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 "runtime/globals.hpp" 27 #include "runtime/os.hpp" 28 #include "runtime/signature.hpp" 29 #include "utilities/globalDefinitions.hpp" 30 #include "utilities/powerOfTwo.hpp" 31 32 // Basic error support 33 34 // Info for oops within a java object. Defaults are zero so 35 // things will break badly if incorrectly initialized. 36 int heapOopSize = 0; 37 int LogBytesPerHeapOop = 0; 38 int LogBitsPerHeapOop = 0; 39 int BytesPerHeapOop = 0; 40 int BitsPerHeapOop = 0; 41 42 // Old CDS options 43 bool RequireSharedSpaces; 44 extern "C" { 45 JNIEXPORT jboolean UseSharedSpaces = true; 46 } 47 48 // Object alignment, in units of HeapWords. 49 // Defaults are -1 so things will break badly if incorrectly initialized. 50 int MinObjAlignment = -1; 51 int MinObjAlignmentInBytes = -1; 52 int MinObjAlignmentInBytesMask = 0; 53 54 int LogMinObjAlignment = -1; 55 int LogMinObjAlignmentInBytes = -1; 56 57 // Oop encoding heap max 58 uint64_t OopEncodingHeapMax = 0; 59 60 // Something to help porters sleep at night 61 62 #ifdef ASSERT 63 BasicType char2type(int ch) { 64 switch (ch) { 65 #define EACH_SIG(ch, bt, ignore) \ 66 case ch: return bt; 67 SIGNATURE_TYPES_DO(EACH_SIG, ignore) 68 #undef EACH_SIG 69 } 70 return T_ILLEGAL; 71 } 72 73 extern bool signature_constants_sane(); 74 #endif //ASSERT 75 76 void basic_types_init() { 77 #ifdef ASSERT 78 #ifdef _LP64 79 static_assert(min_intx == (intx)CONST64(0x8000000000000000), "correct constant"); 80 static_assert(max_intx == CONST64(0x7FFFFFFFFFFFFFFF), "correct constant"); 81 static_assert(max_uintx == CONST64(0xFFFFFFFFFFFFFFFF), "correct constant"); 82 static_assert( 8 == sizeof( intx), "wrong size for basic type"); 83 static_assert( 8 == sizeof( jobject), "wrong size for basic type"); 84 #else 85 static_assert(min_intx == (intx)0x80000000, "correct constant"); 86 static_assert(max_intx == 0x7FFFFFFF, "correct constant"); 87 static_assert(max_uintx == 0xFFFFFFFF, "correct constant"); 88 static_assert( 4 == sizeof( intx), "wrong size for basic type"); 89 static_assert( 4 == sizeof( jobject), "wrong size for basic type"); 90 #endif 91 static_assert( (~max_juint) == 0, "max_juint has all its bits"); 92 static_assert( (~max_uintx) == 0, "max_uintx has all its bits"); 93 static_assert( (~max_julong) == 0, "max_julong has all its bits"); 94 static_assert( 1 == sizeof( jbyte), "wrong size for basic type"); 95 static_assert( 2 == sizeof( jchar), "wrong size for basic type"); 96 static_assert( 2 == sizeof( jshort), "wrong size for basic type"); 97 static_assert( 4 == sizeof( juint), "wrong size for basic type"); 98 static_assert( 4 == sizeof( jint), "wrong size for basic type"); 99 static_assert( 1 == sizeof( jboolean), "wrong size for basic type"); 100 static_assert( 8 == sizeof( jlong), "wrong size for basic type"); 101 static_assert( 4 == sizeof( jfloat), "wrong size for basic type"); 102 static_assert( 8 == sizeof( jdouble), "wrong size for basic type"); 103 static_assert( 1 == sizeof( u1), "wrong size for basic type"); 104 static_assert( 2 == sizeof( u2), "wrong size for basic type"); 105 static_assert( 4 == sizeof( u4), "wrong size for basic type"); 106 static_assert(wordSize == BytesPerWord, "should be the same since they're used interchangeably"); 107 static_assert(wordSize == HeapWordSize, "should be the same since they're also used interchangeably"); 108 109 assert(signature_constants_sane(), ""); 110 111 int num_type_chars = 0; 112 for (int i = 0; i < 99; i++) { 113 if (type2char((BasicType)i) != 0) { 114 assert(char2type(type2char((BasicType)i)) == i, "proper inverses"); 115 assert(Signature::basic_type(type2char((BasicType)i)) == i, "proper inverses"); 116 num_type_chars++; 117 } 118 } 119 assert(num_type_chars == 12, "must have tested the right number of mappings"); 120 assert(char2type(0) == T_ILLEGAL, "correct illegality"); 121 122 { 123 for (int i = T_BOOLEAN; i <= T_CONFLICT; i++) { 124 BasicType vt = (BasicType)i; 125 BasicType ft = type2field[vt]; 126 switch (vt) { 127 // the following types might plausibly show up in memory layouts: 128 case T_BOOLEAN: 129 case T_BYTE: 130 case T_CHAR: 131 case T_SHORT: 132 case T_INT: 133 case T_FLOAT: 134 case T_DOUBLE: 135 case T_LONG: 136 case T_OBJECT: 137 case T_ADDRESS: // random raw pointer 138 case T_METADATA: // metadata pointer 139 case T_NARROWOOP: // compressed pointer 140 case T_NARROWKLASS: // compressed klass pointer 141 case T_CONFLICT: // might as well support a bottom type 142 case T_VOID: // padding or other unaddressed word 143 // layout type must map to itself 144 assert(vt == ft, ""); 145 break; 146 default: 147 // non-layout type must map to a (different) layout type 148 assert(vt != ft, ""); 149 assert(ft == type2field[ft], ""); 150 } 151 // every type must map to same-sized layout type: 152 assert(type2size[vt] == type2size[ft], ""); 153 } 154 } 155 // These are assumed, e.g., when filling HeapWords with juints. 156 static_assert(is_power_of_2(sizeof(juint)), "juint must be power of 2"); 157 static_assert(is_power_of_2(HeapWordSize), "HeapWordSize must be power of 2"); 158 static_assert((size_t)HeapWordSize >= sizeof(juint), 159 "HeapWord should be at least as large as juint"); 160 static_assert(sizeof(NULL) == sizeof(char*), "NULL must be same size as pointer"); 161 #endif 162 163 if( JavaPriority1_To_OSPriority != -1 ) 164 os::java_to_os_priority[1] = JavaPriority1_To_OSPriority; 165 if( JavaPriority2_To_OSPriority != -1 ) 166 os::java_to_os_priority[2] = JavaPriority2_To_OSPriority; 167 if( JavaPriority3_To_OSPriority != -1 ) 168 os::java_to_os_priority[3] = JavaPriority3_To_OSPriority; 169 if( JavaPriority4_To_OSPriority != -1 ) 170 os::java_to_os_priority[4] = JavaPriority4_To_OSPriority; 171 if( JavaPriority5_To_OSPriority != -1 ) 172 os::java_to_os_priority[5] = JavaPriority5_To_OSPriority; 173 if( JavaPriority6_To_OSPriority != -1 ) 174 os::java_to_os_priority[6] = JavaPriority6_To_OSPriority; 175 if( JavaPriority7_To_OSPriority != -1 ) 176 os::java_to_os_priority[7] = JavaPriority7_To_OSPriority; 177 if( JavaPriority8_To_OSPriority != -1 ) 178 os::java_to_os_priority[8] = JavaPriority8_To_OSPriority; 179 if( JavaPriority9_To_OSPriority != -1 ) 180 os::java_to_os_priority[9] = JavaPriority9_To_OSPriority; 181 if(JavaPriority10_To_OSPriority != -1 ) 182 os::java_to_os_priority[10] = JavaPriority10_To_OSPriority; 183 184 // Set the size of basic types here (after argument parsing but before 185 // stub generation). 186 if (UseCompressedOops) { 187 // Size info for oops within java objects is fixed 188 heapOopSize = jintSize; 189 LogBytesPerHeapOop = LogBytesPerInt; 190 LogBitsPerHeapOop = LogBitsPerInt; 191 BytesPerHeapOop = BytesPerInt; 192 BitsPerHeapOop = BitsPerInt; 193 } else { 194 heapOopSize = oopSize; 195 LogBytesPerHeapOop = LogBytesPerWord; 196 LogBitsPerHeapOop = LogBitsPerWord; 197 BytesPerHeapOop = BytesPerWord; 198 BitsPerHeapOop = BitsPerWord; 199 } 200 _type2aelembytes[T_OBJECT] = heapOopSize; 201 _type2aelembytes[T_ARRAY] = heapOopSize; 202 _type2aelembytes[T_PRIMITIVE_OBJECT] = heapOopSize; 203 } 204 205 206 // Map BasicType to signature character 207 char type2char_tab[T_CONFLICT+1] = { 208 0, 0, 0, 0, 209 JVM_SIGNATURE_BOOLEAN, JVM_SIGNATURE_CHAR, 210 JVM_SIGNATURE_FLOAT, JVM_SIGNATURE_DOUBLE, 211 JVM_SIGNATURE_BYTE, JVM_SIGNATURE_SHORT, 212 JVM_SIGNATURE_INT, JVM_SIGNATURE_LONG, 213 JVM_SIGNATURE_CLASS, JVM_SIGNATURE_ARRAY, 214 JVM_SIGNATURE_PRIMITIVE_OBJECT, JVM_SIGNATURE_VOID, 215 0, 0, 0, 0, 0 216 }; 217 218 // Map BasicType to Java type name 219 const char* type2name_tab[T_CONFLICT+1] = { 220 nullptr, nullptr, nullptr, nullptr, 221 "boolean", 222 "char", 223 "float", 224 "double", 225 "byte", 226 "short", 227 "int", 228 "long", 229 "object", 230 "array", 231 "inline_type", 232 "void", 233 "*address*", 234 "*narrowoop*", 235 "*metadata*", 236 "*narrowklass*", 237 "*conflict*" 238 }; 239 const char* type2name(BasicType t) { 240 if (t < ARRAY_SIZE(type2name_tab)) { 241 return type2name_tab[t]; 242 } else if (t == T_ILLEGAL) { 243 return "*illegal*"; 244 } else { 245 fatal("invalid type %d", t); 246 return "invalid type"; 247 } 248 } 249 250 251 252 BasicType name2type(const char* name) { 253 for (int i = T_BOOLEAN; i <= T_VOID; i++) { 254 BasicType t = (BasicType)i; 255 if (type2name_tab[t] != nullptr && 0 == strcmp(type2name_tab[t], name)) 256 return t; 257 } 258 return T_ILLEGAL; 259 } 260 261 // Map BasicType to size in words 262 int type2size[T_CONFLICT+1]={ -1, 0, 0, 0, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 0, 1, 1, 1, 1, -1}; 263 264 BasicType type2field[T_CONFLICT+1] = { 265 (BasicType)0, // 0, 266 (BasicType)0, // 1, 267 (BasicType)0, // 2, 268 (BasicType)0, // 3, 269 T_BOOLEAN, // T_BOOLEAN = 4, 270 T_CHAR, // T_CHAR = 5, 271 T_FLOAT, // T_FLOAT = 6, 272 T_DOUBLE, // T_DOUBLE = 7, 273 T_BYTE, // T_BYTE = 8, 274 T_SHORT, // T_SHORT = 9, 275 T_INT, // T_INT = 10, 276 T_LONG, // T_LONG = 11, 277 T_OBJECT, // T_OBJECT = 12, 278 T_OBJECT, // T_ARRAY = 13, 279 T_OBJECT, // T_PRIMITIVE_OBJECT = 14, 280 T_VOID, // T_VOID = 15, 281 T_ADDRESS, // T_ADDRESS = 16, 282 T_NARROWOOP, // T_NARROWOOP= 17, 283 T_METADATA, // T_METADATA = 18, 284 T_NARROWKLASS, // T_NARROWKLASS = 19, 285 T_CONFLICT // T_CONFLICT = 20 286 }; 287 288 289 BasicType type2wfield[T_CONFLICT+1] = { 290 (BasicType)0, // 0, 291 (BasicType)0, // 1, 292 (BasicType)0, // 2, 293 (BasicType)0, // 3, 294 T_INT, // T_BOOLEAN = 4, 295 T_INT, // T_CHAR = 5, 296 T_FLOAT, // T_FLOAT = 6, 297 T_DOUBLE, // T_DOUBLE = 7, 298 T_INT, // T_BYTE = 8, 299 T_INT, // T_SHORT = 9, 300 T_INT, // T_INT = 10, 301 T_LONG, // T_LONG = 11, 302 T_OBJECT, // T_OBJECT = 12, 303 T_OBJECT, // T_ARRAY = 13, 304 T_OBJECT, // T_PRIMITIVE_OBJECT = 14, 305 T_VOID, // T_VOID = 15, 306 T_ADDRESS, // T_ADDRESS = 16, 307 T_NARROWOOP, // T_NARROWOOP = 17, 308 T_METADATA, // T_METADATA = 18, 309 T_NARROWKLASS, // T_NARROWKLASS = 19, 310 T_CONFLICT // T_CONFLICT = 20 311 }; 312 313 314 int _type2aelembytes[T_CONFLICT+1] = { 315 0, // 0 316 0, // 1 317 0, // 2 318 0, // 3 319 T_BOOLEAN_aelem_bytes, // T_BOOLEAN = 4, 320 T_CHAR_aelem_bytes, // T_CHAR = 5, 321 T_FLOAT_aelem_bytes, // T_FLOAT = 6, 322 T_DOUBLE_aelem_bytes, // T_DOUBLE = 7, 323 T_BYTE_aelem_bytes, // T_BYTE = 8, 324 T_SHORT_aelem_bytes, // T_SHORT = 9, 325 T_INT_aelem_bytes, // T_INT = 10, 326 T_LONG_aelem_bytes, // T_LONG = 11, 327 T_OBJECT_aelem_bytes, // T_OBJECT = 12, 328 T_ARRAY_aelem_bytes, // T_ARRAY = 13, 329 T_PRIMITIVE_OBJECT_aelem_bytes, // T_PRIMITIVE_OBJECT = 14, 330 0, // T_VOID = 15, 331 T_OBJECT_aelem_bytes, // T_ADDRESS = 16, 332 T_NARROWOOP_aelem_bytes, // T_NARROWOOP= 17, 333 T_OBJECT_aelem_bytes, // T_METADATA = 18, 334 T_NARROWKLASS_aelem_bytes, // T_NARROWKLASS= 19, 335 0 // T_CONFLICT = 20 336 }; 337 338 #ifdef ASSERT 339 int type2aelembytes(BasicType t, bool allow_address) { 340 assert((allow_address || t != T_ADDRESS) && t <= T_CONFLICT, "unexpected basic type"); 341 return _type2aelembytes[t]; 342 } 343 #endif 344 345 // Support for 64-bit integer arithmetic 346 347 // The following code is mostly taken from JVM typedefs_md.h and system_md.c 348 349 static const jlong high_bit = (jlong)1 << (jlong)63; 350 static const jlong other_bits = ~high_bit; 351 352 jlong float2long(jfloat f) { 353 jlong tmp = (jlong) f; 354 if (tmp != high_bit) { 355 return tmp; 356 } else { 357 if (g_isnan((jdouble)f)) { 358 return 0; 359 } 360 if (f < 0) { 361 return high_bit; 362 } else { 363 return other_bits; 364 } 365 } 366 } 367 368 369 jlong double2long(jdouble f) { 370 jlong tmp = (jlong) f; 371 if (tmp != high_bit) { 372 return tmp; 373 } else { 374 if (g_isnan(f)) { 375 return 0; 376 } 377 if (f < 0) { 378 return high_bit; 379 } else { 380 return other_bits; 381 } 382 } 383 } 384 385 // least common multiple 386 size_t lcm(size_t a, size_t b) { 387 size_t cur, div, next; 388 389 cur = MAX2(a, b); 390 div = MIN2(a, b); 391 392 assert(div != 0, "lcm requires positive arguments"); 393 394 395 while ((next = cur % div) != 0) { 396 cur = div; div = next; 397 } 398 399 400 julong result = julong(a) * b / div; 401 assert(result <= (size_t)max_uintx, "Integer overflow in lcm"); 402 403 return size_t(result); 404 } 405 406 407 // Test that nth_bit macro and friends behave as 408 // expected, even with low-precedence operators. 409 410 STATIC_ASSERT(nth_bit(3) == 0x8); 411 STATIC_ASSERT(nth_bit(1|2) == 0x8); 412 413 STATIC_ASSERT(right_n_bits(3) == 0x7); 414 STATIC_ASSERT(right_n_bits(1|2) == 0x7); 415 416 // Check for Flush-To-Zero mode 417 418 // On some processors faster execution can be achieved by setting a 419 // mode to return zero for extremely small results, rather than an 420 // IEEE-754 subnormal number. This mode is not compatible with the 421 // Java Language Standard. 422 423 // We need the addition of _large_subnormal and _small_subnormal to be 424 // performed at runtime. _small_subnormal is volatile so that 425 // expressions involving it cannot be evaluated at compile time. 426 static const double large_subnormal_double 427 = jdouble_cast(0x0030000000000000); // 0x1.0p-1020; 428 static const volatile double small_subnormal_double 429 = jdouble_cast(0x0000000000000003); // 0x0.0000000000003p-1022; 430 431 // Quickly test to make sure IEEE-754 subnormal numbers are correctly 432 // handled. 433 bool IEEE_subnormal_handling_OK() { 434 // _small_subnormal is the smallest subnormal number that has two 435 // bits set. _large_subnormal is a number such that, when 436 // _small_subnormal is added to it, must be rounded according to the 437 // mode. These two tests detect the rounding mode in use. If 438 // subnormals are turned off (i.e. subnormals-are-zero) flush-to- 439 // zero mode is in use. 440 441 return (large_subnormal_double + small_subnormal_double > large_subnormal_double 442 && -large_subnormal_double - small_subnormal_double < -large_subnormal_double); 443 }