1 /*
   2  * Copyright (c) 1997, 2023, 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/attributeNoreturn.hpp"
  29 #include "utilities/compilerWarnings.hpp"
  30 #include "utilities/debug.hpp"
  31 #include "utilities/macros.hpp"
  32 
  33 // Get constants like JVM_T_CHAR and JVM_SIGNATURE_INT, before pulling in <jvm.h>.
  34 #include "classfile_constants.h"
  35 
  36 #include COMPILER_HEADER(utilities/globalDefinitions)
  37 
  38 #include <cstddef>
  39 #include <cstdint>
  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 //
 103 // Note that the PTR format specifiers print using 0x with leading zeros,
 104 // just like the _X_0 version for integers.
 105 
 106 // Format 8-bit quantities.
 107 #define INT8_FORMAT_X_0          "0x%02"      PRIx8
 108 #define UINT8_FORMAT_X_0         "0x%02"      PRIx8
 109 
 110 // Format 16-bit quantities.
 111 #define INT16_FORMAT_X_0         "0x%04"      PRIx16
 112 #define UINT16_FORMAT_X_0        "0x%04"      PRIx16
 113 
 114 // Format 32-bit quantities.
 115 #define INT32_FORMAT             "%"          PRId32
 116 #define INT32_FORMAT_X           "0x%"        PRIx32
 117 #define INT32_FORMAT_X_0         "0x%08"      PRIx32
 118 #define INT32_FORMAT_W(width)    "%"   #width PRId32
 119 #define UINT32_FORMAT            "%"          PRIu32
 120 #define UINT32_FORMAT_X          "0x%"        PRIx32
 121 #define UINT32_FORMAT_X_0        "0x%08"      PRIx32
 122 #define UINT32_FORMAT_W(width)   "%"   #width PRIu32
 123 
 124 // Format 64-bit quantities.
 125 #define INT64_FORMAT             "%"          PRId64
 126 #define INT64_PLUS_FORMAT        "%+"         PRId64
 127 #define INT64_FORMAT_X           "0x%"        PRIx64
 128 #define INT64_FORMAT_X_0         "0x%016"     PRIx64
 129 #define INT64_FORMAT_W(width)    "%"   #width PRId64
 130 #define UINT64_FORMAT            "%"          PRIu64
 131 #define UINT64_FORMAT_X          "0x%"        PRIx64
 132 #define UINT64_FORMAT_X_0        "0x%016"     PRIx64
 133 #define UINT64_FORMAT_W(width)   "%"   #width PRIu64
 134 
 135 // Format integers which change size between 32- and 64-bit.
 136 #define SSIZE_FORMAT             "%"          PRIdPTR
 137 #define SSIZE_PLUS_FORMAT        "%+"         PRIdPTR
 138 #define SSIZE_FORMAT_W(width)    "%"   #width PRIdPTR
 139 #define SIZE_FORMAT              "%"          PRIuPTR
 140 #define SIZE_FORMAT_X            "0x%"        PRIxPTR
 141 #ifdef _LP64
 142 #define SIZE_FORMAT_X_0          "0x%016"     PRIxPTR
 143 #else
 144 #define SIZE_FORMAT_X_0          "0x%08"      PRIxPTR
 145 #endif
 146 #define SIZE_FORMAT_W(width)     "%"   #width PRIuPTR
 147 
 148 #define INTX_FORMAT              "%"          PRIdPTR
 149 #define INTX_FORMAT_X            "0x%"        PRIxPTR
 150 #define INTX_FORMAT_W(width)     "%"   #width PRIdPTR
 151 #define UINTX_FORMAT             "%"          PRIuPTR
 152 #define UINTX_FORMAT_X           "0x%"        PRIxPTR
 153 #define UINTX_FORMAT_W(width)    "%"   #width PRIuPTR
 154 
 155 // Format jlong, if necessary
 156 #ifndef JLONG_FORMAT
 157 #define JLONG_FORMAT             INT64_FORMAT
 158 #endif
 159 #ifndef JLONG_FORMAT_W
 160 #define JLONG_FORMAT_W(width)    INT64_FORMAT_W(width)
 161 #endif
 162 #ifndef JULONG_FORMAT
 163 #define JULONG_FORMAT            UINT64_FORMAT
 164 #endif
 165 #ifndef JULONG_FORMAT_X
 166 #define JULONG_FORMAT_X          UINT64_FORMAT_X
 167 #endif
 168 
 169 // Format pointers which change size between 32- and 64-bit.
 170 #ifdef  _LP64
 171 #define INTPTR_FORMAT            "0x%016"     PRIxPTR
 172 #define PTR_FORMAT               "0x%016"     PRIxPTR
 173 #else   // !_LP64
 174 #define INTPTR_FORMAT            "0x%08"      PRIxPTR
 175 #define PTR_FORMAT               "0x%08"      PRIxPTR
 176 #endif  // _LP64
 177 
 178 // Convert pointer to intptr_t, for use in printing pointers.
 179 inline intptr_t p2i(const volatile void* p) {
 180   return (intptr_t) p;
 181 }
 182 
 183 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
 184 
 185 //----------------------------------------------------------------------------------------------------
 186 // Forbid the use of various C library functions.
 187 // Some of these have os:: replacements that should normally be used instead.
 188 // Others are considered security concerns, with preferred alternatives.
 189 
 190 FORBID_C_FUNCTION(void exit(int), "use os::exit");
 191 FORBID_C_FUNCTION(void _exit(int), "use os::exit");
 192 FORBID_C_FUNCTION(char* strerror(int), "use os::strerror");
 193 FORBID_C_FUNCTION(char* strtok(char*, const char*), "use strtok_r");
 194 FORBID_C_FUNCTION(int sprintf(char*, const char*, ...), "use os::snprintf");
 195 FORBID_C_FUNCTION(int vsprintf(char*, const char*, va_list), "use os::vsnprintf");
 196 FORBID_C_FUNCTION(int vsnprintf(char*, size_t, const char*, va_list), "use os::vsnprintf");
 197 
 198 // All of the following functions return raw C-heap pointers (sometimes as an option, e.g. realpath or getwd)
 199 // or, in case of free(), take raw C-heap pointers. Don't use them unless you are really sure you must.
 200 FORBID_C_FUNCTION(void* malloc(size_t size), "use os::malloc");
 201 FORBID_C_FUNCTION(void* calloc(size_t nmemb, size_t size), "use os::malloc and zero out manually");
 202 FORBID_C_FUNCTION(void free(void *ptr), "use os::free");
 203 FORBID_C_FUNCTION(void* realloc(void *ptr, size_t size), "use os::realloc");
 204 FORBID_C_FUNCTION(char* strdup(const char *s), "use os::strdup");
 205 FORBID_C_FUNCTION(char* strndup(const char *s, size_t n), "don't use");
 206 FORBID_C_FUNCTION(int posix_memalign(void **memptr, size_t alignment, size_t size), "don't use");
 207 FORBID_C_FUNCTION(void* aligned_alloc(size_t alignment, size_t size), "don't use");
 208 FORBID_C_FUNCTION(char* realpath(const char* path, char* resolved_path), "use os::Posix::realpath");
 209 FORBID_C_FUNCTION(char* get_current_dir_name(void), "use os::get_current_directory()");
 210 FORBID_C_FUNCTION(char* getwd(char *buf), "use os::get_current_directory()");
 211 FORBID_C_FUNCTION(wchar_t* wcsdup(const wchar_t *s), "don't use");
 212 FORBID_C_FUNCTION(void* reallocf(void *ptr, size_t size), "don't use");
 213 
 214 //----------------------------------------------------------------------------------------------------
 215 // Constants
 216 
 217 const int LogBytesPerShort   = 1;
 218 const int LogBytesPerInt     = 2;
 219 #ifdef _LP64
 220 const int LogBytesPerWord    = 3;
 221 #else
 222 const int LogBytesPerWord    = 2;
 223 #endif
 224 const int LogBytesPerLong    = 3;
 225 
 226 const int BytesPerShort      = 1 << LogBytesPerShort;
 227 const int BytesPerInt        = 1 << LogBytesPerInt;
 228 const int BytesPerWord       = 1 << LogBytesPerWord;
 229 const int BytesPerLong       = 1 << LogBytesPerLong;
 230 
 231 const int LogBitsPerByte     = 3;
 232 const int LogBitsPerShort    = LogBitsPerByte + LogBytesPerShort;
 233 const int LogBitsPerInt      = LogBitsPerByte + LogBytesPerInt;
 234 const int LogBitsPerWord     = LogBitsPerByte + LogBytesPerWord;
 235 const int LogBitsPerLong     = LogBitsPerByte + LogBytesPerLong;
 236 
 237 const int BitsPerByte        = 1 << LogBitsPerByte;
 238 const int BitsPerShort       = 1 << LogBitsPerShort;
 239 const int BitsPerInt         = 1 << LogBitsPerInt;
 240 const int BitsPerWord        = 1 << LogBitsPerWord;
 241 const int BitsPerLong        = 1 << LogBitsPerLong;
 242 
 243 const int WordAlignmentMask  = (1 << LogBytesPerWord) - 1;
 244 const int LongAlignmentMask  = (1 << LogBytesPerLong) - 1;
 245 
 246 const int oopSize            = sizeof(char*); // Full-width oop
 247 extern int heapOopSize;                       // Oop within a java object
 248 const int wordSize           = sizeof(char*);
 249 const int longSize           = sizeof(jlong);
 250 const int jintSize           = sizeof(jint);
 251 const int size_tSize         = sizeof(size_t);
 252 
 253 const int BytesPerOop        = BytesPerWord;  // Full-width oop
 254 
 255 extern int LogBytesPerHeapOop;                // Oop within a java object
 256 extern int LogBitsPerHeapOop;
 257 extern int BytesPerHeapOop;
 258 extern int BitsPerHeapOop;
 259 
 260 const int BitsPerJavaInteger = 32;
 261 const int BitsPerJavaLong    = 64;
 262 const int BitsPerSize_t      = size_tSize * BitsPerByte;
 263 
 264 // Size of a char[] needed to represent a jint as a string in decimal.
 265 const int jintAsStringSize = 12;
 266 
 267 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
 268 // We require that object sizes be measured in units of heap words (e.g.
 269 // pointer-sized values), so that given HeapWord* hw,
 270 //   hw += oop(hw)->foo();
 271 // works, where foo is a method (like size or scavenge) that returns the
 272 // object size.
 273 class HeapWordImpl;             // Opaque, never defined.
 274 typedef HeapWordImpl* HeapWord;
 275 
 276 // Analogous opaque struct for metadata allocated from metaspaces.
 277 class MetaWordImpl;             // Opaque, never defined.
 278 typedef MetaWordImpl* MetaWord;
 279 
 280 // HeapWordSize must be 2^LogHeapWordSize.
 281 const int HeapWordSize        = sizeof(HeapWord);
 282 #ifdef _LP64
 283 const int LogHeapWordSize     = 3;
 284 #else
 285 const int LogHeapWordSize     = 2;
 286 #endif
 287 const int HeapWordsPerLong    = BytesPerLong / HeapWordSize;
 288 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
 289 
 290 // The minimum number of native machine words necessary to contain "byte_size"
 291 // bytes.
 292 inline size_t heap_word_size(size_t byte_size) {
 293   return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
 294 }
 295 
 296 inline jfloat jfloat_cast(jint x);
 297 inline jdouble jdouble_cast(jlong x);
 298 
 299 //-------------------------------------------
 300 // Constant for jlong (standardized by C++11)
 301 
 302 // Build a 64bit integer constant
 303 #define CONST64(x)  (x ## LL)
 304 #define UCONST64(x) (x ## ULL)
 305 
 306 const jlong min_jlong = CONST64(0x8000000000000000);
 307 const jlong max_jlong = CONST64(0x7fffffffffffffff);
 308 
 309 //-------------------------------------------
 310 // Constant for jdouble
 311 const jlong min_jlongDouble = CONST64(0x0000000000000001);
 312 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
 313 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
 314 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
 315 
 316 const size_t K                  = 1024;
 317 const size_t M                  = K*K;
 318 const size_t G                  = M*K;
 319 const size_t HWperKB            = K / sizeof(HeapWord);
 320 
 321 // Constants for converting from a base unit to milli-base units.  For
 322 // example from seconds to milliseconds and microseconds
 323 
 324 const int MILLIUNITS    = 1000;         // milli units per base unit
 325 const int MICROUNITS    = 1000000;      // micro units per base unit
 326 const int NANOUNITS     = 1000000000;   // nano units per base unit
 327 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
 328 
 329 const jlong NANOSECS_PER_SEC      = CONST64(1000000000);
 330 const jint  NANOSECS_PER_MILLISEC = 1000000;
 331 
 332 
 333 // Unit conversion functions
 334 // The caller is responsible for considering overflow.
 335 
 336 inline int64_t nanos_to_millis(int64_t nanos) {
 337   return nanos / NANOUNITS_PER_MILLIUNIT;
 338 }
 339 inline int64_t millis_to_nanos(int64_t millis) {
 340   return millis * NANOUNITS_PER_MILLIUNIT;
 341 }
 342 
 343 // Proper units routines try to maintain at least three significant digits.
 344 // In worst case, it would print five significant digits with lower prefix.
 345 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
 346 // and therefore we need to be careful.
 347 
 348 inline const char* proper_unit_for_byte_size(size_t s) {
 349 #ifdef _LP64
 350   if (s >= 100*G) {
 351     return "G";
 352   }
 353 #endif
 354   if (s >= 100*M) {
 355     return "M";
 356   } else if (s >= 100*K) {
 357     return "K";
 358   } else {
 359     return "B";
 360   }
 361 }
 362 
 363 template <class T>
 364 inline T byte_size_in_proper_unit(T s) {
 365 #ifdef _LP64
 366   if (s >= 100*G) {
 367     return (T)(s/G);
 368   }
 369 #endif
 370   if (s >= 100*M) {
 371     return (T)(s/M);
 372   } else if (s >= 100*K) {
 373     return (T)(s/K);
 374   } else {
 375     return s;
 376   }
 377 }
 378 
 379 #define PROPERFMT             SIZE_FORMAT "%s"
 380 #define PROPERFMTARGS(s)      byte_size_in_proper_unit(s), proper_unit_for_byte_size(s)
 381 
 382 inline const char* exact_unit_for_byte_size(size_t s) {
 383 #ifdef _LP64
 384   if (s >= G && (s % G) == 0) {
 385     return "G";
 386   }
 387 #endif
 388   if (s >= M && (s % M) == 0) {
 389     return "M";
 390   }
 391   if (s >= K && (s % K) == 0) {
 392     return "K";
 393   }
 394   return "B";
 395 }
 396 
 397 inline size_t byte_size_in_exact_unit(size_t s) {
 398 #ifdef _LP64
 399   if (s >= G && (s % G) == 0) {
 400     return s / G;
 401   }
 402 #endif
 403   if (s >= M && (s % M) == 0) {
 404     return s / M;
 405   }
 406   if (s >= K && (s % K) == 0) {
 407     return s / K;
 408   }
 409   return s;
 410 }
 411 
 412 #define EXACTFMT            SIZE_FORMAT "%s"
 413 #define EXACTFMTARGS(s)     byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
 414 
 415 // Memory size transition formatting.
 416 
 417 #define HEAP_CHANGE_FORMAT "%s: " SIZE_FORMAT "K(" SIZE_FORMAT "K)->" SIZE_FORMAT "K(" SIZE_FORMAT "K)"
 418 
 419 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
 420   (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
 421 
 422 //----------------------------------------------------------------------------------------------------
 423 // VM type definitions
 424 
 425 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
 426 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
 427 
 428 typedef intptr_t  intx;
 429 typedef uintptr_t uintx;
 430 
 431 const intx  min_intx  = (intx)1 << (sizeof(intx)*BitsPerByte-1);
 432 const intx  max_intx  = (uintx)min_intx - 1;
 433 const uintx max_uintx = (uintx)-1;
 434 
 435 // Table of values:
 436 //      sizeof intx         4               8
 437 // min_intx             0x80000000      0x8000000000000000
 438 // max_intx             0x7FFFFFFF      0x7FFFFFFFFFFFFFFF
 439 // max_uintx            0xFFFFFFFF      0xFFFFFFFFFFFFFFFF
 440 
 441 typedef unsigned int uint;   NEEDS_CLEANUP
 442 
 443 //----------------------------------------------------------------------------------------------------
 444 // Java type definitions
 445 
 446 // All kinds of 'plain' byte addresses
 447 typedef   signed char s_char;
 448 typedef unsigned char u_char;
 449 typedef u_char*       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 //----------------------------------------------------------------------------------------------------
 550 // JVM spec restrictions
 551 
 552 const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (p.134)
 553 
 554 //----------------------------------------------------------------------------------------------------
 555 // old CDS options
 556 extern bool RequireSharedSpaces;
 557 extern "C" {
 558 // Make sure UseSharedSpaces is accessible to the serviceability agent.
 559 extern JNIEXPORT jboolean UseSharedSpaces;
 560 }
 561 
 562 //----------------------------------------------------------------------------------------------------
 563 // Object alignment, in units of HeapWords.
 564 //
 565 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
 566 // reference fields can be naturally aligned.
 567 
 568 extern int MinObjAlignment;
 569 extern int MinObjAlignmentInBytes;
 570 extern int MinObjAlignmentInBytesMask;
 571 
 572 extern int LogMinObjAlignment;
 573 extern int LogMinObjAlignmentInBytes;
 574 
 575 // Maximal size of heap where unscaled compression can be used. Also upper bound
 576 // for heap placement: 4GB.
 577 const  uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
 578 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
 579 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
 580 extern uint64_t OopEncodingHeapMax;
 581 
 582 // Machine dependent stuff
 583 
 584 // The maximum size of the code cache.  Can be overridden by targets.
 585 #define CODE_CACHE_SIZE_LIMIT (2*G)
 586 // Allow targets to reduce the default size of the code cache.
 587 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
 588 
 589 #include CPU_HEADER(globalDefinitions)
 590 
 591 // To assure the IRIW property on processors that are not multiple copy
 592 // atomic, sync instructions must be issued between volatile reads to
 593 // assure their ordering, instead of after volatile stores.
 594 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
 595 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
 596 #ifdef CPU_MULTI_COPY_ATOMIC
 597 // Not needed.
 598 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
 599 #else
 600 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
 601 // Final decision is subject to JEP 188: Java Memory Model Update.
 602 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
 603 #endif
 604 
 605 // The expected size in bytes of a cache line, used to pad data structures.
 606 #ifndef DEFAULT_CACHE_LINE_SIZE
 607   #define DEFAULT_CACHE_LINE_SIZE 64
 608 #endif
 609 
 610 
 611 //----------------------------------------------------------------------------------------------------
 612 // Utility macros for compilers
 613 // used to silence compiler warnings
 614 
 615 #define Unused_Variable(var) var
 616 
 617 
 618 //----------------------------------------------------------------------------------------------------
 619 // Prototyping
 620 // "Code Missing Here" macro, un-define when integrating back from prototyping stage and break
 621 // compilation on purpose (i.e. "forget me not")
 622 #define PROTOTYPE
 623 #ifdef PROTOTYPE
 624 #define CMH(m)
 625 #endif
 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_PRIMITIVE_OBJECT = 14, // Not a true BasicType, only use in headers of flat arrays
 713   T_VOID        = 15,
 714   T_ADDRESS     = 16,
 715   T_NARROWOOP   = 17,
 716   T_METADATA    = 18,
 717   T_NARROWKLASS = 19,
 718   T_CONFLICT    = 20, // for stack value type with conflicting contents
 719   T_ILLEGAL     = 99
 720 };
 721 
 722 #define SIGNATURE_TYPES_DO(F, N)                \
 723     F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N)      \
 724     F(JVM_SIGNATURE_CHAR,    T_CHAR,    N)      \
 725     F(JVM_SIGNATURE_FLOAT,   T_FLOAT,   N)      \
 726     F(JVM_SIGNATURE_DOUBLE,  T_DOUBLE,  N)      \
 727     F(JVM_SIGNATURE_BYTE,    T_BYTE,    N)      \
 728     F(JVM_SIGNATURE_SHORT,   T_SHORT,   N)      \
 729     F(JVM_SIGNATURE_INT,     T_INT,     N)      \
 730     F(JVM_SIGNATURE_LONG,    T_LONG,    N)      \
 731     F(JVM_SIGNATURE_CLASS,   T_OBJECT,  N)      \
 732     F(JVM_SIGNATURE_ARRAY,   T_ARRAY,   N)      \
 733     F(JVM_SIGNATURE_PRIMITIVE_OBJECT, T_PRIMITIVE_OBJECT, N) \
 734     F(JVM_SIGNATURE_VOID,    T_VOID,    N)      \
 735     /*end*/
 736 
 737 inline bool is_java_type(BasicType t) {
 738   return T_BOOLEAN <= t && t <= T_VOID;
 739 }
 740 
 741 inline bool is_java_primitive(BasicType t) {
 742   return T_BOOLEAN <= t && t <= T_LONG;
 743 }
 744 
 745 inline bool is_subword_type(BasicType t) {
 746   // these guys are processed exactly like T_INT in calling sequences:
 747   return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
 748 }
 749 
 750 inline bool is_signed_subword_type(BasicType t) {
 751   return (t == T_BYTE || t == T_SHORT);
 752 }
 753 
 754 inline bool is_unsigned_subword_type(BasicType t) {
 755   return (t == T_BOOLEAN || t == T_CHAR);
 756 }
 757 
 758 inline bool is_double_word_type(BasicType t) {
 759   return (t == T_DOUBLE || t == T_LONG);
 760 }
 761 
 762 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
 763   // TODO 8325106 Remove the last occurences of T_PRIMITIVE_OBJECT
 764   return (t == T_OBJECT || t == T_ARRAY || t == T_PRIMITIVE_OBJECT || (include_narrow_oop && t == T_NARROWOOP));
 765 }
 766 
 767 inline bool is_integral_type(BasicType t) {
 768   return is_subword_type(t) || t == T_INT || t == T_LONG;
 769 }
 770 
 771 inline bool is_non_subword_integral_type(BasicType t) {
 772   return t == T_INT || t == T_LONG;
 773 }
 774 
 775 inline bool is_floating_point_type(BasicType t) {
 776   return (t == T_FLOAT || t == T_DOUBLE);
 777 }
 778 
 779 extern char type2char_tab[T_CONFLICT+1];     // Map a BasicType to a jchar
 780 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
 781 extern int type2size[T_CONFLICT+1];         // Map BasicType to result stack elements
 782 extern const char* type2name_tab[T_CONFLICT+1];     // Map a BasicType to a char*
 783 extern BasicType name2type(const char* name);
 784 
 785 const char* type2name(BasicType t);
 786 
 787 inline jlong max_signed_integer(BasicType bt) {
 788   if (bt == T_INT) {
 789     return max_jint;
 790   }
 791   assert(bt == T_LONG, "unsupported");
 792   return max_jlong;
 793 }
 794 
 795 inline jlong min_signed_integer(BasicType bt) {
 796   if (bt == T_INT) {
 797     return min_jint;
 798   }
 799   assert(bt == T_LONG, "unsupported");
 800   return min_jlong;
 801 }
 802 
 803 // Auxiliary math routines
 804 // least common multiple
 805 extern size_t lcm(size_t a, size_t b);
 806 
 807 
 808 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
 809 enum BasicTypeSize {
 810   T_BOOLEAN_size     = 1,
 811   T_CHAR_size        = 1,
 812   T_FLOAT_size       = 1,
 813   T_DOUBLE_size      = 2,
 814   T_BYTE_size        = 1,
 815   T_SHORT_size       = 1,
 816   T_INT_size         = 1,
 817   T_LONG_size        = 2,
 818   T_OBJECT_size      = 1,
 819   T_ARRAY_size       = 1,
 820   T_NARROWOOP_size   = 1,
 821   T_NARROWKLASS_size = 1,
 822   T_VOID_size        = 0,
 823   T_PRIMITIVE_OBJECT_size = 1
 824 };
 825 
 826 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
 827 inline int parameter_type_word_count(BasicType t) {
 828   if (is_double_word_type(t))  return 2;
 829   assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
 830   assert(type2size[t] == 1, "must be");
 831   return 1;
 832 }
 833 
 834 // maps a BasicType to its instance field storage type:
 835 // all sub-word integral types are widened to T_INT
 836 extern BasicType type2field[T_CONFLICT+1];
 837 extern BasicType type2wfield[T_CONFLICT+1];
 838 
 839 
 840 // size in bytes
 841 enum ArrayElementSize {
 842   T_BOOLEAN_aelem_bytes     = 1,
 843   T_CHAR_aelem_bytes        = 2,
 844   T_FLOAT_aelem_bytes       = 4,
 845   T_DOUBLE_aelem_bytes      = 8,
 846   T_BYTE_aelem_bytes        = 1,
 847   T_SHORT_aelem_bytes       = 2,
 848   T_INT_aelem_bytes         = 4,
 849   T_LONG_aelem_bytes        = 8,
 850 #ifdef _LP64
 851   T_OBJECT_aelem_bytes      = 8,
 852   T_ARRAY_aelem_bytes       = 8,
 853   T_PRIMITIVE_OBJECT_aelem_bytes = 8,
 854 #else
 855   T_OBJECT_aelem_bytes      = 4,
 856   T_ARRAY_aelem_bytes       = 4,
 857   T_PRIMITIVE_OBJECT_aelem_bytes = 4,
 858 #endif
 859   T_NARROWOOP_aelem_bytes   = 4,
 860   T_NARROWKLASS_aelem_bytes = 4,
 861   T_VOID_aelem_bytes        = 0
 862 };
 863 
 864 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
 865 #ifdef ASSERT
 866 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
 867 #else
 868 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
 869 #endif
 870 
 871 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
 872   return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
 873 }
 874 
 875 // JavaValue serves as a container for arbitrary Java values.
 876 
 877 class JavaValue {
 878 
 879  public:
 880   typedef union JavaCallValue {
 881     jfloat   f;
 882     jdouble  d;
 883     jint     i;
 884     jlong    l;
 885     jobject  h;
 886     oopDesc* o;
 887   } JavaCallValue;
 888 
 889  private:
 890   BasicType _type;
 891   JavaCallValue _value;
 892 
 893  public:
 894   JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
 895 
 896   JavaValue(jfloat value) {
 897     _type    = T_FLOAT;
 898     _value.f = value;
 899   }
 900 
 901   JavaValue(jdouble value) {
 902     _type    = T_DOUBLE;
 903     _value.d = value;
 904   }
 905 
 906  jfloat get_jfloat() const { return _value.f; }
 907  jdouble get_jdouble() const { return _value.d; }
 908  jint get_jint() const { return _value.i; }
 909  jlong get_jlong() const { return _value.l; }
 910  jobject get_jobject() const { return _value.h; }
 911  oopDesc* get_oop() const { return _value.o; }
 912  JavaCallValue* get_value_addr() { return &_value; }
 913  BasicType get_type() const { return _type; }
 914 
 915  void set_jfloat(jfloat f) { _value.f = f;}
 916  void set_jdouble(jdouble d) { _value.d = d;}
 917  void set_jint(jint i) { _value.i = i;}
 918  void set_jlong(jlong l) { _value.l = l;}
 919  void set_jobject(jobject h) { _value.h = h;}
 920  void set_oop(oopDesc* o) { _value.o = o;}
 921  void set_type(BasicType t) { _type = t; }
 922 
 923  jboolean get_jboolean() const { return (jboolean) (_value.i);}
 924  jbyte get_jbyte() const { return (jbyte) (_value.i);}
 925  jchar get_jchar() const { return (jchar) (_value.i);}
 926  jshort get_jshort() const { return (jshort) (_value.i);}
 927 
 928 };
 929 
 930 
 931 // TosState describes the top-of-stack state before and after the execution of
 932 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
 933 // registers. The TosState corresponds to the 'machine representation' of this cached
 934 // value. There's 4 states corresponding to the JAVA types int, long, float & double
 935 // as well as a 5th state in case the top-of-stack value is actually on the top
 936 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
 937 // state when it comes to machine representation but is used separately for (oop)
 938 // type specific operations (e.g. verification code).
 939 
 940 enum TosState {         // describes the tos cache contents
 941   btos = 0,             // byte, bool tos cached
 942   ztos = 1,             // byte, bool tos cached
 943   ctos = 2,             // char tos cached
 944   stos = 3,             // short tos cached
 945   itos = 4,             // int tos cached
 946   ltos = 5,             // long tos cached
 947   ftos = 6,             // float tos cached
 948   dtos = 7,             // double tos cached
 949   atos = 8,             // object cached
 950   vtos = 9,             // tos not cached,
 951   number_of_states,
 952   ilgl                  // illegal state: should not occur
 953 };
 954 
 955 
 956 inline TosState as_TosState(BasicType type) {
 957   switch (type) {
 958     case T_BYTE   : return btos;
 959     case T_BOOLEAN: return ztos;
 960     case T_CHAR   : return ctos;
 961     case T_SHORT  : return stos;
 962     case T_INT    : return itos;
 963     case T_LONG   : return ltos;
 964     case T_FLOAT  : return ftos;
 965     case T_DOUBLE : return dtos;
 966     case T_VOID   : return vtos;
 967     case T_ARRAY  :   // fall through
 968     case T_OBJECT : return atos;
 969     default       : return ilgl;
 970   }
 971 }
 972 
 973 inline BasicType as_BasicType(TosState state) {
 974   switch (state) {
 975     case btos : return T_BYTE;
 976     case ztos : return T_BOOLEAN;
 977     case ctos : return T_CHAR;
 978     case stos : return T_SHORT;
 979     case itos : return T_INT;
 980     case ltos : return T_LONG;
 981     case ftos : return T_FLOAT;
 982     case dtos : return T_DOUBLE;
 983     case atos : return T_OBJECT;
 984     case vtos : return T_VOID;
 985     default   : return T_ILLEGAL;
 986   }
 987 }
 988 
 989 
 990 // Helper function to convert BasicType info into TosState
 991 // Note: Cannot define here as it uses global constant at the time being.
 992 TosState as_TosState(BasicType type);
 993 
 994 
 995 // JavaThreadState keeps track of which part of the code a thread is executing in. This
 996 // information is needed by the safepoint code.
 997 //
 998 // There are 4 essential states:
 999 //
1000 //  _thread_new         : Just started, but not executed init. code yet (most likely still in OS init code)
1001 //  _thread_in_native   : In native code. This is a safepoint region, since all oops will be in jobject handles
1002 //  _thread_in_vm       : Executing in the vm
1003 //  _thread_in_Java     : Executing either interpreted or compiled Java code (or could be in a stub)
1004 //
1005 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1006 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1007 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1008 //
1009 // Given a state, the xxxx_trans state can always be found by adding 1.
1010 //
1011 enum JavaThreadState {
1012   _thread_uninitialized     =  0, // should never happen (missing initialization)
1013   _thread_new               =  2, // just starting up, i.e., in process of being initialized
1014   _thread_new_trans         =  3, // corresponding transition state (not used, included for completeness)
1015   _thread_in_native         =  4, // running in native code
1016   _thread_in_native_trans   =  5, // corresponding transition state
1017   _thread_in_vm             =  6, // running in VM
1018   _thread_in_vm_trans       =  7, // corresponding transition state
1019   _thread_in_Java           =  8, // running in Java or in stub code
1020   _thread_in_Java_trans     =  9, // corresponding transition state (not used, included for completeness)
1021   _thread_blocked           = 10, // blocked in vm
1022   _thread_blocked_trans     = 11, // corresponding transition state
1023   _thread_max_state         = 12  // maximum thread state+1 - used for statistics allocation
1024 };
1025 
1026 enum LockingMode {
1027   // Use only heavy monitors for locking
1028   LM_MONITOR     = 0,
1029   // Legacy stack-locking, with monitors as 2nd tier
1030   LM_LEGACY      = 1,
1031   // New lightweight locking, with monitors as 2nd tier
1032   LM_LIGHTWEIGHT = 2
1033 };
1034 
1035 //----------------------------------------------------------------------------------------------------
1036 // Special constants for debugging
1037 
1038 const jint     badInt           = -3;                       // generic "bad int" value
1039 const intptr_t badAddressVal    = -2;                       // generic "bad address" value
1040 const intptr_t badOopVal        = -1;                       // generic "bad oop" value
1041 const intptr_t badHeapOopVal    = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1042 const int      badStackSegVal   = 0xCA;                     // value used to zap stack segments
1043 const int      badHandleValue   = 0xBC;                     // value used to zap vm handle area
1044 const int      badResourceValue = 0xAB;                     // value used to zap resource area
1045 const int      freeBlockPad     = 0xBA;                     // value used to pad freed blocks.
1046 const int      uninitBlockPad   = 0xF1;                     // value used to zap newly malloc'd blocks.
1047 const juint    uninitMetaWordVal= 0xf7f7f7f7;               // value used to zap newly allocated metachunk
1048 const juint    badHeapWordVal   = 0xBAADBABE;               // value used to zap heap after GC
1049 const juint    badMetaWordVal   = 0xBAADFADE;               // value used to zap metadata heap after GC
1050 const int      badCodeHeapNewVal= 0xCC;                     // value used to zap Code heap at allocation
1051 const int      badCodeHeapFreeVal = 0xDD;                   // value used to zap Code heap at deallocation
1052 const intptr_t badDispHeaderDeopt = 0xDE0BD000;             // value to fill unused displaced header during deoptimization
1053 const intptr_t badDispHeaderOSR   = 0xDEAD05A0;             // value to fill unused displaced header during OSR
1054 
1055 // (These must be implemented as #defines because C++ compilers are
1056 // not obligated to inline non-integral constants!)
1057 #define       badAddress        ((address)::badAddressVal)
1058 #define       badHeapWord       (::badHeapWordVal)
1059 
1060 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1061 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1062 
1063 //----------------------------------------------------------------------------------------------------
1064 // Utility functions for bitfield manipulations
1065 
1066 const intptr_t AllBits    = ~0; // all bits set in a word
1067 const intptr_t NoBits     =  0; // no bits set in a word
1068 const jlong    NoLongBits =  0; // no bits set in a long
1069 const intptr_t OneBit     =  1; // only right_most bit set in a word
1070 
1071 // get a word with the n.th or the right-most or left-most n bits set
1072 // (note: #define used only so that they can be used in enum constant definitions)
1073 #define nth_bit(n)        (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1074 #define right_n_bits(n)   (nth_bit(n) - 1)
1075 
1076 // bit-operations using a mask m
1077 inline void   set_bits    (intptr_t& x, intptr_t m) { x |= m; }
1078 inline void clear_bits    (intptr_t& x, intptr_t m) { x &= ~m; }
1079 inline intptr_t mask_bits      (intptr_t  x, intptr_t m) { return x & m; }
1080 inline jlong    mask_long_bits (jlong     x, jlong    m) { return x & m; }
1081 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1082 
1083 // bit-operations using the n.th bit
1084 inline void    set_nth_bit(intptr_t& x, int n) { set_bits  (x, nth_bit(n)); }
1085 inline void  clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1086 inline bool is_set_nth_bit(intptr_t  x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1087 
1088 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1089 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1090   return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1091 }
1092 
1093 
1094 //----------------------------------------------------------------------------------------------------
1095 // Utility functions for integers
1096 
1097 // Avoid use of global min/max macros which may cause unwanted double
1098 // evaluation of arguments.
1099 #ifdef max
1100 #undef max
1101 #endif
1102 
1103 #ifdef min
1104 #undef min
1105 #endif
1106 
1107 // It is necessary to use templates here. Having normal overloaded
1108 // functions does not work because it is necessary to provide both 32-
1109 // and 64-bit overloaded functions, which does not work, and having
1110 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1111 // will be even more error-prone than macros.
1112 template<class T> constexpr T MAX2(T a, T b)           { return (a > b) ? a : b; }
1113 template<class T> constexpr T MIN2(T a, T b)           { return (a < b) ? a : b; }
1114 template<class T> constexpr T MAX3(T a, T b, T c)      { return MAX2(MAX2(a, b), c); }
1115 template<class T> constexpr T MIN3(T a, T b, T c)      { return MIN2(MIN2(a, b), c); }
1116 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1117 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1118 
1119 template<class T> inline T ABS(T x)                 { return (x > 0) ? x : -x; }
1120 
1121 // Return the given value clamped to the range [min ... max]
1122 template<typename T>
1123 inline T clamp(T value, T min, T max) {
1124   assert(min <= max, "must be");
1125   return MIN2(MAX2(value, min), max);
1126 }
1127 
1128 inline bool is_odd (intx x) { return x & 1;      }
1129 inline bool is_even(intx x) { return !is_odd(x); }
1130 
1131 // abs methods which cannot overflow and so are well-defined across
1132 // the entire domain of integer types.
1133 static inline unsigned int uabs(unsigned int n) {
1134   union {
1135     unsigned int result;
1136     int value;
1137   };
1138   result = n;
1139   if (value < 0) result = 0-result;
1140   return result;
1141 }
1142 static inline julong uabs(julong n) {
1143   union {
1144     julong result;
1145     jlong value;
1146   };
1147   result = n;
1148   if (value < 0) result = 0-result;
1149   return result;
1150 }
1151 static inline julong uabs(jlong n) { return uabs((julong)n); }
1152 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1153 
1154 // "to" should be greater than "from."
1155 inline size_t byte_size(void* from, void* to) {
1156   return pointer_delta(to, from, sizeof(char));
1157 }
1158 
1159 // Pack and extract shorts to/from ints:
1160 
1161 inline u2 extract_low_short_from_int(u4 x) {
1162   return u2(x & 0xffff);
1163 }
1164 
1165 inline u2 extract_high_short_from_int(u4 x) {
1166   return u2((x >> 16) & 0xffff);
1167 }
1168 
1169 inline int build_int_from_shorts( u2 low, u2 high ) {
1170   return ((int)((unsigned int)high << 16) | (unsigned int)low);
1171 }
1172 
1173 // swap a & b
1174 template<class T> static void swap(T& a, T& b) {
1175   T tmp = a;
1176   a = b;
1177   b = tmp;
1178 }
1179 
1180 // array_size_impl is a function that takes a reference to T[N] and
1181 // returns a reference to char[N].  It is not ODR-used, so not defined.
1182 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1183 
1184 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1185 
1186 //----------------------------------------------------------------------------------------------------
1187 // Sum and product which can never overflow: they wrap, just like the
1188 // Java operations.  Note that we don't intend these to be used for
1189 // general-purpose arithmetic: their purpose is to emulate Java
1190 // operations.
1191 
1192 // The goal of this code to avoid undefined or implementation-defined
1193 // behavior.  The use of an lvalue to reference cast is explicitly
1194 // permitted by Lvalues and rvalues [basic.lval].  [Section 3.10 Para
1195 // 15 in C++03]
1196 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE)  \
1197 inline TYPE NAME (TYPE in1, TYPE in2) {                 \
1198   UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1199   ures OP ## = static_cast<UNSIGNED_TYPE>(in2);         \
1200   return reinterpret_cast<TYPE&>(ures);                 \
1201 }
1202 
1203 JAVA_INTEGER_OP(+, java_add, jint, juint)
1204 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1205 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1206 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1207 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1208 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1209 
1210 inline jint  java_negate(jint  v) { return java_subtract((jint) 0, v); }
1211 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1212 
1213 #undef JAVA_INTEGER_OP
1214 
1215 // Provide integer shift operations with Java semantics.  No overflow
1216 // issues - left shifts simply discard shifted out bits.  No undefined
1217 // behavior for large or negative shift quantities; instead the actual
1218 // shift distance is the argument modulo the lhs value's size in bits.
1219 // No undefined or implementation defined behavior for shifting negative
1220 // values; left shift discards bits, right shift sign extends.  We use
1221 // the same safe conversion technique as above for java_add and friends.
1222 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE)    \
1223 inline TYPE NAME (TYPE lhs, jint rhs) {                 \
1224   const uint rhs_mask = (sizeof(TYPE) * 8) - 1;         \
1225   STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63);      \
1226   XTYPE xres = static_cast<XTYPE>(lhs);                 \
1227   xres OP ## = (rhs & rhs_mask);                        \
1228   return reinterpret_cast<TYPE&>(xres);                 \
1229 }
1230 
1231 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1232 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1233 
1234 // For signed shift right, assume C++ implementation >> sign extends.
1235 //
1236 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1237 // and a negative value, the resulting value is implementation-defined."
1238 //
1239 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1240 // requiring two's-complement behavior.
1241 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1242 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1243 // The corresponding C++20 text is "Right-shift on signed integral types is an
1244 // arithmetic right shift, which performs sign-extension."
1245 //
1246 // As discussed in the two's complement proposal, all known modern C++ compilers
1247 // already behave that way. And it is unlikely any would go off and do something
1248 // different now, with C++20 tightening things up.
1249 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1250 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1251 // For >>> use C++ unsigned >>.
1252 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1253 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1254 
1255 #undef JAVA_INTEGER_SHIFT_OP
1256 
1257 //----------------------------------------------------------------------------------------------------
1258 // The goal of this code is to provide saturating operations for int/uint.
1259 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1260 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1261 inline int NAME (TYPE1 in1, TYPE2 in2) {             \
1262   jlong res = static_cast<jlong>(in1);               \
1263   res OP ## = static_cast<jlong>(in2);               \
1264   if (res > max_jint) {                              \
1265     res = max_jint;                                  \
1266   } else if (res < min_jint) {                       \
1267     res = min_jint;                                  \
1268   }                                                  \
1269   return static_cast<int>(res);                      \
1270 }
1271 
1272 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1273 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1274 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1275 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1276 
1277 #undef SATURATED_INTEGER_OP
1278 
1279 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1280 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1281   const uint64_t x1 = x >> 32u;
1282   const uint64_t x2 = x & 0xFFFFFFFF;
1283   const uint64_t y1 = y >> 32u;
1284   const uint64_t y2 = y & 0xFFFFFFFF;
1285   const uint64_t z2 = x2 * y2;
1286   const uint64_t t = x1 * y2 + (z2 >> 32u);
1287   uint64_t z1 = t & 0xFFFFFFFF;
1288   const uint64_t z0 = t >> 32u;
1289   z1 += x2 * y1;
1290 
1291   return x1 * y1 + z0 + (z1 >> 32u);
1292 }
1293 
1294 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1295 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1296 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1297   const jlong x1 = java_shift_right((jlong)x, 32);
1298   const jlong x2 = x & 0xFFFFFFFF;
1299   const jlong y1 = java_shift_right((jlong)y, 32);
1300   const jlong y2 = y & 0xFFFFFFFF;
1301 
1302   const uint64_t z2 = (uint64_t)x2 * y2;
1303   const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1304   int64_t z1 = t & 0xFFFFFFFF;
1305   const int64_t z0 = java_shift_right((jlong)t, 32);
1306   z1 += x2 * y1;
1307 
1308   return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1309 }
1310 
1311 // Dereference vptr
1312 // All C++ compilers that we know of have the vtbl pointer in the first
1313 // word.  If there are exceptions, this function needs to be made compiler
1314 // specific.
1315 static inline void* dereference_vptr(const void* addr) {
1316   return *(void**)addr;
1317 }
1318 
1319 //----------------------------------------------------------------------------------------------------
1320 // String type aliases used by command line flag declarations and
1321 // processing utilities.
1322 
1323 typedef const char* ccstr;
1324 typedef const char* ccstrlist;   // represents string arguments which accumulate
1325 
1326 //----------------------------------------------------------------------------------------------------
1327 // Default hash/equals functions used by ResourceHashtable
1328 
1329 template<typename K> unsigned primitive_hash(const K& k) {
1330   unsigned hash = (unsigned)((uintptr_t)k);
1331   return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1332 }
1333 
1334 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1335   return k0 == k1;
1336 }
1337 
1338 // TEMP!!!!
1339 // This should be removed after LW2 arrays are implemented (JDK-8220790).
1340 // It's an alias to (EnableValhalla && (FlatArrayElementMaxSize != 0)),
1341 // which is actually not 100% correct, but works for the current set of C1/C2
1342 // implementation and test cases.
1343 #define UseFlatArray (EnableValhalla && (FlatArrayElementMaxSize != 0))
1344 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1345   return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1346 }
1347 
1348 //----------------------------------------------------------------------------------------------------
1349 
1350 // Allow use of C++ thread_local when approved - see JDK-8282469.
1351 #define APPROVED_CPP_THREAD_LOCAL thread_local
1352 
1353 // Converts any type T to a reference type.
1354 template<typename T>
1355 std::add_rvalue_reference_t<T> declval() noexcept;
1356 
1357 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1358 // handled.
1359 bool IEEE_subnormal_handling_OK();
1360 
1361 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP