1 /* 2 * Copyright (c) 1997, 2014, 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 "opto/ad.hpp" 27 #include "opto/compile.hpp" 28 #include "opto/matcher.hpp" 29 #include "opto/node.hpp" 30 #include "opto/regmask.hpp" 31 32 #define RM_SIZE _RM_SIZE /* a constant private to the class RegMask */ 33 34 //-------------Non-zero bit search methods used by RegMask--------------------- 35 // Find lowest 1, or return 32 if empty 36 int find_lowest_bit( uint32_t mask ) { 37 int n = 0; 38 if( (mask & 0xffff) == 0 ) { 39 mask >>= 16; 40 n += 16; 41 } 42 if( (mask & 0xff) == 0 ) { 43 mask >>= 8; 44 n += 8; 45 } 46 if( (mask & 0xf) == 0 ) { 47 mask >>= 4; 48 n += 4; 49 } 50 if( (mask & 0x3) == 0 ) { 51 mask >>= 2; 52 n += 2; 53 } 54 if( (mask & 0x1) == 0 ) { 55 mask >>= 1; 56 n += 1; 57 } 58 if( mask == 0 ) { 59 n = 32; 60 } 61 return n; 62 } 63 64 // Find highest 1, or return 32 if empty 65 int find_hihghest_bit( uint32_t mask ) { 66 int n = 0; 67 if( mask > 0xffff ) { 68 mask >>= 16; 69 n += 16; 70 } 71 if( mask > 0xff ) { 72 mask >>= 8; 73 n += 8; 74 } 75 if( mask > 0xf ) { 76 mask >>= 4; 77 n += 4; 78 } 79 if( mask > 0x3 ) { 80 mask >>= 2; 81 n += 2; 82 } 83 if( mask > 0x1 ) { 84 mask >>= 1; 85 n += 1; 86 } 87 if( mask == 0 ) { 88 n = 32; 89 } 90 return n; 91 } 92 93 //------------------------------dump------------------------------------------- 94 95 #ifndef PRODUCT 96 void OptoReg::dump(int r, outputStream *st) { 97 switch (r) { 98 case Special: st->print("r---"); break; 99 case Bad: st->print("rBAD"); break; 100 default: 101 if (r < _last_Mach_Reg) st->print("%s", Matcher::regName[r]); 102 else st->print("rS%d",r); 103 break; 104 } 105 } 106 #endif 107 108 109 //============================================================================= 110 const RegMask RegMask::Empty( 111 # define BODY(I) 0, 112 FORALL_BODY 113 # undef BODY 114 0 115 ); 116 117 //============================================================================= 118 bool RegMask::is_vector(Opcodes ireg) { 119 return (ireg == Opcodes::Op_VecS || ireg == Opcodes::Op_VecD || 120 ireg == Opcodes::Op_VecX || ireg == Opcodes::Op_VecY || ireg == Opcodes::Op_VecZ ); 121 } 122 123 int RegMask::num_registers(Opcodes ireg) { 124 switch(ireg) { 125 case Opcodes::Op_VecZ: 126 return 16; 127 case Opcodes::Op_VecY: 128 return 8; 129 case Opcodes::Op_VecX: 130 return 4; 131 case Opcodes::Op_VecD: 132 case Opcodes::Op_RegD: 133 case Opcodes::Op_RegL: 134 #ifdef _LP64 135 case Opcodes::Op_RegP: 136 #endif 137 return 2; 138 } 139 // Op_VecS and the rest ideal registers. 140 return 1; 141 } 142 143 //------------------------------find_first_pair-------------------------------- 144 // Find the lowest-numbered register pair in the mask. Return the 145 // HIGHEST register number in the pair, or BAD if no pairs. 146 OptoReg::Name RegMask::find_first_pair() const { 147 verify_pairs(); 148 for( int i = 0; i < RM_SIZE; i++ ) { 149 if( _A[i] ) { // Found some bits 150 int bit = _A[i] & -_A[i]; // Extract low bit 151 // Convert to bit number, return hi bit in pair 152 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+1); 153 } 154 } 155 return OptoReg::Bad; 156 } 157 158 //------------------------------ClearToPairs----------------------------------- 159 // Clear out partial bits; leave only bit pairs 160 void RegMask::clear_to_pairs() { 161 for( int i = 0; i < RM_SIZE; i++ ) { 162 int bits = _A[i]; 163 bits &= ((bits & 0x55555555)<<1); // 1 hi-bit set for each pair 164 bits |= (bits>>1); // Smear 1 hi-bit into a pair 165 _A[i] = bits; 166 } 167 verify_pairs(); 168 } 169 170 //------------------------------SmearToPairs----------------------------------- 171 // Smear out partial bits; leave only bit pairs 172 void RegMask::smear_to_pairs() { 173 for( int i = 0; i < RM_SIZE; i++ ) { 174 int bits = _A[i]; 175 bits |= ((bits & 0x55555555)<<1); // Smear lo bit hi per pair 176 bits |= ((bits & 0xAAAAAAAA)>>1); // Smear hi bit lo per pair 177 _A[i] = bits; 178 } 179 verify_pairs(); 180 } 181 182 //------------------------------is_aligned_pairs------------------------------- 183 bool RegMask::is_aligned_pairs() const { 184 // Assert that the register mask contains only bit pairs. 185 for( int i = 0; i < RM_SIZE; i++ ) { 186 int bits = _A[i]; 187 while( bits ) { // Check bits for pairing 188 int bit = bits & -bits; // Extract low bit 189 // Low bit is not odd means its mis-aligned. 190 if( (bit & 0x55555555) == 0 ) return false; 191 bits -= bit; // Remove bit from mask 192 // Check for aligned adjacent bit 193 if( (bits & (bit<<1)) == 0 ) return false; 194 bits -= (bit<<1); // Remove other halve of pair 195 } 196 } 197 return true; 198 } 199 200 //------------------------------is_bound1-------------------------------------- 201 // Return TRUE if the mask contains a single bit 202 int RegMask::is_bound1() const { 203 if( is_AllStack() ) return false; 204 int bit = -1; // Set to hold the one bit allowed 205 for( int i = 0; i < RM_SIZE; i++ ) { 206 if( _A[i] ) { // Found some bits 207 if( bit != -1 ) return false; // Already had bits, so fail 208 bit = _A[i] & -_A[i]; // Extract 1 bit from mask 209 if( bit != _A[i] ) return false; // Found many bits, so fail 210 } 211 } 212 // True for both the empty mask and for a single bit 213 return true; 214 } 215 216 //------------------------------is_bound2-------------------------------------- 217 // Return TRUE if the mask contains an adjacent pair of bits and no other bits. 218 int RegMask::is_bound_pair() const { 219 if( is_AllStack() ) return false; 220 221 int bit = -1; // Set to hold the one bit allowed 222 for( int i = 0; i < RM_SIZE; i++ ) { 223 if( _A[i] ) { // Found some bits 224 if( bit != -1 ) return false; // Already had bits, so fail 225 bit = _A[i] & -(_A[i]); // Extract 1 bit from mask 226 if( (bit << 1) != 0 ) { // Bit pair stays in same word? 227 if( (bit | (bit<<1)) != _A[i] ) 228 return false; // Require adjacent bit pair and no more bits 229 } else { // Else its a split-pair case 230 if( bit != _A[i] ) return false; // Found many bits, so fail 231 i++; // Skip iteration forward 232 if( i >= RM_SIZE || _A[i] != 1 ) 233 return false; // Require 1 lo bit in next word 234 } 235 } 236 } 237 // True for both the empty mask and for a bit pair 238 return true; 239 } 240 241 // only indicies of power 2 are accessed, so index 3 is only filled in for storage. 242 static int low_bits[5] = { 0x55555555, 0x11111111, 0x01010101, 0x00000000, 0x00010001 }; 243 //------------------------------find_first_set--------------------------------- 244 // Find the lowest-numbered register set in the mask. Return the 245 // HIGHEST register number in the set, or BAD if no sets. 246 // Works also for size 1. 247 OptoReg::Name RegMask::find_first_set(const int size) const { 248 verify_sets(size); 249 for (int i = 0; i < RM_SIZE; i++) { 250 if (_A[i]) { // Found some bits 251 int bit = _A[i] & -_A[i]; // Extract low bit 252 // Convert to bit number, return hi bit in pair 253 return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+(size-1)); 254 } 255 } 256 return OptoReg::Bad; 257 } 258 259 //------------------------------clear_to_sets---------------------------------- 260 // Clear out partial bits; leave only aligned adjacent bit pairs 261 void RegMask::clear_to_sets(const int size) { 262 if (size == 1) return; 263 assert(2 <= size && size <= 16, "update low bits table"); 264 assert(is_power_of_2(size), "sanity"); 265 int low_bits_mask = low_bits[size>>2]; 266 for (int i = 0; i < RM_SIZE; i++) { 267 int bits = _A[i]; 268 int sets = (bits & low_bits_mask); 269 for (int j = 1; j < size; j++) { 270 sets = (bits & (sets<<1)); // filter bits which produce whole sets 271 } 272 sets |= (sets>>1); // Smear 1 hi-bit into a set 273 if (size > 2) { 274 sets |= (sets>>2); // Smear 2 hi-bits into a set 275 if (size > 4) { 276 sets |= (sets>>4); // Smear 4 hi-bits into a set 277 if (size > 8) { 278 sets |= (sets>>8); // Smear 8 hi-bits into a set 279 } 280 } 281 } 282 _A[i] = sets; 283 } 284 verify_sets(size); 285 } 286 287 //------------------------------smear_to_sets---------------------------------- 288 // Smear out partial bits to aligned adjacent bit sets 289 void RegMask::smear_to_sets(const int size) { 290 if (size == 1) return; 291 assert(2 <= size && size <= 16, "update low bits table"); 292 assert(is_power_of_2(size), "sanity"); 293 int low_bits_mask = low_bits[size>>2]; 294 for (int i = 0; i < RM_SIZE; i++) { 295 int bits = _A[i]; 296 int sets = 0; 297 for (int j = 0; j < size; j++) { 298 sets |= (bits & low_bits_mask); // collect partial bits 299 bits = bits>>1; 300 } 301 sets |= (sets<<1); // Smear 1 lo-bit into a set 302 if (size > 2) { 303 sets |= (sets<<2); // Smear 2 lo-bits into a set 304 if (size > 4) { 305 sets |= (sets<<4); // Smear 4 lo-bits into a set 306 if (size > 8) { 307 sets |= (sets<<8); // Smear 8 lo-bits into a set 308 } 309 } 310 } 311 _A[i] = sets; 312 } 313 verify_sets(size); 314 } 315 316 //------------------------------is_aligned_set-------------------------------- 317 bool RegMask::is_aligned_sets(const int size) const { 318 if (size == 1) return true; 319 assert(2 <= size && size <= 16, "update low bits table"); 320 assert(is_power_of_2(size), "sanity"); 321 int low_bits_mask = low_bits[size>>2]; 322 // Assert that the register mask contains only bit sets. 323 for (int i = 0; i < RM_SIZE; i++) { 324 int bits = _A[i]; 325 while (bits) { // Check bits for pairing 326 int bit = bits & -bits; // Extract low bit 327 // Low bit is not odd means its mis-aligned. 328 if ((bit & low_bits_mask) == 0) return false; 329 // Do extra work since (bit << size) may overflow. 330 int hi_bit = bit << (size-1); // high bit 331 int set = hi_bit + ((hi_bit-1) & ~(bit-1)); 332 // Check for aligned adjacent bits in this set 333 if ((bits & set) != set) return false; 334 bits -= set; // Remove this set 335 } 336 } 337 return true; 338 } 339 340 //------------------------------is_bound_set----------------------------------- 341 // Return TRUE if the mask contains one adjacent set of bits and no other bits. 342 // Works also for size 1. 343 int RegMask::is_bound_set(const int size) const { 344 if( is_AllStack() ) return false; 345 assert(1 <= size && size <= 16, "update low bits table"); 346 int bit = -1; // Set to hold the one bit allowed 347 for (int i = 0; i < RM_SIZE; i++) { 348 if (_A[i] ) { // Found some bits 349 if (bit != -1) 350 return false; // Already had bits, so fail 351 bit = _A[i] & -_A[i]; // Extract low bit from mask 352 int hi_bit = bit << (size-1); // high bit 353 if (hi_bit != 0) { // Bit set stays in same word? 354 int set = hi_bit + ((hi_bit-1) & ~(bit-1)); 355 if (set != _A[i]) 356 return false; // Require adjacent bit set and no more bits 357 } else { // Else its a split-set case 358 if (((-1) & ~(bit-1)) != _A[i]) 359 return false; // Found many bits, so fail 360 i++; // Skip iteration forward and check high part 361 // The lower (32-size) bits should be 0 since it is split case. 362 int clear_bit_size = 32-size; 363 int shift_back_size = 32-clear_bit_size; 364 int set = bit>>clear_bit_size; 365 set = set & -set; // Remove sign extension. 366 set = (((set << size) - 1) >> shift_back_size); 367 if (i >= RM_SIZE || _A[i] != set) 368 return false; // Require expected low bits in next word 369 } 370 } 371 } 372 // True for both the empty mask and for a bit set 373 return true; 374 } 375 376 //------------------------------is_UP------------------------------------------ 377 // UP means register only, Register plus stack, or stack only is DOWN 378 bool RegMask::is_UP() const { 379 // Quick common case check for DOWN (any stack slot is legal) 380 if( is_AllStack() ) 381 return false; 382 // Slower check for any stack bits set (also DOWN) 383 if( overlap(Matcher::STACK_ONLY_mask) ) 384 return false; 385 // Not DOWN, so must be UP 386 return true; 387 } 388 389 //------------------------------Size------------------------------------------- 390 // Compute size of register mask in bits 391 uint RegMask::Size() const { 392 extern uint8_t bitsInByte[BITS_IN_BYTE_ARRAY_SIZE]; 393 uint sum = 0; 394 for( int i = 0; i < RM_SIZE; i++ ) 395 sum += 396 bitsInByte[(_A[i]>>24) & 0xff] + 397 bitsInByte[(_A[i]>>16) & 0xff] + 398 bitsInByte[(_A[i]>> 8) & 0xff] + 399 bitsInByte[ _A[i] & 0xff]; 400 return sum; 401 } 402 403 #ifndef PRODUCT 404 //------------------------------print------------------------------------------ 405 void RegMask::dump(outputStream *st) const { 406 st->print("["); 407 RegMask rm = *this; // Structure copy into local temp 408 409 OptoReg::Name start = rm.find_first_elem(); // Get a register 410 if (OptoReg::is_valid(start)) { // Check for empty mask 411 rm.Remove(start); // Yank from mask 412 OptoReg::dump(start, st); // Print register 413 OptoReg::Name last = start; 414 415 // Now I have printed an initial register. 416 // Print adjacent registers as "rX-rZ" instead of "rX,rY,rZ". 417 // Begin looping over the remaining registers. 418 while (1) { // 419 OptoReg::Name reg = rm.find_first_elem(); // Get a register 420 if (!OptoReg::is_valid(reg)) 421 break; // Empty mask, end loop 422 rm.Remove(reg); // Yank from mask 423 424 if (last+1 == reg) { // See if they are adjacent 425 // Adjacent registers just collect into long runs, no printing. 426 last = reg; 427 } else { // Ending some kind of run 428 if (start == last) { // 1-register run; no special printing 429 } else if (start+1 == last) { 430 st->print(","); // 2-register run; print as "rX,rY" 431 OptoReg::dump(last, st); 432 } else { // Multi-register run; print as "rX-rZ" 433 st->print("-"); 434 OptoReg::dump(last, st); 435 } 436 st->print(","); // Seperate start of new run 437 start = last = reg; // Start a new register run 438 OptoReg::dump(start, st); // Print register 439 } // End of if ending a register run or not 440 } // End of while regmask not empty 441 442 if (start == last) { // 1-register run; no special printing 443 } else if (start+1 == last) { 444 st->print(","); // 2-register run; print as "rX,rY" 445 OptoReg::dump(last, st); 446 } else { // Multi-register run; print as "rX-rZ" 447 st->print("-"); 448 OptoReg::dump(last, st); 449 } 450 if (rm.is_AllStack()) st->print("..."); 451 } 452 st->print("]"); 453 } 454 #endif