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
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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 #include "utilities/globalDefinitions_vecApi.hpp"
  37 
  38 #include <cstddef>
  39 
  40 class oopDesc;
  41 
  42 // Defaults for macros that might be defined per compiler.
  43 #ifndef NOINLINE
  44 #define NOINLINE
  45 #endif
  46 #ifndef ALWAYSINLINE
  47 #define ALWAYSINLINE inline
  48 #endif
  49 
  50 #ifndef ATTRIBUTE_ALIGNED
  51 #define ATTRIBUTE_ALIGNED(x)
  52 #endif
  53 
  54 #ifndef ATTRIBUTE_FLATTEN
  55 #define ATTRIBUTE_FLATTEN
  56 #endif
  57 
  58 // These are #defines to selectively turn on/off the Print(Opto)Assembly
  59 // capabilities. Choices should be led by a tradeoff between
  60 // code size and improved supportability.
  61 // if PRINT_ASSEMBLY then PRINT_ABSTRACT_ASSEMBLY must be true as well
  62 // to have a fallback in case hsdis is not available.
  63 #if defined(PRODUCT)
  64   #define SUPPORT_ABSTRACT_ASSEMBLY
  65   #define SUPPORT_ASSEMBLY
  66   #undef  SUPPORT_OPTO_ASSEMBLY      // Can't activate. In PRODUCT, many dump methods are missing.
  67   #undef  SUPPORT_DATA_STRUCTS       // Of limited use. In PRODUCT, many print methods are empty.
  68 #else
  69   #define SUPPORT_ABSTRACT_ASSEMBLY
  70   #define SUPPORT_ASSEMBLY
  71   #define SUPPORT_OPTO_ASSEMBLY
  72   #define SUPPORT_DATA_STRUCTS
  73 #endif
  74 #if defined(SUPPORT_ASSEMBLY) && !defined(SUPPORT_ABSTRACT_ASSEMBLY)
  75   #define SUPPORT_ABSTRACT_ASSEMBLY
  76 #endif
  77 
  78 // This file holds all globally used constants & types, class (forward)
  79 // declarations and a few frequently used utility functions.
  80 
  81 // Declare the named class to be noncopyable.  This macro must be followed by
  82 // a semi-colon.  The macro provides deleted declarations for the class's copy
  83 // constructor and assignment operator.  Because these operations are deleted,
  84 // they cannot be defined and potential callers will fail to compile.
  85 #define NONCOPYABLE(C) C(C const&) = delete; C& operator=(C const&) = delete /* next token must be ; */
  86 
  87 
  88 //----------------------------------------------------------------------------------------------------
  89 // Printf-style formatters for fixed- and variable-width types as pointers and
  90 // integers.  These are derived from the definitions in inttypes.h.  If the platform
  91 // doesn't provide appropriate definitions, they should be provided in
  92 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
  93 
  94 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
  95 
  96 // Format 32-bit quantities.
  97 #define INT32_FORMAT           "%" PRId32
  98 #define UINT32_FORMAT          "%" PRIu32
  99 #define INT32_FORMAT_W(width)  "%" #width PRId32
 100 #define UINT32_FORMAT_W(width) "%" #width PRIu32
 101 
 102 #define PTR32_FORMAT           "0x%08" PRIx32
 103 #define PTR32_FORMAT_W(width)  "0x%" #width PRIx32
 104 
 105 // Format 64-bit quantities.
 106 #define INT64_FORMAT           "%" PRId64
 107 #define UINT64_FORMAT          "%" PRIu64
 108 #define UINT64_FORMAT_X        "%" PRIx64
 109 #define INT64_FORMAT_W(width)  "%" #width PRId64
 110 #define UINT64_FORMAT_W(width) "%" #width PRIu64
 111 #define UINT64_FORMAT_X_W(width) "%" #width PRIx64
 112 
 113 #define PTR64_FORMAT           "0x%016" PRIx64
 114 
 115 // Format jlong, if necessary
 116 #ifndef JLONG_FORMAT
 117 #define JLONG_FORMAT           INT64_FORMAT
 118 #endif
 119 #ifndef JLONG_FORMAT_W
 120 #define JLONG_FORMAT_W(width)  INT64_FORMAT_W(width)
 121 #endif
 122 #ifndef JULONG_FORMAT
 123 #define JULONG_FORMAT          UINT64_FORMAT
 124 #endif
 125 #ifndef JULONG_FORMAT_X
 126 #define JULONG_FORMAT_X        UINT64_FORMAT_X
 127 #endif
 128 
 129 // Format pointers which change size between 32- and 64-bit.
 130 #ifdef  _LP64
 131 #define INTPTR_FORMAT "0x%016" PRIxPTR
 132 #define PTR_FORMAT    "0x%016" PRIxPTR
 133 #else   // !_LP64
 134 #define INTPTR_FORMAT "0x%08"  PRIxPTR
 135 #define PTR_FORMAT    "0x%08"  PRIxPTR
 136 #endif  // _LP64
 137 
 138 // Format pointers without leading zeros
 139 #define INTPTRNZ_FORMAT "0x%"  PRIxPTR
 140 
 141 #define INTPTR_FORMAT_W(width)   "%" #width PRIxPTR
 142 
 143 #define SSIZE_FORMAT             "%"   PRIdPTR
 144 #define SIZE_FORMAT              "%"   PRIuPTR
 145 #define SIZE_FORMAT_HEX          "0x%" PRIxPTR
 146 #define SSIZE_FORMAT_W(width)    "%"   #width PRIdPTR
 147 #define SIZE_FORMAT_W(width)     "%"   #width PRIuPTR
 148 #define SIZE_FORMAT_HEX_W(width) "0x%" #width PRIxPTR
 149 
 150 #define INTX_FORMAT           "%" PRIdPTR
 151 #define UINTX_FORMAT          "%" PRIuPTR
 152 #define INTX_FORMAT_W(width)  "%" #width PRIdPTR
 153 #define UINTX_FORMAT_W(width) "%" #width PRIuPTR
 154 
 155 // Convert pointer to intptr_t, for use in printing pointers.
 156 inline intptr_t p2i(const volatile void* p) {
 157   return (intptr_t) p;
 158 }
 159 
 160 //----------------------------------------------------------------------------------------------------
 161 // Constants
 162 
 163 const int LogBytesPerShort   = 1;
 164 const int LogBytesPerInt     = 2;
 165 #ifdef _LP64
 166 const int LogBytesPerWord    = 3;
 167 #else
 168 const int LogBytesPerWord    = 2;
 169 #endif
 170 const int LogBytesPerLong    = 3;
 171 
 172 const int BytesPerShort      = 1 << LogBytesPerShort;
 173 const int BytesPerInt        = 1 << LogBytesPerInt;
 174 const int BytesPerWord       = 1 << LogBytesPerWord;
 175 const int BytesPerLong       = 1 << LogBytesPerLong;
 176 
 177 const int LogBitsPerByte     = 3;
 178 const int LogBitsPerShort    = LogBitsPerByte + LogBytesPerShort;
 179 const int LogBitsPerInt      = LogBitsPerByte + LogBytesPerInt;
 180 const int LogBitsPerWord     = LogBitsPerByte + LogBytesPerWord;
 181 const int LogBitsPerLong     = LogBitsPerByte + LogBytesPerLong;
 182 
 183 const int BitsPerByte        = 1 << LogBitsPerByte;
 184 const int BitsPerShort       = 1 << LogBitsPerShort;
 185 const int BitsPerInt         = 1 << LogBitsPerInt;
 186 const int BitsPerWord        = 1 << LogBitsPerWord;
 187 const int BitsPerLong        = 1 << LogBitsPerLong;
 188 
 189 const int WordAlignmentMask  = (1 << LogBytesPerWord) - 1;
 190 const int LongAlignmentMask  = (1 << LogBytesPerLong) - 1;
 191 
 192 const int WordsPerLong       = 2;       // Number of stack entries for longs
 193 
 194 const int oopSize            = sizeof(char*); // Full-width oop
 195 extern int heapOopSize;                       // Oop within a java object
 196 const int wordSize           = sizeof(char*);
 197 const int longSize           = sizeof(jlong);
 198 const int jintSize           = sizeof(jint);
 199 const int size_tSize         = sizeof(size_t);
 200 
 201 const int BytesPerOop        = BytesPerWord;  // Full-width oop
 202 
 203 extern int LogBytesPerHeapOop;                // Oop within a java object
 204 extern int LogBitsPerHeapOop;
 205 extern int BytesPerHeapOop;
 206 extern int BitsPerHeapOop;
 207 
 208 const int BitsPerJavaInteger = 32;
 209 const int BitsPerJavaLong    = 64;
 210 const int BitsPerSize_t      = size_tSize * BitsPerByte;
 211 
 212 // Size of a char[] needed to represent a jint as a string in decimal.
 213 const int jintAsStringSize = 12;
 214 
 215 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
 216 // We require that object sizes be measured in units of heap words (e.g.
 217 // pointer-sized values), so that given HeapWord* hw,
 218 //   hw += oop(hw)->foo();
 219 // works, where foo is a method (like size or scavenge) that returns the
 220 // object size.
 221 class HeapWordImpl;             // Opaque, never defined.
 222 typedef HeapWordImpl* HeapWord;
 223 
 224 // Analogous opaque struct for metadata allocated from metaspaces.
 225 class MetaWordImpl;             // Opaque, never defined.
 226 typedef MetaWordImpl* MetaWord;
 227 
 228 // HeapWordSize must be 2^LogHeapWordSize.
 229 const int HeapWordSize        = sizeof(HeapWord);
 230 #ifdef _LP64
 231 const int LogHeapWordSize     = 3;
 232 #else
 233 const int LogHeapWordSize     = 2;
 234 #endif
 235 const int HeapWordsPerLong    = BytesPerLong / HeapWordSize;
 236 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
 237 
 238 // The minimum number of native machine words necessary to contain "byte_size"
 239 // bytes.
 240 inline size_t heap_word_size(size_t byte_size) {
 241   return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
 242 }
 243 
 244 inline jfloat jfloat_cast(jint x);
 245 inline jdouble jdouble_cast(jlong x);
 246 
 247 //-------------------------------------------
 248 // Constant for jlong (standardized by C++11)
 249 
 250 // Build a 64bit integer constant
 251 #define CONST64(x)  (x ## LL)
 252 #define UCONST64(x) (x ## ULL)
 253 
 254 const jlong min_jlong = CONST64(0x8000000000000000);
 255 const jlong max_jlong = CONST64(0x7fffffffffffffff);
 256 
 257 //-------------------------------------------
 258 // Constant for jdouble
 259 const jlong min_jlongDouble = CONST64(0x0000000000000001);
 260 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
 261 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
 262 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
 263 
 264 const size_t K                  = 1024;
 265 const size_t M                  = K*K;
 266 const size_t G                  = M*K;
 267 const size_t HWperKB            = K / sizeof(HeapWord);
 268 
 269 // Constants for converting from a base unit to milli-base units.  For
 270 // example from seconds to milliseconds and microseconds
 271 
 272 const int MILLIUNITS    = 1000;         // milli units per base unit
 273 const int MICROUNITS    = 1000000;      // micro units per base unit
 274 const int NANOUNITS     = 1000000000;   // nano units per base unit
 275 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
 276 
 277 const jlong NANOSECS_PER_SEC      = CONST64(1000000000);
 278 const jint  NANOSECS_PER_MILLISEC = 1000000;
 279 
 280 
 281 // Unit conversion functions
 282 // The caller is responsible for considering overlow.
 283 
 284 inline int64_t nanos_to_millis(int64_t nanos) {
 285   return nanos / NANOUNITS_PER_MILLIUNIT;
 286 }
 287 inline int64_t millis_to_nanos(int64_t millis) {
 288   return millis * NANOUNITS_PER_MILLIUNIT;
 289 }
 290 
 291 // Proper units routines try to maintain at least three significant digits.
 292 // In worst case, it would print five significant digits with lower prefix.
 293 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
 294 // and therefore we need to be careful.
 295 
 296 inline const char* proper_unit_for_byte_size(size_t s) {
 297 #ifdef _LP64
 298   if (s >= 100*G) {
 299     return "G";
 300   }
 301 #endif
 302   if (s >= 100*M) {
 303     return "M";
 304   } else if (s >= 100*K) {
 305     return "K";
 306   } else {
 307     return "B";
 308   }
 309 }
 310 
 311 template <class T>
 312 inline T byte_size_in_proper_unit(T s) {
 313 #ifdef _LP64
 314   if (s >= 100*G) {
 315     return (T)(s/G);
 316   }
 317 #endif
 318   if (s >= 100*M) {
 319     return (T)(s/M);
 320   } else if (s >= 100*K) {
 321     return (T)(s/K);
 322   } else {
 323     return s;
 324   }
 325 }
 326 
 327 inline const char* exact_unit_for_byte_size(size_t s) {
 328 #ifdef _LP64
 329   if (s >= G && (s % G) == 0) {
 330     return "G";
 331   }
 332 #endif
 333   if (s >= M && (s % M) == 0) {
 334     return "M";
 335   }
 336   if (s >= K && (s % K) == 0) {
 337     return "K";
 338   }
 339   return "B";
 340 }
 341 
 342 inline size_t byte_size_in_exact_unit(size_t s) {
 343 #ifdef _LP64
 344   if (s >= G && (s % G) == 0) {
 345     return s / G;
 346   }
 347 #endif
 348   if (s >= M && (s % M) == 0) {
 349     return s / M;
 350   }
 351   if (s >= K && (s % K) == 0) {
 352     return s / K;
 353   }
 354   return s;
 355 }
 356 
 357 // Memory size transition formatting.
 358 
 359 #define HEAP_CHANGE_FORMAT "%s: " SIZE_FORMAT "K(" SIZE_FORMAT "K)->" SIZE_FORMAT "K(" SIZE_FORMAT "K)"
 360 
 361 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
 362   (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
 363 
 364 //----------------------------------------------------------------------------------------------------
 365 // VM type definitions
 366 
 367 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
 368 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
 369 
 370 typedef intptr_t  intx;
 371 typedef uintptr_t uintx;
 372 
 373 const intx  min_intx  = (intx)1 << (sizeof(intx)*BitsPerByte-1);
 374 const intx  max_intx  = (uintx)min_intx - 1;
 375 const uintx max_uintx = (uintx)-1;
 376 
 377 // Table of values:
 378 //      sizeof intx         4               8
 379 // min_intx             0x80000000      0x8000000000000000
 380 // max_intx             0x7FFFFFFF      0x7FFFFFFFFFFFFFFF
 381 // max_uintx            0xFFFFFFFF      0xFFFFFFFFFFFFFFFF
 382 
 383 typedef unsigned int uint;   NEEDS_CLEANUP
 384 
 385 
 386 //----------------------------------------------------------------------------------------------------
 387 // Java type definitions
 388 
 389 // All kinds of 'plain' byte addresses
 390 typedef   signed char s_char;
 391 typedef unsigned char u_char;
 392 typedef u_char*       address;
 393 typedef uintptr_t     address_word; // unsigned integer which will hold a pointer
 394                                     // except for some implementations of a C++
 395                                     // linkage pointer to function. Should never
 396                                     // need one of those to be placed in this
 397                                     // type anyway.
 398 
 399 //  Utility functions to "portably" (?) bit twiddle pointers
 400 //  Where portable means keep ANSI C++ compilers quiet
 401 
 402 inline address       set_address_bits(address x, int m)       { return address(intptr_t(x) | m); }
 403 inline address       clear_address_bits(address x, int m)     { return address(intptr_t(x) & ~m); }
 404 
 405 //  Utility functions to "portably" make cast to/from function pointers.
 406 
 407 inline address_word  mask_address_bits(address x, int m)      { return address_word(x) & m; }
 408 inline address_word  castable_address(address x)              { return address_word(x) ; }
 409 inline address_word  castable_address(void* x)                { return address_word(x) ; }
 410 
 411 // Pointer subtraction.
 412 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
 413 // the range we might need to find differences from one end of the heap
 414 // to the other.
 415 // A typical use might be:
 416 //     if (pointer_delta(end(), top()) >= size) {
 417 //       // enough room for an object of size
 418 //       ...
 419 // and then additions like
 420 //       ... top() + size ...
 421 // are safe because we know that top() is at least size below end().
 422 inline size_t pointer_delta(const volatile void* left,
 423                             const volatile void* right,
 424                             size_t element_size) {
 425   assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
 426   return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
 427 }
 428 
 429 // A version specialized for HeapWord*'s.
 430 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
 431   return pointer_delta(left, right, sizeof(HeapWord));
 432 }
 433 // A version specialized for MetaWord*'s.
 434 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
 435   return pointer_delta(left, right, sizeof(MetaWord));
 436 }
 437 
 438 //
 439 // ANSI C++ does not allow casting from one pointer type to a function pointer
 440 // directly without at best a warning. This macro accomplishes it silently
 441 // In every case that is present at this point the value be cast is a pointer
 442 // to a C linkage function. In some case the type used for the cast reflects
 443 // that linkage and a picky compiler would not complain. In other cases because
 444 // there is no convenient place to place a typedef with extern C linkage (i.e
 445 // a platform dependent header file) it doesn't. At this point no compiler seems
 446 // picky enough to catch these instances (which are few). It is possible that
 447 // using templates could fix these for all cases. This use of templates is likely
 448 // so far from the middle of the road that it is likely to be problematic in
 449 // many C++ compilers.
 450 //
 451 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
 452 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((address_word)(func_ptr)))
 453 
 454 // In many places we've added C-style casts to silence compiler
 455 // warnings, for example when truncating a size_t to an int when we
 456 // know the size_t is a small struct. Such casts are risky because
 457 // they effectively disable useful compiler warnings. We can make our
 458 // lives safer with this function, which ensures that any cast is
 459 // reversible without loss of information. It doesn't check
 460 // everything: it isn't intended to make sure that pointer types are
 461 // compatible, for example.
 462 template <typename T2, typename T1>
 463 T2 checked_cast(T1 thing) {
 464   T2 result = static_cast<T2>(thing);
 465   assert(static_cast<T1>(result) == thing, "must be");
 466   return result;
 467 }
 468 
 469 // Need the correct linkage to call qsort without warnings
 470 extern "C" {
 471   typedef int (*_sort_Fn)(const void *, const void *);
 472 }
 473 
 474 // Unsigned byte types for os and stream.hpp
 475 
 476 // Unsigned one, two, four and eigth byte quantities used for describing
 477 // the .class file format. See JVM book chapter 4.
 478 
 479 typedef jubyte  u1;
 480 typedef jushort u2;
 481 typedef juint   u4;
 482 typedef julong  u8;
 483 
 484 const jubyte  max_jubyte  = (jubyte)-1;  // 0xFF       largest jubyte
 485 const jushort max_jushort = (jushort)-1; // 0xFFFF     largest jushort
 486 const juint   max_juint   = (juint)-1;   // 0xFFFFFFFF largest juint
 487 const julong  max_julong  = (julong)-1;  // 0xFF....FF largest julong
 488 
 489 typedef jbyte  s1;
 490 typedef jshort s2;
 491 typedef jint   s4;
 492 typedef jlong  s8;
 493 
 494 const jbyte min_jbyte = -(1 << 7);       // smallest jbyte
 495 const jbyte max_jbyte = (1 << 7) - 1;    // largest jbyte
 496 const jshort min_jshort = -(1 << 15);    // smallest jshort
 497 const jshort max_jshort = (1 << 15) - 1; // largest jshort
 498 
 499 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
 500 const jint max_jint = (juint)min_jint - 1;                     // 0x7FFFFFFF == largest jint
 501 
 502 const jint min_jintFloat = (jint)(0x00000001);
 503 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
 504 const jint max_jintFloat = (jint)(0x7f7fffff);
 505 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
 506 
 507 //----------------------------------------------------------------------------------------------------
 508 // JVM spec restrictions
 509 
 510 const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (p.134)
 511 
 512 //----------------------------------------------------------------------------------------------------
 513 // Object alignment, in units of HeapWords.
 514 //
 515 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
 516 // reference fields can be naturally aligned.
 517 
 518 extern int MinObjAlignment;
 519 extern int MinObjAlignmentInBytes;
 520 extern int MinObjAlignmentInBytesMask;
 521 
 522 extern int LogMinObjAlignment;
 523 extern int LogMinObjAlignmentInBytes;
 524 
 525 const int LogKlassAlignmentInBytes = 3;
 526 const int LogKlassAlignment        = LogKlassAlignmentInBytes - LogHeapWordSize;
 527 const int KlassAlignmentInBytes    = 1 << LogKlassAlignmentInBytes;
 528 const int KlassAlignment           = KlassAlignmentInBytes / HeapWordSize;
 529 
 530 // Maximal size of heap where unscaled compression can be used. Also upper bound
 531 // for heap placement: 4GB.
 532 const  uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
 533 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
 534 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
 535 extern uint64_t OopEncodingHeapMax;
 536 
 537 // Maximal size of compressed class space. Above this limit compression is not possible.
 538 // Also upper bound for placement of zero based class space. (Class space is further limited
 539 // to be < 3G, see arguments.cpp.)
 540 const  uint64_t KlassEncodingMetaspaceMax = (uint64_t(max_juint) + 1) << LogKlassAlignmentInBytes;
 541 
 542 // Machine dependent stuff
 543 
 544 // The maximum size of the code cache.  Can be overridden by targets.
 545 #define CODE_CACHE_SIZE_LIMIT (2*G)
 546 // Allow targets to reduce the default size of the code cache.
 547 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
 548 
 549 #include CPU_HEADER(globalDefinitions)
 550 
 551 // To assure the IRIW property on processors that are not multiple copy
 552 // atomic, sync instructions must be issued between volatile reads to
 553 // assure their ordering, instead of after volatile stores.
 554 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
 555 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
 556 #ifdef CPU_MULTI_COPY_ATOMIC
 557 // Not needed.
 558 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
 559 #else
 560 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
 561 // Final decision is subject to JEP 188: Java Memory Model Update.
 562 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
 563 #endif
 564 
 565 // The expected size in bytes of a cache line, used to pad data structures.
 566 #ifndef DEFAULT_CACHE_LINE_SIZE
 567   #define DEFAULT_CACHE_LINE_SIZE 64
 568 #endif
 569 
 570 
 571 //----------------------------------------------------------------------------------------------------
 572 // Utility macros for compilers
 573 // used to silence compiler warnings
 574 
 575 #define Unused_Variable(var) var
 576 
 577 
 578 //----------------------------------------------------------------------------------------------------
 579 // Miscellaneous
 580 
 581 // 6302670 Eliminate Hotspot __fabsf dependency
 582 // All fabs() callers should call this function instead, which will implicitly
 583 // convert the operand to double, avoiding a dependency on __fabsf which
 584 // doesn't exist in early versions of Solaris 8.
 585 inline double fabsd(double value) {
 586   return fabs(value);
 587 }
 588 
 589 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
 590 // is zero, return 0.0.
 591 template<typename T>
 592 inline double percent_of(T numerator, T denominator) {
 593   return denominator != 0 ? (double)numerator / denominator * 100.0 : 0.0;
 594 }
 595 
 596 //----------------------------------------------------------------------------------------------------
 597 // Special casts
 598 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
 599 typedef union {
 600   jfloat f;
 601   jint i;
 602 } FloatIntConv;
 603 
 604 typedef union {
 605   jdouble d;
 606   jlong l;
 607   julong ul;
 608 } DoubleLongConv;
 609 
 610 inline jint    jint_cast    (jfloat  x)  { return ((FloatIntConv*)&x)->i; }
 611 inline jfloat  jfloat_cast  (jint    x)  { return ((FloatIntConv*)&x)->f; }
 612 
 613 inline jlong   jlong_cast   (jdouble x)  { return ((DoubleLongConv*)&x)->l;  }
 614 inline julong  julong_cast  (jdouble x)  { return ((DoubleLongConv*)&x)->ul; }
 615 inline jdouble jdouble_cast (jlong   x)  { return ((DoubleLongConv*)&x)->d;  }
 616 
 617 inline jint low (jlong value)                    { return jint(value); }
 618 inline jint high(jlong value)                    { return jint(value >> 32); }
 619 
 620 // the fancy casts are a hopefully portable way
 621 // to do unsigned 32 to 64 bit type conversion
 622 inline void set_low (jlong* value, jint low )    { *value &= (jlong)0xffffffff << 32;
 623                                                    *value |= (jlong)(julong)(juint)low; }
 624 
 625 inline void set_high(jlong* value, jint high)    { *value &= (jlong)(julong)(juint)0xffffffff;
 626                                                    *value |= (jlong)high       << 32; }
 627 
 628 inline jlong jlong_from(jint h, jint l) {
 629   jlong result = 0; // initialization to avoid warning
 630   set_high(&result, h);
 631   set_low(&result,  l);
 632   return result;
 633 }
 634 
 635 union jlong_accessor {
 636   jint  words[2];
 637   jlong long_value;
 638 };
 639 
 640 void basic_types_init(); // cannot define here; uses assert
 641 
 642 
 643 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 644 enum BasicType {
 645 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
 646   T_BOOLEAN     = JVM_T_BOOLEAN,
 647   T_CHAR        = JVM_T_CHAR,
 648   T_FLOAT       = JVM_T_FLOAT,
 649   T_DOUBLE      = JVM_T_DOUBLE,
 650   T_BYTE        = JVM_T_BYTE,
 651   T_SHORT       = JVM_T_SHORT,
 652   T_INT         = JVM_T_INT,
 653   T_LONG        = JVM_T_LONG,
 654   // The remaining values are not part of any standard.
 655   // T_OBJECT and T_VOID denote two more semantic choices
 656   // for method return values.
 657   // T_OBJECT and T_ARRAY describe signature syntax.
 658   // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
 659   // internal references within the JVM as if they were Java
 660   // types in their own right.
 661   T_OBJECT      = 12,
 662   T_ARRAY       = 13,
 663   T_VOID        = 14,
 664   T_ADDRESS     = 15,
 665   T_NARROWOOP   = 16,
 666   T_METADATA    = 17,
 667   T_NARROWKLASS = 18,
 668   T_CONFLICT    = 19, // for stack value type with conflicting contents
 669   T_ILLEGAL     = 99
 670 };
 671 
 672 #define SIGNATURE_TYPES_DO(F, N)                \
 673     F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N)      \
 674     F(JVM_SIGNATURE_CHAR,    T_CHAR,    N)      \
 675     F(JVM_SIGNATURE_FLOAT,   T_FLOAT,   N)      \
 676     F(JVM_SIGNATURE_DOUBLE,  T_DOUBLE,  N)      \
 677     F(JVM_SIGNATURE_BYTE,    T_BYTE,    N)      \
 678     F(JVM_SIGNATURE_SHORT,   T_SHORT,   N)      \
 679     F(JVM_SIGNATURE_INT,     T_INT,     N)      \
 680     F(JVM_SIGNATURE_LONG,    T_LONG,    N)      \
 681     F(JVM_SIGNATURE_CLASS,   T_OBJECT,  N)      \
 682     F(JVM_SIGNATURE_ARRAY,   T_ARRAY,   N)      \
 683     F(JVM_SIGNATURE_VOID,    T_VOID,    N)      \
 684     /*end*/
 685 
 686 inline bool is_java_type(BasicType t) {
 687   return T_BOOLEAN <= t && t <= T_VOID;
 688 }
 689 
 690 inline bool is_java_primitive(BasicType t) {
 691   return T_BOOLEAN <= t && t <= T_LONG;
 692 }
 693 
 694 inline bool is_subword_type(BasicType t) {
 695   // these guys are processed exactly like T_INT in calling sequences:
 696   return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
 697 }
 698 
 699 inline bool is_signed_subword_type(BasicType t) {
 700   return (t == T_BYTE || t == T_SHORT);
 701 }
 702 
 703 inline bool is_double_word_type(BasicType t) {
 704   return (t == T_DOUBLE || t == T_LONG);
 705 }
 706 
 707 inline bool is_reference_type(BasicType t) {
 708   return (t == T_OBJECT || t == T_ARRAY);
 709 }
 710 
 711 inline bool is_integral_type(BasicType t) {
 712   return is_subword_type(t) || t == T_INT || t == T_LONG;
 713 }
 714 
 715 inline bool is_floating_point_type(BasicType t) {
 716   return (t == T_FLOAT || t == T_DOUBLE);
 717 }
 718 
 719 extern char type2char_tab[T_CONFLICT+1];     // Map a BasicType to a jchar
 720 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
 721 extern int type2size[T_CONFLICT+1];         // Map BasicType to result stack elements
 722 extern const char* type2name_tab[T_CONFLICT+1];     // Map a BasicType to a jchar
 723 inline const char* type2name(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2name_tab[t] : NULL; }
 724 extern BasicType name2type(const char* name);
 725 
 726 inline jlong max_signed_integer(BasicType bt) {
 727   if (bt == T_INT) {
 728     return max_jint;
 729   }
 730   assert(bt == T_LONG, "unsupported");
 731   return max_jlong;
 732 }
 733 
 734 inline jlong min_signed_integer(BasicType bt) {
 735   if (bt == T_INT) {
 736     return min_jint;
 737   }
 738   assert(bt == T_LONG, "unsupported");
 739   return min_jlong;
 740 }
 741 
 742 // Auxiliary math routines
 743 // least common multiple
 744 extern size_t lcm(size_t a, size_t b);
 745 
 746 
 747 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 748 enum BasicTypeSize {
 749   T_BOOLEAN_size     = 1,
 750   T_CHAR_size        = 1,
 751   T_FLOAT_size       = 1,
 752   T_DOUBLE_size      = 2,
 753   T_BYTE_size        = 1,
 754   T_SHORT_size       = 1,
 755   T_INT_size         = 1,
 756   T_LONG_size        = 2,
 757   T_OBJECT_size      = 1,
 758   T_ARRAY_size       = 1,
 759   T_NARROWOOP_size   = 1,
 760   T_NARROWKLASS_size = 1,
 761   T_VOID_size        = 0
 762 };
 763 
 764 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
 765 inline int parameter_type_word_count(BasicType t) {
 766   if (is_double_word_type(t))  return 2;
 767   assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
 768   assert(type2size[t] == 1, "must be");
 769   return 1;
 770 }
 771 
 772 // maps a BasicType to its instance field storage type:
 773 // all sub-word integral types are widened to T_INT
 774 extern BasicType type2field[T_CONFLICT+1];
 775 extern BasicType type2wfield[T_CONFLICT+1];
 776 
 777 
 778 // size in bytes
 779 enum ArrayElementSize {
 780   T_BOOLEAN_aelem_bytes     = 1,
 781   T_CHAR_aelem_bytes        = 2,
 782   T_FLOAT_aelem_bytes       = 4,
 783   T_DOUBLE_aelem_bytes      = 8,
 784   T_BYTE_aelem_bytes        = 1,
 785   T_SHORT_aelem_bytes       = 2,
 786   T_INT_aelem_bytes         = 4,
 787   T_LONG_aelem_bytes        = 8,
 788 #ifdef _LP64
 789   T_OBJECT_aelem_bytes      = 8,
 790   T_ARRAY_aelem_bytes       = 8,
 791 #else
 792   T_OBJECT_aelem_bytes      = 4,
 793   T_ARRAY_aelem_bytes       = 4,
 794 #endif
 795   T_NARROWOOP_aelem_bytes   = 4,
 796   T_NARROWKLASS_aelem_bytes = 4,
 797   T_VOID_aelem_bytes        = 0
 798 };
 799 
 800 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
 801 #ifdef ASSERT
 802 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
 803 #else
 804 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
 805 #endif
 806 
 807 
 808 // JavaValue serves as a container for arbitrary Java values.
 809 
 810 class JavaValue {
 811 
 812  public:
 813   typedef union JavaCallValue {
 814     jfloat   f;
 815     jdouble  d;
 816     jint     i;
 817     jlong    l;
 818     jobject  h;
 819     oopDesc* o;
 820   } JavaCallValue;
 821 
 822  private:
 823   BasicType _type;
 824   JavaCallValue _value;
 825 
 826  public:
 827   JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
 828 
 829   JavaValue(jfloat value) {
 830     _type    = T_FLOAT;
 831     _value.f = value;
 832   }
 833 
 834   JavaValue(jdouble value) {
 835     _type    = T_DOUBLE;
 836     _value.d = value;
 837   }
 838 
 839  jfloat get_jfloat() const { return _value.f; }
 840  jdouble get_jdouble() const { return _value.d; }
 841  jint get_jint() const { return _value.i; }
 842  jlong get_jlong() const { return _value.l; }
 843  jobject get_jobject() const { return _value.h; }
 844  oopDesc* get_oop() const { return _value.o; }
 845  JavaCallValue* get_value_addr() { return &_value; }
 846  BasicType get_type() const { return _type; }
 847 
 848  void set_jfloat(jfloat f) { _value.f = f;}
 849  void set_jdouble(jdouble d) { _value.d = d;}
 850  void set_jint(jint i) { _value.i = i;}
 851  void set_jlong(jlong l) { _value.l = l;}
 852  void set_jobject(jobject h) { _value.h = h;}
 853  void set_oop(oopDesc* o) { _value.o = o;}
 854  void set_type(BasicType t) { _type = t; }
 855 
 856  jboolean get_jboolean() const { return (jboolean) (_value.i);}
 857  jbyte get_jbyte() const { return (jbyte) (_value.i);}
 858  jchar get_jchar() const { return (jchar) (_value.i);}
 859  jshort get_jshort() const { return (jshort) (_value.i);}
 860 
 861 };
 862 
 863 
 864 // TosState describes the top-of-stack state before and after the execution of
 865 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
 866 // registers. The TosState corresponds to the 'machine representation' of this cached
 867 // value. There's 4 states corresponding to the JAVA types int, long, float & double
 868 // as well as a 5th state in case the top-of-stack value is actually on the top
 869 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
 870 // state when it comes to machine representation but is used separately for (oop)
 871 // type specific operations (e.g. verification code).
 872 
 873 enum TosState {         // describes the tos cache contents
 874   btos = 0,             // byte, bool tos cached
 875   ztos = 1,             // byte, bool tos cached
 876   ctos = 2,             // char tos cached
 877   stos = 3,             // short tos cached
 878   itos = 4,             // int tos cached
 879   ltos = 5,             // long tos cached
 880   ftos = 6,             // float tos cached
 881   dtos = 7,             // double tos cached
 882   atos = 8,             // object cached
 883   vtos = 9,             // tos not cached
 884   number_of_states,
 885   ilgl                  // illegal state: should not occur
 886 };
 887 
 888 
 889 inline TosState as_TosState(BasicType type) {
 890   switch (type) {
 891     case T_BYTE   : return btos;
 892     case T_BOOLEAN: return ztos;
 893     case T_CHAR   : return ctos;
 894     case T_SHORT  : return stos;
 895     case T_INT    : return itos;
 896     case T_LONG   : return ltos;
 897     case T_FLOAT  : return ftos;
 898     case T_DOUBLE : return dtos;
 899     case T_VOID   : return vtos;
 900     case T_ARRAY  : // fall through
 901     case T_OBJECT : return atos;
 902     default       : return ilgl;
 903   }
 904 }
 905 
 906 inline BasicType as_BasicType(TosState state) {
 907   switch (state) {
 908     case btos : return T_BYTE;
 909     case ztos : return T_BOOLEAN;
 910     case ctos : return T_CHAR;
 911     case stos : return T_SHORT;
 912     case itos : return T_INT;
 913     case ltos : return T_LONG;
 914     case ftos : return T_FLOAT;
 915     case dtos : return T_DOUBLE;
 916     case atos : return T_OBJECT;
 917     case vtos : return T_VOID;
 918     default   : return T_ILLEGAL;
 919   }
 920 }
 921 
 922 
 923 // Helper function to convert BasicType info into TosState
 924 // Note: Cannot define here as it uses global constant at the time being.
 925 TosState as_TosState(BasicType type);
 926 
 927 
 928 // JavaThreadState keeps track of which part of the code a thread is executing in. This
 929 // information is needed by the safepoint code.
 930 //
 931 // There are 4 essential states:
 932 //
 933 //  _thread_new         : Just started, but not executed init. code yet (most likely still in OS init code)
 934 //  _thread_in_native   : In native code. This is a safepoint region, since all oops will be in jobject handles
 935 //  _thread_in_vm       : Executing in the vm
 936 //  _thread_in_Java     : Executing either interpreted or compiled Java code (or could be in a stub)
 937 //
 938 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
 939 // a transition from one state to another. These extra states makes it possible for the safepoint code to
 940 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
 941 //
 942 // Given a state, the xxxx_trans state can always be found by adding 1.
 943 //
 944 enum JavaThreadState {
 945   _thread_uninitialized     =  0, // should never happen (missing initialization)
 946   _thread_new               =  2, // just starting up, i.e., in process of being initialized
 947   _thread_new_trans         =  3, // corresponding transition state (not used, included for completness)
 948   _thread_in_native         =  4, // running in native code
 949   _thread_in_native_trans   =  5, // corresponding transition state
 950   _thread_in_vm             =  6, // running in VM
 951   _thread_in_vm_trans       =  7, // corresponding transition state
 952   _thread_in_Java           =  8, // running in Java or in stub code
 953   _thread_in_Java_trans     =  9, // corresponding transition state (not used, included for completness)
 954   _thread_blocked           = 10, // blocked in vm
 955   _thread_blocked_trans     = 11, // corresponding transition state
 956   _thread_max_state         = 12  // maximum thread state+1 - used for statistics allocation
 957 };
 958 
 959 //----------------------------------------------------------------------------------------------------
 960 // Special constants for debugging
 961 
 962 const jint     badInt           = -3;                       // generic "bad int" value
 963 const intptr_t badAddressVal    = -2;                       // generic "bad address" value
 964 const intptr_t badOopVal        = -1;                       // generic "bad oop" value
 965 const intptr_t badHeapOopVal    = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
 966 const int      badStackSegVal   = 0xCA;                     // value used to zap stack segments
 967 const int      badHandleValue   = 0xBC;                     // value used to zap vm handle area
 968 const int      badResourceValue = 0xAB;                     // value used to zap resource area
 969 const int      freeBlockPad     = 0xBA;                     // value used to pad freed blocks.
 970 const int      uninitBlockPad   = 0xF1;                     // value used to zap newly malloc'd blocks.
 971 const juint    uninitMetaWordVal= 0xf7f7f7f7;               // value used to zap newly allocated metachunk
 972 const juint    badHeapWordVal   = 0xBAADBABE;               // value used to zap heap after GC
 973 const juint    badMetaWordVal   = 0xBAADFADE;               // value used to zap metadata heap after GC
 974 const int      badCodeHeapNewVal= 0xCC;                     // value used to zap Code heap at allocation
 975 const int      badCodeHeapFreeVal = 0xDD;                   // value used to zap Code heap at deallocation
 976 
 977 
 978 // (These must be implemented as #defines because C++ compilers are
 979 // not obligated to inline non-integral constants!)
 980 #define       badAddress        ((address)::badAddressVal)
 981 #define       badOop            (cast_to_oop(::badOopVal))
 982 #define       badHeapWord       (::badHeapWordVal)
 983 
 984 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
 985 #define TASKQUEUE_SIZE (NOT_LP64(1<<14) LP64_ONLY(1<<17))
 986 
 987 //----------------------------------------------------------------------------------------------------
 988 // Utility functions for bitfield manipulations
 989 
 990 const intptr_t AllBits    = ~0; // all bits set in a word
 991 const intptr_t NoBits     =  0; // no bits set in a word
 992 const jlong    NoLongBits =  0; // no bits set in a long
 993 const intptr_t OneBit     =  1; // only right_most bit set in a word
 994 
 995 // get a word with the n.th or the right-most or left-most n bits set
 996 // (note: #define used only so that they can be used in enum constant definitions)
 997 #define nth_bit(n)        (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
 998 #define right_n_bits(n)   (nth_bit(n) - 1)
 999 
1000 // bit-operations using a mask m
1001 inline void   set_bits    (intptr_t& x, intptr_t m) { x |= m; }
1002 inline void clear_bits    (intptr_t& x, intptr_t m) { x &= ~m; }
1003 inline intptr_t mask_bits      (intptr_t  x, intptr_t m) { return x & m; }
1004 inline jlong    mask_long_bits (jlong     x, jlong    m) { return x & m; }
1005 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1006 
1007 // bit-operations using the n.th bit
1008 inline void    set_nth_bit(intptr_t& x, int n) { set_bits  (x, nth_bit(n)); }
1009 inline void  clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1010 inline bool is_set_nth_bit(intptr_t  x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1011 
1012 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1013 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1014   return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1015 }
1016 
1017 
1018 //----------------------------------------------------------------------------------------------------
1019 // Utility functions for integers
1020 
1021 // Avoid use of global min/max macros which may cause unwanted double
1022 // evaluation of arguments.
1023 #ifdef max
1024 #undef max
1025 #endif
1026 
1027 #ifdef min
1028 #undef min
1029 #endif
1030 
1031 // It is necessary to use templates here. Having normal overloaded
1032 // functions does not work because it is necessary to provide both 32-
1033 // and 64-bit overloaded functions, which does not work, and having
1034 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1035 // will be even more error-prone than macros.
1036 template<class T> constexpr T MAX2(T a, T b)           { return (a > b) ? a : b; }
1037 template<class T> constexpr T MIN2(T a, T b)           { return (a < b) ? a : b; }
1038 template<class T> constexpr T MAX3(T a, T b, T c)      { return MAX2(MAX2(a, b), c); }
1039 template<class T> constexpr T MIN3(T a, T b, T c)      { return MIN2(MIN2(a, b), c); }
1040 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1041 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1042 
1043 template<class T> inline T ABS(T x)                 { return (x > 0) ? x : -x; }
1044 
1045 // Return the given value clamped to the range [min ... max]
1046 template<typename T>
1047 inline T clamp(T value, T min, T max) {
1048   assert(min <= max, "must be");
1049   return MIN2(MAX2(value, min), max);
1050 }
1051 
1052 inline bool is_odd (intx x) { return x & 1;      }
1053 inline bool is_even(intx x) { return !is_odd(x); }
1054 
1055 // abs methods which cannot overflow and so are well-defined across
1056 // the entire domain of integer types.
1057 static inline unsigned int uabs(unsigned int n) {
1058   union {
1059     unsigned int result;
1060     int value;
1061   };
1062   result = n;
1063   if (value < 0) result = 0-result;
1064   return result;
1065 }
1066 static inline julong uabs(julong n) {
1067   union {
1068     julong result;
1069     jlong value;
1070   };
1071   result = n;
1072   if (value < 0) result = 0-result;
1073   return result;
1074 }
1075 static inline julong uabs(jlong n) { return uabs((julong)n); }
1076 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1077 
1078 // "to" should be greater than "from."
1079 inline intx byte_size(void* from, void* to) {
1080   return (address)to - (address)from;
1081 }
1082 
1083 
1084 // Pack and extract shorts to/from ints:
1085 
1086 inline int extract_low_short_from_int(jint x) {
1087   return x & 0xffff;
1088 }
1089 
1090 inline int extract_high_short_from_int(jint x) {
1091   return (x >> 16) & 0xffff;
1092 }
1093 
1094 inline int build_int_from_shorts( jushort low, jushort high ) {
1095   return ((int)((unsigned int)high << 16) | (unsigned int)low);
1096 }
1097 
1098 // swap a & b
1099 template<class T> static void swap(T& a, T& b) {
1100   T tmp = a;
1101   a = b;
1102   b = tmp;
1103 }
1104 
1105 // array_size_impl is a function that takes a reference to T[N] and
1106 // returns a reference to char[N].  It is not ODR-used, so not defined.
1107 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1108 
1109 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1110 
1111 //----------------------------------------------------------------------------------------------------
1112 // Sum and product which can never overflow: they wrap, just like the
1113 // Java operations.  Note that we don't intend these to be used for
1114 // general-purpose arithmetic: their purpose is to emulate Java
1115 // operations.
1116 
1117 // The goal of this code to avoid undefined or implementation-defined
1118 // behavior.  The use of an lvalue to reference cast is explicitly
1119 // permitted by Lvalues and rvalues [basic.lval].  [Section 3.10 Para
1120 // 15 in C++03]
1121 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE)  \
1122 inline TYPE NAME (TYPE in1, TYPE in2) {                 \
1123   UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1124   ures OP ## = static_cast<UNSIGNED_TYPE>(in2);         \
1125   return reinterpret_cast<TYPE&>(ures);                 \
1126 }
1127 
1128 JAVA_INTEGER_OP(+, java_add, jint, juint)
1129 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1130 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1131 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1132 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1133 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1134 
1135 #undef JAVA_INTEGER_OP
1136 
1137 // Provide integer shift operations with Java semantics.  No overflow
1138 // issues - left shifts simply discard shifted out bits.  No undefined
1139 // behavior for large or negative shift quantities; instead the actual
1140 // shift distance is the argument modulo the lhs value's size in bits.
1141 // No undefined or implementation defined behavior for shifting negative
1142 // values; left shift discards bits, right shift sign extends.  We use
1143 // the same safe conversion technique as above for java_add and friends.
1144 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE)    \
1145 inline TYPE NAME (TYPE lhs, jint rhs) {                 \
1146   const uint rhs_mask = (sizeof(TYPE) * 8) - 1;         \
1147   STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63);      \
1148   XTYPE xres = static_cast<XTYPE>(lhs);                 \
1149   xres OP ## = (rhs & rhs_mask);                        \
1150   return reinterpret_cast<TYPE&>(xres);                 \
1151 }
1152 
1153 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1154 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1155 // For signed shift right, assume C++ implementation >> sign extends.
1156 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1157 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1158 // For >>> use C++ unsigned >>.
1159 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1160 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1161 
1162 #undef JAVA_INTEGER_SHIFT_OP
1163 
1164 //----------------------------------------------------------------------------------------------------
1165 // The goal of this code is to provide saturating operations for int/uint.
1166 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1167 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1168 inline int NAME (TYPE1 in1, TYPE2 in2) {             \
1169   jlong res = static_cast<jlong>(in1);               \
1170   res OP ## = static_cast<jlong>(in2);               \
1171   if (res > max_jint) {                              \
1172     res = max_jint;                                  \
1173   } else if (res < min_jint) {                       \
1174     res = min_jint;                                  \
1175   }                                                  \
1176   return static_cast<int>(res);                      \
1177 }
1178 
1179 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1180 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1181 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1182 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1183 
1184 #undef SATURATED_INTEGER_OP
1185 
1186 // Dereference vptr
1187 // All C++ compilers that we know of have the vtbl pointer in the first
1188 // word.  If there are exceptions, this function needs to be made compiler
1189 // specific.
1190 static inline void* dereference_vptr(const void* addr) {
1191   return *(void**)addr;
1192 }
1193 
1194 //----------------------------------------------------------------------------------------------------
1195 // String type aliases used by command line flag declarations and
1196 // processing utilities.
1197 
1198 typedef const char* ccstr;
1199 typedef const char* ccstrlist;   // represents string arguments which accumulate
1200 
1201 //----------------------------------------------------------------------------------------------------
1202 // Default hash/equals functions used by ResourceHashtable
1203 
1204 template<typename K> unsigned primitive_hash(const K& k) {
1205   unsigned hash = (unsigned)((uintptr_t)k);
1206   return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1207 }
1208 
1209 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1210   return k0 == k1;
1211 }
1212 
1213 
1214 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP