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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  22  *
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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 #include <type_traits>
  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 SSIZE_PLUS_FORMAT        "%+"  PRIdPTR
 145 #define SIZE_FORMAT              "%"   PRIuPTR
 146 #define SIZE_FORMAT_HEX          "0x%" PRIxPTR
 147 #define SSIZE_FORMAT_W(width)    "%"   #width PRIdPTR
 148 #define SIZE_FORMAT_W(width)     "%"   #width PRIuPTR
 149 #define SIZE_FORMAT_HEX_W(width) "0x%" #width PRIxPTR
 150 
 151 #define INTX_FORMAT           "%" PRIdPTR
 152 #define UINTX_FORMAT          "%" PRIuPTR
 153 #define INTX_FORMAT_W(width)  "%" #width PRIdPTR
 154 #define UINTX_FORMAT_W(width) "%" #width PRIuPTR
 155 
 156 // Convert pointer to intptr_t, for use in printing pointers.
 157 inline intptr_t p2i(const volatile void* p) {
 158   return (intptr_t) p;
 159 }
 160 
 161 //----------------------------------------------------------------------------------------------------
 162 // Constants
 163 
 164 const int LogBytesPerShort   = 1;
 165 const int LogBytesPerInt     = 2;
 166 #ifdef _LP64
 167 const int LogBytesPerWord    = 3;
 168 #else
 169 const int LogBytesPerWord    = 2;
 170 #endif
 171 const int LogBytesPerLong    = 3;
 172 
 173 const int BytesPerShort      = 1 << LogBytesPerShort;
 174 const int BytesPerInt        = 1 << LogBytesPerInt;
 175 const int BytesPerWord       = 1 << LogBytesPerWord;
 176 const int BytesPerLong       = 1 << LogBytesPerLong;
 177 
 178 const int LogBitsPerByte     = 3;
 179 const int LogBitsPerShort    = LogBitsPerByte + LogBytesPerShort;
 180 const int LogBitsPerInt      = LogBitsPerByte + LogBytesPerInt;
 181 const int LogBitsPerWord     = LogBitsPerByte + LogBytesPerWord;
 182 const int LogBitsPerLong     = LogBitsPerByte + LogBytesPerLong;
 183 
 184 const int BitsPerByte        = 1 << LogBitsPerByte;
 185 const int BitsPerShort       = 1 << LogBitsPerShort;
 186 const int BitsPerInt         = 1 << LogBitsPerInt;
 187 const int BitsPerWord        = 1 << LogBitsPerWord;
 188 const int BitsPerLong        = 1 << LogBitsPerLong;
 189 
 190 const int WordAlignmentMask  = (1 << LogBytesPerWord) - 1;
 191 const int LongAlignmentMask  = (1 << LogBytesPerLong) - 1;
 192 
 193 const int WordsPerLong       = 2;       // Number of stack entries for longs
 194 
 195 const int oopSize            = sizeof(char*); // Full-width oop
 196 extern int heapOopSize;                       // Oop within a java object
 197 const int wordSize           = sizeof(char*);
 198 const int longSize           = sizeof(jlong);
 199 const int jintSize           = sizeof(jint);
 200 const int size_tSize         = sizeof(size_t);
 201 
 202 const int BytesPerOop        = BytesPerWord;  // Full-width oop
 203 
 204 extern int LogBytesPerHeapOop;                // Oop within a java object
 205 extern int LogBitsPerHeapOop;
 206 extern int BytesPerHeapOop;
 207 extern int BitsPerHeapOop;
 208 
 209 const int BitsPerJavaInteger = 32;
 210 const int BitsPerJavaLong    = 64;
 211 const int BitsPerSize_t      = size_tSize * BitsPerByte;
 212 
 213 // Size of a char[] needed to represent a jint as a string in decimal.
 214 const int jintAsStringSize = 12;
 215 
 216 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
 217 // We require that object sizes be measured in units of heap words (e.g.
 218 // pointer-sized values), so that given HeapWord* hw,
 219 //   hw += oop(hw)->foo();
 220 // works, where foo is a method (like size or scavenge) that returns the
 221 // object size.
 222 class HeapWordImpl;             // Opaque, never defined.
 223 typedef HeapWordImpl* HeapWord;
 224 
 225 // Analogous opaque struct for metadata allocated from metaspaces.
 226 class MetaWordImpl;             // Opaque, never defined.
 227 typedef MetaWordImpl* MetaWord;
 228 
 229 // HeapWordSize must be 2^LogHeapWordSize.
 230 const int HeapWordSize        = sizeof(HeapWord);
 231 #ifdef _LP64
 232 const int LogHeapWordSize     = 3;
 233 #else
 234 const int LogHeapWordSize     = 2;
 235 #endif
 236 const int HeapWordsPerLong    = BytesPerLong / HeapWordSize;
 237 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
 238 
 239 // The minimum number of native machine words necessary to contain "byte_size"
 240 // bytes.
 241 inline size_t heap_word_size(size_t byte_size) {
 242   return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
 243 }
 244 
 245 inline jfloat jfloat_cast(jint x);
 246 inline jdouble jdouble_cast(jlong x);
 247 
 248 //-------------------------------------------
 249 // Constant for jlong (standardized by C++11)
 250 
 251 // Build a 64bit integer constant
 252 #define CONST64(x)  (x ## LL)
 253 #define UCONST64(x) (x ## ULL)
 254 
 255 const jlong min_jlong = CONST64(0x8000000000000000);
 256 const jlong max_jlong = CONST64(0x7fffffffffffffff);
 257 
 258 //-------------------------------------------
 259 // Constant for jdouble
 260 const jlong min_jlongDouble = CONST64(0x0000000000000001);
 261 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
 262 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
 263 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
 264 
 265 const size_t K                  = 1024;
 266 const size_t M                  = K*K;
 267 const size_t G                  = M*K;
 268 const size_t HWperKB            = K / sizeof(HeapWord);
 269 
 270 // Constants for converting from a base unit to milli-base units.  For
 271 // example from seconds to milliseconds and microseconds
 272 
 273 const int MILLIUNITS    = 1000;         // milli units per base unit
 274 const int MICROUNITS    = 1000000;      // micro units per base unit
 275 const int NANOUNITS     = 1000000000;   // nano units per base unit
 276 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
 277 
 278 const jlong NANOSECS_PER_SEC      = CONST64(1000000000);
 279 const jint  NANOSECS_PER_MILLISEC = 1000000;
 280 
 281 
 282 // Unit conversion functions
 283 // The caller is responsible for considering overlow.
 284 
 285 inline int64_t nanos_to_millis(int64_t nanos) {
 286   return nanos / NANOUNITS_PER_MILLIUNIT;
 287 }
 288 inline int64_t millis_to_nanos(int64_t millis) {
 289   return millis * NANOUNITS_PER_MILLIUNIT;
 290 }
 291 
 292 // Proper units routines try to maintain at least three significant digits.
 293 // In worst case, it would print five significant digits with lower prefix.
 294 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
 295 // and therefore we need to be careful.
 296 
 297 inline const char* proper_unit_for_byte_size(size_t s) {
 298 #ifdef _LP64
 299   if (s >= 100*G) {
 300     return "G";
 301   }
 302 #endif
 303   if (s >= 100*M) {
 304     return "M";
 305   } else if (s >= 100*K) {
 306     return "K";
 307   } else {
 308     return "B";
 309   }
 310 }
 311 
 312 template <class T>
 313 inline T byte_size_in_proper_unit(T s) {
 314 #ifdef _LP64
 315   if (s >= 100*G) {
 316     return (T)(s/G);
 317   }
 318 #endif
 319   if (s >= 100*M) {
 320     return (T)(s/M);
 321   } else if (s >= 100*K) {
 322     return (T)(s/K);
 323   } else {
 324     return s;
 325   }
 326 }
 327 
 328 #define PROPERFMT             SIZE_FORMAT "%s"
 329 #define PROPERFMTARGS(s)      byte_size_in_proper_unit(s), proper_unit_for_byte_size(s)
 330 
 331 inline const char* exact_unit_for_byte_size(size_t s) {
 332 #ifdef _LP64
 333   if (s >= G && (s % G) == 0) {
 334     return "G";
 335   }
 336 #endif
 337   if (s >= M && (s % M) == 0) {
 338     return "M";
 339   }
 340   if (s >= K && (s % K) == 0) {
 341     return "K";
 342   }
 343   return "B";
 344 }
 345 
 346 inline size_t byte_size_in_exact_unit(size_t s) {
 347 #ifdef _LP64
 348   if (s >= G && (s % G) == 0) {
 349     return s / G;
 350   }
 351 #endif
 352   if (s >= M && (s % M) == 0) {
 353     return s / M;
 354   }
 355   if (s >= K && (s % K) == 0) {
 356     return s / K;
 357   }
 358   return s;
 359 }
 360 
 361 #define EXACTFMT            SIZE_FORMAT "%s"
 362 #define EXACTFMTARGS(s)     byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
 363 
 364 // Memory size transition formatting.
 365 
 366 #define HEAP_CHANGE_FORMAT "%s: " SIZE_FORMAT "K(" SIZE_FORMAT "K)->" SIZE_FORMAT "K(" SIZE_FORMAT "K)"
 367 
 368 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
 369   (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
 370 
 371 //----------------------------------------------------------------------------------------------------
 372 // VM type definitions
 373 
 374 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
 375 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
 376 
 377 typedef intptr_t  intx;
 378 typedef uintptr_t uintx;
 379 
 380 const intx  min_intx  = (intx)1 << (sizeof(intx)*BitsPerByte-1);
 381 const intx  max_intx  = (uintx)min_intx - 1;
 382 const uintx max_uintx = (uintx)-1;
 383 
 384 // Table of values:
 385 //      sizeof intx         4               8
 386 // min_intx             0x80000000      0x8000000000000000
 387 // max_intx             0x7FFFFFFF      0x7FFFFFFFFFFFFFFF
 388 // max_uintx            0xFFFFFFFF      0xFFFFFFFFFFFFFFFF
 389 
 390 typedef unsigned int uint;   NEEDS_CLEANUP
 391 
 392 
 393 //----------------------------------------------------------------------------------------------------
 394 // Java type definitions
 395 
 396 // All kinds of 'plain' byte addresses
 397 typedef   signed char s_char;
 398 typedef unsigned char u_char;
 399 typedef u_char*       address;
 400 typedef uintptr_t     address_word; // unsigned integer which will hold a pointer
 401                                     // except for some implementations of a C++
 402                                     // linkage pointer to function. Should never
 403                                     // need one of those to be placed in this
 404                                     // type anyway.
 405 
 406 //  Utility functions to "portably" (?) bit twiddle pointers
 407 //  Where portable means keep ANSI C++ compilers quiet
 408 
 409 inline address       set_address_bits(address x, int m)       { return address(intptr_t(x) | m); }
 410 inline address       clear_address_bits(address x, int m)     { return address(intptr_t(x) & ~m); }
 411 
 412 //  Utility functions to "portably" make cast to/from function pointers.
 413 
 414 inline address_word  mask_address_bits(address x, int m)      { return address_word(x) & m; }
 415 inline address_word  castable_address(address x)              { return address_word(x) ; }
 416 inline address_word  castable_address(void* x)                { return address_word(x) ; }
 417 
 418 // Pointer subtraction.
 419 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
 420 // the range we might need to find differences from one end of the heap
 421 // to the other.
 422 // A typical use might be:
 423 //     if (pointer_delta(end(), top()) >= size) {
 424 //       // enough room for an object of size
 425 //       ...
 426 // and then additions like
 427 //       ... top() + size ...
 428 // are safe because we know that top() is at least size below end().
 429 inline size_t pointer_delta(const volatile void* left,
 430                             const volatile void* right,
 431                             size_t element_size) {
 432   assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
 433   return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
 434 }
 435 
 436 // A version specialized for HeapWord*'s.
 437 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
 438   return pointer_delta(left, right, sizeof(HeapWord));
 439 }
 440 // A version specialized for MetaWord*'s.
 441 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
 442   return pointer_delta(left, right, sizeof(MetaWord));
 443 }
 444 
 445 //
 446 // ANSI C++ does not allow casting from one pointer type to a function pointer
 447 // directly without at best a warning. This macro accomplishes it silently
 448 // In every case that is present at this point the value be cast is a pointer
 449 // to a C linkage function. In some case the type used for the cast reflects
 450 // that linkage and a picky compiler would not complain. In other cases because
 451 // there is no convenient place to place a typedef with extern C linkage (i.e
 452 // a platform dependent header file) it doesn't. At this point no compiler seems
 453 // picky enough to catch these instances (which are few). It is possible that
 454 // using templates could fix these for all cases. This use of templates is likely
 455 // so far from the middle of the road that it is likely to be problematic in
 456 // many C++ compilers.
 457 //
 458 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
 459 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((address_word)(func_ptr)))
 460 
 461 // In many places we've added C-style casts to silence compiler
 462 // warnings, for example when truncating a size_t to an int when we
 463 // know the size_t is a small struct. Such casts are risky because
 464 // they effectively disable useful compiler warnings. We can make our
 465 // lives safer with this function, which ensures that any cast is
 466 // reversible without loss of information. It doesn't check
 467 // everything: it isn't intended to make sure that pointer types are
 468 // compatible, for example.
 469 template <typename T2, typename T1>
 470 T2 checked_cast(T1 thing) {
 471   T2 result = static_cast<T2>(thing);
 472   assert(static_cast<T1>(result) == thing, "must be");
 473   return result;
 474 }
 475 
 476 // Need the correct linkage to call qsort without warnings
 477 extern "C" {
 478   typedef int (*_sort_Fn)(const void *, const void *);
 479 }
 480 
 481 // Unsigned byte types for os and stream.hpp
 482 
 483 // Unsigned one, two, four and eigth byte quantities used for describing
 484 // the .class file format. See JVM book chapter 4.
 485 
 486 typedef jubyte  u1;
 487 typedef jushort u2;
 488 typedef juint   u4;
 489 typedef julong  u8;
 490 
 491 const jubyte  max_jubyte  = (jubyte)-1;  // 0xFF       largest jubyte
 492 const jushort max_jushort = (jushort)-1; // 0xFFFF     largest jushort
 493 const juint   max_juint   = (juint)-1;   // 0xFFFFFFFF largest juint
 494 const julong  max_julong  = (julong)-1;  // 0xFF....FF largest julong
 495 
 496 typedef jbyte  s1;
 497 typedef jshort s2;
 498 typedef jint   s4;
 499 typedef jlong  s8;
 500 
 501 const jbyte min_jbyte = -(1 << 7);       // smallest jbyte
 502 const jbyte max_jbyte = (1 << 7) - 1;    // largest jbyte
 503 const jshort min_jshort = -(1 << 15);    // smallest jshort
 504 const jshort max_jshort = (1 << 15) - 1; // largest jshort
 505 
 506 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
 507 const jint max_jint = (juint)min_jint - 1;                     // 0x7FFFFFFF == largest jint
 508 
 509 const jint min_jintFloat = (jint)(0x00000001);
 510 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
 511 const jint max_jintFloat = (jint)(0x7f7fffff);
 512 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
 513 
 514 //----------------------------------------------------------------------------------------------------
 515 // JVM spec restrictions
 516 
 517 const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (p.134)
 518 
 519 //----------------------------------------------------------------------------------------------------
 520 // Object alignment, in units of HeapWords.
 521 //
 522 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
 523 // reference fields can be naturally aligned.
 524 
 525 extern int MinObjAlignment;
 526 extern int MinObjAlignmentInBytes;
 527 extern int MinObjAlignmentInBytesMask;
 528 
 529 extern int LogMinObjAlignment;
 530 extern int LogMinObjAlignmentInBytes;
 531 
 532 const int LogKlassAlignmentInBytes = 3;
 533 const int LogKlassAlignment        = LogKlassAlignmentInBytes - LogHeapWordSize;
 534 const int KlassAlignmentInBytes    = 1 << LogKlassAlignmentInBytes;
 535 const int KlassAlignment           = KlassAlignmentInBytes / HeapWordSize;
 536 
 537 // Maximal size of heap where unscaled compression can be used. Also upper bound
 538 // for heap placement: 4GB.
 539 const  uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
 540 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
 541 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
 542 extern uint64_t OopEncodingHeapMax;
 543 
 544 // Maximal size of compressed class space. Above this limit compression is not possible.
 545 // Also upper bound for placement of zero based class space. (Class space is further limited
 546 // to be < 3G, see arguments.cpp.)
 547 const  uint64_t KlassEncodingMetaspaceMax = (uint64_t(max_juint) + 1) << LogKlassAlignmentInBytes;
 548 
 549 // Machine dependent stuff
 550 
 551 // The maximum size of the code cache.  Can be overridden by targets.
 552 #define CODE_CACHE_SIZE_LIMIT (2*G)
 553 // Allow targets to reduce the default size of the code cache.
 554 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
 555 
 556 #include CPU_HEADER(globalDefinitions)
 557 
 558 // To assure the IRIW property on processors that are not multiple copy
 559 // atomic, sync instructions must be issued between volatile reads to
 560 // assure their ordering, instead of after volatile stores.
 561 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
 562 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
 563 #ifdef CPU_MULTI_COPY_ATOMIC
 564 // Not needed.
 565 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
 566 #else
 567 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
 568 // Final decision is subject to JEP 188: Java Memory Model Update.
 569 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
 570 #endif
 571 
 572 // The expected size in bytes of a cache line, used to pad data structures.
 573 #ifndef DEFAULT_CACHE_LINE_SIZE
 574   #define DEFAULT_CACHE_LINE_SIZE 64
 575 #endif
 576 
 577 
 578 //----------------------------------------------------------------------------------------------------
 579 // Utility macros for compilers
 580 // used to silence compiler warnings
 581 
 582 #define Unused_Variable(var) var
 583 
 584 
 585 //----------------------------------------------------------------------------------------------------
 586 // Miscellaneous
 587 
 588 // 6302670 Eliminate Hotspot __fabsf dependency
 589 // All fabs() callers should call this function instead, which will implicitly
 590 // convert the operand to double, avoiding a dependency on __fabsf which
 591 // doesn't exist in early versions of Solaris 8.
 592 inline double fabsd(double value) {
 593   return fabs(value);
 594 }
 595 
 596 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
 597 // is zero, return 0.0.
 598 template<typename T>
 599 inline double percent_of(T numerator, T denominator) {
 600   return denominator != 0 ? (double)numerator / denominator * 100.0 : 0.0;
 601 }
 602 
 603 //----------------------------------------------------------------------------------------------------
 604 // Special casts
 605 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
 606 typedef union {
 607   jfloat f;
 608   jint i;
 609 } FloatIntConv;
 610 
 611 typedef union {
 612   jdouble d;
 613   jlong l;
 614   julong ul;
 615 } DoubleLongConv;
 616 
 617 inline jint    jint_cast    (jfloat  x)  { return ((FloatIntConv*)&x)->i; }
 618 inline jfloat  jfloat_cast  (jint    x)  { return ((FloatIntConv*)&x)->f; }
 619 
 620 inline jlong   jlong_cast   (jdouble x)  { return ((DoubleLongConv*)&x)->l;  }
 621 inline julong  julong_cast  (jdouble x)  { return ((DoubleLongConv*)&x)->ul; }
 622 inline jdouble jdouble_cast (jlong   x)  { return ((DoubleLongConv*)&x)->d;  }
 623 
 624 inline jint low (jlong value)                    { return jint(value); }
 625 inline jint high(jlong value)                    { return jint(value >> 32); }
 626 
 627 // the fancy casts are a hopefully portable way
 628 // to do unsigned 32 to 64 bit type conversion
 629 inline void set_low (jlong* value, jint low )    { *value &= (jlong)0xffffffff << 32;
 630                                                    *value |= (jlong)(julong)(juint)low; }
 631 
 632 inline void set_high(jlong* value, jint high)    { *value &= (jlong)(julong)(juint)0xffffffff;
 633                                                    *value |= (jlong)high       << 32; }
 634 
 635 inline jlong jlong_from(jint h, jint l) {
 636   jlong result = 0; // initialization to avoid warning
 637   set_high(&result, h);
 638   set_low(&result,  l);
 639   return result;
 640 }
 641 
 642 union jlong_accessor {
 643   jint  words[2];
 644   jlong long_value;
 645 };
 646 
 647 void basic_types_init(); // cannot define here; uses assert
 648 
 649 
 650 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 651 enum BasicType {
 652 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
 653   T_BOOLEAN     = JVM_T_BOOLEAN,
 654   T_CHAR        = JVM_T_CHAR,
 655   T_FLOAT       = JVM_T_FLOAT,
 656   T_DOUBLE      = JVM_T_DOUBLE,
 657   T_BYTE        = JVM_T_BYTE,
 658   T_SHORT       = JVM_T_SHORT,
 659   T_INT         = JVM_T_INT,
 660   T_LONG        = JVM_T_LONG,
 661   // The remaining values are not part of any standard.
 662   // T_OBJECT and T_VOID denote two more semantic choices
 663   // for method return values.
 664   // T_OBJECT and T_ARRAY describe signature syntax.
 665   // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
 666   // internal references within the JVM as if they were Java
 667   // types in their own right.
 668   T_OBJECT      = 12,
 669   T_ARRAY       = 13,
 670   T_VOID        = 14,
 671   T_ADDRESS     = 15,
 672   T_NARROWOOP   = 16,
 673   T_METADATA    = 17,
 674   T_NARROWKLASS = 18,
 675   T_CONFLICT    = 19, // for stack value type with conflicting contents
 676   T_ILLEGAL     = 99
 677 };
 678 
 679 #define SIGNATURE_TYPES_DO(F, N)                \
 680     F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N)      \
 681     F(JVM_SIGNATURE_CHAR,    T_CHAR,    N)      \
 682     F(JVM_SIGNATURE_FLOAT,   T_FLOAT,   N)      \
 683     F(JVM_SIGNATURE_DOUBLE,  T_DOUBLE,  N)      \
 684     F(JVM_SIGNATURE_BYTE,    T_BYTE,    N)      \
 685     F(JVM_SIGNATURE_SHORT,   T_SHORT,   N)      \
 686     F(JVM_SIGNATURE_INT,     T_INT,     N)      \
 687     F(JVM_SIGNATURE_LONG,    T_LONG,    N)      \
 688     F(JVM_SIGNATURE_CLASS,   T_OBJECT,  N)      \
 689     F(JVM_SIGNATURE_ARRAY,   T_ARRAY,   N)      \
 690     F(JVM_SIGNATURE_VOID,    T_VOID,    N)      \
 691     /*end*/
 692 
 693 inline bool is_java_type(BasicType t) {
 694   return T_BOOLEAN <= t && t <= T_VOID;
 695 }
 696 
 697 inline bool is_java_primitive(BasicType t) {
 698   return T_BOOLEAN <= t && t <= T_LONG;
 699 }
 700 
 701 inline bool is_subword_type(BasicType t) {
 702   // these guys are processed exactly like T_INT in calling sequences:
 703   return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
 704 }
 705 
 706 inline bool is_signed_subword_type(BasicType t) {
 707   return (t == T_BYTE || t == T_SHORT);
 708 }
 709 
 710 inline bool is_double_word_type(BasicType t) {
 711   return (t == T_DOUBLE || t == T_LONG);
 712 }
 713 
 714 inline bool is_reference_type(BasicType t) {
 715   return (t == T_OBJECT || t == T_ARRAY);
 716 }
 717 
 718 inline bool is_integral_type(BasicType t) {
 719   return is_subword_type(t) || t == T_INT || t == T_LONG;
 720 }
 721 
 722 inline bool is_floating_point_type(BasicType t) {
 723   return (t == T_FLOAT || t == T_DOUBLE);
 724 }
 725 
 726 extern char type2char_tab[T_CONFLICT+1];     // Map a BasicType to a jchar
 727 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
 728 extern int type2size[T_CONFLICT+1];         // Map BasicType to result stack elements
 729 extern const char* type2name_tab[T_CONFLICT+1];     // Map a BasicType to a char*
 730 extern BasicType name2type(const char* name);
 731 
 732 const char* type2name(BasicType t);
 733 
 734 inline jlong max_signed_integer(BasicType bt) {
 735   if (bt == T_INT) {
 736     return max_jint;
 737   }
 738   assert(bt == T_LONG, "unsupported");
 739   return max_jlong;
 740 }
 741 
 742 inline jlong min_signed_integer(BasicType bt) {
 743   if (bt == T_INT) {
 744     return min_jint;
 745   }
 746   assert(bt == T_LONG, "unsupported");
 747   return min_jlong;
 748 }
 749 
 750 // Auxiliary math routines
 751 // least common multiple
 752 extern size_t lcm(size_t a, size_t b);
 753 
 754 
 755 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 756 enum BasicTypeSize {
 757   T_BOOLEAN_size     = 1,
 758   T_CHAR_size        = 1,
 759   T_FLOAT_size       = 1,
 760   T_DOUBLE_size      = 2,
 761   T_BYTE_size        = 1,
 762   T_SHORT_size       = 1,
 763   T_INT_size         = 1,
 764   T_LONG_size        = 2,
 765   T_OBJECT_size      = 1,
 766   T_ARRAY_size       = 1,
 767   T_NARROWOOP_size   = 1,
 768   T_NARROWKLASS_size = 1,
 769   T_VOID_size        = 0
 770 };
 771 
 772 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
 773 inline int parameter_type_word_count(BasicType t) {
 774   if (is_double_word_type(t))  return 2;
 775   assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
 776   assert(type2size[t] == 1, "must be");
 777   return 1;
 778 }
 779 
 780 // maps a BasicType to its instance field storage type:
 781 // all sub-word integral types are widened to T_INT
 782 extern BasicType type2field[T_CONFLICT+1];
 783 extern BasicType type2wfield[T_CONFLICT+1];
 784 
 785 
 786 // size in bytes
 787 enum ArrayElementSize {
 788   T_BOOLEAN_aelem_bytes     = 1,
 789   T_CHAR_aelem_bytes        = 2,
 790   T_FLOAT_aelem_bytes       = 4,
 791   T_DOUBLE_aelem_bytes      = 8,
 792   T_BYTE_aelem_bytes        = 1,
 793   T_SHORT_aelem_bytes       = 2,
 794   T_INT_aelem_bytes         = 4,
 795   T_LONG_aelem_bytes        = 8,
 796 #ifdef _LP64
 797   T_OBJECT_aelem_bytes      = 8,
 798   T_ARRAY_aelem_bytes       = 8,
 799 #else
 800   T_OBJECT_aelem_bytes      = 4,
 801   T_ARRAY_aelem_bytes       = 4,
 802 #endif
 803   T_NARROWOOP_aelem_bytes   = 4,
 804   T_NARROWKLASS_aelem_bytes = 4,
 805   T_VOID_aelem_bytes        = 0
 806 };
 807 
 808 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
 809 #ifdef ASSERT
 810 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
 811 #else
 812 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
 813 #endif
 814 
 815 
 816 // JavaValue serves as a container for arbitrary Java values.
 817 
 818 class JavaValue {
 819 
 820  public:
 821   typedef union JavaCallValue {
 822     jfloat   f;
 823     jdouble  d;
 824     jint     i;
 825     jlong    l;
 826     jobject  h;
 827     oopDesc* o;
 828   } JavaCallValue;
 829 
 830  private:
 831   BasicType _type;
 832   JavaCallValue _value;
 833 
 834  public:
 835   JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
 836 
 837   JavaValue(jfloat value) {
 838     _type    = T_FLOAT;
 839     _value.f = value;
 840   }
 841 
 842   JavaValue(jdouble value) {
 843     _type    = T_DOUBLE;
 844     _value.d = value;
 845   }
 846 
 847  jfloat get_jfloat() const { return _value.f; }
 848  jdouble get_jdouble() const { return _value.d; }
 849  jint get_jint() const { return _value.i; }
 850  jlong get_jlong() const { return _value.l; }
 851  jobject get_jobject() const { return _value.h; }
 852  oopDesc* get_oop() const { return _value.o; }
 853  JavaCallValue* get_value_addr() { return &_value; }
 854  BasicType get_type() const { return _type; }
 855 
 856  void set_jfloat(jfloat f) { _value.f = f;}
 857  void set_jdouble(jdouble d) { _value.d = d;}
 858  void set_jint(jint i) { _value.i = i;}
 859  void set_jlong(jlong l) { _value.l = l;}
 860  void set_jobject(jobject h) { _value.h = h;}
 861  void set_oop(oopDesc* o) { _value.o = o;}
 862  void set_type(BasicType t) { _type = t; }
 863 
 864  jboolean get_jboolean() const { return (jboolean) (_value.i);}
 865  jbyte get_jbyte() const { return (jbyte) (_value.i);}
 866  jchar get_jchar() const { return (jchar) (_value.i);}
 867  jshort get_jshort() const { return (jshort) (_value.i);}
 868 
 869 };
 870 
 871 
 872 // TosState describes the top-of-stack state before and after the execution of
 873 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
 874 // registers. The TosState corresponds to the 'machine representation' of this cached
 875 // value. There's 4 states corresponding to the JAVA types int, long, float & double
 876 // as well as a 5th state in case the top-of-stack value is actually on the top
 877 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
 878 // state when it comes to machine representation but is used separately for (oop)
 879 // type specific operations (e.g. verification code).
 880 
 881 enum TosState {         // describes the tos cache contents
 882   btos = 0,             // byte, bool tos cached
 883   ztos = 1,             // byte, bool tos cached
 884   ctos = 2,             // char tos cached
 885   stos = 3,             // short tos cached
 886   itos = 4,             // int tos cached
 887   ltos = 5,             // long tos cached
 888   ftos = 6,             // float tos cached
 889   dtos = 7,             // double tos cached
 890   atos = 8,             // object cached
 891   vtos = 9,             // tos not cached
 892   number_of_states,
 893   ilgl                  // illegal state: should not occur
 894 };
 895 
 896 
 897 inline TosState as_TosState(BasicType type) {
 898   switch (type) {
 899     case T_BYTE   : return btos;
 900     case T_BOOLEAN: return ztos;
 901     case T_CHAR   : return ctos;
 902     case T_SHORT  : return stos;
 903     case T_INT    : return itos;
 904     case T_LONG   : return ltos;
 905     case T_FLOAT  : return ftos;
 906     case T_DOUBLE : return dtos;
 907     case T_VOID   : return vtos;
 908     case T_ARRAY  : // fall through
 909     case T_OBJECT : return atos;
 910     default       : return ilgl;
 911   }
 912 }
 913 
 914 inline BasicType as_BasicType(TosState state) {
 915   switch (state) {
 916     case btos : return T_BYTE;
 917     case ztos : return T_BOOLEAN;
 918     case ctos : return T_CHAR;
 919     case stos : return T_SHORT;
 920     case itos : return T_INT;
 921     case ltos : return T_LONG;
 922     case ftos : return T_FLOAT;
 923     case dtos : return T_DOUBLE;
 924     case atos : return T_OBJECT;
 925     case vtos : return T_VOID;
 926     default   : return T_ILLEGAL;
 927   }
 928 }
 929 
 930 
 931 // Helper function to convert BasicType info into TosState
 932 // Note: Cannot define here as it uses global constant at the time being.
 933 TosState as_TosState(BasicType type);
 934 
 935 
 936 // JavaThreadState keeps track of which part of the code a thread is executing in. This
 937 // information is needed by the safepoint code.
 938 //
 939 // There are 4 essential states:
 940 //
 941 //  _thread_new         : Just started, but not executed init. code yet (most likely still in OS init code)
 942 //  _thread_in_native   : In native code. This is a safepoint region, since all oops will be in jobject handles
 943 //  _thread_in_vm       : Executing in the vm
 944 //  _thread_in_Java     : Executing either interpreted or compiled Java code (or could be in a stub)
 945 //
 946 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
 947 // a transition from one state to another. These extra states makes it possible for the safepoint code to
 948 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
 949 //
 950 // Given a state, the xxxx_trans state can always be found by adding 1.
 951 //
 952 enum JavaThreadState {
 953   _thread_uninitialized     =  0, // should never happen (missing initialization)
 954   _thread_new               =  2, // just starting up, i.e., in process of being initialized
 955   _thread_new_trans         =  3, // corresponding transition state (not used, included for completness)
 956   _thread_in_native         =  4, // running in native code
 957   _thread_in_native_trans   =  5, // corresponding transition state
 958   _thread_in_vm             =  6, // running in VM
 959   _thread_in_vm_trans       =  7, // corresponding transition state
 960   _thread_in_Java           =  8, // running in Java or in stub code
 961   _thread_in_Java_trans     =  9, // corresponding transition state (not used, included for completness)
 962   _thread_blocked           = 10, // blocked in vm
 963   _thread_blocked_trans     = 11, // corresponding transition state
 964   _thread_max_state         = 12  // maximum thread state+1 - used for statistics allocation
 965 };
 966 
 967 enum LockingMode {
 968   // Use only heavy monitors for locking
 969   LM_MONITOR     = 0,
 970   // Legacy stack-locking, with monitors as 2nd tier
 971   LM_LEGACY      = 1,
 972   // New lightweight locking, with monitors as 2nd tier
 973   LM_LIGHTWEIGHT = 2
 974 };
 975 
 976 //----------------------------------------------------------------------------------------------------
 977 // Special constants for debugging
 978 
 979 const jint     badInt           = -3;                       // generic "bad int" value
 980 const intptr_t badAddressVal    = -2;                       // generic "bad address" value
 981 const intptr_t badOopVal        = -1;                       // generic "bad oop" value
 982 const intptr_t badHeapOopVal    = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
 983 const int      badStackSegVal   = 0xCA;                     // value used to zap stack segments
 984 const int      badHandleValue   = 0xBC;                     // value used to zap vm handle area
 985 const int      badResourceValue = 0xAB;                     // value used to zap resource area
 986 const int      freeBlockPad     = 0xBA;                     // value used to pad freed blocks.
 987 const int      uninitBlockPad   = 0xF1;                     // value used to zap newly malloc'd blocks.
 988 const juint    uninitMetaWordVal= 0xf7f7f7f7;               // value used to zap newly allocated metachunk
 989 const juint    badHeapWordVal   = 0xBAADBABE;               // value used to zap heap after GC
 990 const juint    badMetaWordVal   = 0xBAADFADE;               // value used to zap metadata heap after GC
 991 const int      badCodeHeapNewVal= 0xCC;                     // value used to zap Code heap at allocation
 992 const int      badCodeHeapFreeVal = 0xDD;                   // value used to zap Code heap at deallocation
 993 
 994 
 995 // (These must be implemented as #defines because C++ compilers are
 996 // not obligated to inline non-integral constants!)
 997 #define       badAddress        ((address)::badAddressVal)
 998 #define       badOop            (cast_to_oop(::badOopVal))
 999 #define       badHeapWord       (::badHeapWordVal)
1000 
1001 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1002 #define TASKQUEUE_SIZE (NOT_LP64(1<<14) LP64_ONLY(1<<17))
1003 
1004 //----------------------------------------------------------------------------------------------------
1005 // Utility functions for bitfield manipulations
1006 
1007 const intptr_t AllBits    = ~0; // all bits set in a word
1008 const intptr_t NoBits     =  0; // no bits set in a word
1009 const jlong    NoLongBits =  0; // no bits set in a long
1010 const intptr_t OneBit     =  1; // only right_most bit set in a word
1011 
1012 // get a word with the n.th or the right-most or left-most n bits set
1013 // (note: #define used only so that they can be used in enum constant definitions)
1014 #define nth_bit(n)        (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1015 #define right_n_bits(n)   (nth_bit(n) - 1)
1016 
1017 // bit-operations using a mask m
1018 inline void   set_bits    (intptr_t& x, intptr_t m) { x |= m; }
1019 inline void clear_bits    (intptr_t& x, intptr_t m) { x &= ~m; }
1020 inline intptr_t mask_bits      (intptr_t  x, intptr_t m) { return x & m; }
1021 inline jlong    mask_long_bits (jlong     x, jlong    m) { return x & m; }
1022 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1023 
1024 // bit-operations using the n.th bit
1025 inline void    set_nth_bit(intptr_t& x, int n) { set_bits  (x, nth_bit(n)); }
1026 inline void  clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1027 inline bool is_set_nth_bit(intptr_t  x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1028 
1029 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1030 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1031   return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1032 }
1033 
1034 
1035 //----------------------------------------------------------------------------------------------------
1036 // Utility functions for integers
1037 
1038 // Avoid use of global min/max macros which may cause unwanted double
1039 // evaluation of arguments.
1040 #ifdef max
1041 #undef max
1042 #endif
1043 
1044 #ifdef min
1045 #undef min
1046 #endif
1047 
1048 // It is necessary to use templates here. Having normal overloaded
1049 // functions does not work because it is necessary to provide both 32-
1050 // and 64-bit overloaded functions, which does not work, and having
1051 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1052 // will be even more error-prone than macros.
1053 template<class T> constexpr T MAX2(T a, T b)           { return (a > b) ? a : b; }
1054 template<class T> constexpr T MIN2(T a, T b)           { return (a < b) ? a : b; }
1055 template<class T> constexpr T MAX3(T a, T b, T c)      { return MAX2(MAX2(a, b), c); }
1056 template<class T> constexpr T MIN3(T a, T b, T c)      { return MIN2(MIN2(a, b), c); }
1057 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1058 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1059 
1060 template<class T> inline T ABS(T x)                 { return (x > 0) ? x : -x; }
1061 
1062 // Return the given value clamped to the range [min ... max]
1063 template<typename T>
1064 inline T clamp(T value, T min, T max) {
1065   assert(min <= max, "must be");
1066   return MIN2(MAX2(value, min), max);
1067 }
1068 
1069 inline bool is_odd (intx x) { return x & 1;      }
1070 inline bool is_even(intx x) { return !is_odd(x); }
1071 
1072 // abs methods which cannot overflow and so are well-defined across
1073 // the entire domain of integer types.
1074 static inline unsigned int uabs(unsigned int n) {
1075   union {
1076     unsigned int result;
1077     int value;
1078   };
1079   result = n;
1080   if (value < 0) result = 0-result;
1081   return result;
1082 }
1083 static inline julong uabs(julong n) {
1084   union {
1085     julong result;
1086     jlong value;
1087   };
1088   result = n;
1089   if (value < 0) result = 0-result;
1090   return result;
1091 }
1092 static inline julong uabs(jlong n) { return uabs((julong)n); }
1093 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1094 
1095 // "to" should be greater than "from."
1096 inline intx byte_size(void* from, void* to) {
1097   return (address)to - (address)from;
1098 }
1099 
1100 
1101 // Pack and extract shorts to/from ints:
1102 
1103 inline int extract_low_short_from_int(jint x) {
1104   return x & 0xffff;
1105 }
1106 
1107 inline int extract_high_short_from_int(jint x) {
1108   return (x >> 16) & 0xffff;
1109 }
1110 
1111 inline int build_int_from_shorts( jushort low, jushort high ) {
1112   return ((int)((unsigned int)high << 16) | (unsigned int)low);
1113 }
1114 
1115 // swap a & b
1116 template<class T> static void swap(T& a, T& b) {
1117   T tmp = a;
1118   a = b;
1119   b = tmp;
1120 }
1121 
1122 // array_size_impl is a function that takes a reference to T[N] and
1123 // returns a reference to char[N].  It is not ODR-used, so not defined.
1124 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1125 
1126 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1127 
1128 //----------------------------------------------------------------------------------------------------
1129 // Sum and product which can never overflow: they wrap, just like the
1130 // Java operations.  Note that we don't intend these to be used for
1131 // general-purpose arithmetic: their purpose is to emulate Java
1132 // operations.
1133 
1134 // The goal of this code to avoid undefined or implementation-defined
1135 // behavior.  The use of an lvalue to reference cast is explicitly
1136 // permitted by Lvalues and rvalues [basic.lval].  [Section 3.10 Para
1137 // 15 in C++03]
1138 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE)  \
1139 inline TYPE NAME (TYPE in1, TYPE in2) {                 \
1140   UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1141   ures OP ## = static_cast<UNSIGNED_TYPE>(in2);         \
1142   return reinterpret_cast<TYPE&>(ures);                 \
1143 }
1144 
1145 JAVA_INTEGER_OP(+, java_add, jint, juint)
1146 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1147 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1148 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1149 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1150 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1151 
1152 #undef JAVA_INTEGER_OP
1153 
1154 // Provide integer shift operations with Java semantics.  No overflow
1155 // issues - left shifts simply discard shifted out bits.  No undefined
1156 // behavior for large or negative shift quantities; instead the actual
1157 // shift distance is the argument modulo the lhs value's size in bits.
1158 // No undefined or implementation defined behavior for shifting negative
1159 // values; left shift discards bits, right shift sign extends.  We use
1160 // the same safe conversion technique as above for java_add and friends.
1161 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE)    \
1162 inline TYPE NAME (TYPE lhs, jint rhs) {                 \
1163   const uint rhs_mask = (sizeof(TYPE) * 8) - 1;         \
1164   STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63);      \
1165   XTYPE xres = static_cast<XTYPE>(lhs);                 \
1166   xres OP ## = (rhs & rhs_mask);                        \
1167   return reinterpret_cast<TYPE&>(xres);                 \
1168 }
1169 
1170 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1171 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1172 // For signed shift right, assume C++ implementation >> sign extends.
1173 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1174 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1175 // For >>> use C++ unsigned >>.
1176 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1177 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1178 
1179 #undef JAVA_INTEGER_SHIFT_OP
1180 
1181 //----------------------------------------------------------------------------------------------------
1182 // The goal of this code is to provide saturating operations for int/uint.
1183 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1184 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1185 inline int NAME (TYPE1 in1, TYPE2 in2) {             \
1186   jlong res = static_cast<jlong>(in1);               \
1187   res OP ## = static_cast<jlong>(in2);               \
1188   if (res > max_jint) {                              \
1189     res = max_jint;                                  \
1190   } else if (res < min_jint) {                       \
1191     res = min_jint;                                  \
1192   }                                                  \
1193   return static_cast<int>(res);                      \
1194 }
1195 
1196 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1197 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1198 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1199 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1200 
1201 #undef SATURATED_INTEGER_OP
1202 
1203 // Dereference vptr
1204 // All C++ compilers that we know of have the vtbl pointer in the first
1205 // word.  If there are exceptions, this function needs to be made compiler
1206 // specific.
1207 static inline void* dereference_vptr(const void* addr) {
1208   return *(void**)addr;
1209 }
1210 
1211 //----------------------------------------------------------------------------------------------------
1212 // String type aliases used by command line flag declarations and
1213 // processing utilities.
1214 
1215 typedef const char* ccstr;
1216 typedef const char* ccstrlist;   // represents string arguments which accumulate
1217 
1218 //----------------------------------------------------------------------------------------------------
1219 // Default hash/equals functions used by ResourceHashtable and KVHashtable
1220 
1221 template<typename K> unsigned primitive_hash(const K& k) {
1222   unsigned hash = (unsigned)((uintptr_t)k);
1223   return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1224 }
1225 
1226 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1227   return k0 == k1;
1228 }
1229 
1230 
1231 // Converts any type T to a reference type.
1232 template<typename T>
1233 std::add_rvalue_reference_t<T> declval() noexcept;
1234 
1235 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP