1 /*
   2  * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
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  24 
  25 #ifndef SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
  26 #define SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
  27 
  28 #include "utilities/compilerWarnings.hpp"
  29 #include "utilities/debug.hpp"
  30 #include "utilities/macros.hpp"
  31 
  32 // Get constants like JVM_T_CHAR and JVM_SIGNATURE_INT, before pulling in <jvm.h>.
  33 #include "classfile_constants.h"
  34 
  35 #include COMPILER_HEADER(utilities/globalDefinitions)
  36 
  37 #include <cstddef>
  38 #include <cstdint>
  39 #include <limits>
  40 #include <type_traits>
  41 
  42 class oopDesc;
  43 
  44 // Defaults for macros that might be defined per compiler.
  45 #ifndef NOINLINE
  46 #define NOINLINE
  47 #endif
  48 #ifndef ALWAYSINLINE
  49 #define ALWAYSINLINE inline
  50 #endif
  51 
  52 #ifndef ATTRIBUTE_ALIGNED
  53 #define ATTRIBUTE_ALIGNED(x) alignas(x)
  54 #endif
  55 
  56 #ifndef ATTRIBUTE_FLATTEN
  57 #define ATTRIBUTE_FLATTEN
  58 #endif
  59 
  60 // These are #defines to selectively turn on/off the Print(Opto)Assembly
  61 // capabilities. Choices should be led by a tradeoff between
  62 // code size and improved supportability.
  63 // if PRINT_ASSEMBLY then PRINT_ABSTRACT_ASSEMBLY must be true as well
  64 // to have a fallback in case hsdis is not available.
  65 #if defined(PRODUCT)
  66   #define SUPPORT_ABSTRACT_ASSEMBLY
  67   #define SUPPORT_ASSEMBLY
  68   #undef  SUPPORT_OPTO_ASSEMBLY      // Can't activate. In PRODUCT, many dump methods are missing.
  69   #undef  SUPPORT_DATA_STRUCTS       // Of limited use. In PRODUCT, many print methods are empty.
  70 #else
  71   #define SUPPORT_ABSTRACT_ASSEMBLY
  72   #define SUPPORT_ASSEMBLY
  73   #define SUPPORT_OPTO_ASSEMBLY
  74   #define SUPPORT_DATA_STRUCTS
  75 #endif
  76 #if defined(SUPPORT_ASSEMBLY) && !defined(SUPPORT_ABSTRACT_ASSEMBLY)
  77   #define SUPPORT_ABSTRACT_ASSEMBLY
  78 #endif
  79 
  80 // This file holds all globally used constants & types, class (forward)
  81 // declarations and a few frequently used utility functions.
  82 
  83 // Declare the named class to be noncopyable.  This macro must be followed by
  84 // a semi-colon.  The macro provides deleted declarations for the class's copy
  85 // constructor and assignment operator.  Because these operations are deleted,
  86 // they cannot be defined and potential callers will fail to compile.
  87 #define NONCOPYABLE(C) C(C const&) = delete; C& operator=(C const&) = delete /* next token must be ; */
  88 
  89 
  90 //----------------------------------------------------------------------------------------------------
  91 // Printf-style formatters for fixed- and variable-width types as pointers and
  92 // integers.  These are derived from the definitions in inttypes.h.  If the platform
  93 // doesn't provide appropriate definitions, they should be provided in
  94 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
  95 
  96 // Guide to the suffixes used in the format specifiers for integers:
  97 //        - print the decimal value:                   745565
  98 //  _X    - print as hexadecimal, without leading 0s: 0x12345
  99 //  _X_0  - print as hexadecimal, with leading 0s: 0x00012345
 100 //  _W(w) - prints w sized string with the given value right
 101 //          adjusted. Use -w to print left adjusted.
 102 //  _0    - print as hexadecimal, with leading 0s, without 0x prefix: 0012345
 103 //
 104 // Note that the PTR format specifiers print using 0x with leading zeros,
 105 // just like the _X_0 version for integers.
 106 
 107 // Format 8-bit quantities.
 108 #define INT8_FORMAT_X_0          "0x%02"      PRIx8
 109 #define UINT8_FORMAT_X_0         "0x%02"      PRIx8
 110 
 111 // Format 16-bit quantities.
 112 #define INT16_FORMAT_X_0         "0x%04"      PRIx16
 113 #define UINT16_FORMAT_X_0        "0x%04"      PRIx16
 114 
 115 // Format 32-bit quantities.
 116 #define INT32_FORMAT             "%"          PRId32
 117 #define INT32_FORMAT_X           "0x%"        PRIx32
 118 #define INT32_FORMAT_X_0         "0x%08"      PRIx32
 119 #define INT32_FORMAT_W(width)    "%"   #width PRId32
 120 #define UINT32_FORMAT            "%"          PRIu32
 121 #define UINT32_FORMAT_X          "0x%"        PRIx32
 122 #define UINT32_FORMAT_X_0        "0x%08"      PRIx32
 123 #define UINT32_FORMAT_W(width)   "%"   #width PRIu32
 124 
 125 // Format 64-bit quantities.
 126 #define INT64_FORMAT             "%"          PRId64
 127 #define INT64_PLUS_FORMAT        "%+"         PRId64
 128 #define INT64_FORMAT_X           "0x%"        PRIx64
 129 #define INT64_FORMAT_X_0         "0x%016"     PRIx64
 130 #define INT64_FORMAT_W(width)    "%"   #width PRId64
 131 #define UINT64_FORMAT            "%"          PRIu64
 132 #define UINT64_FORMAT_X          "0x%"        PRIx64
 133 #define UINT64_FORMAT_X_0        "0x%016"     PRIx64
 134 #define UINT64_FORMAT_W(width)   "%"   #width PRIu64
 135 #define UINT64_FORMAT_0          "%016"       PRIx64
 136 
 137 // Format jlong, if necessary
 138 #ifndef JLONG_FORMAT
 139 #define JLONG_FORMAT             INT64_FORMAT
 140 #endif
 141 #ifndef JLONG_FORMAT_W
 142 #define JLONG_FORMAT_W(width)    INT64_FORMAT_W(width)
 143 #endif
 144 #ifndef JULONG_FORMAT
 145 #define JULONG_FORMAT            UINT64_FORMAT
 146 #endif
 147 #ifndef JULONG_FORMAT_X
 148 #define JULONG_FORMAT_X          UINT64_FORMAT_X
 149 #endif
 150 
 151 // Format pointers and padded integral values which change size between 32- and 64-bit.
 152 #ifdef  _LP64
 153 #define INTPTR_FORMAT            "0x%016"     PRIxPTR
 154 #define PTR_FORMAT               "0x%016"     PRIxPTR
 155 #define UINTX_FORMAT_X_0         "0x%016"     PRIxPTR
 156 #define SIZE_FORMAT_X_0          "0x%016"     PRIxPTR
 157 #else   // !_LP64
 158 #define INTPTR_FORMAT            "0x%08"      PRIxPTR
 159 #define PTR_FORMAT               "0x%08"      PRIxPTR
 160 #define UINTX_FORMAT_X_0         "0x%08"      PRIxPTR
 161 #define SIZE_FORMAT_X_0          "0x%08"      PRIxPTR
 162 #endif  // _LP64
 163 
 164 // Convert pointer to intptr_t, for use in printing pointers.
 165 inline intptr_t p2i(const volatile void* p) {
 166   return (intptr_t) p;
 167 }
 168 
 169 // Convert pointer to uintptr_t
 170 inline uintptr_t p2u(const volatile void* p) {
 171   return (uintptr_t) p;
 172 }
 173 
 174 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
 175 
 176 //----------------------------------------------------------------------------------------------------
 177 // Forbid the use of various C library functions.
 178 // Some of these have os:: replacements that should normally be used instead.
 179 // Others are considered security concerns, with preferred alternatives.
 180 
 181 FORBID_C_FUNCTION(void exit(int), "use os::exit");
 182 FORBID_C_FUNCTION(void _exit(int), "use os::exit");
 183 FORBID_C_FUNCTION(char* strerror(int), "use os::strerror");
 184 FORBID_C_FUNCTION(char* strtok(char*, const char*), "use strtok_r");
 185 FORBID_C_FUNCTION(int sprintf(char*, const char*, ...), "use os::snprintf");
 186 FORBID_C_FUNCTION(int vsprintf(char*, const char*, va_list), "use os::vsnprintf");
 187 FORBID_C_FUNCTION(int vsnprintf(char*, size_t, const char*, va_list), "use os::vsnprintf");
 188 
 189 // All of the following functions return raw C-heap pointers (sometimes as an option, e.g. realpath or getwd)
 190 // or, in case of free(), take raw C-heap pointers. Don't use them unless you are really sure you must.
 191 FORBID_C_FUNCTION(void* malloc(size_t size), "use os::malloc");
 192 FORBID_C_FUNCTION(void* calloc(size_t nmemb, size_t size), "use os::malloc and zero out manually");
 193 FORBID_C_FUNCTION(void free(void *ptr), "use os::free");
 194 FORBID_C_FUNCTION(void* realloc(void *ptr, size_t size), "use os::realloc");
 195 FORBID_C_FUNCTION(char* strdup(const char *s), "use os::strdup");
 196 FORBID_C_FUNCTION(char* strndup(const char *s, size_t n), "don't use");
 197 FORBID_C_FUNCTION(int posix_memalign(void **memptr, size_t alignment, size_t size), "don't use");
 198 FORBID_C_FUNCTION(void* aligned_alloc(size_t alignment, size_t size), "don't use");
 199 FORBID_C_FUNCTION(char* realpath(const char* path, char* resolved_path), "use os::realpath");
 200 FORBID_C_FUNCTION(char* get_current_dir_name(void), "use os::get_current_directory()");
 201 FORBID_C_FUNCTION(char* getwd(char *buf), "use os::get_current_directory()");
 202 FORBID_C_FUNCTION(wchar_t* wcsdup(const wchar_t *s), "don't use");
 203 FORBID_C_FUNCTION(void* reallocf(void *ptr, size_t size), "don't use");
 204 
 205 //----------------------------------------------------------------------------------------------------
 206 // Constants
 207 
 208 const int LogBytesPerShort   = 1;
 209 const int LogBytesPerInt     = 2;
 210 #ifdef _LP64
 211 constexpr int LogBytesPerWord    = 3;
 212 #else
 213 constexpr int LogBytesPerWord    = 2;
 214 #endif
 215 const int LogBytesPerLong    = 3;
 216 
 217 const int BytesPerShort      = 1 << LogBytesPerShort;
 218 const int BytesPerInt        = 1 << LogBytesPerInt;
 219 const int BytesPerWord       = 1 << LogBytesPerWord;
 220 const int BytesPerLong       = 1 << LogBytesPerLong;
 221 
 222 constexpr int LogBitsPerByte     = 3;
 223 const int LogBitsPerShort    = LogBitsPerByte + LogBytesPerShort;
 224 const int LogBitsPerInt      = LogBitsPerByte + LogBytesPerInt;
 225 constexpr int LogBitsPerWord     = LogBitsPerByte + LogBytesPerWord;
 226 const int LogBitsPerLong     = LogBitsPerByte + LogBytesPerLong;
 227 
 228 const int BitsPerByte        = 1 << LogBitsPerByte;
 229 const int BitsPerShort       = 1 << LogBitsPerShort;
 230 const int BitsPerInt         = 1 << LogBitsPerInt;
 231 constexpr int BitsPerWord        = 1 << LogBitsPerWord;
 232 const int BitsPerLong        = 1 << LogBitsPerLong;
 233 
 234 const int WordAlignmentMask  = (1 << LogBytesPerWord) - 1;
 235 const int LongAlignmentMask  = (1 << LogBytesPerLong) - 1;
 236 
 237 const int oopSize            = sizeof(char*); // Full-width oop
 238 extern int heapOopSize;                       // Oop within a java object
 239 const int wordSize           = sizeof(char*);
 240 const int longSize           = sizeof(jlong);
 241 const int jintSize           = sizeof(jint);
 242 const int size_tSize         = sizeof(size_t);
 243 
 244 const int BytesPerOop        = BytesPerWord;  // Full-width oop
 245 
 246 extern int LogBytesPerHeapOop;                // Oop within a java object
 247 extern int LogBitsPerHeapOop;
 248 extern int BytesPerHeapOop;
 249 extern int BitsPerHeapOop;
 250 
 251 const int BitsPerJavaInteger = 32;
 252 const int BitsPerJavaLong    = 64;
 253 const int BitsPerSize_t      = size_tSize * BitsPerByte;
 254 
 255 // Size of a char[] needed to represent a jint as a string in decimal.
 256 const int jintAsStringSize = 12;
 257 
 258 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
 259 // We require that object sizes be measured in units of heap words (e.g.
 260 // pointer-sized values), so that given HeapWord* hw,
 261 //   hw += oop(hw)->foo();
 262 // works, where foo is a method (like size or scavenge) that returns the
 263 // object size.
 264 class HeapWordImpl;             // Opaque, never defined.
 265 typedef HeapWordImpl* HeapWord;
 266 
 267 // Analogous opaque struct for metadata allocated from metaspaces.
 268 class MetaWordImpl;             // Opaque, never defined.
 269 typedef MetaWordImpl* MetaWord;
 270 
 271 // HeapWordSize must be 2^LogHeapWordSize.
 272 const int HeapWordSize        = sizeof(HeapWord);
 273 #ifdef _LP64
 274 const int LogHeapWordSize     = 3;
 275 #else
 276 const int LogHeapWordSize     = 2;
 277 #endif
 278 const int HeapWordsPerLong    = BytesPerLong / HeapWordSize;
 279 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
 280 
 281 // The minimum number of native machine words necessary to contain "byte_size"
 282 // bytes.
 283 inline size_t heap_word_size(size_t byte_size) {
 284   return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
 285 }
 286 
 287 inline jfloat jfloat_cast(jint x);
 288 inline jdouble jdouble_cast(jlong x);
 289 
 290 //-------------------------------------------
 291 // Constant for jlong (standardized by C++11)
 292 
 293 // Build a 64bit integer constant
 294 #define CONST64(x)  (x ## LL)
 295 #define UCONST64(x) (x ## ULL)
 296 
 297 const jlong min_jlong = CONST64(0x8000000000000000);
 298 const jlong max_jlong = CONST64(0x7fffffffffffffff);
 299 
 300 //-------------------------------------------
 301 // Constant for jdouble
 302 const jlong min_jlongDouble = CONST64(0x0000000000000001);
 303 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
 304 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
 305 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
 306 
 307 const size_t K                  = 1024;
 308 const size_t M                  = K*K;
 309 const size_t G                  = M*K;
 310 const size_t HWperKB            = K / sizeof(HeapWord);
 311 
 312 // Constants for converting from a base unit to milli-base units.  For
 313 // example from seconds to milliseconds and microseconds
 314 
 315 const int MILLIUNITS    = 1000;         // milli units per base unit
 316 const int MICROUNITS    = 1000000;      // micro units per base unit
 317 const int NANOUNITS     = 1000000000;   // nano units per base unit
 318 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
 319 
 320 const jlong NANOSECS_PER_SEC      = CONST64(1000000000);
 321 const jint  NANOSECS_PER_MILLISEC = 1000000;
 322 
 323 
 324 // Unit conversion functions
 325 // The caller is responsible for considering overflow.
 326 
 327 inline int64_t nanos_to_millis(int64_t nanos) {
 328   return nanos / NANOUNITS_PER_MILLIUNIT;
 329 }
 330 inline int64_t millis_to_nanos(int64_t millis) {
 331   return millis * NANOUNITS_PER_MILLIUNIT;
 332 }
 333 
 334 // Proper units routines try to maintain at least three significant digits.
 335 // In worst case, it would print five significant digits with lower prefix.
 336 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
 337 // and therefore we need to be careful.
 338 
 339 inline const char* proper_unit_for_byte_size(size_t s) {
 340 #ifdef _LP64
 341   if (s >= 100*G) {
 342     return "G";
 343   }
 344 #endif
 345   if (s >= 100*M) {
 346     return "M";
 347   } else if (s >= 100*K) {
 348     return "K";
 349   } else {
 350     return "B";
 351   }
 352 }
 353 
 354 template <class T>
 355 inline T byte_size_in_proper_unit(T s) {
 356 #ifdef _LP64
 357   if (s >= 100*G) {
 358     return (T)(s/G);
 359   }
 360 #endif
 361   if (s >= 100*M) {
 362     return (T)(s/M);
 363   } else if (s >= 100*K) {
 364     return (T)(s/K);
 365   } else {
 366     return s;
 367   }
 368 }
 369 
 370 #define PROPERFMT             "%zu%s"
 371 #define PROPERFMTARGS(s)      byte_size_in_proper_unit(s), proper_unit_for_byte_size(s)
 372 
 373 // Printing a range, with start and bytes given
 374 #define RANGEFMT              "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
 375 #define RANGEFMTARGS(p1, size) p2i(p1), p2i(p1 + size), size
 376 
 377 // Printing a range, with start and end given
 378 #define RANGE2FMT             "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
 379 #define RANGE2FMTARGS(p1, p2) p2i(p1), p2i(p2), ((uintptr_t)p2 - (uintptr_t)p1)
 380 
 381 inline const char* exact_unit_for_byte_size(size_t s) {
 382 #ifdef _LP64
 383   if (s >= G && (s % G) == 0) {
 384     return "G";
 385   }
 386 #endif
 387   if (s >= M && (s % M) == 0) {
 388     return "M";
 389   }
 390   if (s >= K && (s % K) == 0) {
 391     return "K";
 392   }
 393   return "B";
 394 }
 395 
 396 inline size_t byte_size_in_exact_unit(size_t s) {
 397 #ifdef _LP64
 398   if (s >= G && (s % G) == 0) {
 399     return s / G;
 400   }
 401 #endif
 402   if (s >= M && (s % M) == 0) {
 403     return s / M;
 404   }
 405   if (s >= K && (s % K) == 0) {
 406     return s / K;
 407   }
 408   return s;
 409 }
 410 
 411 #define EXACTFMT            "%zu%s"
 412 #define EXACTFMTARGS(s)     byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
 413 
 414 // Memory size transition formatting.
 415 
 416 #define HEAP_CHANGE_FORMAT "%s: %zuK(%zuK)->%zuK(%zuK)"
 417 
 418 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
 419   (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
 420 
 421 //----------------------------------------------------------------------------------------------------
 422 // VM type definitions
 423 
 424 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
 425 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
 426 
 427 typedef intptr_t  intx;
 428 typedef uintptr_t uintx;
 429 
 430 const intx  min_intx  = (intx)1 << (sizeof(intx)*BitsPerByte-1);
 431 const intx  max_intx  = (uintx)min_intx - 1;
 432 const uintx max_uintx = (uintx)-1;
 433 
 434 // Table of values:
 435 //      sizeof intx         4               8
 436 // min_intx             0x80000000      0x8000000000000000
 437 // max_intx             0x7FFFFFFF      0x7FFFFFFFFFFFFFFF
 438 // max_uintx            0xFFFFFFFF      0xFFFFFFFFFFFFFFFF
 439 
 440 typedef unsigned int uint;   NEEDS_CLEANUP
 441 
 442 //----------------------------------------------------------------------------------------------------
 443 // Java type definitions
 444 
 445 // All kinds of 'plain' byte addresses
 446 typedef   signed char s_char;
 447 typedef unsigned char u_char;
 448 typedef u_char*       address;
 449 typedef const u_char* const_address;
 450 
 451 // Pointer subtraction.
 452 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
 453 // the range we might need to find differences from one end of the heap
 454 // to the other.
 455 // A typical use might be:
 456 //     if (pointer_delta(end(), top()) >= size) {
 457 //       // enough room for an object of size
 458 //       ...
 459 // and then additions like
 460 //       ... top() + size ...
 461 // are safe because we know that top() is at least size below end().
 462 inline size_t pointer_delta(const volatile void* left,
 463                             const volatile void* right,
 464                             size_t element_size) {
 465   assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
 466   return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
 467 }
 468 
 469 // A version specialized for HeapWord*'s.
 470 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
 471   return pointer_delta(left, right, sizeof(HeapWord));
 472 }
 473 // A version specialized for MetaWord*'s.
 474 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
 475   return pointer_delta(left, right, sizeof(MetaWord));
 476 }
 477 
 478 // pointer_delta_as_int is called to do pointer subtraction for nearby pointers that
 479 // returns a non-negative int, usually used as a size of a code buffer range.
 480 // This scales to sizeof(T).
 481 template <typename T>
 482 inline int pointer_delta_as_int(const volatile T* left, const volatile T* right) {
 483   size_t delta = pointer_delta(left, right, sizeof(T));
 484   assert(delta <= size_t(INT_MAX), "pointer delta out of range: %zu", delta);
 485   return static_cast<int>(delta);
 486 }
 487 
 488 //
 489 // ANSI C++ does not allow casting from one pointer type to a function pointer
 490 // directly without at best a warning. This macro accomplishes it silently
 491 // In every case that is present at this point the value be cast is a pointer
 492 // to a C linkage function. In some case the type used for the cast reflects
 493 // that linkage and a picky compiler would not complain. In other cases because
 494 // there is no convenient place to place a typedef with extern C linkage (i.e
 495 // a platform dependent header file) it doesn't. At this point no compiler seems
 496 // picky enough to catch these instances (which are few). It is possible that
 497 // using templates could fix these for all cases. This use of templates is likely
 498 // so far from the middle of the road that it is likely to be problematic in
 499 // many C++ compilers.
 500 //
 501 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
 502 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((uintptr_t)(func_ptr)))
 503 
 504 // Need the correct linkage to call qsort without warnings
 505 extern "C" {
 506   typedef int (*_sort_Fn)(const void *, const void *);
 507 }
 508 
 509 // Additional Java basic types
 510 
 511 typedef uint8_t  jubyte;
 512 typedef uint16_t jushort;
 513 typedef uint32_t juint;
 514 typedef uint64_t julong;
 515 
 516 // Unsigned byte types for os and stream.hpp
 517 
 518 // Unsigned one, two, four and eight byte quantities used for describing
 519 // the .class file format. See JVM book chapter 4.
 520 
 521 typedef jubyte  u1;
 522 typedef jushort u2;
 523 typedef juint   u4;
 524 typedef julong  u8;
 525 
 526 const jubyte  max_jubyte  = (jubyte)-1;  // 0xFF       largest jubyte
 527 const jushort max_jushort = (jushort)-1; // 0xFFFF     largest jushort
 528 const juint   max_juint   = (juint)-1;   // 0xFFFFFFFF largest juint
 529 const julong  max_julong  = (julong)-1;  // 0xFF....FF largest julong
 530 
 531 typedef jbyte  s1;
 532 typedef jshort s2;
 533 typedef jint   s4;
 534 typedef jlong  s8;
 535 
 536 const jbyte min_jbyte = -(1 << 7);       // smallest jbyte
 537 const jbyte max_jbyte = (1 << 7) - 1;    // largest jbyte
 538 const jshort min_jshort = -(1 << 15);    // smallest jshort
 539 const jshort max_jshort = (1 << 15) - 1; // largest jshort
 540 
 541 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
 542 const jint max_jint = (juint)min_jint - 1;                     // 0x7FFFFFFF == largest jint
 543 
 544 const jint min_jintFloat = (jint)(0x00000001);
 545 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
 546 const jint max_jintFloat = (jint)(0x7f7fffff);
 547 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
 548 
 549 const jshort max_jfloat16 = 31743;
 550 const jshort min_jfloat16 = 1;
 551 const jshort one_jfloat16 = 15360;
 552 const jshort pos_inf_jfloat16 = 31744;
 553 const jshort neg_inf_jfloat16 = -1024;
 554 // A named constant for the integral representation of a Java null.
 555 const intptr_t NULL_WORD = 0;
 556 
 557 //----------------------------------------------------------------------------------------------------
 558 // JVM spec restrictions
 559 
 560 const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (p.134)
 561 
 562 //----------------------------------------------------------------------------------------------------
 563 // old CDS options
 564 extern bool RequireSharedSpaces;
 565 extern "C" {
 566 // Make sure UseSharedSpaces is accessible to the serviceability agent.
 567 extern JNIEXPORT jboolean UseSharedSpaces;
 568 }
 569 
 570 //----------------------------------------------------------------------------------------------------
 571 // Object alignment, in units of HeapWords.
 572 //
 573 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
 574 // reference fields can be naturally aligned.
 575 
 576 extern int MinObjAlignment;
 577 extern int MinObjAlignmentInBytes;
 578 extern int MinObjAlignmentInBytesMask;
 579 
 580 extern int LogMinObjAlignment;
 581 extern int LogMinObjAlignmentInBytes;
 582 
 583 // Maximal size of heap where unscaled compression can be used. Also upper bound
 584 // for heap placement: 4GB.
 585 const  uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
 586 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
 587 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
 588 extern uint64_t OopEncodingHeapMax;
 589 
 590 // Machine dependent stuff
 591 
 592 #include CPU_HEADER(globalDefinitions)
 593 
 594 // The maximum size of the code cache.  Can be overridden by targets.
 595 #ifndef CODE_CACHE_SIZE_LIMIT
 596 #define CODE_CACHE_SIZE_LIMIT (2*G)
 597 #endif
 598 
 599 // Allow targets to reduce the default size of the code cache.
 600 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
 601 
 602 // To assure the IRIW property on processors that are not multiple copy
 603 // atomic, sync instructions must be issued between volatile reads to
 604 // assure their ordering, instead of after volatile stores.
 605 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
 606 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
 607 #ifdef CPU_MULTI_COPY_ATOMIC
 608 // Not needed.
 609 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
 610 #else
 611 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
 612 // Final decision is subject to JEP 188: Java Memory Model Update.
 613 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
 614 #endif
 615 
 616 // The expected size in bytes of a cache line.
 617 #ifndef DEFAULT_CACHE_LINE_SIZE
 618 #error "Platform should define DEFAULT_CACHE_LINE_SIZE"
 619 #endif
 620 
 621 // The default padding size for data structures to avoid false sharing.
 622 #ifndef DEFAULT_PADDING_SIZE
 623 #error "Platform should define DEFAULT_PADDING_SIZE"
 624 #endif
 625 
 626 
 627 //----------------------------------------------------------------------------------------------------
 628 // Miscellaneous
 629 
 630 // 6302670 Eliminate Hotspot __fabsf dependency
 631 // All fabs() callers should call this function instead, which will implicitly
 632 // convert the operand to double, avoiding a dependency on __fabsf which
 633 // doesn't exist in early versions of Solaris 8.
 634 inline double fabsd(double value) {
 635   return fabs(value);
 636 }
 637 
 638 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
 639 // is zero, return 0.0.
 640 template<typename T>
 641 inline double percent_of(T numerator, T denominator) {
 642   return denominator != 0 ? (double)numerator / (double)denominator * 100.0 : 0.0;
 643 }
 644 
 645 //----------------------------------------------------------------------------------------------------
 646 // Special casts
 647 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
 648 typedef union {
 649   jfloat f;
 650   jint i;
 651 } FloatIntConv;
 652 
 653 typedef union {
 654   jdouble d;
 655   jlong l;
 656   julong ul;
 657 } DoubleLongConv;
 658 
 659 inline jint    jint_cast    (jfloat  x)  { return ((FloatIntConv*)&x)->i; }
 660 inline jfloat  jfloat_cast  (jint    x)  { return ((FloatIntConv*)&x)->f; }
 661 
 662 inline jlong   jlong_cast   (jdouble x)  { return ((DoubleLongConv*)&x)->l;  }
 663 inline julong  julong_cast  (jdouble x)  { return ((DoubleLongConv*)&x)->ul; }
 664 inline jdouble jdouble_cast (jlong   x)  { return ((DoubleLongConv*)&x)->d;  }
 665 
 666 inline jint low (jlong value)                    { return jint(value); }
 667 inline jint high(jlong value)                    { return jint(value >> 32); }
 668 
 669 // the fancy casts are a hopefully portable way
 670 // to do unsigned 32 to 64 bit type conversion
 671 inline void set_low (jlong* value, jint low )    { *value &= (jlong)0xffffffff << 32;
 672                                                    *value |= (jlong)(julong)(juint)low; }
 673 
 674 inline void set_high(jlong* value, jint high)    { *value &= (jlong)(julong)(juint)0xffffffff;
 675                                                    *value |= (jlong)high       << 32; }
 676 
 677 inline jlong jlong_from(jint h, jint l) {
 678   jlong result = 0; // initialization to avoid warning
 679   set_high(&result, h);
 680   set_low(&result,  l);
 681   return result;
 682 }
 683 
 684 union jlong_accessor {
 685   jint  words[2];
 686   jlong long_value;
 687 };
 688 
 689 void basic_types_init(); // cannot define here; uses assert
 690 
 691 
 692 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 693 enum BasicType : u1 {
 694 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
 695   T_BOOLEAN     = JVM_T_BOOLEAN,
 696   T_CHAR        = JVM_T_CHAR,
 697   T_FLOAT       = JVM_T_FLOAT,
 698   T_DOUBLE      = JVM_T_DOUBLE,
 699   T_BYTE        = JVM_T_BYTE,
 700   T_SHORT       = JVM_T_SHORT,
 701   T_INT         = JVM_T_INT,
 702   T_LONG        = JVM_T_LONG,
 703   // The remaining values are not part of any standard.
 704   // T_OBJECT and T_VOID denote two more semantic choices
 705   // for method return values.
 706   // T_OBJECT and T_ARRAY describe signature syntax.
 707   // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
 708   // internal references within the JVM as if they were Java
 709   // types in their own right.
 710   T_OBJECT      = 12,
 711   T_ARRAY       = 13,
 712   T_VOID        = 14,
 713   T_ADDRESS     = 15,
 714   T_NARROWOOP   = 16,
 715   T_METADATA    = 17,
 716   T_NARROWKLASS = 18,
 717   T_CONFLICT    = 19, // for stack value type with conflicting contents
 718   T_ILLEGAL     = 99
 719 };
 720 
 721 #define SIGNATURE_TYPES_DO(F, N)                \
 722     F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N)      \
 723     F(JVM_SIGNATURE_CHAR,    T_CHAR,    N)      \
 724     F(JVM_SIGNATURE_FLOAT,   T_FLOAT,   N)      \
 725     F(JVM_SIGNATURE_DOUBLE,  T_DOUBLE,  N)      \
 726     F(JVM_SIGNATURE_BYTE,    T_BYTE,    N)      \
 727     F(JVM_SIGNATURE_SHORT,   T_SHORT,   N)      \
 728     F(JVM_SIGNATURE_INT,     T_INT,     N)      \
 729     F(JVM_SIGNATURE_LONG,    T_LONG,    N)      \
 730     F(JVM_SIGNATURE_CLASS,   T_OBJECT,  N)      \
 731     F(JVM_SIGNATURE_ARRAY,   T_ARRAY,   N)      \
 732     F(JVM_SIGNATURE_VOID,    T_VOID,    N)      \
 733     /*end*/
 734 
 735 inline bool is_java_type(BasicType t) {
 736   return T_BOOLEAN <= t && t <= T_VOID;
 737 }
 738 
 739 inline bool is_java_primitive(BasicType t) {
 740   return T_BOOLEAN <= t && t <= T_LONG;
 741 }
 742 
 743 inline bool is_subword_type(BasicType t) {
 744   // these guys are processed exactly like T_INT in calling sequences:
 745   return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
 746 }
 747 
 748 inline bool is_signed_subword_type(BasicType t) {
 749   return (t == T_BYTE || t == T_SHORT);
 750 }
 751 
 752 inline bool is_unsigned_subword_type(BasicType t) {
 753   return (t == T_BOOLEAN || t == T_CHAR);
 754 }
 755 
 756 inline bool is_double_word_type(BasicType t) {
 757   return (t == T_DOUBLE || t == T_LONG);
 758 }
 759 
 760 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
 761   return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
 762 }
 763 
 764 inline bool is_integral_type(BasicType t) {
 765   return is_subword_type(t) || t == T_INT || t == T_LONG;
 766 }
 767 
 768 inline bool is_non_subword_integral_type(BasicType t) {
 769   return t == T_INT || t == T_LONG;
 770 }
 771 
 772 inline bool is_floating_point_type(BasicType t) {
 773   return (t == T_FLOAT || t == T_DOUBLE);
 774 }
 775 
 776 extern char type2char_tab[T_CONFLICT+1];     // Map a BasicType to a jchar
 777 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
 778 extern int type2size[T_CONFLICT+1];         // Map BasicType to result stack elements
 779 extern const char* type2name_tab[T_CONFLICT+1];     // Map a BasicType to a char*
 780 extern BasicType name2type(const char* name);
 781 
 782 const char* type2name(BasicType t);
 783 
 784 inline jlong max_signed_integer(BasicType bt) {
 785   if (bt == T_INT) {
 786     return max_jint;
 787   }
 788   assert(bt == T_LONG, "unsupported");
 789   return max_jlong;
 790 }
 791 
 792 inline jlong min_signed_integer(BasicType bt) {
 793   if (bt == T_INT) {
 794     return min_jint;
 795   }
 796   assert(bt == T_LONG, "unsupported");
 797   return min_jlong;
 798 }
 799 
 800 inline uint bits_per_java_integer(BasicType bt) {
 801   if (bt == T_INT) {
 802     return BitsPerJavaInteger;
 803   }
 804   assert(bt == T_LONG, "int or long only");
 805   return BitsPerJavaLong;
 806 }
 807 
 808 // Auxiliary math routines
 809 // least common multiple
 810 extern size_t lcm(size_t a, size_t b);
 811 
 812 
 813 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 814 enum BasicTypeSize {
 815   T_BOOLEAN_size     = 1,
 816   T_CHAR_size        = 1,
 817   T_FLOAT_size       = 1,
 818   T_DOUBLE_size      = 2,
 819   T_BYTE_size        = 1,
 820   T_SHORT_size       = 1,
 821   T_INT_size         = 1,
 822   T_LONG_size        = 2,
 823   T_OBJECT_size      = 1,
 824   T_ARRAY_size       = 1,
 825   T_NARROWOOP_size   = 1,
 826   T_NARROWKLASS_size = 1,
 827   T_VOID_size        = 0
 828 };
 829 
 830 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
 831 inline int parameter_type_word_count(BasicType t) {
 832   if (is_double_word_type(t))  return 2;
 833   assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
 834   assert(type2size[t] == 1, "must be");
 835   return 1;
 836 }
 837 
 838 // maps a BasicType to its instance field storage type:
 839 // all sub-word integral types are widened to T_INT
 840 extern BasicType type2field[T_CONFLICT+1];
 841 extern BasicType type2wfield[T_CONFLICT+1];
 842 
 843 
 844 // size in bytes
 845 enum ArrayElementSize {
 846   T_BOOLEAN_aelem_bytes     = 1,
 847   T_CHAR_aelem_bytes        = 2,
 848   T_FLOAT_aelem_bytes       = 4,
 849   T_DOUBLE_aelem_bytes      = 8,
 850   T_BYTE_aelem_bytes        = 1,
 851   T_SHORT_aelem_bytes       = 2,
 852   T_INT_aelem_bytes         = 4,
 853   T_LONG_aelem_bytes        = 8,
 854 #ifdef _LP64
 855   T_OBJECT_aelem_bytes      = 8,
 856   T_ARRAY_aelem_bytes       = 8,
 857 #else
 858   T_OBJECT_aelem_bytes      = 4,
 859   T_ARRAY_aelem_bytes       = 4,
 860 #endif
 861   T_NARROWOOP_aelem_bytes   = 4,
 862   T_NARROWKLASS_aelem_bytes = 4,
 863   T_VOID_aelem_bytes        = 0
 864 };
 865 
 866 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
 867 #ifdef ASSERT
 868 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
 869 #else
 870 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
 871 #endif
 872 
 873 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
 874   return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
 875 }
 876 
 877 // JavaValue serves as a container for arbitrary Java values.
 878 
 879 class JavaValue {
 880 
 881  public:
 882   typedef union JavaCallValue {
 883     jfloat   f;
 884     jdouble  d;
 885     jint     i;
 886     jlong    l;
 887     jobject  h;
 888     oopDesc* o;
 889   } JavaCallValue;
 890 
 891  private:
 892   BasicType _type;
 893   JavaCallValue _value;
 894 
 895  public:
 896   JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
 897 
 898   JavaValue(jfloat value) {
 899     _type    = T_FLOAT;
 900     _value.f = value;
 901   }
 902 
 903   JavaValue(jdouble value) {
 904     _type    = T_DOUBLE;
 905     _value.d = value;
 906   }
 907 
 908  jfloat get_jfloat() const { return _value.f; }
 909  jdouble get_jdouble() const { return _value.d; }
 910  jint get_jint() const { return _value.i; }
 911  jlong get_jlong() const { return _value.l; }
 912  jobject get_jobject() const { return _value.h; }
 913  oopDesc* get_oop() const { return _value.o; }
 914  JavaCallValue* get_value_addr() { return &_value; }
 915  BasicType get_type() const { return _type; }
 916 
 917  void set_jfloat(jfloat f) { _value.f = f;}
 918  void set_jdouble(jdouble d) { _value.d = d;}
 919  void set_jint(jint i) { _value.i = i;}
 920  void set_jshort(jshort i) { _value.i = i;}
 921  void set_jlong(jlong l) { _value.l = l;}
 922  void set_jobject(jobject h) { _value.h = h;}
 923  void set_oop(oopDesc* o) { _value.o = o;}
 924  void set_type(BasicType t) { _type = t; }
 925 
 926  jboolean get_jboolean() const { return (jboolean) (_value.i);}
 927  jbyte get_jbyte() const { return (jbyte) (_value.i);}
 928  jchar get_jchar() const { return (jchar) (_value.i);}
 929  jshort get_jshort() const { return (jshort) (_value.i);}
 930 
 931 };
 932 
 933 
 934 // TosState describes the top-of-stack state before and after the execution of
 935 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
 936 // registers. The TosState corresponds to the 'machine representation' of this cached
 937 // value. There's 4 states corresponding to the JAVA types int, long, float & double
 938 // as well as a 5th state in case the top-of-stack value is actually on the top
 939 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
 940 // state when it comes to machine representation but is used separately for (oop)
 941 // type specific operations (e.g. verification code).
 942 
 943 enum TosState {         // describes the tos cache contents
 944   btos = 0,             // byte, bool tos cached
 945   ztos = 1,             // byte, bool tos cached
 946   ctos = 2,             // char tos cached
 947   stos = 3,             // short tos cached
 948   itos = 4,             // int tos cached
 949   ltos = 5,             // long tos cached
 950   ftos = 6,             // float tos cached
 951   dtos = 7,             // double tos cached
 952   atos = 8,             // object cached
 953   vtos = 9,             // tos not cached
 954   number_of_states,
 955   ilgl                  // illegal state: should not occur
 956 };
 957 
 958 
 959 inline TosState as_TosState(BasicType type) {
 960   switch (type) {
 961     case T_BYTE   : return btos;
 962     case T_BOOLEAN: return ztos;
 963     case T_CHAR   : return ctos;
 964     case T_SHORT  : return stos;
 965     case T_INT    : return itos;
 966     case T_LONG   : return ltos;
 967     case T_FLOAT  : return ftos;
 968     case T_DOUBLE : return dtos;
 969     case T_VOID   : return vtos;
 970     case T_ARRAY  : // fall through
 971     case T_OBJECT : return atos;
 972     default       : return ilgl;
 973   }
 974 }
 975 
 976 inline BasicType as_BasicType(TosState state) {
 977   switch (state) {
 978     case btos : return T_BYTE;
 979     case ztos : return T_BOOLEAN;
 980     case ctos : return T_CHAR;
 981     case stos : return T_SHORT;
 982     case itos : return T_INT;
 983     case ltos : return T_LONG;
 984     case ftos : return T_FLOAT;
 985     case dtos : return T_DOUBLE;
 986     case atos : return T_OBJECT;
 987     case vtos : return T_VOID;
 988     default   : return T_ILLEGAL;
 989   }
 990 }
 991 
 992 
 993 // Helper function to convert BasicType info into TosState
 994 // Note: Cannot define here as it uses global constant at the time being.
 995 TosState as_TosState(BasicType type);
 996 
 997 
 998 // JavaThreadState keeps track of which part of the code a thread is executing in. This
 999 // information is needed by the safepoint code.
1000 //
1001 // There are 4 essential states:
1002 //
1003 //  _thread_new         : Just started, but not executed init. code yet (most likely still in OS init code)
1004 //  _thread_in_native   : In native code. This is a safepoint region, since all oops will be in jobject handles
1005 //  _thread_in_vm       : Executing in the vm
1006 //  _thread_in_Java     : Executing either interpreted or compiled Java code (or could be in a stub)
1007 //
1008 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1009 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1010 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1011 //
1012 // Given a state, the xxxx_trans state can always be found by adding 1.
1013 //
1014 enum JavaThreadState {
1015   _thread_uninitialized     =  0, // should never happen (missing initialization)
1016   _thread_new               =  2, // just starting up, i.e., in process of being initialized
1017   _thread_new_trans         =  3, // corresponding transition state (not used, included for completeness)
1018   _thread_in_native         =  4, // running in native code
1019   _thread_in_native_trans   =  5, // corresponding transition state
1020   _thread_in_vm             =  6, // running in VM
1021   _thread_in_vm_trans       =  7, // corresponding transition state
1022   _thread_in_Java           =  8, // running in Java or in stub code
1023   _thread_in_Java_trans     =  9, // corresponding transition state (not used, included for completeness)
1024   _thread_blocked           = 10, // blocked in vm
1025   _thread_blocked_trans     = 11, // corresponding transition state
1026   _thread_max_state         = 12  // maximum thread state+1 - used for statistics allocation
1027 };
1028 
1029 enum LockingMode {
1030   // Use only heavy monitors for locking
1031   LM_MONITOR     = 0,
1032   // Legacy stack-locking, with monitors as 2nd tier
1033   LM_LEGACY      = 1,
1034   // New lightweight locking, with monitors as 2nd tier
1035   LM_LIGHTWEIGHT = 2
1036 };
1037 
1038 //----------------------------------------------------------------------------------------------------
1039 // Special constants for debugging
1040 
1041 const jint     badInt             = -3;                     // generic "bad int" value
1042 const intptr_t badAddressVal      = -2;                     // generic "bad address" value
1043 const intptr_t badOopVal          = -1;                     // generic "bad oop" value
1044 const intptr_t badHeapOopVal      = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1045 const int      badStackSegVal     = 0xCA;                   // value used to zap stack segments
1046 const int      badHandleValue     = 0xBC;                   // value used to zap vm handle area
1047 const int      badResourceValue   = 0xAB;                   // value used to zap resource area
1048 const int      freeBlockPad       = 0xBA;                   // value used to pad freed blocks.
1049 const int      uninitBlockPad     = 0xF1;                   // value used to zap newly malloc'd blocks.
1050 const juint    uninitMetaWordVal  = 0xf7f7f7f7;             // value used to zap newly allocated metachunk
1051 const jubyte   heapPaddingByteVal = 0xBD;                   // value used to zap object padding in the heap
1052 const juint    badHeapWordVal     = 0xBAADBABE;             // value used to zap heap after GC
1053 const int      badCodeHeapNewVal  = 0xCC;                   // value used to zap Code heap at allocation
1054 const int      badCodeHeapFreeVal = 0xDD;                   // value used to zap Code heap at deallocation
1055 const intptr_t badDispHeaderDeopt = 0xDE0BD000;             // value to fill unused displaced header during deoptimization
1056 const intptr_t badDispHeaderOSR   = 0xDEAD05A0;             // value to fill unused displaced header during OSR
1057 
1058 // (These must be implemented as #defines because C++ compilers are
1059 // not obligated to inline non-integral constants!)
1060 #define       badAddress        ((address)::badAddressVal)
1061 #define       badHeapWord       (::badHeapWordVal)
1062 
1063 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1064 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1065 
1066 //----------------------------------------------------------------------------------------------------
1067 // Utility functions for bitfield manipulations
1068 
1069 const intptr_t AllBits    = ~0; // all bits set in a word
1070 const intptr_t NoBits     =  0; // no bits set in a word
1071 const jlong    NoLongBits =  0; // no bits set in a long
1072 const intptr_t OneBit     =  1; // only right_most bit set in a word
1073 
1074 // get a word with the n.th or the right-most or left-most n bits set
1075 // (note: #define used only so that they can be used in enum constant definitions)
1076 #define nth_bit(n)        (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1077 #define right_n_bits(n)   (nth_bit(n) - 1)
1078 
1079 // bit-operations using a mask m
1080 inline void   set_bits    (intptr_t& x, intptr_t m) { x |= m; }
1081 inline void clear_bits    (intptr_t& x, intptr_t m) { x &= ~m; }
1082 inline intptr_t mask_bits      (intptr_t  x, intptr_t m) { return x & m; }
1083 inline jlong    mask_long_bits (jlong     x, jlong    m) { return x & m; }
1084 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1085 
1086 // bit-operations using the n.th bit
1087 inline void    set_nth_bit(intptr_t& x, int n) { set_bits  (x, nth_bit(n)); }
1088 inline void  clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1089 inline bool is_set_nth_bit(intptr_t  x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1090 
1091 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1092 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1093   return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1094 }
1095 
1096 
1097 //----------------------------------------------------------------------------------------------------
1098 // Utility functions for integers
1099 
1100 // Avoid use of global min/max macros which may cause unwanted double
1101 // evaluation of arguments.
1102 #ifdef max
1103 #undef max
1104 #endif
1105 
1106 #ifdef min
1107 #undef min
1108 #endif
1109 
1110 // It is necessary to use templates here. Having normal overloaded
1111 // functions does not work because it is necessary to provide both 32-
1112 // and 64-bit overloaded functions, which does not work, and having
1113 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1114 // will be even more error-prone than macros.
1115 template<class T> constexpr T MAX2(T a, T b)           { return (a > b) ? a : b; }
1116 template<class T> constexpr T MIN2(T a, T b)           { return (a < b) ? a : b; }
1117 template<class T> constexpr T MAX3(T a, T b, T c)      { return MAX2(MAX2(a, b), c); }
1118 template<class T> constexpr T MIN3(T a, T b, T c)      { return MIN2(MIN2(a, b), c); }
1119 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1120 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1121 
1122 #define ABS(x) asserted_abs(x, __FILE__, __LINE__)
1123 
1124 template<class T> inline T asserted_abs(T x, const char* file, int line) {
1125   bool valid_arg = !(std::is_integral<T>::value && x == std::numeric_limits<T>::min());
1126 #ifdef ASSERT
1127   if (!valid_arg) {
1128     report_vm_error(file, line, "ABS: argument should not allow overflow");
1129   }
1130 #endif
1131   // Prevent exposure to UB by checking valid_arg here as well.
1132   return (x < 0 && valid_arg) ? -x : x;
1133 }
1134 
1135 // Return the given value clamped to the range [min ... max]
1136 template<typename T>
1137 inline T clamp(T value, T min, T max) {
1138   assert(min <= max, "must be");
1139   return MIN2(MAX2(value, min), max);
1140 }
1141 
1142 inline bool is_odd (intx x) { return x & 1;      }
1143 inline bool is_even(intx x) { return !is_odd(x); }
1144 
1145 // abs methods which cannot overflow and so are well-defined across
1146 // the entire domain of integer types.
1147 static inline unsigned int uabs(unsigned int n) {
1148   union {
1149     unsigned int result;
1150     int value;
1151   };
1152   result = n;
1153   if (value < 0) result = 0-result;
1154   return result;
1155 }
1156 static inline julong uabs(julong n) {
1157   union {
1158     julong result;
1159     jlong value;
1160   };
1161   result = n;
1162   if (value < 0) result = 0-result;
1163   return result;
1164 }
1165 static inline julong uabs(jlong n) { return uabs((julong)n); }
1166 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1167 
1168 // "to" should be greater than "from."
1169 inline size_t byte_size(void* from, void* to) {
1170   return pointer_delta(to, from, sizeof(char));
1171 }
1172 
1173 // Pack and extract shorts to/from ints:
1174 
1175 inline u2 extract_low_short_from_int(u4 x) {
1176   return u2(x & 0xffff);
1177 }
1178 
1179 inline u2 extract_high_short_from_int(u4 x) {
1180   return u2((x >> 16) & 0xffff);
1181 }
1182 
1183 inline int build_int_from_shorts( u2 low, u2 high ) {
1184   return ((int)((unsigned int)high << 16) | (unsigned int)low);
1185 }
1186 
1187 // swap a & b
1188 template<class T> static void swap(T& a, T& b) {
1189   T tmp = a;
1190   a = b;
1191   b = tmp;
1192 }
1193 
1194 // array_size_impl is a function that takes a reference to T[N] and
1195 // returns a reference to char[N].  It is not ODR-used, so not defined.
1196 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1197 
1198 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1199 
1200 //----------------------------------------------------------------------------------------------------
1201 // Sum and product which can never overflow: they wrap, just like the
1202 // Java operations.  Note that we don't intend these to be used for
1203 // general-purpose arithmetic: their purpose is to emulate Java
1204 // operations.
1205 
1206 // The goal of this code to avoid undefined or implementation-defined
1207 // behavior.  The use of an lvalue to reference cast is explicitly
1208 // permitted by Lvalues and rvalues [basic.lval].  [Section 3.10 Para
1209 // 15 in C++03]
1210 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE)  \
1211 inline TYPE NAME (TYPE in1, TYPE in2) {                 \
1212   UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1213   ures OP ## = static_cast<UNSIGNED_TYPE>(in2);         \
1214   return reinterpret_cast<TYPE&>(ures);                 \
1215 }
1216 
1217 JAVA_INTEGER_OP(+, java_add, jint, juint)
1218 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1219 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1220 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1221 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1222 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1223 
1224 inline jint  java_negate(jint  v) { return java_subtract((jint) 0, v); }
1225 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1226 
1227 #undef JAVA_INTEGER_OP
1228 
1229 // Provide integer shift operations with Java semantics.  No overflow
1230 // issues - left shifts simply discard shifted out bits.  No undefined
1231 // behavior for large or negative shift quantities; instead the actual
1232 // shift distance is the argument modulo the lhs value's size in bits.
1233 // No undefined or implementation defined behavior for shifting negative
1234 // values; left shift discards bits, right shift sign extends.  We use
1235 // the same safe conversion technique as above for java_add and friends.
1236 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE)    \
1237 inline TYPE NAME (TYPE lhs, jint rhs) {                 \
1238   const uint rhs_mask = (sizeof(TYPE) * 8) - 1;         \
1239   STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63);      \
1240   XTYPE xres = static_cast<XTYPE>(lhs);                 \
1241   xres OP ## = (rhs & rhs_mask);                        \
1242   return reinterpret_cast<TYPE&>(xres);                 \
1243 }
1244 
1245 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1246 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1247 
1248 // For signed shift right, assume C++ implementation >> sign extends.
1249 //
1250 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1251 // and a negative value, the resulting value is implementation-defined."
1252 //
1253 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1254 // requiring two's-complement behavior.
1255 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1256 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1257 // The corresponding C++20 text is "Right-shift on signed integral types is an
1258 // arithmetic right shift, which performs sign-extension."
1259 //
1260 // As discussed in the two's complement proposal, all known modern C++ compilers
1261 // already behave that way. And it is unlikely any would go off and do something
1262 // different now, with C++20 tightening things up.
1263 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1264 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1265 // For >>> use C++ unsigned >>.
1266 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1267 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1268 
1269 #undef JAVA_INTEGER_SHIFT_OP
1270 
1271 //----------------------------------------------------------------------------------------------------
1272 // The goal of this code is to provide saturating operations for int/uint.
1273 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1274 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1275 inline int NAME (TYPE1 in1, TYPE2 in2) {             \
1276   jlong res = static_cast<jlong>(in1);               \
1277   res OP ## = static_cast<jlong>(in2);               \
1278   if (res > max_jint) {                              \
1279     res = max_jint;                                  \
1280   } else if (res < min_jint) {                       \
1281     res = min_jint;                                  \
1282   }                                                  \
1283   return static_cast<int>(res);                      \
1284 }
1285 
1286 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1287 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1288 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1289 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1290 
1291 #undef SATURATED_INTEGER_OP
1292 
1293 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1294 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1295   const uint64_t x1 = x >> 32u;
1296   const uint64_t x2 = x & 0xFFFFFFFF;
1297   const uint64_t y1 = y >> 32u;
1298   const uint64_t y2 = y & 0xFFFFFFFF;
1299   const uint64_t z2 = x2 * y2;
1300   const uint64_t t = x1 * y2 + (z2 >> 32u);
1301   uint64_t z1 = t & 0xFFFFFFFF;
1302   const uint64_t z0 = t >> 32u;
1303   z1 += x2 * y1;
1304 
1305   return x1 * y1 + z0 + (z1 >> 32u);
1306 }
1307 
1308 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1309 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1310 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1311   const jlong x1 = java_shift_right((jlong)x, 32);
1312   const jlong x2 = x & 0xFFFFFFFF;
1313   const jlong y1 = java_shift_right((jlong)y, 32);
1314   const jlong y2 = y & 0xFFFFFFFF;
1315 
1316   const uint64_t z2 = (uint64_t)x2 * y2;
1317   const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1318   int64_t z1 = t & 0xFFFFFFFF;
1319   const int64_t z0 = java_shift_right((jlong)t, 32);
1320   z1 += x2 * y1;
1321 
1322   return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1323 }
1324 
1325 // Dereference vptr
1326 // All C++ compilers that we know of have the vtbl pointer in the first
1327 // word.  If there are exceptions, this function needs to be made compiler
1328 // specific.
1329 static inline void* dereference_vptr(const void* addr) {
1330   return *(void**)addr;
1331 }
1332 
1333 //----------------------------------------------------------------------------------------------------
1334 // String type aliases used by command line flag declarations and
1335 // processing utilities.
1336 
1337 typedef const char* ccstr;
1338 typedef const char* ccstrlist;   // represents string arguments which accumulate
1339 
1340 //----------------------------------------------------------------------------------------------------
1341 // Default hash/equals functions used by ResourceHashtable
1342 
1343 template<typename K> unsigned primitive_hash(const K& k) {
1344   unsigned hash = (unsigned)((uintptr_t)k);
1345   return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1346 }
1347 
1348 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1349   return k0 == k1;
1350 }
1351 
1352 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1353   return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1354 }
1355 
1356 //----------------------------------------------------------------------------------------------------
1357 
1358 // Allow use of C++ thread_local when approved - see JDK-8282469.
1359 #define APPROVED_CPP_THREAD_LOCAL thread_local
1360 
1361 // Converts any type T to a reference type.
1362 template<typename T>
1363 std::add_rvalue_reference_t<T> declval() noexcept;
1364 
1365 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1366 // handled.
1367 bool IEEE_subnormal_handling_OK();
1368 
1369 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP