate the value
rasbold@580 296 q = new (phase->C, 3) SubLNode(phase->longcon(0), dividend);
rasbold@580 297 }
rasbold@580 298 } else if ( is_power_of_2_long(d) ) {
rasbold@580 299
rasbold@580 300 // division by +/- a power of 2
rasbold@580 301
rasbold@580 302 // See if we can simply do a shift without rounding
rasbold@580 303 bool needs_rounding = true;
rasbold@580 304 const Type *dt = phase->type(dividend);
rasbold@580 305 const TypeLong *dtl = dt->isa_long();
rasbold@580 306
rasbold@580 307 if (dtl && dtl->_lo > 0) {
rasbold@580 308 // we don't need to round a positive dividend
rasbold@580 309 needs_rounding = false;
rasbold@580 310 } else if( dividend->Opcode() == Op_AndL ) {
rasbold@580 311 // An AND mask of sufficient size clears the low bits and
rasbold@580 312 // I can avoid rounding.
rasbold@580 313 const TypeLong *andconl = phase->type( dividend->in(2) )->isa_long();
rasbold@580 314 if( andconl && andconl->is_con(-d)) {
rasbold@580 315 dividend = dividend->in(1);
rasbold@580 316 needs_rounding = false;
rasbold@580 317 }
rasbold@580 318 }
rasbold@580 319
rasbold@580 320 // Add rounding to the shift to handle the sign bit
rasbold@580 321 int l = log2_long(d-1)+1;
rasbold@580 322 if (needs_rounding) {
rasbold@580 323 // Divide-by-power-of-2 can be made into a shift, but you have to do
rasbold@580 324 // more math for the rounding. You need to add 0 for positive
rasbold@580 325 // numbers, and "i-1" for negative numbers. Example: i=4, so the
rasbold@580 326 // shift is by 2. You need to add 3 to negative dividends and 0 to
rasbold@580 327 // positive ones. So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1,
rasbold@580 328 // (-2+3)>>2 becomes 0, etc.
rasbold@580 329
rasbold@580 330 // Compute 0 or -1, based on sign bit
rasbold@580 331 Node *sign = phase->transform(new (phase->C, 3) RShiftLNode(dividend, phase->intcon(N - 1)));
rasbold@580 332 // Mask sign bit to the low sign bits
rasbold@580 333 Node *round = phase->transform(new (phase->C, 3) URShiftLNode(sign, phase->intcon(N - l)));
rasbold@580 334 // Round up before shifting
rasbold@580 335 dividend = phase->transform(new (phase->C, 3) AddLNode(dividend, round));
rasbold@580 336 }
rasbold@580 337
rasbold@580 338 // Shift for division
rasbold@580 339 q = new (phase->C, 3) RShiftLNode(dividend, phase->intcon(l));
rasbold@580 340
rasbold@580 341 if (!d_pos) {
rasbold@580 342 q = new (phase->C, 3) SubLNode(phase->longcon(0), phase->transform(q));
rasbold@580 343 }
rasbold@580 344 } else {
rasbold@580 345 // Attempt the jlong constant divide -> multiply transform found in
rasbold@580 346 // "Division by Invariant Integers using Multiplication"
rasbold@580 347 // by Granlund and Montgomery
rasbold@580 348 // See also "Hacker's Delight", chapter 10 by Warren.
rasbold@580 349
rasbold@580 350 jlong magic_const;
rasbold@580 351 jint shift_const;
rasbold@580 352 if (magic_long_divide_constants(d, magic_const, shift_const)) {
rasbold@580 353 // Compute the high half of the dividend x magic multiplication
rasbold@580 354 Node *mul_hi = phase->transform(long_by_long_mulhi(phase, dividend, magic_const));
rasbold@580 355
rasbold@580 356 // The high half of the 128-bit multiply is computed.
rasbold@580 357 if (magic_const < 0) {
rasbold@580 358 // The magic multiplier is too large for a 64 bit constant. We've adjusted
rasbold@580 359 // it down by 2^64, but have to add 1 dividend back in after the multiplication.
rasbold@580 360 // This handles the "overflow" case described by Granlund and Montgomery.
rasbold@580 361 mul_hi = phase->transform(new (phase->C, 3) AddLNode(dividend, mul_hi));
rasbold@580 362 }
rasbold@580 363
rasbold@580 364 // Shift over the (adjusted) mulhi
rasbold@580 365 if (shift_const != 0) {
rasbold@580 366 mul_hi = phase->transform(new (phase->C, 3) RShiftLNode(mul_hi, phase->intcon(shift_const)));
rasbold@580 367 }
rasbold@580 368
rasbold@580 369 // Get a 0 or -1 from the sign of the dividend.
rasbold@580 370 Node *addend0 = mul_hi;
rasbold@580 371 Node *addend1 = phase->transform(new (phase->C, 3) RShiftLNode(dividend, phase->intcon(N-1)));
rasbold@580 372
rasbold@580 373 // If the divisor is negative, swap the order of the input addends;
rasbold@580 374 // this has the effect of negating the quotient.
rasbold@580 375 if (!d_pos) {
rasbold@580 376 Node *temp = addend0; addend0 = addend1; addend1 = temp;
rasbold@580 377 }
rasbold@580 378
rasbold@580 379 // Adjust the final quotient by subtracting -1 (adding 1)
rasbold@580 380 // from the mul_hi.
rasbold@580 381 q = new (phase->C, 3) SubLNode(addend0, addend1);
rasbold@580 382 }
duke@435 383 }
duke@435 384
rasbold@580 385 return q;
duke@435 386 }
duke@435 387
duke@435 388 //=============================================================================
duke@435 389 //------------------------------Identity---------------------------------------
duke@435 390 // If the divisor is 1, we are an identity on the dividend.
duke@435 391 Node *DivINode::Identity( PhaseTransform *phase ) {
duke@435 392 return (phase->type( in(2) )->higher_equal(TypeInt::ONE)) ? in(1) : this;
duke@435 393 }
duke@435 394
duke@435 395 //------------------------------Idealize---------------------------------------
duke@435 396 // Divides can be changed to multiplies and/or shifts
duke@435 397 Node *DivINode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@435 398 if (in(0) && remove_dead_region(phase, can_reshape)) return this;
duke@435 399
duke@435 400 const Type *t = phase->type( in(2) );
duke@435 401 if( t == TypeInt::ONE ) // Identity?
duke@435 402 return NULL; // Skip it
duke@435 403
duke@435 404 const TypeInt *ti = t->isa_int();
duke@435 405 if( !ti ) return NULL;
duke@435 406 if( !ti->is_con() ) return NULL;
rasbold@580 407 jint i = ti->get_con(); // Get divisor
duke@435 408
duke@435 409 if (i == 0) return NULL; // Dividing by zero constant does not idealize
duke@435 410
duke@435 411 set_req(0,NULL); // Dividing by a not-zero constant; no faulting
duke@435 412
duke@435 413 // Dividing by MININT does not optimize as a power-of-2 shift.
duke@435 414 if( i == min_jint ) return NULL;
duke@435 415
rasbold@580 416 return transform_int_divide( phase, in(1), i );
duke@435 417 }
duke@435 418
duke@435 419 //------------------------------Value------------------------------------------
duke@435 420 // A DivINode divides its inputs. The third input is a Control input, used to
duke@435 421 // prevent hoisting the divide above an unsafe test.
duke@435 422 const Type *DivINode::Value( PhaseTransform *phase ) const {
duke@435 423 // Either input is TOP ==> the result is TOP
duke@435 424 const Type *t1 = phase->type( in(1) );
duke@435 425 const Type *t2 = phase->type( in(2) );
duke@435 426 if( t1 == Type::TOP ) return Type::TOP;
duke@435 427 if( t2 == Type::TOP ) return Type::TOP;
duke@435 428
duke@435 429 // x/x == 1 since we always generate the dynamic divisor check for 0.
duke@435 430 if( phase->eqv( in(1), in(2) ) )
duke@435 431 return TypeInt::ONE;
duke@435 432
duke@435 433 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@435 434 const Type *bot = bottom_type();
duke@435 435 if( (t1 == bot) || (t2 == bot) ||
duke@435 436 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@435 437 return bot;
duke@435 438
duke@435 439 // Divide the two numbers. We approximate.
duke@435 440 // If divisor is a constant and not zero
duke@435 441 const TypeInt *i1 = t1->is_int();
duke@435 442 const TypeInt *i2 = t2->is_int();
duke@435 443 int widen = MAX2(i1->_widen, i2->_widen);
duke@435 444
duke@435 445 if( i2->is_con() && i2->get_con() != 0 ) {
duke@435 446 int32 d = i2->get_con(); // Divisor
duke@435 447 jint lo, hi;
duke@435 448 if( d >= 0 ) {
duke@435 449 lo = i1->_lo/d;
duke@435 450 hi = i1->_hi/d;
duke@435 451 } else {
duke@435 452 if( d == -1 && i1->_lo == min_jint ) {
duke@435 453 // 'min_jint/-1' throws arithmetic exception during compilation
duke@435 454 lo = min_jint;
duke@435 455 // do not support holes, 'hi' must go to either min_jint or max_jint:
duke@435 456 // [min_jint, -10]/[-1,-1] ==> [min_jint] UNION [10,max_jint]
duke@435 457 hi = i1->_hi == min_jint ? min_jint : max_jint;
duke@435 458 } else {
duke@435 459 lo = i1->_hi/d;
duke@435 460 hi = i1->_lo/d;
duke@435 461 }
duke@435 462 }
duke@435 463 return TypeInt::make(lo, hi, widen);
duke@435 464 }
duke@435 465
duke@435 466 // If the dividend is a constant
duke@435 467 if( i1->is_con() ) {
duke@435 468 int32 d = i1->get_con();
duke@435 469 if( d < 0 ) {
duke@435 470 if( d == min_jint ) {
duke@435 471 // (-min_jint) == min_jint == (min_jint / -1)
duke@435 472 return TypeInt::make(min_jint, max_jint/2 + 1, widen);
duke@435 473 } else {
duke@435 474 return TypeInt::make(d, -d, widen);
duke@435 475 }
duke@435 476 }
duke@435 477 return TypeInt::make(-d, d, widen);
duke@435 478 }
duke@435 479
duke@435 480 // Otherwise we give up all hope
duke@435 481 return TypeInt::INT;
duke@435 482 }
duke@435 483
duke@435 484
duke@435 485 //=============================================================================
duke@435 486 //------------------------------Identity---------------------------------------
duke@435 487 // If the divisor is 1, we are an identity on the dividend.
duke@435 488 Node *DivLNode::Identity( PhaseTransform *phase ) {
duke@435 489 return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : this;
duke@435 490 }
duke@435 491
duke@435 492 //------------------------------Idealize---------------------------------------
duke@435 493 // Dividing by a power of 2 is a shift.
duke@435 494 Node *DivLNode::Ideal( PhaseGVN *phase, bool can_reshape) {
duke@435 495 if (in(0) && remove_dead_region(phase, can_reshape)) return this;
duke@435 496
duke@435 497 const Type *t = phase->type( in(2) );
rasbold@580 498 if( t == TypeLong::ONE ) // Identity?
duke@435 499 return NULL; // Skip it
duke@435 500
rasbold@580 501 const TypeLong *tl = t->isa_long();
rasbold@580 502 if( !tl ) return NULL;
rasbold@580 503 if( !tl->is_con() ) return NULL;
rasbold@580 504 jlong l = tl->get_con(); // Get divisor
rasbold@580 505
rasbold@580 506 if (l == 0) return NULL; // Dividing by zero constant does not idealize
rasbold@580 507
rasbold@580 508 set_req(0,NULL); // Dividing by a not-zero constant; no faulting
duke@435 509
duke@435 510 // Dividing by MININT does not optimize as a power-of-2 shift.
rasbold@580 511 if( l == min_jlong ) return NULL;
duke@435 512
rasbold@580 513 return transform_long_divide( phase, in(1), l );
duke@435 514 }
duke@435 515
duke@435 516 //------------------------------Value------------------------------------------
duke@435 517 // A DivLNode divides its inputs. The third input is a Control input, used to
duke@435 518 // prevent hoisting the divide above an unsafe test.
duke@435 519 const Type *DivLNode::Value( PhaseTransform *phase ) const {
duke@435 520 // Either input is TOP ==> the result is TOP
duke@435 521 const Type *t1 = phase->type( in(1) );
duke@435 522 const Type *t2 = phase->type( in(2) );
duke@435 523 if( t1 == Type::TOP ) return Type::TOP;
duke@435 524 if( t2 == Type::TOP ) return Type::TOP;
duke@435 525
duke@435 526 // x/x == 1 since we always generate the dynamic divisor check for 0.
duke@435 527 if( phase->eqv( in(1), in(2) ) )
duke@435 528 return TypeLong::ONE;
duke@435 529
duke@435 530 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@435 531 const Type *bot = bottom_type();
duke@435 532 if( (t1 == bot) || (t2 == bot) ||
duke@435 533 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@435 534 return bot;
duke@435 535
duke@435 536 // Divide the two numbers. We approximate.
duke@435 537 // If divisor is a constant and not zero
duke@435 538 const TypeLong *i1 = t1->is_long();
duke@435 539 const TypeLong *i2 = t2->is_long();
duke@435 540 int widen = MAX2(i1->_widen, i2->_widen);
duke@435 541
duke@435 542 if( i2->is_con() && i2->get_con() != 0 ) {
duke@435 543 jlong d = i2->get_con(); // Divisor
duke@435 544 jlong lo, hi;
duke@435 545 if( d >= 0 ) {
duke@435 546 lo = i1->_lo/d;
duke@435 547 hi = i1->_hi/d;
duke@435 548 } else {
duke@435 549 if( d == CONST64(-1) && i1->_lo == min_jlong ) {
duke@435 550 // 'min_jlong/-1' throws arithmetic exception during compilation
duke@435 551 lo = min_jlong;
duke@435 552 // do not support holes, 'hi' must go to either min_jlong or max_jlong:
duke@435 553 // [min_jlong, -10]/[-1,-1] ==> [min_jlong] UNION [10,max_jlong]
duke@435 554 hi = i1->_hi == min_jlong ? min_jlong : max_jlong;
duke@435 555 } else {
duke@435 556 lo = i1->_hi/d;
duke@435 557 hi = i1->_lo/d;
duke@435 558 }
duke@435 559 }
duke@435 560 return TypeLong::make(lo, hi, widen);
duke@435 561 }
duke@435 562
duke@435 563 // If the dividend is a constant
duke@435 564 if( i1->is_con() ) {
duke@435 565 jlong d = i1->get_con();
duke@435 566 if( d < 0 ) {
duke@435 567 if( d == min_jlong ) {
duke@435 568 // (-min_jlong) == min_jlong == (min_jlong / -1)
duke@435 569 return TypeLong::make(min_jlong, max_jlong/2 + 1, widen);
duke@435 570 } else {
duke@435 571 return TypeLong::make(d, -d, widen);
duke@435 572 }
duke@435 573 }
duke@435 574 return TypeLong::make(-d, d, widen);
duke@435 575 }
duke@435 576
duke@435 577 // Otherwise we give up all hope
duke@435 578 return TypeLong::LONG;
duke@435 579 }
duke@435 580
duke@435 581
duke@435 582 //=============================================================================
duke@435 583 //------------------------------Value------------------------------------------
duke@435 584 // An DivFNode divides its inputs. The third input is a Control input, used to
duke@435 585 // prevent hoisting the divide above an unsafe test.
duke@435 586 const Type *DivFNode::Value( PhaseTransform *phase ) const {
duke@435 587 // Either input is TOP ==> the result is TOP
duke@435 588 const Type *t1 = phase->type( in(1) );
duke@435 589 const Type *t2 = phase->type( in(2) );
duke@435 590 if( t1 == Type::TOP ) return Type::TOP;
duke@435 591 if( t2 == Type::TOP ) return Type::TOP;
duke@435 592
duke@435 593 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@435 594 const Type *bot = bottom_type();
duke@435 595 if( (t1 == bot) || (t2 == bot) ||
duke@435 596 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@435 597 return bot;
duke@435 598
duke@435 599 // x/x == 1, we ignore 0/0.
duke@435 600 // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
jrose@566 601 // Does not work for variables because of NaN's
duke@435 602 if( phase->eqv( in(1), in(2) ) && t1->base() == Type::FloatCon)
duke@435 603 if (!g_isnan(t1->getf()) && g_isfinite(t1->getf()) && t1->getf() != 0.0) // could be negative ZERO or NaN
duke@435 604 return TypeF::ONE;
duke@435 605
duke@435 606 if( t2 == TypeF::ONE )
duke@435 607 return t1;
duke@435 608
duke@435 609 // If divisor is a constant and not zero, divide them numbers
duke@435 610 if( t1->base() == Type::FloatCon &&
duke@435 611 t2->base() == Type::FloatCon &&
duke@435 612 t2->getf() != 0.0 ) // could be negative zero
duke@435 613 return TypeF::make( t1->getf()/t2->getf() );
duke@435 614
duke@435 615 // If the dividend is a constant zero
duke@435 616 // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
duke@435 617 // Test TypeF::ZERO is not sufficient as it could be negative zero
duke@435 618
duke@435 619 if( t1 == TypeF::ZERO && !g_isnan(t2->getf()) && t2->getf() != 0.0 )
duke@435 620 return TypeF::ZERO;
duke@435 621
duke@435 622 // Otherwise we give up all hope
duke@435 623 return Type::FLOAT;
duke@435 624 }
duke@435 625
duke@435 626 //------------------------------isA_Copy---------------------------------------
duke@435 627 // Dividing by self is 1.
duke@435 628 // If the divisor is 1, we are an identity on the dividend.
duke@435 629 Node *DivFNode::Identity( PhaseTransform *phase ) {
duke@435 630 return (phase->type( in(2) ) == TypeF::ONE) ? in(1) : this;
duke@435 631 }
duke@435 632
duke@435 633
duke@435 634 //------------------------------Idealize---------------------------------------
duke@435 635 Node *DivFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@435 636 if (in(0) && remove_dead_region(phase, can_reshape)) return this;
duke@435 637
duke@435 638 const Type *t2 = phase->type( in(2) );
duke@435 639 if( t2 == TypeF::ONE ) // Identity?
duke@435 640 return NULL; // Skip it
duke@435 641
duke@435 642 const TypeF *tf = t2->isa_float_constant();
duke@435 643 if( !tf ) return NULL;
duke@435 644 if( tf->base() != Type::FloatCon ) return NULL;
duke@435 645
duke@435 646 // Check for out of range values
duke@435 647 if( tf->is_nan() || !tf->is_finite() ) return NULL;
duke@435 648
duke@435 649 // Get the value
duke@435 650 float f = tf->getf();
duke@435 651 int exp;
duke@435 652
duke@435 653 // Only for special case of dividing by a power of 2
duke@435 654 if( frexp((double)f, &exp) != 0.5 ) return NULL;
duke@435 655
duke@435 656 // Limit the range of acceptable exponents
duke@435 657 if( exp < -126 || exp > 126 ) return NULL;
duke@435 658
duke@435 659 // Compute the reciprocal
duke@435 660 float reciprocal = ((float)1.0) / f;
duke@435 661
duke@435 662 assert( frexp((double)reciprocal, &exp) == 0.5, "reciprocal should be power of 2" );
duke@435 663
duke@435 664 // return multiplication by the reciprocal
duke@435 665 return (new (phase->C, 3) MulFNode(in(1), phase->makecon(TypeF::make(reciprocal))));
duke@435 666 }
duke@435 667
duke@435 668 //=============================================================================
duke@435 669 //------------------------------Value------------------------------------------
duke@435 670 // An DivDNode divides its inputs. The third input is a Control input, used to
jrose@566 671 // prevent hoisting the divide above an unsafe test.
duke@435 672 const Type *DivDNode::Value( PhaseTransform *phase ) const {
duke@435 673 // Either input is TOP ==> the result is TOP
duke@435 674 const Type *t1 = phase->type( in(1) );
duke@435 675 const Type *t2 = phase->type( in(2) );
duke@435 676 if( t1 == Type::TOP ) return Type::TOP;
duke@435 677 if( t2 == Type::TOP ) return Type::TOP;
duke@435 678
duke@435 679 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@435 680 const Type *bot = bottom_type();
duke@435 681 if( (t1 == bot) || (t2 == bot) ||
duke@435 682 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@435 683 return bot;
duke@435 684
duke@435 685 // x/x == 1, we ignore 0/0.
duke@435 686 // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
duke@435 687 // Does not work for variables because of NaN's
duke@435 688 if( phase->eqv( in(1), in(2) ) && t1->base() == Type::DoubleCon)
duke@435 689 if (!g_isnan(t1->getd()) && g_isfinite(t1->getd()) && t1->getd() != 0.0) // could be negative ZERO or NaN
duke@435 690 return TypeD::ONE;
duke@435 691
duke@435 692 if( t2 == TypeD::ONE )
duke@435 693 return t1;
duke@435 694
duke@435 695 // If divisor is a constant and not zero, divide them numbers
duke@435 696 if( t1->base() == Type::DoubleCon &&
duke@435 697 t2->base() == Type::DoubleCon &&
duke@435 698 t2->getd() != 0.0 ) // could be negative zero
duke@435 699 return TypeD::make( t1->getd()/t2->getd() );
duke@435 700
duke@435 701 // If the dividend is a constant zero
duke@435 702 // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
duke@435 703 // Test TypeF::ZERO is not sufficient as it could be negative zero
duke@435 704 if( t1 == TypeD::ZERO && !g_isnan(t2->getd()) && t2->getd() != 0.0 )
duke@435 705 return TypeD::ZERO;
duke@435 706
duke@435 707 // Otherwise we give up all hope
duke@435 708 return Type::DOUBLE;
duke@435 709 }
duke@435 710
duke@435 711
duke@435 712 //------------------------------isA_Copy---------------------------------------
duke@435 713 // Dividing by self is 1.
duke@435 714 // If the divisor is 1, we are an identity on the dividend.
duke@435 715 Node *DivDNode::Identity( PhaseTransform *phase ) {
duke@435 716 return (phase->type( in(2) ) == TypeD::ONE) ? in(1) : this;
duke@435 717 }
duke@435 718
duke@435 719 //------------------------------Idealize---------------------------------------
duke@435 720 Node *DivDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@435 721 if (in(0) && remove_dead_region(phase, can_reshape)) return this;
duke@435 722
duke@435 723 const Type *t2 = phase->type( in(2) );
duke@435 724 if( t2 == TypeD::ONE ) // Identity?
duke@435 725 return NULL; // Skip it
duke@435 726
duke@435 727 const TypeD *td = t2->isa_double_constant();
duke@435 728 if( !td ) return NULL;
duke@435 729 if( td->base() != Type::DoubleCon ) return NULL;
duke@435 730
duke@435 731 // Check for out of range values
duke@435 732 if( td->is_nan() || !td->is_finite() ) return NULL;
duke@435 733
duke@435 734 // Get the value
duke@435 735 double d = td->getd();
duke@435 736 int exp;
duke@435 737
duke@435 738 // Only for special case of dividing by a power of 2
duke@435 739 if( frexp(d, &exp) != 0.5 ) return NULL;
duke@435 740
duke@435 741 // Limit the range of acceptable exponents
duke@435 742 if( exp < -1021 || exp > 1022 ) return NULL;
duke@435 743
duke@435 744 // Compute the reciprocal
duke@435 745 double reciprocal = 1.0 / d;
duke@435 746
duke@435 747 assert( frexp(reciprocal, &exp) == 0.5, "reciprocal should be power of 2" );
duke@435 748
duke@435 749 // return multiplication by the reciprocal
duke@435 750 return (new (phase->C, 3) MulDNode(in(1), phase->makecon(TypeD::make(reciprocal))));
duke@435 751 }
duke@435 752
duke@435 753 //=============================================================================
duke@435 754 //------------------------------Idealize---------------------------------------
duke@435 755 Node *ModINode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@435 756 // Check for dead control input
duke@435 757 if( remove_dead_region(phase, can_reshape) ) return this;
duke@435 758
duke@435 759 // Get the modulus
duke@435 760 const Type *t = phase->type( in(2) );
duke@435 761 if( t == Type::TOP ) return NULL;
duke@435 762 const TypeInt *ti = t->is_int();
duke@435 763
duke@435 764 // Check for useless control input
duke@435 765 // Check for excluding mod-zero case
duke@435 766 if( in(0) && (ti->_hi < 0 || ti->_lo > 0) ) {
duke@435 767 set_req(0, NULL); // Yank control input
duke@435 768 return this;
duke@435 769 }
duke@435 770
duke@435 771 // See if we are MOD'ing by 2^k or 2^k-1.
duke@435 772 if( !ti->is_con() ) return NULL;
duke@435 773 jint con = ti->get_con();
duke@435 774
duke@435 775 Node *hook = new (phase->C, 1) Node(1);
duke@435 776
duke@435 777 // First, special check for modulo 2^k-1
duke@435 778 if( con >= 0 && con < max_jint && is_power_of_2(con+1) ) {
duke@435 779 uint k = exact_log2(con+1); // Extract k
duke@435 780
duke@435 781 // Basic algorithm by David Detlefs. See fastmod_int.java for gory details.
duke@435 782 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*/};
duke@435 783 int trip_count = 1;
duke@435 784 if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k];
duke@435 785
duke@435 786 // If the unroll factor is not too large, and if conditional moves are
duke@435 787 // ok, then use this case
duke@435 788 if( trip_count <= 5 && ConditionalMoveLimit != 0 ) {
duke@435 789 Node *x = in(1); // Value being mod'd
duke@435 790 Node *divisor = in(2); // Also is mask
duke@435 791
duke@435 792 hook->init_req(0, x); // Add a use to x to prevent him from dying
duke@435 793 // Generate code to reduce X rapidly to nearly 2^k-1.
duke@435 794 for( int i = 0; i < trip_count; i++ ) {
rasbold@580 795 Node *xl = phase->transform( new (phase->C, 3) AndINode(x,divisor) );
rasbold@580 796 Node *xh = phase->transform( new (phase->C, 3) RShiftINode(x,phase->intcon(k)) ); // Must be signed
rasbold@580 797 x = phase->transform( new (phase->C, 3) AddINode(xh,xl) );
rasbold@580 798 hook->set_req(0, x);
duke@435 799 }
duke@435 800
duke@435 801 // Generate sign-fixup code. Was original value positive?
duke@435 802 // int hack_res = (i >= 0) ? divisor : 1;
duke@435 803 Node *cmp1 = phase->transform( new (phase->C, 3) CmpINode( in(1), phase->intcon(0) ) );
duke@435 804 Node *bol1 = phase->transform( new (phase->C, 2) BoolNode( cmp1, BoolTest::ge ) );
duke@435 805 Node *cmov1= phase->transform( new (phase->C, 4) CMoveINode(bol1, phase->intcon(1), divisor, TypeInt::POS) );
duke@435 806 // if( x >= hack_res ) x -= divisor;
duke@435 807 Node *sub = phase->transform( new (phase->C, 3) SubINode( x, divisor ) );
duke@435 808 Node *cmp2 = phase->transform( new (phase->C, 3) CmpINode( x, cmov1 ) );
duke@435 809 Node *bol2 = phase->transform( new (phase->C, 2) BoolNode( cmp2, BoolTest::ge ) );
duke@435 810 // Convention is to not transform the return value of an Ideal
duke@435 811 // since Ideal is expected to return a modified 'this' or a new node.
duke@435 812 Node *cmov2= new (phase->C, 4) CMoveINode(bol2, x, sub, TypeInt::INT);
duke@435 813 // cmov2 is now the mod
duke@435 814
duke@435 815 // Now remove the bogus extra edges used to keep things alive
duke@435 816 if (can_reshape) {
duke@435 817 phase->is_IterGVN()->remove_dead_node(hook);
duke@435 818 } else {
duke@435 819 hook->set_req(0, NULL); // Just yank bogus edge during Parse phase
duke@435 820 }
duke@435 821 return cmov2;
duke@435 822 }
duke@435 823 }
duke@435 824
duke@435 825 // Fell thru, the unroll case is not appropriate. Transform the modulo
duke@435 826 // into a long multiply/int multiply/subtract case
duke@435 827
duke@435 828 // Cannot handle mod 0, and min_jint isn't handled by the transform
duke@435 829 if( con == 0 || con == min_jint ) return NULL;
duke@435 830
duke@435 831 // Get the absolute value of the constant; at this point, we can use this
duke@435 832 jint pos_con = (con >= 0) ? con : -con;
duke@435 833
duke@435 834 // integer Mod 1 is always 0
duke@435 835 if( pos_con == 1 ) return new (phase->C, 1) ConINode(TypeInt::ZERO);
duke@435 836
duke@435 837 int log2_con = -1;
duke@435 838
duke@435 839 // If this is a power of two, they maybe we can mask it
duke@435 840 if( is_power_of_2(pos_con) ) {
duke@435 841 log2_con = log2_intptr((intptr_t)pos_con);
duke@435 842
duke@435 843 const Type *dt = phase->type(in(1));
duke@435 844 const TypeInt *dti = dt->isa_int();
duke@435 845
duke@435 846 // See if this can be masked, if the dividend is non-negative
duke@435 847 if( dti && dti->_lo >= 0 )
duke@435 848 return ( new (phase->C, 3) AndINode( in(1), phase->intcon( pos_con-1 ) ) );
duke@435 849 }
duke@435 850
duke@435 851 // Save in(1) so that it cannot be changed or deleted
duke@435 852 hook->init_req(0, in(1));
duke@435 853
duke@435 854 // Divide using the transform from DivI to MulL
rasbold@580 855 Node *result = transform_int_divide( phase, in(1), pos_con );
rasbold@580 856 if (result != NULL) {
rasbold@580 857 Node *divide = phase->transform(result);
duke@435 858
rasbold@580 859 // Re-multiply, using a shift if this is a power of two
rasbold@580 860 Node *mult = NULL;
duke@435 861
rasbold@580 862 if( log2_con >= 0 )
rasbold@580 863 mult = phase->transform( new (phase->C, 3) LShiftINode( divide, phase->intcon( log2_con ) ) );
rasbold@580 864 else
rasbold@580 865 mult = phase->transform( new (phase->C, 3) MulINode( divide, phase->intcon( pos_con ) ) );
duke@435 866
rasbold@580 867 // Finally, subtract the multiplied divided value from the original
rasbold@580 868 result = new (phase->C, 3) SubINode( in(1), mult );
rasbold@580 869 }
duke@435 870
duke@435 871 // Now remove the bogus extra edges used to keep things alive
duke@435 872 if (can_reshape) {
duke@435 873 phase->is_IterGVN()->remove_dead_node(hook);
duke@435 874 } else {
duke@435 875 hook->set_req(0, NULL); // Just yank bogus edge during Parse phase
duke@435 876 }
duke@435 877
duke@435 878 // return the value
duke@435 879 return result;
duke@435 880 }
duke@435 881
duke@435 882 //------------------------------Value------------------------------------------
duke@435 883 const Type *ModINode::Value( PhaseTransform *phase ) const {
duke@435 884 // Either input is TOP ==> the result is TOP
duke@435 885 const Type *t1 = phase->type( in(1) );
duke@435 886 const Type *t2 = phase->type( in(2) );
duke@435 887 if( t1 == Type::TOP ) return Type::TOP;
duke@435 888 if( t2 == Type::TOP ) return Type::TOP;
duke@435 889
duke@435 890 // We always generate the dynamic check for 0.
duke@435 891 // 0 MOD X is 0
duke@435 892 if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
duke@435 893 // X MOD X is 0
duke@435 894 if( phase->eqv( in(1), in(2) ) ) return TypeInt::ZERO;
duke@435 895
duke@435 896 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@435 897 const Type *bot = bottom_type();
duke@435 898 if( (t1 == bot) || (t2 == bot) ||
duke@435 899 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@435 900 return bot;
duke@435 901
duke@435 902 const TypeInt *i1 = t1->is_int();
duke@435 903 const TypeInt *i2 = t2->is_int();
duke@435 904 if( !i1->is_con() || !i2->is_con() ) {
duke@435 905 if( i1->_lo >= 0 && i2->_lo >= 0 )
duke@435 906 return TypeInt::POS;
duke@435 907 // If both numbers are not constants, we know little.
duke@435 908 return TypeInt::INT;
duke@435 909 }
duke@435 910 // Mod by zero? Throw exception at runtime!
duke@435 911 if( !i2->get_con() ) return TypeInt::POS;
duke@435 912
duke@435 913 // We must be modulo'ing 2 float constants.
duke@435 914 // Check for min_jint % '-1', result is defined to be '0'.
duke@435 915 if( i1->get_con() == min_jint && i2->get_con() == -1 )
duke@435 916 return TypeInt::ZERO;
duke@435 917
duke@435 918 return TypeInt::make( i1->get_con() % i2->get_con() );
duke@435 919 }
duke@435 920
duke@435 921
duke@435 922 //=============================================================================
duke@435 923 //------------------------------Idealize---------------------------------------
duke@435 924 Node *ModLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@435 925 // Check for dead control input
duke@435 926 if( remove_dead_region(phase, can_reshape) ) return this;
duke@435 927
duke@435 928 // Get the modulus
duke@435 929 const Type *t = phase->type( in(2) );
duke@435 930 if( t == Type::TOP ) return NULL;
rasbold@580 931 const TypeLong *tl = t->is_long();
duke@435 932
duke@435 933 // Check for useless control input
duke@435 934 // Check for excluding mod-zero case
rasbold@580 935 if( in(0) && (tl->_hi < 0 || tl->_lo > 0) ) {
duke@435 936 set_req(0, NULL); // Yank control input
duke@435 937 return this;
duke@435 938 }
duke@435 939
duke@435 940 // See if we are MOD'ing by 2^k or 2^k-1.
rasbold@580 941 if( !tl->is_con() ) return NULL;
rasbold@580 942 jlong con = tl->get_con();
rasbold@580 943
rasbold@580 944 Node *hook = new (phase->C, 1) Node(1);
duke@435 945
duke@435 946 // Expand mod
rasbold@580 947 if( con >= 0 && con < max_jlong && is_power_of_2_long(con+1) ) {
rasbold@580 948 uint k = log2_long(con); // Extract k
rasbold@580 949
duke@435 950 // Basic algorithm by David Detlefs. See fastmod_long.java for gory details.
duke@435 951 // Used to help a popular random number generator which does a long-mod
duke@435 952 // of 2^31-1 and shows up in SpecJBB and SciMark.
duke@435 953 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*/};
duke@435 954 int trip_count = 1;
duke@435 955 if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k];
duke@435 956
rasbold@580 957 // If the unroll factor is not too large, and if conditional moves are
rasbold@580 958 // ok, then use this case
rasbold@580 959 if( trip_count <= 5 && ConditionalMoveLimit != 0 ) {
rasbold@580 960 Node *x = in(1); // Value being mod'd
rasbold@580 961 Node *divisor = in(2); // Also is mask
duke@435 962
rasbold@580 963 hook->init_req(0, x); // Add a use to x to prevent him from dying
rasbold@580 964 // Generate code to reduce X rapidly to nearly 2^k-1.
rasbold@580 965 for( int i = 0; i < trip_count; i++ ) {
duke@435 966 Node *xl = phase->transform( new (phase->C, 3) AndLNode(x,divisor) );
duke@435 967 Node *xh = phase->transform( new (phase->C, 3) RShiftLNode(x,phase->intcon(k)) ); // Must be signed
duke@435 968 x = phase->transform( new (phase->C, 3) AddLNode(xh,xl) );
duke@435 969 hook->set_req(0, x); // Add a use to x to prevent him from dying
rasbold@580 970 }
rasbold@580 971
rasbold@580 972 // Generate sign-fixup code. Was original value positive?
rasbold@580 973 // long hack_res = (i >= 0) ? divisor : CONST64(1);
rasbold@580 974 Node *cmp1 = phase->transform( new (phase->C, 3) CmpLNode( in(1), phase->longcon(0) ) );
rasbold@580 975 Node *bol1 = phase->transform( new (phase->C, 2) BoolNode( cmp1, BoolTest::ge ) );
rasbold@580 976 Node *cmov1= phase->transform( new (phase->C, 4) CMoveLNode(bol1, phase->longcon(1), divisor, TypeLong::LONG) );
rasbold@580 977 // if( x >= hack_res ) x -= divisor;
rasbold@580 978 Node *sub = phase->transform( new (phase->C, 3) SubLNode( x, divisor ) );
rasbold@580 979 Node *cmp2 = phase->transform( new (phase->C, 3) CmpLNode( x, cmov1 ) );
rasbold@580 980 Node *bol2 = phase->transform( new (phase->C, 2) BoolNode( cmp2, BoolTest::ge ) );
rasbold@580 981 // Convention is to not transform the return value of an Ideal
rasbold@580 982 // since Ideal is expected to return a modified 'this' or a new node.
rasbold@580 983 Node *cmov2= new (phase->C, 4) CMoveLNode(bol2, x, sub, TypeLong::LONG);
rasbold@580 984 // cmov2 is now the mod
rasbold@580 985
rasbold@580 986 // Now remove the bogus extra edges used to keep things alive
rasbold@580 987 if (can_reshape) {
rasbold@580 988 phase->is_IterGVN()->remove_dead_node(hook);
rasbold@580 989 } else {
rasbold@580 990 hook->set_req(0, NULL); // Just yank bogus edge during Parse phase
rasbold@580 991 }
rasbold@580 992 return cmov2;
duke@435 993 }
rasbold@580 994 }
duke@435 995
rasbold@580 996 // Fell thru, the unroll case is not appropriate. Transform the modulo
rasbold@580 997 // into a long multiply/int multiply/subtract case
rasbold@580 998
rasbold@580 999 // Cannot handle mod 0, and min_jint isn't handled by the transform
rasbold@580 1000 if( con == 0 || con == min_jlong ) return NULL;
rasbold@580 1001
rasbold@580 1002 // Get the absolute value of the constant; at this point, we can use this
rasbold@580 1003 jlong pos_con = (con >= 0) ? con : -con;
rasbold@580 1004
rasbold@580 1005 // integer Mod 1 is always 0
rasbold@580 1006 if( pos_con == 1 ) return new (phase->C, 1) ConLNode(TypeLong::ZERO);
rasbold@580 1007
rasbold@580 1008 int log2_con = -1;
rasbold@580 1009
rasbold@580 1010 // If this is a power of two, they maybe we can mask it
rasbold@580 1011 if( is_power_of_2_long(pos_con) ) {
rasbold@580 1012 log2_con = log2_long(pos_con);
rasbold@580 1013
rasbold@580 1014 const Type *dt = phase->type(in(1));
rasbold@580 1015 const TypeLong *dtl = dt->isa_long();
rasbold@580 1016
rasbold@580 1017 // See if this can be masked, if the dividend is non-negative
rasbold@580 1018 if( dtl && dtl->_lo >= 0 )
rasbold@580 1019 return ( new (phase->C, 3) AndLNode( in(1), phase->longcon( pos_con-1 ) ) );
duke@435 1020 }
rasbold@580 1021
rasbold@580 1022 // Save in(1) so that it cannot be changed or deleted
rasbold@580 1023 hook->init_req(0, in(1));
rasbold@580 1024
rasbold@580 1025 // Divide using the transform from DivI to MulL
rasbold@580 1026 Node *result = transform_long_divide( phase, in(1), pos_con );
rasbold@580 1027 if (result != NULL) {
rasbold@580 1028 Node *divide = phase->transform(result);
rasbold@580 1029
rasbold@580 1030 // Re-multiply, using a shift if this is a power of two
rasbold@580 1031 Node *mult = NULL;
rasbold@580 1032
rasbold@580 1033 if( log2_con >= 0 )
rasbold@580 1034 mult = phase->transform( new (phase->C, 3) LShiftLNode( divide, phase->intcon( log2_con ) ) );
rasbold@580 1035 else
rasbold@580 1036 mult = phase->transform( new (phase->C, 3) MulLNode( divide, phase->longcon( pos_con ) ) );
rasbold@580 1037
rasbold@580 1038 // Finally, subtract the multiplied divided value from the original
rasbold@580 1039 result = new (phase->C, 3) SubLNode( in(1), mult );
rasbold@580 1040 }
rasbold@580 1041
rasbold@580 1042 // Now remove the bogus extra edges used to keep things alive
rasbold@580 1043 if (can_reshape) {
rasbold@580 1044 phase->is_IterGVN()->remove_dead_node(hook);
rasbold@580 1045 } else {
rasbold@580 1046 hook->set_req(0, NULL); // Just yank bogus edge during Parse phase
rasbold@580 1047 }
rasbold@580 1048
rasbold@580 1049 // return the value
rasbold@580 1050 return result;
duke@435 1051 }
duke@435 1052
duke@435 1053 //------------------------------Value------------------------------------------
duke@435 1054 const Type *ModLNode::Value( PhaseTransform *phase ) const {
duke@435 1055 // Either input is TOP ==> the result is TOP
duke@435 1056 const Type *t1 = phase->type( in(1) );
duke@435 1057 const Type *t2 = phase->type( in(2) );
duke@435 1058 if( t1 == Type::TOP ) return Type::TOP;
duke@435 1059 if( t2 == Type::TOP ) return Type::TOP;
duke@435 1060
duke@435 1061 // We always generate the dynamic check for 0.
duke@435 1062 // 0 MOD X is 0
duke@435 1063 if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
duke@435 1064 // X MOD X is 0
duke@435 1065 if( phase->eqv( in(1), in(2) ) ) return TypeLong::ZERO;
duke@435 1066
duke@435 1067 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@435 1068 const Type *bot = bottom_type();
duke@435 1069 if( (t1 == bot) || (t2 == bot) ||
duke@435 1070 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@435 1071 return bot;
duke@435 1072
duke@435 1073 const TypeLong *i1 = t1->is_long();
duke@435 1074 const TypeLong *i2 = t2->is_long();
duke@435 1075 if( !i1->is_con() || !i2->is_con() ) {
duke@435 1076 if( i1->_lo >= CONST64(0) && i2->_lo >= CONST64(0) )
duke@435 1077 return TypeLong::POS;
duke@435 1078 // If both numbers are not constants, we know little.
duke@435 1079 return TypeLong::LONG;
duke@435 1080 }
duke@435 1081 // Mod by zero? Throw exception at runtime!
duke@435 1082 if( !i2->get_con() ) return TypeLong::POS;
duke@435 1083
duke@435 1084 // We must be modulo'ing 2 float constants.
duke@435 1085 // Check for min_jint % '-1', result is defined to be '0'.
duke@435 1086 if( i1->get_con() == min_jlong && i2->get_con() == -1 )
duke@435 1087 return TypeLong::ZERO;
duke@435 1088
duke@435 1089 return TypeLong::make( i1->get_con() % i2->get_con() );
duke@435 1090 }
duke@435 1091
duke@435 1092
duke@435 1093 //=============================================================================
duke@435 1094 //------------------------------Value------------------------------------------
duke@435 1095 const Type *ModFNode::Value( PhaseTransform *phase ) const {
duke@435 1096 // Either input is TOP ==> the result is TOP
duke@435 1097 const Type *t1 = phase->type( in(1) );
duke@435 1098 const Type *t2 = phase->type( in(2) );
duke@435 1099 if( t1 == Type::TOP ) return Type::TOP;
duke@435 1100 if( t2 == Type::TOP ) return Type::TOP;
duke@435 1101
duke@435 1102 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@435 1103 const Type *bot = bottom_type();
duke@435 1104 if( (t1 == bot) || (t2 == bot) ||
duke@435 1105 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@435 1106 return bot;
duke@435 1107
jrose@566 1108 // If either number is not a constant, we know nothing.
jrose@566 1109 if ((t1->base() != Type::FloatCon) || (t2->base() != Type::FloatCon)) {
jrose@566 1110 return Type::FLOAT; // note: x%x can be either NaN or 0
jrose@566 1111 }
jrose@566 1112
jrose@566 1113 float f1 = t1->getf();
jrose@566 1114 float f2 = t2->getf();
jrose@566 1115 jint x1 = jint_cast(f1); // note: *(int*)&f1, not just (int)f1
jrose@566 1116 jint x2 = jint_cast(f2);
jrose@566 1117
duke@435 1118 // If either is a NaN, return an input NaN
jrose@566 1119 if (g_isnan(f1)) return t1;
jrose@566 1120 if (g_isnan(f2)) return t2;
duke@435 1121
jrose@566 1122 // If an operand is infinity or the divisor is +/- zero, punt.
jrose@566 1123 if (!g_isfinite(f1) || !g_isfinite(f2) || x2 == 0 || x2 == min_jint)
duke@435 1124 return Type::FLOAT;
duke@435 1125
duke@435 1126 // We must be modulo'ing 2 float constants.
duke@435 1127 // Make sure that the sign of the fmod is equal to the sign of the dividend
jrose@566 1128 jint xr = jint_cast(fmod(f1, f2));
jrose@566 1129 if ((x1 ^ xr) < 0) {
jrose@566 1130 xr ^= min_jint;
duke@435 1131 }
jrose@566 1132
jrose@566 1133 return TypeF::make(jfloat_cast(xr));
duke@435 1134 }
duke@435 1135
duke@435 1136
duke@435 1137 //=============================================================================
duke@435 1138 //------------------------------Value------------------------------------------
duke@435 1139 const Type *ModDNode::Value( PhaseTransform *phase ) const {
duke@435 1140 // Either input is TOP ==> the result is TOP
duke@435 1141 const Type *t1 = phase->type( in(1) );
duke@435 1142 const Type *t2 = phase->type( in(2) );
duke@435 1143 if( t1 == Type::TOP ) return Type::TOP;
duke@435 1144 if( t2 == Type::TOP ) return Type::TOP;
duke@435 1145
duke@435 1146 // Either input is BOTTOM ==> the result is the local BOTTOM
duke@435 1147 const Type *bot = bottom_type();
duke@435 1148 if( (t1 == bot) || (t2 == bot) ||
duke@435 1149 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
duke@435 1150 return bot;
duke@435 1151
jrose@566 1152 // If either number is not a constant, we know nothing.
jrose@566 1153 if ((t1->base() != Type::DoubleCon) || (t2->base() != Type::DoubleCon)) {
jrose@566 1154 return Type::DOUBLE; // note: x%x can be either NaN or 0
duke@435 1155 }
duke@435 1156
jrose@566 1157 double f1 = t1->getd();
jrose@566 1158 double f2 = t2->getd();
jrose@566 1159 jlong x1 = jlong_cast(f1); // note: *(long*)&f1, not just (long)f1
jrose@566 1160 jlong x2 = jlong_cast(f2);
duke@435 1161
jrose@566 1162 // If either is a NaN, return an input NaN
jrose@566 1163 if (g_isnan(f1)) return t1;
jrose@566 1164 if (g_isnan(f2)) return t2;
duke@435 1165
jrose@566 1166 // If an operand is infinity or the divisor is +/- zero, punt.
jrose@566 1167 if (!g_isfinite(f1) || !g_isfinite(f2) || x2 == 0 || x2 == min_jlong)
duke@435 1168 return Type::DOUBLE;
duke@435 1169
duke@435 1170 // We must be modulo'ing 2 double constants.
jrose@566 1171 // Make sure that the sign of the fmod is equal to the sign of the dividend
jrose@566 1172 jlong xr = jlong_cast(fmod(f1, f2));
jrose@566 1173 if ((x1 ^ xr) < 0) {
jrose@566 1174 xr ^= min_jlong;
jrose@566 1175 }
jrose@566 1176
jrose@566 1177 return TypeD::make(jdouble_cast(xr));
duke@435 1178 }
duke@435 1179
duke@435 1180 //=============================================================================
duke@435 1181
duke@435 1182 DivModNode::DivModNode( Node *c, Node *dividend, Node *divisor ) : MultiNode(3) {
duke@435 1183 init_req(0, c);
duke@435 1184 init_req(1, dividend);
duke@435 1185 init_req(2, divisor);
duke@435 1186 }
duke@435 1187
duke@435 1188 //------------------------------make------------------------------------------
duke@435 1189 DivModINode* DivModINode::make(Compile* C, Node* div_or_mod) {
duke@435 1190 Node* n = div_or_mod;
duke@435 1191 assert(n->Opcode() == Op_DivI || n->Opcode() == Op_ModI,
duke@435 1192 "only div or mod input pattern accepted");
duke@435 1193
duke@435 1194 DivModINode* divmod = new (C, 3) DivModINode(n->in(0), n->in(1), n->in(2));
duke@435 1195 Node* dproj = new (C, 1) ProjNode(divmod, DivModNode::div_proj_num);
duke@435 1196 Node* mproj = new (C, 1) ProjNode(divmod, DivModNode::mod_proj_num);
duke@435 1197 return divmod;
duke@435 1198 }
duke@435 1199
duke@435 1200 //------------------------------make------------------------------------------
duke@435 1201 DivModLNode* DivModLNode::make(Compile* C, Node* div_or_mod) {
duke@435 1202 Node* n = div_or_mod;
duke@435 1203 assert(n->Opcode() == Op_DivL || n->Opcode() == Op_ModL,
duke@435 1204 "only div or mod input pattern accepted");
duke@435 1205
duke@435 1206 DivModLNode* divmod = new (C, 3) DivModLNode(n->in(0), n->in(1), n->in(2));
duke@435 1207 Node* dproj = new (C, 1) ProjNode(divmod, DivModNode::div_proj_num);
duke@435 1208 Node* mproj = new (C, 1) ProjNode(divmod, DivModNode::mod_proj_num);
duke@435 1209 return divmod;
duke@435 1210 }
duke@435 1211
duke@435 1212 //------------------------------match------------------------------------------
duke@435 1213 // return result(s) along with their RegMask info
duke@435 1214 Node *DivModINode::match( const ProjNode *proj, const Matcher *match ) {
duke@435 1215 uint ideal_reg = proj->ideal_reg();
duke@435 1216 RegMask rm;
duke@435 1217 if (proj->_con == div_proj_num) {
duke@435 1218 rm = match->divI_proj_mask();
duke@435 1219 } else {
duke@435 1220 assert(proj->_con == mod_proj_num, "must be div or mod projection");
duke@435 1221 rm = match->modI_proj_mask();
duke@435 1222 }
duke@435 1223 return new (match->C, 1)MachProjNode(this, proj->_con, rm, ideal_reg);
duke@435 1224 }
duke@435 1225
duke@435 1226
duke@435 1227 //------------------------------match------------------------------------------
duke@435 1228 // return result(s) along with their RegMask info
duke@435 1229 Node *DivModLNode::match( const ProjNode *proj, const Matcher *match ) {
duke@435 1230 uint ideal_reg = proj->ideal_reg();
duke@435 1231 RegMask rm;
duke@435 1232 if (proj->_con == div_proj_num) {
duke@435 1233 rm = match->divL_proj_mask();
duke@435 1234 } else {
duke@435 1235 assert(proj->_con == mod_proj_num, "must be div or mod projection");
duke@435 1236 rm = match->modL_proj_mask();
duke@435 1237 }
duke@435 1238 return new (match->C, 1)MachProjNode(this, proj->_con, rm, ideal_reg);
duke@435 1239 }

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