1 /*
   2  * Copyright (c) 1997, 2021, 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
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  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.
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  24 
  25 #ifndef SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
  26 #define SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
  27 
  28 #include "utilities/compilerWarnings.hpp"
  29 #include "utilities/debug.hpp"
  30 #include "utilities/macros.hpp"
  31 
  32 // Get constants like JVM_T_CHAR and JVM_SIGNATURE_INT, before pulling in <jvm.h>.
  33 #include "classfile_constants.h"
  34 
  35 #include COMPILER_HEADER(utilities/globalDefinitions)
  36 
  37 #include <cstddef>
  38 
  39 class oopDesc;
  40 
  41 // Defaults for macros that might be defined per compiler.
  42 #ifndef NOINLINE
  43 #define NOINLINE
  44 #endif
  45 #ifndef ALWAYSINLINE
  46 #define ALWAYSINLINE inline
  47 #endif
  48 
  49 #ifndef ATTRIBUTE_ALIGNED
  50 #define ATTRIBUTE_ALIGNED(x)
  51 #endif
  52 
  53 #ifndef ATTRIBUTE_FLATTEN
  54 #define ATTRIBUTE_FLATTEN
  55 #endif
  56 
  57 // These are #defines to selectively turn on/off the Print(Opto)Assembly
  58 // capabilities. Choices should be led by a tradeoff between
  59 // code size and improved supportability.
  60 // if PRINT_ASSEMBLY then PRINT_ABSTRACT_ASSEMBLY must be true as well
  61 // to have a fallback in case hsdis is not available.
  62 #if defined(PRODUCT)
  63   #define SUPPORT_ABSTRACT_ASSEMBLY
  64   #define SUPPORT_ASSEMBLY
  65   #undef  SUPPORT_OPTO_ASSEMBLY      // Can't activate. In PRODUCT, many dump methods are missing.
  66   #undef  SUPPORT_DATA_STRUCTS       // Of limited use. In PRODUCT, many print methods are empty.
  67 #else
  68   #define SUPPORT_ABSTRACT_ASSEMBLY
  69   #define SUPPORT_ASSEMBLY
  70   #define SUPPORT_OPTO_ASSEMBLY
  71   #define SUPPORT_DATA_STRUCTS
  72 #endif
  73 #if defined(SUPPORT_ASSEMBLY) && !defined(SUPPORT_ABSTRACT_ASSEMBLY)
  74   #define SUPPORT_ABSTRACT_ASSEMBLY
  75 #endif
  76 
  77 // This file holds all globally used constants & types, class (forward)
  78 // declarations and a few frequently used utility functions.
  79 
  80 // Declare the named class to be noncopyable.  This macro must be followed by
  81 // a semi-colon.  The macro provides deleted declarations for the class's copy
  82 // constructor and assignment operator.  Because these operations are deleted,
  83 // they cannot be defined and potential callers will fail to compile.
  84 #define NONCOPYABLE(C) C(C const&) = delete; C& operator=(C const&) = delete /* next token must be ; */
  85 
  86 
  87 //----------------------------------------------------------------------------------------------------
  88 // Printf-style formatters for fixed- and variable-width types as pointers and
  89 // integers.  These are derived from the definitions in inttypes.h.  If the platform
  90 // doesn't provide appropriate definitions, they should be provided in
  91 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
  92 
  93 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
  94 
  95 // Format 32-bit quantities.
  96 #define INT32_FORMAT           "%" PRId32
  97 #define UINT32_FORMAT          "%" PRIu32
  98 #define INT32_FORMAT_W(width)  "%" #width PRId32
  99 #define UINT32_FORMAT_W(width) "%" #width PRIu32
 100 
 101 #define PTR32_FORMAT           "0x%08" PRIx32
 102 #define PTR32_FORMAT_W(width)  "0x%" #width PRIx32
 103 
 104 // Format 64-bit quantities.
 105 #define INT64_FORMAT           "%" PRId64
 106 #define UINT64_FORMAT          "%" PRIu64
 107 #define UINT64_FORMAT_X        "%" PRIx64
 108 #define INT64_FORMAT_W(width)  "%" #width PRId64
 109 #define UINT64_FORMAT_W(width) "%" #width PRIu64
 110 #define UINT64_FORMAT_X_W(width) "%" #width PRIx64
 111 
 112 #define PTR64_FORMAT           "0x%016" PRIx64
 113 
 114 // Format jlong, if necessary
 115 #ifndef JLONG_FORMAT
 116 #define JLONG_FORMAT           INT64_FORMAT
 117 #endif
 118 #ifndef JLONG_FORMAT_W
 119 #define JLONG_FORMAT_W(width)  INT64_FORMAT_W(width)
 120 #endif
 121 #ifndef JULONG_FORMAT
 122 #define JULONG_FORMAT          UINT64_FORMAT
 123 #endif
 124 #ifndef JULONG_FORMAT_X
 125 #define JULONG_FORMAT_X        UINT64_FORMAT_X
 126 #endif
 127 
 128 // Format pointers which change size between 32- and 64-bit.
 129 #ifdef  _LP64
 130 #define INTPTR_FORMAT "0x%016" PRIxPTR
 131 #define PTR_FORMAT    "0x%016" PRIxPTR
 132 #else   // !_LP64
 133 #define INTPTR_FORMAT "0x%08"  PRIxPTR
 134 #define PTR_FORMAT    "0x%08"  PRIxPTR
 135 #endif  // _LP64
 136 
 137 // Format pointers without leading zeros
 138 #define INTPTRNZ_FORMAT "0x%"  PRIxPTR
 139 
 140 #define INTPTR_FORMAT_W(width)   "%" #width PRIxPTR
 141 
 142 #define SSIZE_FORMAT             "%"   PRIdPTR
 143 #define SIZE_FORMAT              "%"   PRIuPTR
 144 #define SIZE_FORMAT_HEX          "0x%" PRIxPTR
 145 #define SSIZE_FORMAT_W(width)    "%"   #width PRIdPTR
 146 #define SIZE_FORMAT_W(width)     "%"   #width PRIuPTR
 147 #define SIZE_FORMAT_HEX_W(width) "0x%" #width PRIxPTR
 148 
 149 #define INTX_FORMAT           "%" PRIdPTR
 150 #define UINTX_FORMAT          "%" PRIuPTR
 151 #define INTX_FORMAT_W(width)  "%" #width PRIdPTR
 152 #define UINTX_FORMAT_W(width) "%" #width PRIuPTR
 153 
 154 // Convert pointer to intptr_t, for use in printing pointers.
 155 inline intptr_t p2i(const volatile void* p) {
 156   return (intptr_t) p;
 157 }
 158 
 159 //----------------------------------------------------------------------------------------------------
 160 // Constants
 161 
 162 const int LogBytesPerShort   = 1;
 163 const int LogBytesPerInt     = 2;
 164 #ifdef _LP64
 165 const int LogBytesPerWord    = 3;
 166 #else
 167 const int LogBytesPerWord    = 2;
 168 #endif
 169 const int LogBytesPerLong    = 3;
 170 
 171 const int BytesPerShort      = 1 << LogBytesPerShort;
 172 const int BytesPerInt        = 1 << LogBytesPerInt;
 173 const int BytesPerWord       = 1 << LogBytesPerWord;
 174 const int BytesPerLong       = 1 << LogBytesPerLong;
 175 
 176 const int LogBitsPerByte     = 3;
 177 const int LogBitsPerShort    = LogBitsPerByte + LogBytesPerShort;
 178 const int LogBitsPerInt      = LogBitsPerByte + LogBytesPerInt;
 179 const int LogBitsPerWord     = LogBitsPerByte + LogBytesPerWord;
 180 const int LogBitsPerLong     = LogBitsPerByte + LogBytesPerLong;
 181 
 182 const int BitsPerByte        = 1 << LogBitsPerByte;
 183 const int BitsPerShort       = 1 << LogBitsPerShort;
 184 const int BitsPerInt         = 1 << LogBitsPerInt;
 185 const int BitsPerWord        = 1 << LogBitsPerWord;
 186 const int BitsPerLong        = 1 << LogBitsPerLong;
 187 
 188 const int WordAlignmentMask  = (1 << LogBytesPerWord) - 1;
 189 const int LongAlignmentMask  = (1 << LogBytesPerLong) - 1;
 190 
 191 const int WordsPerLong       = 2;       // Number of stack entries for longs
 192 
 193 const int oopSize            = sizeof(char*); // Full-width oop
 194 extern int heapOopSize;                       // Oop within a java object
 195 const int wordSize           = sizeof(char*);
 196 const int longSize           = sizeof(jlong);
 197 const int jintSize           = sizeof(jint);
 198 const int size_tSize         = sizeof(size_t);
 199 
 200 const int BytesPerOop        = BytesPerWord;  // Full-width oop
 201 
 202 extern int LogBytesPerHeapOop;                // Oop within a java object
 203 extern int LogBitsPerHeapOop;
 204 extern int BytesPerHeapOop;
 205 extern int BitsPerHeapOop;
 206 
 207 const int BitsPerJavaInteger = 32;
 208 const int BitsPerJavaLong    = 64;
 209 const int BitsPerSize_t      = size_tSize * BitsPerByte;
 210 
 211 // Size of a char[] needed to represent a jint as a string in decimal.
 212 const int jintAsStringSize = 12;
 213 
 214 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
 215 // We require that object sizes be measured in units of heap words (e.g.
 216 // pointer-sized values), so that given HeapWord* hw,
 217 //   hw += oop(hw)->foo();
 218 // works, where foo is a method (like size or scavenge) that returns the
 219 // object size.
 220 class HeapWordImpl;             // Opaque, never defined.
 221 typedef HeapWordImpl* HeapWord;
 222 
 223 // Analogous opaque struct for metadata allocated from metaspaces.
 224 class MetaWordImpl;             // Opaque, never defined.
 225 typedef MetaWordImpl* MetaWord;
 226 
 227 // HeapWordSize must be 2^LogHeapWordSize.
 228 const int HeapWordSize        = sizeof(HeapWord);
 229 #ifdef _LP64
 230 const int LogHeapWordSize     = 3;
 231 #else
 232 const int LogHeapWordSize     = 2;
 233 #endif
 234 const int HeapWordsPerLong    = BytesPerLong / HeapWordSize;
 235 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
 236 
 237 // The minimum number of native machine words necessary to contain "byte_size"
 238 // bytes.
 239 inline size_t heap_word_size(size_t byte_size) {
 240   return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
 241 }
 242 
 243 inline jfloat jfloat_cast(jint x);
 244 inline jdouble jdouble_cast(jlong x);
 245 
 246 //-------------------------------------------
 247 // Constant for jlong (standardized by C++11)
 248 
 249 // Build a 64bit integer constant
 250 #define CONST64(x)  (x ## LL)
 251 #define UCONST64(x) (x ## ULL)
 252 
 253 const jlong min_jlong = CONST64(0x8000000000000000);
 254 const jlong max_jlong = CONST64(0x7fffffffffffffff);
 255 
 256 //-------------------------------------------
 257 // Constant for jdouble
 258 const jlong min_jlongDouble = CONST64(0x0000000000000001);
 259 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
 260 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
 261 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
 262 
 263 const size_t K                  = 1024;
 264 const size_t M                  = K*K;
 265 const size_t G                  = M*K;
 266 const size_t HWperKB            = K / sizeof(HeapWord);
 267 
 268 // Constants for converting from a base unit to milli-base units.  For
 269 // example from seconds to milliseconds and microseconds
 270 
 271 const int MILLIUNITS    = 1000;         // milli units per base unit
 272 const int MICROUNITS    = 1000000;      // micro units per base unit
 273 const int NANOUNITS     = 1000000000;   // nano units per base unit
 274 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
 275 
 276 const jlong NANOSECS_PER_SEC      = CONST64(1000000000);
 277 const jint  NANOSECS_PER_MILLISEC = 1000000;
 278 
 279 
 280 // Unit conversion functions
 281 // The caller is responsible for considering overlow.
 282 
 283 inline int64_t nanos_to_millis(int64_t nanos) {
 284   return nanos / NANOUNITS_PER_MILLIUNIT;
 285 }
 286 inline int64_t millis_to_nanos(int64_t millis) {
 287   return millis * NANOUNITS_PER_MILLIUNIT;
 288 }
 289 
 290 // Proper units routines try to maintain at least three significant digits.
 291 // In worst case, it would print five significant digits with lower prefix.
 292 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
 293 // and therefore we need to be careful.
 294 
 295 inline const char* proper_unit_for_byte_size(size_t s) {
 296 #ifdef _LP64
 297   if (s >= 100*G) {
 298     return "G";
 299   }
 300 #endif
 301   if (s >= 100*M) {
 302     return "M";
 303   } else if (s >= 100*K) {
 304     return "K";
 305   } else {
 306     return "B";
 307   }
 308 }
 309 
 310 template <class T>
 311 inline T byte_size_in_proper_unit(T s) {
 312 #ifdef _LP64
 313   if (s >= 100*G) {
 314     return (T)(s/G);
 315   }
 316 #endif
 317   if (s >= 100*M) {
 318     return (T)(s/M);
 319   } else if (s >= 100*K) {
 320     return (T)(s/K);
 321   } else {
 322     return s;
 323   }
 324 }
 325 
 326 inline const char* exact_unit_for_byte_size(size_t s) {
 327 #ifdef _LP64
 328   if (s >= G && (s % G) == 0) {
 329     return "G";
 330   }
 331 #endif
 332   if (s >= M && (s % M) == 0) {
 333     return "M";
 334   }
 335   if (s >= K && (s % K) == 0) {
 336     return "K";
 337   }
 338   return "B";
 339 }
 340 
 341 inline size_t byte_size_in_exact_unit(size_t s) {
 342 #ifdef _LP64
 343   if (s >= G && (s % G) == 0) {
 344     return s / G;
 345   }
 346 #endif
 347   if (s >= M && (s % M) == 0) {
 348     return s / M;
 349   }
 350   if (s >= K && (s % K) == 0) {
 351     return s / K;
 352   }
 353   return s;
 354 }
 355 
 356 // Memory size transition formatting.
 357 
 358 #define HEAP_CHANGE_FORMAT "%s: " SIZE_FORMAT "K(" SIZE_FORMAT "K)->" SIZE_FORMAT "K(" SIZE_FORMAT "K)"
 359 
 360 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
 361   (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
 362 
 363 //----------------------------------------------------------------------------------------------------
 364 // VM type definitions
 365 
 366 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
 367 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
 368 
 369 typedef intptr_t  intx;
 370 typedef uintptr_t uintx;
 371 
 372 const intx  min_intx  = (intx)1 << (sizeof(intx)*BitsPerByte-1);
 373 const intx  max_intx  = (uintx)min_intx - 1;
 374 const uintx max_uintx = (uintx)-1;
 375 
 376 // Table of values:
 377 //      sizeof intx         4               8
 378 // min_intx             0x80000000      0x8000000000000000
 379 // max_intx             0x7FFFFFFF      0x7FFFFFFFFFFFFFFF
 380 // max_uintx            0xFFFFFFFF      0xFFFFFFFFFFFFFFFF
 381 
 382 typedef unsigned int uint;   NEEDS_CLEANUP
 383 
 384 
 385 //----------------------------------------------------------------------------------------------------
 386 // Java type definitions
 387 
 388 // All kinds of 'plain' byte addresses
 389 typedef   signed char s_char;
 390 typedef unsigned char u_char;
 391 typedef u_char*       address;
 392 typedef uintptr_t     address_word; // unsigned integer which will hold a pointer
 393                                     // except for some implementations of a C++
 394                                     // linkage pointer to function. Should never
 395                                     // need one of those to be placed in this
 396                                     // type anyway.
 397 
 398 //  Utility functions to "portably" (?) bit twiddle pointers
 399 //  Where portable means keep ANSI C++ compilers quiet
 400 
 401 inline address       set_address_bits(address x, int m)       { return address(intptr_t(x) | m); }
 402 inline address       clear_address_bits(address x, int m)     { return address(intptr_t(x) & ~m); }
 403 
 404 //  Utility functions to "portably" make cast to/from function pointers.
 405 
 406 inline address_word  mask_address_bits(address x, int m)      { return address_word(x) & m; }
 407 inline address_word  castable_address(address x)              { return address_word(x) ; }
 408 inline address_word  castable_address(void* x)                { return address_word(x) ; }
 409 
 410 // Pointer subtraction.
 411 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
 412 // the range we might need to find differences from one end of the heap
 413 // to the other.
 414 // A typical use might be:
 415 //     if (pointer_delta(end(), top()) >= size) {
 416 //       // enough room for an object of size
 417 //       ...
 418 // and then additions like
 419 //       ... top() + size ...
 420 // are safe because we know that top() is at least size below end().
 421 inline size_t pointer_delta(const volatile void* left,
 422                             const volatile void* right,
 423                             size_t element_size) {
 424   assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
 425   return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
 426 }
 427 
 428 // A version specialized for HeapWord*'s.
 429 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
 430   return pointer_delta(left, right, sizeof(HeapWord));
 431 }
 432 // A version specialized for MetaWord*'s.
 433 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
 434   return pointer_delta(left, right, sizeof(MetaWord));
 435 }
 436 
 437 //
 438 // ANSI C++ does not allow casting from one pointer type to a function pointer
 439 // directly without at best a warning. This macro accomplishes it silently
 440 // In every case that is present at this point the value be cast is a pointer
 441 // to a C linkage function. In some case the type used for the cast reflects
 442 // that linkage and a picky compiler would not complain. In other cases because
 443 // there is no convenient place to place a typedef with extern C linkage (i.e
 444 // a platform dependent header file) it doesn't. At this point no compiler seems
 445 // picky enough to catch these instances (which are few). It is possible that
 446 // using templates could fix these for all cases. This use of templates is likely
 447 // so far from the middle of the road that it is likely to be problematic in
 448 // many C++ compilers.
 449 //
 450 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
 451 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((address_word)(func_ptr)))
 452 
 453 // In many places we've added C-style casts to silence compiler
 454 // warnings, for example when truncating a size_t to an int when we
 455 // know the size_t is a small struct. Such casts are risky because
 456 // they effectively disable useful compiler warnings. We can make our
 457 // lives safer with this function, which ensures that any cast is
 458 // reversible without loss of information. It doesn't check
 459 // everything: it isn't intended to make sure that pointer types are
 460 // compatible, for example.
 461 template <typename T2, typename T1>
 462 T2 checked_cast(T1 thing) {
 463   T2 result = static_cast<T2>(thing);
 464   assert(static_cast<T1>(result) == thing, "must be");
 465   return result;
 466 }
 467 
 468 // Need the correct linkage to call qsort without warnings
 469 extern "C" {
 470   typedef int (*_sort_Fn)(const void *, const void *);
 471 }
 472 
 473 // Unsigned byte types for os and stream.hpp
 474 
 475 // Unsigned one, two, four and eigth byte quantities used for describing
 476 // the .class file format. See JVM book chapter 4.
 477 
 478 typedef jubyte  u1;
 479 typedef jushort u2;
 480 typedef juint   u4;
 481 typedef julong  u8;
 482 
 483 const jubyte  max_jubyte  = (jubyte)-1;  // 0xFF       largest jubyte
 484 const jushort max_jushort = (jushort)-1; // 0xFFFF     largest jushort
 485 const juint   max_juint   = (juint)-1;   // 0xFFFFFFFF largest juint
 486 const julong  max_julong  = (julong)-1;  // 0xFF....FF largest julong
 487 
 488 typedef jbyte  s1;
 489 typedef jshort s2;
 490 typedef jint   s4;
 491 typedef jlong  s8;
 492 
 493 const jbyte min_jbyte = -(1 << 7);       // smallest jbyte
 494 const jbyte max_jbyte = (1 << 7) - 1;    // largest jbyte
 495 const jshort min_jshort = -(1 << 15);    // smallest jshort
 496 const jshort max_jshort = (1 << 15) - 1; // largest jshort
 497 
 498 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
 499 const jint max_jint = (juint)min_jint - 1;                     // 0x7FFFFFFF == largest jint
 500 
 501 const jint min_jintFloat = (jint)(0x00000001);
 502 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
 503 const jint max_jintFloat = (jint)(0x7f7fffff);
 504 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
 505 
 506 //----------------------------------------------------------------------------------------------------
 507 // JVM spec restrictions
 508 
 509 const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (p.134)
 510 
 511 //----------------------------------------------------------------------------------------------------
 512 // Object alignment, in units of HeapWords.
 513 //
 514 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
 515 // reference fields can be naturally aligned.
 516 
 517 extern int MinObjAlignment;
 518 extern int MinObjAlignmentInBytes;
 519 extern int MinObjAlignmentInBytesMask;
 520 
 521 extern int LogMinObjAlignment;
 522 extern int LogMinObjAlignmentInBytes;
 523 
 524 const int LogKlassAlignmentInBytes = 3;
 525 const int LogKlassAlignment        = LogKlassAlignmentInBytes - LogHeapWordSize;
 526 const int KlassAlignmentInBytes    = 1 << LogKlassAlignmentInBytes;
 527 const int KlassAlignment           = KlassAlignmentInBytes / HeapWordSize;
 528 
 529 // Maximal size of heap where unscaled compression can be used. Also upper bound
 530 // for heap placement: 4GB.
 531 const  uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
 532 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
 533 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
 534 extern uint64_t OopEncodingHeapMax;
 535 
 536 // Maximal size of compressed class space. Above this limit compression is not possible.
 537 // Also upper bound for placement of zero based class space. (Class space is further limited
 538 // to be < 3G, see arguments.cpp.)
 539 const  uint64_t KlassEncodingMetaspaceMax = (uint64_t(max_juint) + 1) << LogKlassAlignmentInBytes;
 540 
 541 // Machine dependent stuff
 542 
 543 // The maximum size of the code cache.  Can be overridden by targets.
 544 #define CODE_CACHE_SIZE_LIMIT (2*G)
 545 // Allow targets to reduce the default size of the code cache.
 546 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
 547 
 548 #include CPU_HEADER(globalDefinitions)
 549 
 550 // To assure the IRIW property on processors that are not multiple copy
 551 // atomic, sync instructions must be issued between volatile reads to
 552 // assure their ordering, instead of after volatile stores.
 553 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
 554 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
 555 #ifdef CPU_MULTI_COPY_ATOMIC
 556 // Not needed.
 557 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
 558 #else
 559 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
 560 // Final decision is subject to JEP 188: Java Memory Model Update.
 561 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
 562 #endif
 563 
 564 // The expected size in bytes of a cache line, used to pad data structures.
 565 #ifndef DEFAULT_CACHE_LINE_SIZE
 566   #define DEFAULT_CACHE_LINE_SIZE 64
 567 #endif
 568 
 569 
 570 //----------------------------------------------------------------------------------------------------
 571 // Utility macros for compilers
 572 // used to silence compiler warnings
 573 
 574 #define Unused_Variable(var) var
 575 
 576 
 577 //----------------------------------------------------------------------------------------------------
 578 // Miscellaneous
 579 
 580 // 6302670 Eliminate Hotspot __fabsf dependency
 581 // All fabs() callers should call this function instead, which will implicitly
 582 // convert the operand to double, avoiding a dependency on __fabsf which
 583 // doesn't exist in early versions of Solaris 8.
 584 inline double fabsd(double value) {
 585   return fabs(value);
 586 }
 587 
 588 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
 589 // is zero, return 0.0.
 590 template<typename T>
 591 inline double percent_of(T numerator, T denominator) {
 592   return denominator != 0 ? (double)numerator / denominator * 100.0 : 0.0;
 593 }
 594 
 595 //----------------------------------------------------------------------------------------------------
 596 // Special casts
 597 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
 598 typedef union {
 599   jfloat f;
 600   jint i;
 601 } FloatIntConv;
 602 
 603 typedef union {
 604   jdouble d;
 605   jlong l;
 606   julong ul;
 607 } DoubleLongConv;
 608 
 609 inline jint    jint_cast    (jfloat  x)  { return ((FloatIntConv*)&x)->i; }
 610 inline jfloat  jfloat_cast  (jint    x)  { return ((FloatIntConv*)&x)->f; }
 611 
 612 inline jlong   jlong_cast   (jdouble x)  { return ((DoubleLongConv*)&x)->l;  }
 613 inline julong  julong_cast  (jdouble x)  { return ((DoubleLongConv*)&x)->ul; }
 614 inline jdouble jdouble_cast (jlong   x)  { return ((DoubleLongConv*)&x)->d;  }
 615 
 616 inline jint low (jlong value)                    { return jint(value); }
 617 inline jint high(jlong value)                    { return jint(value >> 32); }
 618 
 619 // the fancy casts are a hopefully portable way
 620 // to do unsigned 32 to 64 bit type conversion
 621 inline void set_low (jlong* value, jint low )    { *value &= (jlong)0xffffffff << 32;
 622                                                    *value |= (jlong)(julong)(juint)low; }
 623 
 624 inline void set_high(jlong* value, jint high)    { *value &= (jlong)(julong)(juint)0xffffffff;
 625                                                    *value |= (jlong)high       << 32; }
 626 
 627 inline jlong jlong_from(jint h, jint l) {
 628   jlong result = 0; // initialization to avoid warning
 629   set_high(&result, h);
 630   set_low(&result,  l);
 631   return result;
 632 }
 633 
 634 union jlong_accessor {
 635   jint  words[2];
 636   jlong long_value;
 637 };
 638 
 639 void basic_types_init(); // cannot define here; uses assert
 640 
 641 
 642 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 643 enum BasicType {
 644 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
 645   T_BOOLEAN     = JVM_T_BOOLEAN,
 646   T_CHAR        = JVM_T_CHAR,
 647   T_FLOAT       = JVM_T_FLOAT,
 648   T_DOUBLE      = JVM_T_DOUBLE,
 649   T_BYTE        = JVM_T_BYTE,
 650   T_SHORT       = JVM_T_SHORT,
 651   T_INT         = JVM_T_INT,
 652   T_LONG        = JVM_T_LONG,
 653   // The remaining values are not part of any standard.
 654   // T_OBJECT and T_VOID denote two more semantic choices
 655   // for method return values.
 656   // T_OBJECT and T_ARRAY describe signature syntax.
 657   // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
 658   // internal references within the JVM as if they were Java
 659   // types in their own right.
 660   T_OBJECT      = 12,
 661   T_ARRAY       = 13,
 662   T_VOID        = 14,
 663   T_ADDRESS     = 15,
 664   T_NARROWOOP   = 16,
 665   T_METADATA    = 17,
 666   T_NARROWKLASS = 18,
 667   T_CONFLICT    = 19, // for stack value type with conflicting contents
 668   T_ILLEGAL     = 99
 669 };
 670 
 671 #define SIGNATURE_TYPES_DO(F, N)                \
 672     F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N)      \
 673     F(JVM_SIGNATURE_CHAR,    T_CHAR,    N)      \
 674     F(JVM_SIGNATURE_FLOAT,   T_FLOAT,   N)      \
 675     F(JVM_SIGNATURE_DOUBLE,  T_DOUBLE,  N)      \
 676     F(JVM_SIGNATURE_BYTE,    T_BYTE,    N)      \
 677     F(JVM_SIGNATURE_SHORT,   T_SHORT,   N)      \
 678     F(JVM_SIGNATURE_INT,     T_INT,     N)      \
 679     F(JVM_SIGNATURE_LONG,    T_LONG,    N)      \
 680     F(JVM_SIGNATURE_CLASS,   T_OBJECT,  N)      \
 681     F(JVM_SIGNATURE_ARRAY,   T_ARRAY,   N)      \
 682     F(JVM_SIGNATURE_VOID,    T_VOID,    N)      \
 683     /*end*/
 684 
 685 inline bool is_java_type(BasicType t) {
 686   return T_BOOLEAN <= t && t <= T_VOID;
 687 }
 688 
 689 inline bool is_java_primitive(BasicType t) {
 690   return T_BOOLEAN <= t && t <= T_LONG;
 691 }
 692 
 693 inline bool is_subword_type(BasicType t) {
 694   // these guys are processed exactly like T_INT in calling sequences:
 695   return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
 696 }
 697 
 698 inline bool is_signed_subword_type(BasicType t) {
 699   return (t == T_BYTE || t == T_SHORT);
 700 }
 701 
 702 inline bool is_double_word_type(BasicType t) {
 703   return (t == T_DOUBLE || t == T_LONG);
 704 }
 705 
 706 inline bool is_reference_type(BasicType t) {
 707   return (t == T_OBJECT || t == T_ARRAY);
 708 }
 709 
 710 inline bool is_integral_type(BasicType t) {
 711   return is_subword_type(t) || t == T_INT || t == T_LONG;
 712 }
 713 
 714 inline bool is_floating_point_type(BasicType t) {
 715   return (t == T_FLOAT || t == T_DOUBLE);
 716 }
 717 
 718 extern char type2char_tab[T_CONFLICT+1];     // Map a BasicType to a jchar
 719 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
 720 extern int type2size[T_CONFLICT+1];         // Map BasicType to result stack elements
 721 extern const char* type2name_tab[T_CONFLICT+1];     // Map a BasicType to a jchar
 722 inline const char* type2name(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2name_tab[t] : NULL; }
 723 extern BasicType name2type(const char* name);
 724 
 725 inline jlong max_signed_integer(BasicType bt) {
 726   if (bt == T_INT) {
 727     return max_jint;
 728   }
 729   assert(bt == T_LONG, "unsupported");
 730   return max_jlong;
 731 }
 732 
 733 inline jlong min_signed_integer(BasicType bt) {
 734   if (bt == T_INT) {
 735     return min_jint;
 736   }
 737   assert(bt == T_LONG, "unsupported");
 738   return min_jlong;
 739 }
 740 
 741 // Auxiliary math routines
 742 // least common multiple
 743 extern size_t lcm(size_t a, size_t b);
 744 
 745 
 746 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 747 enum BasicTypeSize {
 748   T_BOOLEAN_size     = 1,
 749   T_CHAR_size        = 1,
 750   T_FLOAT_size       = 1,
 751   T_DOUBLE_size      = 2,
 752   T_BYTE_size        = 1,
 753   T_SHORT_size       = 1,
 754   T_INT_size         = 1,
 755   T_LONG_size        = 2,
 756   T_OBJECT_size      = 1,
 757   T_ARRAY_size       = 1,
 758   T_NARROWOOP_size   = 1,
 759   T_NARROWKLASS_size = 1,
 760   T_VOID_size        = 0
 761 };
 762 
 763 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
 764 inline int parameter_type_word_count(BasicType t) {
 765   if (is_double_word_type(t))  return 2;
 766   assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
 767   assert(type2size[t] == 1, "must be");
 768   return 1;
 769 }
 770 
 771 // maps a BasicType to its instance field storage type:
 772 // all sub-word integral types are widened to T_INT
 773 extern BasicType type2field[T_CONFLICT+1];
 774 extern BasicType type2wfield[T_CONFLICT+1];
 775 
 776 
 777 // size in bytes
 778 enum ArrayElementSize {
 779   T_BOOLEAN_aelem_bytes     = 1,
 780   T_CHAR_aelem_bytes        = 2,
 781   T_FLOAT_aelem_bytes       = 4,
 782   T_DOUBLE_aelem_bytes      = 8,
 783   T_BYTE_aelem_bytes        = 1,
 784   T_SHORT_aelem_bytes       = 2,
 785   T_INT_aelem_bytes         = 4,
 786   T_LONG_aelem_bytes        = 8,
 787 #ifdef _LP64
 788   T_OBJECT_aelem_bytes      = 8,
 789   T_ARRAY_aelem_bytes       = 8,
 790 #else
 791   T_OBJECT_aelem_bytes      = 4,
 792   T_ARRAY_aelem_bytes       = 4,
 793 #endif
 794   T_NARROWOOP_aelem_bytes   = 4,
 795   T_NARROWKLASS_aelem_bytes = 4,
 796   T_VOID_aelem_bytes        = 0
 797 };
 798 
 799 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
 800 #ifdef ASSERT
 801 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
 802 #else
 803 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
 804 #endif
 805 
 806 
 807 // JavaValue serves as a container for arbitrary Java values.
 808 
 809 class JavaValue {
 810 
 811  public:
 812   typedef union JavaCallValue {
 813     jfloat   f;
 814     jdouble  d;
 815     jint     i;
 816     jlong    l;
 817     jobject  h;
 818     oopDesc* o;
 819   } JavaCallValue;
 820 
 821  private:
 822   BasicType _type;
 823   JavaCallValue _value;
 824 
 825  public:
 826   JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
 827 
 828   JavaValue(jfloat value) {
 829     _type    = T_FLOAT;
 830     _value.f = value;
 831   }
 832 
 833   JavaValue(jdouble value) {
 834     _type    = T_DOUBLE;
 835     _value.d = value;
 836   }
 837 
 838  jfloat get_jfloat() const { return _value.f; }
 839  jdouble get_jdouble() const { return _value.d; }
 840  jint get_jint() const { return _value.i; }
 841  jlong get_jlong() const { return _value.l; }
 842  jobject get_jobject() const { return _value.h; }
 843  oopDesc* get_oop() const { return _value.o; }
 844  JavaCallValue* get_value_addr() { return &_value; }
 845  BasicType get_type() const { return _type; }
 846 
 847  void set_jfloat(jfloat f) { _value.f = f;}
 848  void set_jdouble(jdouble d) { _value.d = d;}
 849  void set_jint(jint i) { _value.i = i;}
 850  void set_jlong(jlong l) { _value.l = l;}
 851  void set_jobject(jobject h) { _value.h = h;}
 852  void set_oop(oopDesc* o) { _value.o = o;}
 853  void set_type(BasicType t) { _type = t; }
 854 
 855  jboolean get_jboolean() const { return (jboolean) (_value.i);}
 856  jbyte get_jbyte() const { return (jbyte) (_value.i);}
 857  jchar get_jchar() const { return (jchar) (_value.i);}
 858  jshort get_jshort() const { return (jshort) (_value.i);}
 859 
 860 };
 861 
 862 
 863 // TosState describes the top-of-stack state before and after the execution of
 864 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
 865 // registers. The TosState corresponds to the 'machine representation' of this cached
 866 // value. There's 4 states corresponding to the JAVA types int, long, float & double
 867 // as well as a 5th state in case the top-of-stack value is actually on the top
 868 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
 869 // state when it comes to machine representation but is used separately for (oop)
 870 // type specific operations (e.g. verification code).
 871 
 872 enum TosState {         // describes the tos cache contents
 873   btos = 0,             // byte, bool tos cached
 874   ztos = 1,             // byte, bool tos cached
 875   ctos = 2,             // char tos cached
 876   stos = 3,             // short tos cached
 877   itos = 4,             // int tos cached
 878   ltos = 5,             // long tos cached
 879   ftos = 6,             // float tos cached
 880   dtos = 7,             // double tos cached
 881   atos = 8,             // object cached
 882   vtos = 9,             // tos not cached
 883   number_of_states,
 884   ilgl                  // illegal state: should not occur
 885 };
 886 
 887 
 888 inline TosState as_TosState(BasicType type) {
 889   switch (type) {
 890     case T_BYTE   : return btos;
 891     case T_BOOLEAN: return ztos;
 892     case T_CHAR   : return ctos;
 893     case T_SHORT  : return stos;
 894     case T_INT    : return itos;
 895     case T_LONG   : return ltos;
 896     case T_FLOAT  : return ftos;
 897     case T_DOUBLE : return dtos;
 898     case T_VOID   : return vtos;
 899     case T_ARRAY  : // fall through
 900     case T_OBJECT : return atos;
 901     default       : return ilgl;
 902   }
 903 }
 904 
 905 inline BasicType as_BasicType(TosState state) {
 906   switch (state) {
 907     case btos : return T_BYTE;
 908     case ztos : return T_BOOLEAN;
 909     case ctos : return T_CHAR;
 910     case stos : return T_SHORT;
 911     case itos : return T_INT;
 912     case ltos : return T_LONG;
 913     case ftos : return T_FLOAT;
 914     case dtos : return T_DOUBLE;
 915     case atos : return T_OBJECT;
 916     case vtos : return T_VOID;
 917     default   : return T_ILLEGAL;
 918   }
 919 }
 920 
 921 
 922 // Helper function to convert BasicType info into TosState
 923 // Note: Cannot define here as it uses global constant at the time being.
 924 TosState as_TosState(BasicType type);
 925 
 926 
 927 // JavaThreadState keeps track of which part of the code a thread is executing in. This
 928 // information is needed by the safepoint code.
 929 //
 930 // There are 4 essential states:
 931 //
 932 //  _thread_new         : Just started, but not executed init. code yet (most likely still in OS init code)
 933 //  _thread_in_native   : In native code. This is a safepoint region, since all oops will be in jobject handles
 934 //  _thread_in_vm       : Executing in the vm
 935 //  _thread_in_Java     : Executing either interpreted or compiled Java code (or could be in a stub)
 936 //
 937 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
 938 // a transition from one state to another. These extra states makes it possible for the safepoint code to
 939 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
 940 //
 941 // Given a state, the xxxx_trans state can always be found by adding 1.
 942 //
 943 enum JavaThreadState {
 944   _thread_uninitialized     =  0, // should never happen (missing initialization)
 945   _thread_new               =  2, // just starting up, i.e., in process of being initialized
 946   _thread_new_trans         =  3, // corresponding transition state (not used, included for completness)
 947   _thread_in_native         =  4, // running in native code
 948   _thread_in_native_trans   =  5, // corresponding transition state
 949   _thread_in_vm             =  6, // running in VM
 950   _thread_in_vm_trans       =  7, // corresponding transition state
 951   _thread_in_Java           =  8, // running in Java or in stub code
 952   _thread_in_Java_trans     =  9, // corresponding transition state (not used, included for completness)
 953   _thread_blocked           = 10, // blocked in vm
 954   _thread_blocked_trans     = 11, // corresponding transition state
 955   _thread_max_state         = 12  // maximum thread state+1 - used for statistics allocation
 956 };
 957 
 958 //----------------------------------------------------------------------------------------------------
 959 // Special constants for debugging
 960 
 961 const jint     badInt           = -3;                       // generic "bad int" value
 962 const intptr_t badAddressVal    = -2;                       // generic "bad address" value
 963 const intptr_t badOopVal        = -1;                       // generic "bad oop" value
 964 const intptr_t badHeapOopVal    = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
 965 const int      badStackSegVal   = 0xCA;                     // value used to zap stack segments
 966 const int      badHandleValue   = 0xBC;                     // value used to zap vm handle area
 967 const int      badResourceValue = 0xAB;                     // value used to zap resource area
 968 const int      freeBlockPad     = 0xBA;                     // value used to pad freed blocks.
 969 const int      uninitBlockPad   = 0xF1;                     // value used to zap newly malloc'd blocks.
 970 const juint    uninitMetaWordVal= 0xf7f7f7f7;               // value used to zap newly allocated metachunk
 971 const juint    badHeapWordVal   = 0xBAADBABE;               // value used to zap heap after GC
 972 const juint    badMetaWordVal   = 0xBAADFADE;               // value used to zap metadata heap after GC
 973 const int      badCodeHeapNewVal= 0xCC;                     // value used to zap Code heap at allocation
 974 const int      badCodeHeapFreeVal = 0xDD;                   // value used to zap Code heap at deallocation
 975 
 976 
 977 // (These must be implemented as #defines because C++ compilers are
 978 // not obligated to inline non-integral constants!)
 979 #define       badAddress        ((address)::badAddressVal)
 980 #define       badOop            (cast_to_oop(::badOopVal))
 981 #define       badHeapWord       (::badHeapWordVal)
 982 
 983 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
 984 #define TASKQUEUE_SIZE (NOT_LP64(1<<14) LP64_ONLY(1<<17))
 985 
 986 //----------------------------------------------------------------------------------------------------
 987 // Utility functions for bitfield manipulations
 988 
 989 const intptr_t AllBits    = ~0; // all bits set in a word
 990 const intptr_t NoBits     =  0; // no bits set in a word
 991 const jlong    NoLongBits =  0; // no bits set in a long
 992 const intptr_t OneBit     =  1; // only right_most bit set in a word
 993 
 994 // get a word with the n.th or the right-most or left-most n bits set
 995 // (note: #define used only so that they can be used in enum constant definitions)
 996 #define nth_bit(n)        (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
 997 #define right_n_bits(n)   (nth_bit(n) - 1)
 998 
 999 // bit-operations using a mask m
1000 inline void   set_bits    (intptr_t& x, intptr_t m) { x |= m; }
1001 inline void clear_bits    (intptr_t& x, intptr_t m) { x &= ~m; }
1002 inline intptr_t mask_bits      (intptr_t  x, intptr_t m) { return x & m; }
1003 inline jlong    mask_long_bits (jlong     x, jlong    m) { return x & m; }
1004 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1005 
1006 // bit-operations using the n.th bit
1007 inline void    set_nth_bit(intptr_t& x, int n) { set_bits  (x, nth_bit(n)); }
1008 inline void  clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1009 inline bool is_set_nth_bit(intptr_t  x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1010 
1011 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1012 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1013   return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1014 }
1015 
1016 
1017 //----------------------------------------------------------------------------------------------------
1018 // Utility functions for integers
1019 
1020 // Avoid use of global min/max macros which may cause unwanted double
1021 // evaluation of arguments.
1022 #ifdef max
1023 #undef max
1024 #endif
1025 
1026 #ifdef min
1027 #undef min
1028 #endif
1029 
1030 // It is necessary to use templates here. Having normal overloaded
1031 // functions does not work because it is necessary to provide both 32-
1032 // and 64-bit overloaded functions, which does not work, and having
1033 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1034 // will be even more error-prone than macros.
1035 template<class T> constexpr T MAX2(T a, T b)           { return (a > b) ? a : b; }
1036 template<class T> constexpr T MIN2(T a, T b)           { return (a < b) ? a : b; }
1037 template<class T> constexpr T MAX3(T a, T b, T c)      { return MAX2(MAX2(a, b), c); }
1038 template<class T> constexpr T MIN3(T a, T b, T c)      { return MIN2(MIN2(a, b), c); }
1039 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1040 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1041 
1042 template<class T> inline T ABS(T x)                 { return (x > 0) ? x : -x; }
1043 
1044 // Return the given value clamped to the range [min ... max]
1045 template<typename T>
1046 inline T clamp(T value, T min, T max) {
1047   assert(min <= max, "must be");
1048   return MIN2(MAX2(value, min), max);
1049 }
1050 
1051 inline bool is_odd (intx x) { return x & 1;      }
1052 inline bool is_even(intx x) { return !is_odd(x); }
1053 
1054 // abs methods which cannot overflow and so are well-defined across
1055 // the entire domain of integer types.
1056 static inline unsigned int uabs(unsigned int n) {
1057   union {
1058     unsigned int result;
1059     int value;
1060   };
1061   result = n;
1062   if (value < 0) result = 0-result;
1063   return result;
1064 }
1065 static inline julong uabs(julong n) {
1066   union {
1067     julong result;
1068     jlong value;
1069   };
1070   result = n;
1071   if (value < 0) result = 0-result;
1072   return result;
1073 }
1074 static inline julong uabs(jlong n) { return uabs((julong)n); }
1075 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1076 
1077 // "to" should be greater than "from."
1078 inline intx byte_size(void* from, void* to) {
1079   return (address)to - (address)from;
1080 }
1081 
1082 
1083 // Pack and extract shorts to/from ints:
1084 
1085 inline int extract_low_short_from_int(jint x) {
1086   return x & 0xffff;
1087 }
1088 
1089 inline int extract_high_short_from_int(jint x) {
1090   return (x >> 16) & 0xffff;
1091 }
1092 
1093 inline int build_int_from_shorts( jushort low, jushort high ) {
1094   return ((int)((unsigned int)high << 16) | (unsigned int)low);
1095 }
1096 
1097 // swap a & b
1098 template<class T> static void swap(T& a, T& b) {
1099   T tmp = a;
1100   a = b;
1101   b = tmp;
1102 }
1103 
1104 // array_size_impl is a function that takes a reference to T[N] and
1105 // returns a reference to char[N].  It is not ODR-used, so not defined.
1106 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1107 
1108 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1109 
1110 //----------------------------------------------------------------------------------------------------
1111 // Sum and product which can never overflow: they wrap, just like the
1112 // Java operations.  Note that we don't intend these to be used for
1113 // general-purpose arithmetic: their purpose is to emulate Java
1114 // operations.
1115 
1116 // The goal of this code to avoid undefined or implementation-defined
1117 // behavior.  The use of an lvalue to reference cast is explicitly
1118 // permitted by Lvalues and rvalues [basic.lval].  [Section 3.10 Para
1119 // 15 in C++03]
1120 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE)  \
1121 inline TYPE NAME (TYPE in1, TYPE in2) {                 \
1122   UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1123   ures OP ## = static_cast<UNSIGNED_TYPE>(in2);         \
1124   return reinterpret_cast<TYPE&>(ures);                 \
1125 }
1126 
1127 JAVA_INTEGER_OP(+, java_add, jint, juint)
1128 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1129 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1130 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1131 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1132 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1133 
1134 #undef JAVA_INTEGER_OP
1135 
1136 // Provide integer shift operations with Java semantics.  No overflow
1137 // issues - left shifts simply discard shifted out bits.  No undefined
1138 // behavior for large or negative shift quantities; instead the actual
1139 // shift distance is the argument modulo the lhs value's size in bits.
1140 // No undefined or implementation defined behavior for shifting negative
1141 // values; left shift discards bits, right shift sign extends.  We use
1142 // the same safe conversion technique as above for java_add and friends.
1143 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE)    \
1144 inline TYPE NAME (TYPE lhs, jint rhs) {                 \
1145   const uint rhs_mask = (sizeof(TYPE) * 8) - 1;         \
1146   STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63);      \
1147   XTYPE xres = static_cast<XTYPE>(lhs);                 \
1148   xres OP ## = (rhs & rhs_mask);                        \
1149   return reinterpret_cast<TYPE&>(xres);                 \
1150 }
1151 
1152 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1153 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1154 // For signed shift right, assume C++ implementation >> sign extends.
1155 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1156 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1157 // For >>> use C++ unsigned >>.
1158 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1159 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1160 
1161 #undef JAVA_INTEGER_SHIFT_OP
1162 
1163 //----------------------------------------------------------------------------------------------------
1164 // The goal of this code is to provide saturating operations for int/uint.
1165 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1166 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1167 inline int NAME (TYPE1 in1, TYPE2 in2) {             \
1168   jlong res = static_cast<jlong>(in1);               \
1169   res OP ## = static_cast<jlong>(in2);               \
1170   if (res > max_jint) {                              \
1171     res = max_jint;                                  \
1172   } else if (res < min_jint) {                       \
1173     res = min_jint;                                  \
1174   }                                                  \
1175   return static_cast<int>(res);                      \
1176 }
1177 
1178 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1179 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1180 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1181 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1182 
1183 #undef SATURATED_INTEGER_OP
1184 
1185 // Dereference vptr
1186 // All C++ compilers that we know of have the vtbl pointer in the first
1187 // word.  If there are exceptions, this function needs to be made compiler
1188 // specific.
1189 static inline void* dereference_vptr(const void* addr) {
1190   return *(void**)addr;
1191 }
1192 
1193 //----------------------------------------------------------------------------------------------------
1194 // String type aliases used by command line flag declarations and
1195 // processing utilities.
1196 
1197 typedef const char* ccstr;
1198 typedef const char* ccstrlist;   // represents string arguments which accumulate
1199 
1200 //----------------------------------------------------------------------------------------------------
1201 // Default hash/equals functions used by ResourceHashtable
1202 
1203 template<typename K> unsigned primitive_hash(const K& k) {
1204   unsigned hash = (unsigned)((uintptr_t)k);
1205   return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1206 }
1207 
1208 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1209   return k0 == k1;
1210 }
1211 
1212 
1213 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP