1 /*
   2  * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
  26 #define SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
  27 
  28 #include "utilities/compilerWarnings.hpp"
  29 #include "utilities/debug.hpp"
  30 #include "utilities/macros.hpp"
  31 
  32 // Get constants like JVM_T_CHAR and JVM_SIGNATURE_INT, before pulling in <jvm.h>.
  33 #include "classfile_constants.h"
  34 
  35 #include COMPILER_HEADER(utilities/globalDefinitions)
  36 
  37 #include <cstddef>
  38 
  39 class oopDesc;
  40 
  41 // Defaults for macros that might be defined per compiler.
  42 #ifndef NOINLINE
  43 #define NOINLINE
  44 #endif
  45 #ifndef ALWAYSINLINE
  46 #define ALWAYSINLINE inline
  47 #endif
  48 
  49 #ifndef ATTRIBUTE_ALIGNED
  50 #define ATTRIBUTE_ALIGNED(x)
  51 #endif
  52 
  53 #ifndef ATTRIBUTE_FLATTEN
  54 #define ATTRIBUTE_FLATTEN
  55 #endif
  56 
  57 // These are #defines to selectively turn on/off the Print(Opto)Assembly
  58 // capabilities. Choices should be led by a tradeoff between
  59 // code size and improved supportability.
  60 // if PRINT_ASSEMBLY then PRINT_ABSTRACT_ASSEMBLY must be true as well
  61 // to have a fallback in case hsdis is not available.
  62 #if defined(PRODUCT)
  63   #define SUPPORT_ABSTRACT_ASSEMBLY
  64   #define SUPPORT_ASSEMBLY
  65   #undef  SUPPORT_OPTO_ASSEMBLY      // Can't activate. In PRODUCT, many dump methods are missing.
  66   #undef  SUPPORT_DATA_STRUCTS       // Of limited use. In PRODUCT, many print methods are empty.
  67 #else
  68   #define SUPPORT_ABSTRACT_ASSEMBLY
  69   #define SUPPORT_ASSEMBLY
  70   #define SUPPORT_OPTO_ASSEMBLY
  71   #define SUPPORT_DATA_STRUCTS
  72 #endif
  73 #if defined(SUPPORT_ASSEMBLY) && !defined(SUPPORT_ABSTRACT_ASSEMBLY)
  74   #define SUPPORT_ABSTRACT_ASSEMBLY
  75 #endif
  76 
  77 // This file holds all globally used constants & types, class (forward)
  78 // declarations and a few frequently used utility functions.
  79 
  80 // Declare the named class to be noncopyable.  This macro must be followed by
  81 // a semi-colon.  The macro provides deleted declarations for the class's copy
  82 // constructor and assignment operator.  Because these operations are deleted,
  83 // they cannot be defined and potential callers will fail to compile.
  84 #define NONCOPYABLE(C) C(C const&) = delete; C& operator=(C const&) = delete /* next token must be ; */
  85 
  86 
  87 //----------------------------------------------------------------------------------------------------
  88 // Printf-style formatters for fixed- and variable-width types as pointers and
  89 // integers.  These are derived from the definitions in inttypes.h.  If the platform
  90 // doesn't provide appropriate definitions, they should be provided in
  91 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
  92 
  93 // Guide to the suffixes used in the format specifiers for integers:
  94 //        - print the decimal value:                   745565
  95 //  _X    - print as hexadecimal, without leading 0s: 0x12345
  96 //  _X_0  - print as hexadecimal, with leading 0s: 0x00012345
  97 //  _W(w) - prints w sized string with the given value right
  98 //          adjusted. Use -w to print left adjusted.
  99 //
 100 // Note that the PTR format specifiers print using 0x with leading zeros,
 101 // just like the _X_0 version for integers.
 102 
 103 // Format 8-bit quantities.
 104 #define INT8_FORMAT_X_0          "0x%02"      PRIx8
 105 #define UINT8_FORMAT_X_0         "0x%02"      PRIx8
 106 
 107 // Format 16-bit quantities.
 108 #define INT16_FORMAT_X_0         "0x%04"      PRIx16
 109 #define UINT16_FORMAT_X_0        "0x%04"      PRIx16
 110 
 111 // Format 32-bit quantities.
 112 #define INT32_FORMAT             "%"          PRId32
 113 #define INT32_FORMAT_X_0         "0x%08"      PRIx32
 114 #define INT32_FORMAT_W(width)    "%"   #width PRId32
 115 #define UINT32_FORMAT            "%"          PRIu32
 116 #define UINT32_FORMAT_X_0        "0x%08"      PRIx32
 117 #define UINT32_FORMAT_W(width)   "%"   #width PRIu32
 118 
 119 // Format 64-bit quantities.
 120 #define INT64_FORMAT             "%"          PRId64
 121 #define INT64_FORMAT_X           "0x%"        PRIx64
 122 #define INT64_FORMAT_X_0         "0x%016"     PRIx64
 123 #define INT64_FORMAT_W(width)    "%"   #width PRId64
 124 #define UINT64_FORMAT            "%"          PRIu64
 125 #define UINT64_FORMAT_X          "0x%"        PRIx64
 126 #define UINT64_FORMAT_X_0        "0x%016"     PRIx64
 127 #define UINT64_FORMAT_W(width)   "%"   #width PRIu64
 128 
 129 // Format integers which change size between 32- and 64-bit.
 130 #define SSIZE_FORMAT             "%"          PRIdPTR
 131 #define SSIZE_FORMAT_W(width)    "%"   #width PRIdPTR
 132 #define SIZE_FORMAT              "%"          PRIuPTR
 133 #define SIZE_FORMAT_X            "0x%"        PRIxPTR
 134 #ifdef _LP64
 135 #define SIZE_FORMAT_X_0          "0x%016"     PRIxPTR
 136 #else
 137 #define SIZE_FORMAT_X_0          "0x%08"      PRIxPTR
 138 #endif
 139 #define SIZE_FORMAT_W(width)     "%"   #width PRIuPTR
 140 
 141 #define INTX_FORMAT              "%"          PRIdPTR
 142 #define INTX_FORMAT_X            "0x%"        PRIxPTR
 143 #define INTX_FORMAT_W(width)     "%"   #width PRIdPTR
 144 #define UINTX_FORMAT             "%"          PRIuPTR
 145 #define UINTX_FORMAT_X           "0x%"        PRIxPTR
 146 #define UINTX_FORMAT_W(width)    "%"   #width PRIuPTR
 147 
 148 // Format jlong, if necessary
 149 #ifndef JLONG_FORMAT
 150 #define JLONG_FORMAT             INT64_FORMAT
 151 #endif
 152 #ifndef JLONG_FORMAT_W
 153 #define JLONG_FORMAT_W(width)    INT64_FORMAT_W(width)
 154 #endif
 155 #ifndef JULONG_FORMAT
 156 #define JULONG_FORMAT            UINT64_FORMAT
 157 #endif
 158 #ifndef JULONG_FORMAT_X
 159 #define JULONG_FORMAT_X          UINT64_FORMAT_X
 160 #endif
 161 
 162 // Format pointers which change size between 32- and 64-bit.
 163 #ifdef  _LP64
 164 #define INTPTR_FORMAT            "0x%016"     PRIxPTR
 165 #define PTR_FORMAT               "0x%016"     PRIxPTR
 166 #else   // !_LP64
 167 #define INTPTR_FORMAT            "0x%08"      PRIxPTR
 168 #define PTR_FORMAT               "0x%08"      PRIxPTR
 169 #endif  // _LP64
 170 
 171 // Convert pointer to intptr_t, for use in printing pointers.
 172 inline intptr_t p2i(const volatile void* p) {
 173   return (intptr_t) p;
 174 }
 175 
 176 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
 177 
 178 //----------------------------------------------------------------------------------------------------
 179 // Forbid the use of various C library functions.
 180 // Some of these have os:: replacements that should normally be used instead.
 181 // Others are considered security concerns, with preferred alternatives.
 182 
 183 FORBID_C_FUNCTION(void exit(int), "use os::exit");
 184 FORBID_C_FUNCTION(void _exit(int), "use os::exit");
 185 FORBID_C_FUNCTION(char* strerror(int), "use os::strerror");
 186 FORBID_C_FUNCTION(char* strtok(char*, const char*), "use strtok_r");
 187 FORBID_C_FUNCTION(int vsprintf(char*, const char*, va_list), "use os::vsnprintf");
 188 FORBID_C_FUNCTION(int vsnprintf(char*, size_t, const char*, va_list), "use os::vsnprintf");
 189 
 190 // All of the following functions return raw C-heap pointers (sometimes as an option, e.g. realpath or getwd)
 191 // or, in case of free(), take raw C-heap pointers. Don't use them unless you are really sure you must.
 192 FORBID_C_FUNCTION(void* malloc(size_t size), "use os::malloc");
 193 FORBID_C_FUNCTION(void* calloc(size_t nmemb, size_t size), "use os::malloc and zero out manually");
 194 FORBID_C_FUNCTION(void free(void *ptr), "use os::free");
 195 FORBID_C_FUNCTION(void* realloc(void *ptr, size_t size), "use os::realloc");
 196 FORBID_C_FUNCTION(char* strdup(const char *s), "use os::strdup");
 197 FORBID_C_FUNCTION(char* strndup(const char *s, size_t n), "don't use");
 198 FORBID_C_FUNCTION(int posix_memalign(void **memptr, size_t alignment, size_t size), "don't use");
 199 FORBID_C_FUNCTION(void* aligned_alloc(size_t alignment, size_t size), "don't use");
 200 FORBID_C_FUNCTION(char* realpath(const char* path, char* resolved_path), "use os::Posix::realpath");
 201 FORBID_C_FUNCTION(char* get_current_dir_name(void), "use os::get_current_directory()");
 202 FORBID_C_FUNCTION(char* getwd(char *buf), "use os::get_current_directory()");
 203 FORBID_C_FUNCTION(wchar_t* wcsdup(const wchar_t *s), "don't use");
 204 FORBID_C_FUNCTION(void* reallocf(void *ptr, size_t size), "don't use");
 205 
 206 //----------------------------------------------------------------------------------------------------
 207 // Constants
 208 
 209 const int LogBytesPerShort   = 1;
 210 const int LogBytesPerInt     = 2;
 211 #ifdef _LP64
 212 const int LogBytesPerWord    = 3;
 213 #else
 214 const int LogBytesPerWord    = 2;
 215 #endif
 216 const int LogBytesPerLong    = 3;
 217 
 218 const int BytesPerShort      = 1 << LogBytesPerShort;
 219 const int BytesPerInt        = 1 << LogBytesPerInt;
 220 const int BytesPerWord       = 1 << LogBytesPerWord;
 221 const int BytesPerLong       = 1 << LogBytesPerLong;
 222 
 223 const int LogBitsPerByte     = 3;
 224 const int LogBitsPerShort    = LogBitsPerByte + LogBytesPerShort;
 225 const int LogBitsPerInt      = LogBitsPerByte + LogBytesPerInt;
 226 const int LogBitsPerWord     = LogBitsPerByte + LogBytesPerWord;
 227 const int LogBitsPerLong     = LogBitsPerByte + LogBytesPerLong;
 228 
 229 const int BitsPerByte        = 1 << LogBitsPerByte;
 230 const int BitsPerShort       = 1 << LogBitsPerShort;
 231 const int BitsPerInt         = 1 << LogBitsPerInt;
 232 const int BitsPerWord        = 1 << LogBitsPerWord;
 233 const int BitsPerLong        = 1 << LogBitsPerLong;
 234 
 235 const int WordAlignmentMask  = (1 << LogBytesPerWord) - 1;
 236 const int LongAlignmentMask  = (1 << LogBytesPerLong) - 1;
 237 
 238 const int WordsPerLong       = 2;       // Number of stack entries for longs
 239 
 240 const int oopSize            = sizeof(char*); // Full-width oop
 241 extern int heapOopSize;                       // Oop within a java object
 242 const int wordSize           = sizeof(char*);
 243 const int longSize           = sizeof(jlong);
 244 const int jintSize           = sizeof(jint);
 245 const int size_tSize         = sizeof(size_t);
 246 
 247 const int BytesPerOop        = BytesPerWord;  // Full-width oop
 248 
 249 extern int LogBytesPerHeapOop;                // Oop within a java object
 250 extern int LogBitsPerHeapOop;
 251 extern int BytesPerHeapOop;
 252 extern int BitsPerHeapOop;
 253 
 254 const int BitsPerJavaInteger = 32;
 255 const int BitsPerJavaLong    = 64;
 256 const int BitsPerSize_t      = size_tSize * BitsPerByte;
 257 
 258 // Size of a char[] needed to represent a jint as a string in decimal.
 259 const int jintAsStringSize = 12;
 260 
 261 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
 262 // We require that object sizes be measured in units of heap words (e.g.
 263 // pointer-sized values), so that given HeapWord* hw,
 264 //   hw += oop(hw)->foo();
 265 // works, where foo is a method (like size or scavenge) that returns the
 266 // object size.
 267 class HeapWordImpl;             // Opaque, never defined.
 268 typedef HeapWordImpl* HeapWord;
 269 
 270 // Analogous opaque struct for metadata allocated from metaspaces.
 271 class MetaWordImpl;             // Opaque, never defined.
 272 typedef MetaWordImpl* MetaWord;
 273 
 274 // HeapWordSize must be 2^LogHeapWordSize.
 275 const int HeapWordSize        = sizeof(HeapWord);
 276 #ifdef _LP64
 277 const int LogHeapWordSize     = 3;
 278 #else
 279 const int LogHeapWordSize     = 2;
 280 #endif
 281 const int HeapWordsPerLong    = BytesPerLong / HeapWordSize;
 282 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
 283 
 284 // The minimum number of native machine words necessary to contain "byte_size"
 285 // bytes.
 286 inline size_t heap_word_size(size_t byte_size) {
 287   return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
 288 }
 289 
 290 inline jfloat jfloat_cast(jint x);
 291 inline jdouble jdouble_cast(jlong x);
 292 
 293 //-------------------------------------------
 294 // Constant for jlong (standardized by C++11)
 295 
 296 // Build a 64bit integer constant
 297 #define CONST64(x)  (x ## LL)
 298 #define UCONST64(x) (x ## ULL)
 299 
 300 const jlong min_jlong = CONST64(0x8000000000000000);
 301 const jlong max_jlong = CONST64(0x7fffffffffffffff);
 302 
 303 //-------------------------------------------
 304 // Constant for jdouble
 305 const jlong min_jlongDouble = CONST64(0x0000000000000001);
 306 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
 307 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
 308 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
 309 
 310 const size_t K                  = 1024;
 311 const size_t M                  = K*K;
 312 const size_t G                  = M*K;
 313 const size_t HWperKB            = K / sizeof(HeapWord);
 314 
 315 // Constants for converting from a base unit to milli-base units.  For
 316 // example from seconds to milliseconds and microseconds
 317 
 318 const int MILLIUNITS    = 1000;         // milli units per base unit
 319 const int MICROUNITS    = 1000000;      // micro units per base unit
 320 const int NANOUNITS     = 1000000000;   // nano units per base unit
 321 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
 322 
 323 const jlong NANOSECS_PER_SEC      = CONST64(1000000000);
 324 const jint  NANOSECS_PER_MILLISEC = 1000000;
 325 
 326 
 327 // Unit conversion functions
 328 // The caller is responsible for considering overflow.
 329 
 330 inline int64_t nanos_to_millis(int64_t nanos) {
 331   return nanos / NANOUNITS_PER_MILLIUNIT;
 332 }
 333 inline int64_t millis_to_nanos(int64_t millis) {
 334   return millis * NANOUNITS_PER_MILLIUNIT;
 335 }
 336 
 337 // Proper units routines try to maintain at least three significant digits.
 338 // In worst case, it would print five significant digits with lower prefix.
 339 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
 340 // and therefore we need to be careful.
 341 
 342 inline const char* proper_unit_for_byte_size(size_t s) {
 343 #ifdef _LP64
 344   if (s >= 100*G) {
 345     return "G";
 346   }
 347 #endif
 348   if (s >= 100*M) {
 349     return "M";
 350   } else if (s >= 100*K) {
 351     return "K";
 352   } else {
 353     return "B";
 354   }
 355 }
 356 
 357 template <class T>
 358 inline T byte_size_in_proper_unit(T s) {
 359 #ifdef _LP64
 360   if (s >= 100*G) {
 361     return (T)(s/G);
 362   }
 363 #endif
 364   if (s >= 100*M) {
 365     return (T)(s/M);
 366   } else if (s >= 100*K) {
 367     return (T)(s/K);
 368   } else {
 369     return s;
 370   }
 371 }
 372 
 373 inline const char* exact_unit_for_byte_size(size_t s) {
 374 #ifdef _LP64
 375   if (s >= G && (s % G) == 0) {
 376     return "G";
 377   }
 378 #endif
 379   if (s >= M && (s % M) == 0) {
 380     return "M";
 381   }
 382   if (s >= K && (s % K) == 0) {
 383     return "K";
 384   }
 385   return "B";
 386 }
 387 
 388 inline size_t byte_size_in_exact_unit(size_t s) {
 389 #ifdef _LP64
 390   if (s >= G && (s % G) == 0) {
 391     return s / G;
 392   }
 393 #endif
 394   if (s >= M && (s % M) == 0) {
 395     return s / M;
 396   }
 397   if (s >= K && (s % K) == 0) {
 398     return s / K;
 399   }
 400   return s;
 401 }
 402 
 403 // Memory size transition formatting.
 404 
 405 #define HEAP_CHANGE_FORMAT "%s: " SIZE_FORMAT "K(" SIZE_FORMAT "K)->" SIZE_FORMAT "K(" SIZE_FORMAT "K)"
 406 
 407 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
 408   (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
 409 
 410 //----------------------------------------------------------------------------------------------------
 411 // VM type definitions
 412 
 413 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
 414 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
 415 
 416 typedef intptr_t  intx;
 417 typedef uintptr_t uintx;
 418 
 419 const intx  min_intx  = (intx)1 << (sizeof(intx)*BitsPerByte-1);
 420 const intx  max_intx  = (uintx)min_intx - 1;
 421 const uintx max_uintx = (uintx)-1;
 422 
 423 // Table of values:
 424 //      sizeof intx         4               8
 425 // min_intx             0x80000000      0x8000000000000000
 426 // max_intx             0x7FFFFFFF      0x7FFFFFFFFFFFFFFF
 427 // max_uintx            0xFFFFFFFF      0xFFFFFFFFFFFFFFFF
 428 
 429 typedef unsigned int uint;   NEEDS_CLEANUP
 430 
 431 
 432 //----------------------------------------------------------------------------------------------------
 433 // Java type definitions
 434 
 435 // All kinds of 'plain' byte addresses
 436 typedef   signed char s_char;
 437 typedef unsigned char u_char;
 438 typedef u_char*       address;
 439 typedef uintptr_t     address_word; // unsigned integer which will hold a pointer
 440                                     // except for some implementations of a C++
 441                                     // linkage pointer to function. Should never
 442                                     // need one of those to be placed in this
 443                                     // type anyway.
 444 
 445 //  Utility functions to "portably" (?) bit twiddle pointers
 446 //  Where portable means keep ANSI C++ compilers quiet
 447 
 448 inline address       set_address_bits(address x, int m)       { return address(intptr_t(x) | m); }
 449 inline address       clear_address_bits(address x, int m)     { return address(intptr_t(x) & ~m); }
 450 
 451 //  Utility functions to "portably" make cast to/from function pointers.
 452 
 453 inline address_word  mask_address_bits(address x, int m)      { return address_word(x) & m; }
 454 inline address_word  castable_address(address x)              { return address_word(x) ; }
 455 inline address_word  castable_address(void* x)                { return address_word(x) ; }
 456 
 457 // Pointer subtraction.
 458 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
 459 // the range we might need to find differences from one end of the heap
 460 // to the other.
 461 // A typical use might be:
 462 //     if (pointer_delta(end(), top()) >= size) {
 463 //       // enough room for an object of size
 464 //       ...
 465 // and then additions like
 466 //       ... top() + size ...
 467 // are safe because we know that top() is at least size below end().
 468 inline size_t pointer_delta(const volatile void* left,
 469                             const volatile void* right,
 470                             size_t element_size) {
 471   assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
 472   return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
 473 }
 474 
 475 // A version specialized for HeapWord*'s.
 476 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
 477   return pointer_delta(left, right, sizeof(HeapWord));
 478 }
 479 // A version specialized for MetaWord*'s.
 480 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
 481   return pointer_delta(left, right, sizeof(MetaWord));
 482 }
 483 
 484 //
 485 // ANSI C++ does not allow casting from one pointer type to a function pointer
 486 // directly without at best a warning. This macro accomplishes it silently
 487 // In every case that is present at this point the value be cast is a pointer
 488 // to a C linkage function. In some case the type used for the cast reflects
 489 // that linkage and a picky compiler would not complain. In other cases because
 490 // there is no convenient place to place a typedef with extern C linkage (i.e
 491 // a platform dependent header file) it doesn't. At this point no compiler seems
 492 // picky enough to catch these instances (which are few). It is possible that
 493 // using templates could fix these for all cases. This use of templates is likely
 494 // so far from the middle of the road that it is likely to be problematic in
 495 // many C++ compilers.
 496 //
 497 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
 498 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((address_word)(func_ptr)))
 499 
 500 // In many places we've added C-style casts to silence compiler
 501 // warnings, for example when truncating a size_t to an int when we
 502 // know the size_t is a small struct. Such casts are risky because
 503 // they effectively disable useful compiler warnings. We can make our
 504 // lives safer with this function, which ensures that any cast is
 505 // reversible without loss of information. It doesn't check
 506 // everything: it isn't intended to make sure that pointer types are
 507 // compatible, for example.
 508 template <typename T2, typename T1>
 509 T2 checked_cast(T1 thing) {
 510   T2 result = static_cast<T2>(thing);
 511   assert(static_cast<T1>(result) == thing, "must be");
 512   return result;
 513 }
 514 
 515 // Need the correct linkage to call qsort without warnings
 516 extern "C" {
 517   typedef int (*_sort_Fn)(const void *, const void *);
 518 }
 519 
 520 // Unsigned byte types for os and stream.hpp
 521 
 522 // Unsigned one, two, four and eight byte quantities used for describing
 523 // the .class file format. See JVM book chapter 4.
 524 
 525 typedef jubyte  u1;
 526 typedef jushort u2;
 527 typedef juint   u4;
 528 typedef julong  u8;
 529 
 530 const jubyte  max_jubyte  = (jubyte)-1;  // 0xFF       largest jubyte
 531 const jushort max_jushort = (jushort)-1; // 0xFFFF     largest jushort
 532 const juint   max_juint   = (juint)-1;   // 0xFFFFFFFF largest juint
 533 const julong  max_julong  = (julong)-1;  // 0xFF....FF largest julong
 534 
 535 typedef jbyte  s1;
 536 typedef jshort s2;
 537 typedef jint   s4;
 538 typedef jlong  s8;
 539 
 540 const jbyte min_jbyte = -(1 << 7);       // smallest jbyte
 541 const jbyte max_jbyte = (1 << 7) - 1;    // largest jbyte
 542 const jshort min_jshort = -(1 << 15);    // smallest jshort
 543 const jshort max_jshort = (1 << 15) - 1; // largest jshort
 544 
 545 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
 546 const jint max_jint = (juint)min_jint - 1;                     // 0x7FFFFFFF == largest jint
 547 
 548 const jint min_jintFloat = (jint)(0x00000001);
 549 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
 550 const jint max_jintFloat = (jint)(0x7f7fffff);
 551 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
 552 
 553 //----------------------------------------------------------------------------------------------------
 554 // JVM spec restrictions
 555 
 556 const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (p.134)
 557 
 558 //----------------------------------------------------------------------------------------------------
 559 // old CDS options
 560 extern bool DumpSharedSpaces;
 561 extern bool DynamicDumpSharedSpaces;
 562 extern bool RequireSharedSpaces;
 563 extern "C" {
 564 // Make sure UseSharedSpaces is accessible to the serviceability agent.
 565 extern JNIEXPORT jboolean UseSharedSpaces;
 566 }
 567 
 568 //----------------------------------------------------------------------------------------------------
 569 // Object alignment, in units of HeapWords.
 570 //
 571 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
 572 // reference fields can be naturally aligned.
 573 
 574 extern int MinObjAlignment;
 575 extern int MinObjAlignmentInBytes;
 576 extern int MinObjAlignmentInBytesMask;
 577 
 578 extern int LogMinObjAlignment;
 579 extern int LogMinObjAlignmentInBytes;
 580 
 581 const int LogKlassAlignmentInBytes = 3;
 582 const int LogKlassAlignment        = LogKlassAlignmentInBytes - LogHeapWordSize;
 583 const int KlassAlignmentInBytes    = 1 << LogKlassAlignmentInBytes;
 584 const int KlassAlignment           = KlassAlignmentInBytes / HeapWordSize;
 585 
 586 // Maximal size of heap where unscaled compression can be used. Also upper bound
 587 // for heap placement: 4GB.
 588 const  uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
 589 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
 590 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
 591 extern uint64_t OopEncodingHeapMax;
 592 
 593 // Maximal size of compressed class space. Above this limit compression is not possible.
 594 // Also upper bound for placement of zero based class space. (Class space is further limited
 595 // to be < 3G, see arguments.cpp.)
 596 const  uint64_t KlassEncodingMetaspaceMax = (uint64_t(max_juint) + 1) << LogKlassAlignmentInBytes;
 597 
 598 // Machine dependent stuff
 599 
 600 // The maximum size of the code cache.  Can be overridden by targets.
 601 #define CODE_CACHE_SIZE_LIMIT (2*G)
 602 // Allow targets to reduce the default size of the code cache.
 603 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
 604 
 605 #include CPU_HEADER(globalDefinitions)
 606 
 607 // To assure the IRIW property on processors that are not multiple copy
 608 // atomic, sync instructions must be issued between volatile reads to
 609 // assure their ordering, instead of after volatile stores.
 610 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
 611 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
 612 #ifdef CPU_MULTI_COPY_ATOMIC
 613 // Not needed.
 614 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
 615 #else
 616 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
 617 // Final decision is subject to JEP 188: Java Memory Model Update.
 618 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
 619 #endif
 620 
 621 // The expected size in bytes of a cache line, used to pad data structures.
 622 #ifndef DEFAULT_CACHE_LINE_SIZE
 623   #define DEFAULT_CACHE_LINE_SIZE 64
 624 #endif
 625 
 626 
 627 //----------------------------------------------------------------------------------------------------
 628 // Utility macros for compilers
 629 // used to silence compiler warnings
 630 
 631 #define Unused_Variable(var) var
 632 
 633 
 634 //----------------------------------------------------------------------------------------------------
 635 // Miscellaneous
 636 
 637 // 6302670 Eliminate Hotspot __fabsf dependency
 638 // All fabs() callers should call this function instead, which will implicitly
 639 // convert the operand to double, avoiding a dependency on __fabsf which
 640 // doesn't exist in early versions of Solaris 8.
 641 inline double fabsd(double value) {
 642   return fabs(value);
 643 }
 644 
 645 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
 646 // is zero, return 0.0.
 647 template<typename T>
 648 inline double percent_of(T numerator, T denominator) {
 649   return denominator != 0 ? (double)numerator / denominator * 100.0 : 0.0;
 650 }
 651 
 652 //----------------------------------------------------------------------------------------------------
 653 // Special casts
 654 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
 655 typedef union {
 656   jfloat f;
 657   jint i;
 658 } FloatIntConv;
 659 
 660 typedef union {
 661   jdouble d;
 662   jlong l;
 663   julong ul;
 664 } DoubleLongConv;
 665 
 666 inline jint    jint_cast    (jfloat  x)  { return ((FloatIntConv*)&x)->i; }
 667 inline jfloat  jfloat_cast  (jint    x)  { return ((FloatIntConv*)&x)->f; }
 668 
 669 inline jlong   jlong_cast   (jdouble x)  { return ((DoubleLongConv*)&x)->l;  }
 670 inline julong  julong_cast  (jdouble x)  { return ((DoubleLongConv*)&x)->ul; }
 671 inline jdouble jdouble_cast (jlong   x)  { return ((DoubleLongConv*)&x)->d;  }
 672 
 673 inline jint low (jlong value)                    { return jint(value); }
 674 inline jint high(jlong value)                    { return jint(value >> 32); }
 675 
 676 // the fancy casts are a hopefully portable way
 677 // to do unsigned 32 to 64 bit type conversion
 678 inline void set_low (jlong* value, jint low )    { *value &= (jlong)0xffffffff << 32;
 679                                                    *value |= (jlong)(julong)(juint)low; }
 680 
 681 inline void set_high(jlong* value, jint high)    { *value &= (jlong)(julong)(juint)0xffffffff;
 682                                                    *value |= (jlong)high       << 32; }
 683 
 684 inline jlong jlong_from(jint h, jint l) {
 685   jlong result = 0; // initialization to avoid warning
 686   set_high(&result, h);
 687   set_low(&result,  l);
 688   return result;
 689 }
 690 
 691 union jlong_accessor {
 692   jint  words[2];
 693   jlong long_value;
 694 };
 695 
 696 void basic_types_init(); // cannot define here; uses assert
 697 
 698 
 699 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 700 enum BasicType {
 701 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
 702   T_BOOLEAN     = JVM_T_BOOLEAN,
 703   T_CHAR        = JVM_T_CHAR,
 704   T_FLOAT       = JVM_T_FLOAT,
 705   T_DOUBLE      = JVM_T_DOUBLE,
 706   T_BYTE        = JVM_T_BYTE,
 707   T_SHORT       = JVM_T_SHORT,
 708   T_INT         = JVM_T_INT,
 709   T_LONG        = JVM_T_LONG,
 710   // The remaining values are not part of any standard.
 711   // T_OBJECT and T_VOID denote two more semantic choices
 712   // for method return values.
 713   // T_OBJECT and T_ARRAY describe signature syntax.
 714   // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
 715   // internal references within the JVM as if they were Java
 716   // types in their own right.
 717   T_OBJECT      = 12,
 718   T_ARRAY       = 13,
 719   T_VOID        = 14,
 720   T_ADDRESS     = 15,
 721   T_NARROWOOP   = 16,
 722   T_METADATA    = 17,
 723   T_NARROWKLASS = 18,
 724   T_CONFLICT    = 19, // for stack value type with conflicting contents
 725   T_ILLEGAL     = 99
 726 };
 727 
 728 #define SIGNATURE_TYPES_DO(F, N)                \
 729     F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N)      \
 730     F(JVM_SIGNATURE_CHAR,    T_CHAR,    N)      \
 731     F(JVM_SIGNATURE_FLOAT,   T_FLOAT,   N)      \
 732     F(JVM_SIGNATURE_DOUBLE,  T_DOUBLE,  N)      \
 733     F(JVM_SIGNATURE_BYTE,    T_BYTE,    N)      \
 734     F(JVM_SIGNATURE_SHORT,   T_SHORT,   N)      \
 735     F(JVM_SIGNATURE_INT,     T_INT,     N)      \
 736     F(JVM_SIGNATURE_LONG,    T_LONG,    N)      \
 737     F(JVM_SIGNATURE_CLASS,   T_OBJECT,  N)      \
 738     F(JVM_SIGNATURE_ARRAY,   T_ARRAY,   N)      \
 739     F(JVM_SIGNATURE_VOID,    T_VOID,    N)      \
 740     /*end*/
 741 
 742 inline bool is_java_type(BasicType t) {
 743   return T_BOOLEAN <= t && t <= T_VOID;
 744 }
 745 
 746 inline bool is_java_primitive(BasicType t) {
 747   return T_BOOLEAN <= t && t <= T_LONG;
 748 }
 749 
 750 inline bool is_subword_type(BasicType t) {
 751   // these guys are processed exactly like T_INT in calling sequences:
 752   return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
 753 }
 754 
 755 inline bool is_signed_subword_type(BasicType t) {
 756   return (t == T_BYTE || t == T_SHORT);
 757 }
 758 
 759 inline bool is_unsigned_subword_type(BasicType t) {
 760   return (t == T_BOOLEAN || t == T_CHAR);
 761 }
 762 
 763 inline bool is_double_word_type(BasicType t) {
 764   return (t == T_DOUBLE || t == T_LONG);
 765 }
 766 
 767 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
 768   return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
 769 }
 770 
 771 inline bool is_integral_type(BasicType t) {
 772   return is_subword_type(t) || t == T_INT || t == T_LONG;
 773 }
 774 
 775 inline bool is_non_subword_integral_type(BasicType t) {
 776   return t == T_INT || t == T_LONG;
 777 }
 778 
 779 inline bool is_floating_point_type(BasicType t) {
 780   return (t == T_FLOAT || t == T_DOUBLE);
 781 }
 782 
 783 extern char type2char_tab[T_CONFLICT+1];     // Map a BasicType to a jchar
 784 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
 785 extern int type2size[T_CONFLICT+1];         // Map BasicType to result stack elements
 786 extern const char* type2name_tab[T_CONFLICT+1];     // Map a BasicType to a char*
 787 extern BasicType name2type(const char* name);
 788 
 789 inline const char* type2name(BasicType t) {
 790   assert((uint)t < T_CONFLICT + 1, "invalid type");
 791   return type2name_tab[t];
 792 }
 793 
 794 inline jlong max_signed_integer(BasicType bt) {
 795   if (bt == T_INT) {
 796     return max_jint;
 797   }
 798   assert(bt == T_LONG, "unsupported");
 799   return max_jlong;
 800 }
 801 
 802 inline jlong min_signed_integer(BasicType bt) {
 803   if (bt == T_INT) {
 804     return min_jint;
 805   }
 806   assert(bt == T_LONG, "unsupported");
 807   return min_jlong;
 808 }
 809 
 810 // Auxiliary math routines
 811 // least common multiple
 812 extern size_t lcm(size_t a, size_t b);
 813 
 814 
 815 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 816 enum BasicTypeSize {
 817   T_BOOLEAN_size     = 1,
 818   T_CHAR_size        = 1,
 819   T_FLOAT_size       = 1,
 820   T_DOUBLE_size      = 2,
 821   T_BYTE_size        = 1,
 822   T_SHORT_size       = 1,
 823   T_INT_size         = 1,
 824   T_LONG_size        = 2,
 825   T_OBJECT_size      = 1,
 826   T_ARRAY_size       = 1,
 827   T_NARROWOOP_size   = 1,
 828   T_NARROWKLASS_size = 1,
 829   T_VOID_size        = 0
 830 };
 831 
 832 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
 833 inline int parameter_type_word_count(BasicType t) {
 834   if (is_double_word_type(t))  return 2;
 835   assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
 836   assert(type2size[t] == 1, "must be");
 837   return 1;
 838 }
 839 
 840 // maps a BasicType to its instance field storage type:
 841 // all sub-word integral types are widened to T_INT
 842 extern BasicType type2field[T_CONFLICT+1];
 843 extern BasicType type2wfield[T_CONFLICT+1];
 844 
 845 
 846 // size in bytes
 847 enum ArrayElementSize {
 848   T_BOOLEAN_aelem_bytes     = 1,
 849   T_CHAR_aelem_bytes        = 2,
 850   T_FLOAT_aelem_bytes       = 4,
 851   T_DOUBLE_aelem_bytes      = 8,
 852   T_BYTE_aelem_bytes        = 1,
 853   T_SHORT_aelem_bytes       = 2,
 854   T_INT_aelem_bytes         = 4,
 855   T_LONG_aelem_bytes        = 8,
 856 #ifdef _LP64
 857   T_OBJECT_aelem_bytes      = 8,
 858   T_ARRAY_aelem_bytes       = 8,
 859 #else
 860   T_OBJECT_aelem_bytes      = 4,
 861   T_ARRAY_aelem_bytes       = 4,
 862 #endif
 863   T_NARROWOOP_aelem_bytes   = 4,
 864   T_NARROWKLASS_aelem_bytes = 4,
 865   T_VOID_aelem_bytes        = 0
 866 };
 867 
 868 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
 869 #ifdef ASSERT
 870 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
 871 #else
 872 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
 873 #endif
 874 
 875 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
 876   return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
 877 }
 878 
 879 // JavaValue serves as a container for arbitrary Java values.
 880 
 881 class JavaValue {
 882 
 883  public:
 884   typedef union JavaCallValue {
 885     jfloat   f;
 886     jdouble  d;
 887     jint     i;
 888     jlong    l;
 889     jobject  h;
 890     oopDesc* o;
 891   } JavaCallValue;
 892 
 893  private:
 894   BasicType _type;
 895   JavaCallValue _value;
 896 
 897  public:
 898   JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
 899 
 900   JavaValue(jfloat value) {
 901     _type    = T_FLOAT;
 902     _value.f = value;
 903   }
 904 
 905   JavaValue(jdouble value) {
 906     _type    = T_DOUBLE;
 907     _value.d = value;
 908   }
 909 
 910  jfloat get_jfloat() const { return _value.f; }
 911  jdouble get_jdouble() const { return _value.d; }
 912  jint get_jint() const { return _value.i; }
 913  jlong get_jlong() const { return _value.l; }
 914  jobject get_jobject() const { return _value.h; }
 915  oopDesc* get_oop() const { return _value.o; }
 916  JavaCallValue* get_value_addr() { return &_value; }
 917  BasicType get_type() const { return _type; }
 918 
 919  void set_jfloat(jfloat f) { _value.f = f;}
 920  void set_jdouble(jdouble d) { _value.d = d;}
 921  void set_jint(jint i) { _value.i = i;}
 922  void set_jlong(jlong l) { _value.l = l;}
 923  void set_jobject(jobject h) { _value.h = h;}
 924  void set_oop(oopDesc* o) { _value.o = o;}
 925  void set_type(BasicType t) { _type = t; }
 926 
 927  jboolean get_jboolean() const { return (jboolean) (_value.i);}
 928  jbyte get_jbyte() const { return (jbyte) (_value.i);}
 929  jchar get_jchar() const { return (jchar) (_value.i);}
 930  jshort get_jshort() const { return (jshort) (_value.i);}
 931 
 932 };
 933 
 934 
 935 // TosState describes the top-of-stack state before and after the execution of
 936 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
 937 // registers. The TosState corresponds to the 'machine representation' of this cached
 938 // value. There's 4 states corresponding to the JAVA types int, long, float & double
 939 // as well as a 5th state in case the top-of-stack value is actually on the top
 940 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
 941 // state when it comes to machine representation but is used separately for (oop)
 942 // type specific operations (e.g. verification code).
 943 
 944 enum TosState {         // describes the tos cache contents
 945   btos = 0,             // byte, bool tos cached
 946   ztos = 1,             // byte, bool tos cached
 947   ctos = 2,             // char tos cached
 948   stos = 3,             // short tos cached
 949   itos = 4,             // int tos cached
 950   ltos = 5,             // long tos cached
 951   ftos = 6,             // float tos cached
 952   dtos = 7,             // double tos cached
 953   atos = 8,             // object cached
 954   vtos = 9,             // tos not cached
 955   number_of_states,
 956   ilgl                  // illegal state: should not occur
 957 };
 958 
 959 
 960 inline TosState as_TosState(BasicType type) {
 961   switch (type) {
 962     case T_BYTE   : return btos;
 963     case T_BOOLEAN: return ztos;
 964     case T_CHAR   : return ctos;
 965     case T_SHORT  : return stos;
 966     case T_INT    : return itos;
 967     case T_LONG   : return ltos;
 968     case T_FLOAT  : return ftos;
 969     case T_DOUBLE : return dtos;
 970     case T_VOID   : return vtos;
 971     case T_ARRAY  : // fall through
 972     case T_OBJECT : return atos;
 973     default       : return ilgl;
 974   }
 975 }
 976 
 977 inline BasicType as_BasicType(TosState state) {
 978   switch (state) {
 979     case btos : return T_BYTE;
 980     case ztos : return T_BOOLEAN;
 981     case ctos : return T_CHAR;
 982     case stos : return T_SHORT;
 983     case itos : return T_INT;
 984     case ltos : return T_LONG;
 985     case ftos : return T_FLOAT;
 986     case dtos : return T_DOUBLE;
 987     case atos : return T_OBJECT;
 988     case vtos : return T_VOID;
 989     default   : return T_ILLEGAL;
 990   }
 991 }
 992 
 993 
 994 // Helper function to convert BasicType info into TosState
 995 // Note: Cannot define here as it uses global constant at the time being.
 996 TosState as_TosState(BasicType type);
 997 
 998 
 999 // JavaThreadState keeps track of which part of the code a thread is executing in. This
1000 // information is needed by the safepoint code.
1001 //
1002 // There are 4 essential states:
1003 //
1004 //  _thread_new         : Just started, but not executed init. code yet (most likely still in OS init code)
1005 //  _thread_in_native   : In native code. This is a safepoint region, since all oops will be in jobject handles
1006 //  _thread_in_vm       : Executing in the vm
1007 //  _thread_in_Java     : Executing either interpreted or compiled Java code (or could be in a stub)
1008 //
1009 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1010 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1011 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1012 //
1013 // Given a state, the xxxx_trans state can always be found by adding 1.
1014 //
1015 enum JavaThreadState {
1016   _thread_uninitialized     =  0, // should never happen (missing initialization)
1017   _thread_new               =  2, // just starting up, i.e., in process of being initialized
1018   _thread_new_trans         =  3, // corresponding transition state (not used, included for completeness)
1019   _thread_in_native         =  4, // running in native code
1020   _thread_in_native_trans   =  5, // corresponding transition state
1021   _thread_in_vm             =  6, // running in VM
1022   _thread_in_vm_trans       =  7, // corresponding transition state
1023   _thread_in_Java           =  8, // running in Java or in stub code
1024   _thread_in_Java_trans     =  9, // corresponding transition state (not used, included for completeness)
1025   _thread_blocked           = 10, // blocked in vm
1026   _thread_blocked_trans     = 11, // corresponding transition state
1027   _thread_max_state         = 12  // maximum thread state+1 - used for statistics allocation
1028 };
1029 
1030 //----------------------------------------------------------------------------------------------------
1031 // Special constants for debugging
1032 
1033 const jint     badInt           = -3;                       // generic "bad int" value
1034 const intptr_t badAddressVal    = -2;                       // generic "bad address" value
1035 const intptr_t badOopVal        = -1;                       // generic "bad oop" value
1036 const intptr_t badHeapOopVal    = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1037 const int      badStackSegVal   = 0xCA;                     // value used to zap stack segments
1038 const int      badHandleValue   = 0xBC;                     // value used to zap vm handle area
1039 const int      badResourceValue = 0xAB;                     // value used to zap resource area
1040 const int      freeBlockPad     = 0xBA;                     // value used to pad freed blocks.
1041 const int      uninitBlockPad   = 0xF1;                     // value used to zap newly malloc'd blocks.
1042 const juint    uninitMetaWordVal= 0xf7f7f7f7;               // value used to zap newly allocated metachunk
1043 const juint    badHeapWordVal   = 0xBAADBABE;               // value used to zap heap after GC
1044 const juint    badMetaWordVal   = 0xBAADFADE;               // value used to zap metadata heap after GC
1045 const int      badCodeHeapNewVal= 0xCC;                     // value used to zap Code heap at allocation
1046 const int      badCodeHeapFreeVal = 0xDD;                   // value used to zap Code heap at deallocation
1047 
1048 
1049 // (These must be implemented as #defines because C++ compilers are
1050 // not obligated to inline non-integral constants!)
1051 #define       badAddress        ((address)::badAddressVal)
1052 #define       badOop            (cast_to_oop(::badOopVal))
1053 #define       badHeapWord       (::badHeapWordVal)
1054 
1055 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1056 #define TASKQUEUE_SIZE (NOT_LP64(1<<14) LP64_ONLY(1<<17))
1057 
1058 //----------------------------------------------------------------------------------------------------
1059 // Utility functions for bitfield manipulations
1060 
1061 const intptr_t AllBits    = ~0; // all bits set in a word
1062 const intptr_t NoBits     =  0; // no bits set in a word
1063 const jlong    NoLongBits =  0; // no bits set in a long
1064 const intptr_t OneBit     =  1; // only right_most bit set in a word
1065 
1066 // get a word with the n.th or the right-most or left-most n bits set
1067 // (note: #define used only so that they can be used in enum constant definitions)
1068 #define nth_bit(n)        (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1069 #define right_n_bits(n)   (nth_bit(n) - 1)
1070 
1071 // bit-operations using a mask m
1072 inline void   set_bits    (intptr_t& x, intptr_t m) { x |= m; }
1073 inline void clear_bits    (intptr_t& x, intptr_t m) { x &= ~m; }
1074 inline intptr_t mask_bits      (intptr_t  x, intptr_t m) { return x & m; }
1075 inline jlong    mask_long_bits (jlong     x, jlong    m) { return x & m; }
1076 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1077 
1078 // bit-operations using the n.th bit
1079 inline void    set_nth_bit(intptr_t& x, int n) { set_bits  (x, nth_bit(n)); }
1080 inline void  clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1081 inline bool is_set_nth_bit(intptr_t  x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1082 
1083 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1084 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1085   return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1086 }
1087 
1088 
1089 //----------------------------------------------------------------------------------------------------
1090 // Utility functions for integers
1091 
1092 // Avoid use of global min/max macros which may cause unwanted double
1093 // evaluation of arguments.
1094 #ifdef max
1095 #undef max
1096 #endif
1097 
1098 #ifdef min
1099 #undef min
1100 #endif
1101 
1102 // It is necessary to use templates here. Having normal overloaded
1103 // functions does not work because it is necessary to provide both 32-
1104 // and 64-bit overloaded functions, which does not work, and having
1105 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1106 // will be even more error-prone than macros.
1107 template<class T> constexpr T MAX2(T a, T b)           { return (a > b) ? a : b; }
1108 template<class T> constexpr T MIN2(T a, T b)           { return (a < b) ? a : b; }
1109 template<class T> constexpr T MAX3(T a, T b, T c)      { return MAX2(MAX2(a, b), c); }
1110 template<class T> constexpr T MIN3(T a, T b, T c)      { return MIN2(MIN2(a, b), c); }
1111 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1112 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1113 
1114 template<class T> inline T ABS(T x)                 { return (x > 0) ? x : -x; }
1115 
1116 // Return the given value clamped to the range [min ... max]
1117 template<typename T>
1118 inline T clamp(T value, T min, T max) {
1119   assert(min <= max, "must be");
1120   return MIN2(MAX2(value, min), max);
1121 }
1122 
1123 inline bool is_odd (intx x) { return x & 1;      }
1124 inline bool is_even(intx x) { return !is_odd(x); }
1125 
1126 // abs methods which cannot overflow and so are well-defined across
1127 // the entire domain of integer types.
1128 static inline unsigned int uabs(unsigned int n) {
1129   union {
1130     unsigned int result;
1131     int value;
1132   };
1133   result = n;
1134   if (value < 0) result = 0-result;
1135   return result;
1136 }
1137 static inline julong uabs(julong n) {
1138   union {
1139     julong result;
1140     jlong value;
1141   };
1142   result = n;
1143   if (value < 0) result = 0-result;
1144   return result;
1145 }
1146 static inline julong uabs(jlong n) { return uabs((julong)n); }
1147 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1148 
1149 // "to" should be greater than "from."
1150 inline intx byte_size(void* from, void* to) {
1151   return (address)to - (address)from;
1152 }
1153 
1154 // Pack and extract shorts to/from ints:
1155 
1156 inline int extract_low_short_from_int(jint x) {
1157   return x & 0xffff;
1158 }
1159 
1160 inline int extract_high_short_from_int(jint x) {
1161   return (x >> 16) & 0xffff;
1162 }
1163 
1164 inline int build_int_from_shorts( jushort low, jushort high ) {
1165   return ((int)((unsigned int)high << 16) | (unsigned int)low);
1166 }
1167 
1168 // swap a & b
1169 template<class T> static void swap(T& a, T& b) {
1170   T tmp = a;
1171   a = b;
1172   b = tmp;
1173 }
1174 
1175 // array_size_impl is a function that takes a reference to T[N] and
1176 // returns a reference to char[N].  It is not ODR-used, so not defined.
1177 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1178 
1179 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1180 
1181 //----------------------------------------------------------------------------------------------------
1182 // Sum and product which can never overflow: they wrap, just like the
1183 // Java operations.  Note that we don't intend these to be used for
1184 // general-purpose arithmetic: their purpose is to emulate Java
1185 // operations.
1186 
1187 // The goal of this code to avoid undefined or implementation-defined
1188 // behavior.  The use of an lvalue to reference cast is explicitly
1189 // permitted by Lvalues and rvalues [basic.lval].  [Section 3.10 Para
1190 // 15 in C++03]
1191 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE)  \
1192 inline TYPE NAME (TYPE in1, TYPE in2) {                 \
1193   UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1194   ures OP ## = static_cast<UNSIGNED_TYPE>(in2);         \
1195   return reinterpret_cast<TYPE&>(ures);                 \
1196 }
1197 
1198 JAVA_INTEGER_OP(+, java_add, jint, juint)
1199 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1200 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1201 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1202 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1203 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1204 
1205 #undef JAVA_INTEGER_OP
1206 
1207 // Provide integer shift operations with Java semantics.  No overflow
1208 // issues - left shifts simply discard shifted out bits.  No undefined
1209 // behavior for large or negative shift quantities; instead the actual
1210 // shift distance is the argument modulo the lhs value's size in bits.
1211 // No undefined or implementation defined behavior for shifting negative
1212 // values; left shift discards bits, right shift sign extends.  We use
1213 // the same safe conversion technique as above for java_add and friends.
1214 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE)    \
1215 inline TYPE NAME (TYPE lhs, jint rhs) {                 \
1216   const uint rhs_mask = (sizeof(TYPE) * 8) - 1;         \
1217   STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63);      \
1218   XTYPE xres = static_cast<XTYPE>(lhs);                 \
1219   xres OP ## = (rhs & rhs_mask);                        \
1220   return reinterpret_cast<TYPE&>(xres);                 \
1221 }
1222 
1223 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1224 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1225 // For signed shift right, assume C++ implementation >> sign extends.
1226 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1227 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1228 // For >>> use C++ unsigned >>.
1229 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1230 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1231 
1232 #undef JAVA_INTEGER_SHIFT_OP
1233 
1234 //----------------------------------------------------------------------------------------------------
1235 // The goal of this code is to provide saturating operations for int/uint.
1236 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1237 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1238 inline int NAME (TYPE1 in1, TYPE2 in2) {             \
1239   jlong res = static_cast<jlong>(in1);               \
1240   res OP ## = static_cast<jlong>(in2);               \
1241   if (res > max_jint) {                              \
1242     res = max_jint;                                  \
1243   } else if (res < min_jint) {                       \
1244     res = min_jint;                                  \
1245   }                                                  \
1246   return static_cast<int>(res);                      \
1247 }
1248 
1249 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1250 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1251 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1252 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1253 
1254 #undef SATURATED_INTEGER_OP
1255 
1256 // Dereference vptr
1257 // All C++ compilers that we know of have the vtbl pointer in the first
1258 // word.  If there are exceptions, this function needs to be made compiler
1259 // specific.
1260 static inline void* dereference_vptr(const void* addr) {
1261   return *(void**)addr;
1262 }
1263 
1264 //----------------------------------------------------------------------------------------------------
1265 // String type aliases used by command line flag declarations and
1266 // processing utilities.
1267 
1268 typedef const char* ccstr;
1269 typedef const char* ccstrlist;   // represents string arguments which accumulate
1270 
1271 //----------------------------------------------------------------------------------------------------
1272 // Default hash/equals functions used by ResourceHashtable
1273 
1274 template<typename K> unsigned primitive_hash(const K& k) {
1275   unsigned hash = (unsigned)((uintptr_t)k);
1276   return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1277 }
1278 
1279 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1280   return k0 == k1;
1281 }
1282 
1283 //----------------------------------------------------------------------------------------------------
1284 
1285 // Allow use of C++ thread_local when approved - see JDK-8282469.
1286 #define APPROVED_CPP_THREAD_LOCAL thread_local
1287 
1288 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP