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/compilerWarnings.hpp"
29 #include "utilities/debug.hpp"
30 #include "utilities/macros.hpp"
31
32 // Get constants like JVM_T_CHAR and JVM_SIGNATURE_INT, before pulling in <jvm.h>.
33 #include "classfile_constants.h"
34
35 #include COMPILER_HEADER(utilities/globalDefinitions)
36
37 #include <cstddef>
38 #include <cstdint>
39 #include <type_traits>
40
41 class oopDesc;
42
43 // Defaults for macros that might be defined per compiler.
44 #ifndef NOINLINE
45 #define NOINLINE
46 #endif
47 #ifndef ALWAYSINLINE
48 #define ALWAYSINLINE inline
49 #endif
50
51 #ifndef ATTRIBUTE_ALIGNED
52 #define ATTRIBUTE_ALIGNED(x)
53 #endif
54
55 #ifndef ATTRIBUTE_FLATTEN
56 #define ATTRIBUTE_FLATTEN
57 #endif
58
59 // These are #defines to selectively turn on/off the Print(Opto)Assembly
60 // capabilities. Choices should be led by a tradeoff between
61 // code size and improved supportability.
62 // if PRINT_ASSEMBLY then PRINT_ABSTRACT_ASSEMBLY must be true as well
63 // to have a fallback in case hsdis is not available.
64 #if defined(PRODUCT)
65 #define SUPPORT_ABSTRACT_ASSEMBLY
66 #define SUPPORT_ASSEMBLY
67 #undef SUPPORT_OPTO_ASSEMBLY // Can't activate. In PRODUCT, many dump methods are missing.
68 #undef SUPPORT_DATA_STRUCTS // Of limited use. In PRODUCT, many print methods are empty.
69 #else
70 #define SUPPORT_ABSTRACT_ASSEMBLY
71 #define SUPPORT_ASSEMBLY
72 #define SUPPORT_OPTO_ASSEMBLY
73 #define SUPPORT_DATA_STRUCTS
74 #endif
75 #if defined(SUPPORT_ASSEMBLY) && !defined(SUPPORT_ABSTRACT_ASSEMBLY)
76 #define SUPPORT_ABSTRACT_ASSEMBLY
77 #endif
78
79 // This file holds all globally used constants & types, class (forward)
80 // declarations and a few frequently used utility functions.
81
82 // Declare the named class to be noncopyable. This macro must be followed by
83 // a semi-colon. The macro provides deleted declarations for the class's copy
84 // constructor and assignment operator. Because these operations are deleted,
85 // they cannot be defined and potential callers will fail to compile.
86 #define NONCOPYABLE(C) C(C const&) = delete; C& operator=(C const&) = delete /* next token must be ; */
87
88
89 //----------------------------------------------------------------------------------------------------
90 // Printf-style formatters for fixed- and variable-width types as pointers and
91 // integers. These are derived from the definitions in inttypes.h. If the platform
92 // doesn't provide appropriate definitions, they should be provided in
93 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
94
95 // Guide to the suffixes used in the format specifiers for integers:
96 // - print the decimal value: 745565
97 // _X - print as hexadecimal, without leading 0s: 0x12345
98 // _X_0 - print as hexadecimal, with leading 0s: 0x00012345
99 // _W(w) - prints w sized string with the given value right
100 // adjusted. Use -w to print left adjusted.
101 //
102 // Note that the PTR format specifiers print using 0x with leading zeros,
103 // just like the _X_0 version for integers.
104
105 // Format 8-bit quantities.
106 #define INT8_FORMAT_X_0 "0x%02" PRIx8
107 #define UINT8_FORMAT_X_0 "0x%02" PRIx8
108
109 // Format 16-bit quantities.
110 #define INT16_FORMAT_X_0 "0x%04" PRIx16
111 #define UINT16_FORMAT_X_0 "0x%04" PRIx16
112
113 // Format 32-bit quantities.
114 #define INT32_FORMAT "%" PRId32
115 #define INT32_FORMAT_X "0x%" PRIx32
116 #define INT32_FORMAT_X_0 "0x%08" PRIx32
117 #define INT32_FORMAT_W(width) "%" #width PRId32
118 #define UINT32_FORMAT "%" PRIu32
119 #define UINT32_FORMAT_X "0x%" PRIx32
120 #define UINT32_FORMAT_X_0 "0x%08" PRIx32
121 #define UINT32_FORMAT_W(width) "%" #width PRIu32
122
123 // Format 64-bit quantities.
124 #define INT64_FORMAT "%" PRId64
125 #define INT64_PLUS_FORMAT "%+" PRId64
126 #define INT64_FORMAT_X "0x%" PRIx64
127 #define INT64_FORMAT_X_0 "0x%016" PRIx64
128 #define INT64_FORMAT_W(width) "%" #width PRId64
129 #define UINT64_FORMAT "%" PRIu64
130 #define UINT64_FORMAT_X "0x%" PRIx64
131 #define UINT64_FORMAT_X_0 "0x%016" PRIx64
132 #define UINT64_FORMAT_W(width) "%" #width PRIu64
133
134 // Format integers which change size between 32- and 64-bit.
135 #define SSIZE_FORMAT "%" PRIdPTR
136 #define SSIZE_PLUS_FORMAT "%+" PRIdPTR
137 #define SSIZE_FORMAT_W(width) "%" #width PRIdPTR
138 #define SIZE_FORMAT "%" PRIuPTR
139 #define SIZE_FORMAT_X "0x%" PRIxPTR
140 #ifdef _LP64
141 #define SIZE_FORMAT_X_0 "0x%016" PRIxPTR
142 #else
143 #define SIZE_FORMAT_X_0 "0x%08" PRIxPTR
144 #endif
145 #define SIZE_FORMAT_W(width) "%" #width PRIuPTR
146
147 #define INTX_FORMAT "%" PRIdPTR
148 #define INTX_FORMAT_X "0x%" PRIxPTR
149 #define INTX_FORMAT_W(width) "%" #width PRIdPTR
150 #define UINTX_FORMAT "%" PRIuPTR
151 #define UINTX_FORMAT_X "0x%" PRIxPTR
152 #define UINTX_FORMAT_W(width) "%" #width PRIuPTR
153
154 // Format jlong, if necessary
155 #ifndef JLONG_FORMAT
156 #define JLONG_FORMAT INT64_FORMAT
157 #endif
158 #ifndef JLONG_FORMAT_W
159 #define JLONG_FORMAT_W(width) INT64_FORMAT_W(width)
160 #endif
161 #ifndef JULONG_FORMAT
162 #define JULONG_FORMAT UINT64_FORMAT
163 #endif
164 #ifndef JULONG_FORMAT_X
165 #define JULONG_FORMAT_X UINT64_FORMAT_X
166 #endif
167
168 // Format pointers which change size between 32- and 64-bit.
169 #ifdef _LP64
170 #define INTPTR_FORMAT "0x%016" PRIxPTR
171 #define PTR_FORMAT "0x%016" PRIxPTR
172 #else // !_LP64
173 #define INTPTR_FORMAT "0x%08" PRIxPTR
174 #define PTR_FORMAT "0x%08" PRIxPTR
175 #endif // _LP64
176
177 // Convert pointer to intptr_t, for use in printing pointers.
178 inline intptr_t p2i(const volatile void* p) {
179 return (intptr_t) p;
180 }
181
182 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
183
184 //----------------------------------------------------------------------------------------------------
185 // Forbid the use of various C library functions.
186 // Some of these have os:: replacements that should normally be used instead.
187 // Others are considered security concerns, with preferred alternatives.
188
189 FORBID_C_FUNCTION(void exit(int), "use os::exit");
190 FORBID_C_FUNCTION(void _exit(int), "use os::exit");
191 FORBID_C_FUNCTION(char* strerror(int), "use os::strerror");
192 FORBID_C_FUNCTION(char* strtok(char*, const char*), "use strtok_r");
193 FORBID_C_FUNCTION(int sprintf(char*, const char*, ...), "use os::snprintf");
194 FORBID_C_FUNCTION(int vsprintf(char*, const char*, va_list), "use os::vsnprintf");
195 FORBID_C_FUNCTION(int vsnprintf(char*, size_t, const char*, va_list), "use os::vsnprintf");
196
197 // All of the following functions return raw C-heap pointers (sometimes as an option, e.g. realpath or getwd)
198 // or, in case of free(), take raw C-heap pointers. Don't use them unless you are really sure you must.
199 FORBID_C_FUNCTION(void* malloc(size_t size), "use os::malloc");
200 FORBID_C_FUNCTION(void* calloc(size_t nmemb, size_t size), "use os::malloc and zero out manually");
201 FORBID_C_FUNCTION(void free(void *ptr), "use os::free");
202 FORBID_C_FUNCTION(void* realloc(void *ptr, size_t size), "use os::realloc");
203 FORBID_C_FUNCTION(char* strdup(const char *s), "use os::strdup");
204 FORBID_C_FUNCTION(char* strndup(const char *s, size_t n), "don't use");
205 FORBID_C_FUNCTION(int posix_memalign(void **memptr, size_t alignment, size_t size), "don't use");
206 FORBID_C_FUNCTION(void* aligned_alloc(size_t alignment, size_t size), "don't use");
207 FORBID_C_FUNCTION(char* realpath(const char* path, char* resolved_path), "use os::Posix::realpath");
208 FORBID_C_FUNCTION(char* get_current_dir_name(void), "use os::get_current_directory()");
209 FORBID_C_FUNCTION(char* getwd(char *buf), "use os::get_current_directory()");
210 FORBID_C_FUNCTION(wchar_t* wcsdup(const wchar_t *s), "don't use");
211 FORBID_C_FUNCTION(void* reallocf(void *ptr, size_t size), "don't use");
212
213 //----------------------------------------------------------------------------------------------------
214 // Constants
215
216 const int LogBytesPerShort = 1;
217 const int LogBytesPerInt = 2;
218 #ifdef _LP64
219 const int LogBytesPerWord = 3;
220 #else
221 const int LogBytesPerWord = 2;
222 #endif
223 const int LogBytesPerLong = 3;
224
225 const int BytesPerShort = 1 << LogBytesPerShort;
226 const int BytesPerInt = 1 << LogBytesPerInt;
227 const int BytesPerWord = 1 << LogBytesPerWord;
228 const int BytesPerLong = 1 << LogBytesPerLong;
229
230 const int LogBitsPerByte = 3;
231 const int LogBitsPerShort = LogBitsPerByte + LogBytesPerShort;
232 const int LogBitsPerInt = LogBitsPerByte + LogBytesPerInt;
233 const int LogBitsPerWord = LogBitsPerByte + LogBytesPerWord;
234 const int LogBitsPerLong = LogBitsPerByte + LogBytesPerLong;
235
236 const int BitsPerByte = 1 << LogBitsPerByte;
237 const int BitsPerShort = 1 << LogBitsPerShort;
238 const int BitsPerInt = 1 << LogBitsPerInt;
239 const int BitsPerWord = 1 << LogBitsPerWord;
240 const int BitsPerLong = 1 << LogBitsPerLong;
241
242 const int WordAlignmentMask = (1 << LogBytesPerWord) - 1;
243 const int LongAlignmentMask = (1 << LogBytesPerLong) - 1;
244
245 const int WordsPerLong = 2; // Number of stack entries for longs
246
247 const int oopSize = sizeof(char*); // Full-width oop
248 extern int heapOopSize; // Oop within a java object
249 const int wordSize = sizeof(char*);
250 const int longSize = sizeof(jlong);
251 const int jintSize = sizeof(jint);
252 const int size_tSize = sizeof(size_t);
253
254 const int BytesPerOop = BytesPerWord; // Full-width oop
255
256 extern int LogBytesPerHeapOop; // Oop within a java object
257 extern int LogBitsPerHeapOop;
258 extern int BytesPerHeapOop;
259 extern int BitsPerHeapOop;
260
261 const int BitsPerJavaInteger = 32;
262 const int BitsPerJavaLong = 64;
263 const int BitsPerSize_t = size_tSize * BitsPerByte;
264
265 // Size of a char[] needed to represent a jint as a string in decimal.
266 const int jintAsStringSize = 12;
267
268 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
269 // We require that object sizes be measured in units of heap words (e.g.
270 // pointer-sized values), so that given HeapWord* hw,
271 // hw += oop(hw)->foo();
272 // works, where foo is a method (like size or scavenge) that returns the
273 // object size.
274 class HeapWordImpl; // Opaque, never defined.
275 typedef HeapWordImpl* HeapWord;
276
277 // Analogous opaque struct for metadata allocated from metaspaces.
278 class MetaWordImpl; // Opaque, never defined.
279 typedef MetaWordImpl* MetaWord;
280
281 // HeapWordSize must be 2^LogHeapWordSize.
282 const int HeapWordSize = sizeof(HeapWord);
283 #ifdef _LP64
284 const int LogHeapWordSize = 3;
285 #else
286 const int LogHeapWordSize = 2;
287 #endif
288 const int HeapWordsPerLong = BytesPerLong / HeapWordSize;
289 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
290
291 // The minimum number of native machine words necessary to contain "byte_size"
292 // bytes.
293 inline size_t heap_word_size(size_t byte_size) {
294 return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
295 }
296
297 inline jfloat jfloat_cast(jint x);
298 inline jdouble jdouble_cast(jlong x);
299
300 //-------------------------------------------
301 // Constant for jlong (standardized by C++11)
302
303 // Build a 64bit integer constant
304 #define CONST64(x) (x ## LL)
305 #define UCONST64(x) (x ## ULL)
306
307 const jlong min_jlong = CONST64(0x8000000000000000);
308 const jlong max_jlong = CONST64(0x7fffffffffffffff);
309
310 //-------------------------------------------
311 // Constant for jdouble
312 const jlong min_jlongDouble = CONST64(0x0000000000000001);
313 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
314 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
315 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
316
317 const size_t K = 1024;
318 const size_t M = K*K;
319 const size_t G = M*K;
320 const size_t HWperKB = K / sizeof(HeapWord);
321
322 // Constants for converting from a base unit to milli-base units. For
323 // example from seconds to milliseconds and microseconds
324
325 const int MILLIUNITS = 1000; // milli units per base unit
326 const int MICROUNITS = 1000000; // micro units per base unit
327 const int NANOUNITS = 1000000000; // nano units per base unit
328 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
329
330 const jlong NANOSECS_PER_SEC = CONST64(1000000000);
331 const jint NANOSECS_PER_MILLISEC = 1000000;
332
333
334 // Unit conversion functions
335 // The caller is responsible for considering overflow.
336
337 inline int64_t nanos_to_millis(int64_t nanos) {
338 return nanos / NANOUNITS_PER_MILLIUNIT;
339 }
340 inline int64_t millis_to_nanos(int64_t millis) {
341 return millis * NANOUNITS_PER_MILLIUNIT;
342 }
343
344 // Proper units routines try to maintain at least three significant digits.
345 // In worst case, it would print five significant digits with lower prefix.
346 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
347 // and therefore we need to be careful.
348
349 inline const char* proper_unit_for_byte_size(size_t s) {
350 #ifdef _LP64
351 if (s >= 100*G) {
352 return "G";
353 }
354 #endif
355 if (s >= 100*M) {
356 return "M";
357 } else if (s >= 100*K) {
358 return "K";
359 } else {
360 return "B";
361 }
362 }
363
364 template <class T>
365 inline T byte_size_in_proper_unit(T s) {
366 #ifdef _LP64
367 if (s >= 100*G) {
368 return (T)(s/G);
369 }
370 #endif
371 if (s >= 100*M) {
372 return (T)(s/M);
373 } else if (s >= 100*K) {
374 return (T)(s/K);
375 } else {
376 return s;
377 }
378 }
379
380 #define PROPERFMT SIZE_FORMAT "%s"
381 #define PROPERFMTARGS(s) byte_size_in_proper_unit(s), proper_unit_for_byte_size(s)
382
383 inline const char* exact_unit_for_byte_size(size_t s) {
384 #ifdef _LP64
385 if (s >= G && (s % G) == 0) {
386 return "G";
387 }
388 #endif
389 if (s >= M && (s % M) == 0) {
390 return "M";
391 }
392 if (s >= K && (s % K) == 0) {
393 return "K";
394 }
395 return "B";
396 }
397
398 inline size_t byte_size_in_exact_unit(size_t s) {
399 #ifdef _LP64
400 if (s >= G && (s % G) == 0) {
401 return s / G;
402 }
403 #endif
404 if (s >= M && (s % M) == 0) {
405 return s / M;
406 }
407 if (s >= K && (s % K) == 0) {
408 return s / K;
409 }
410 return s;
411 }
412
413 // Memory size transition formatting.
414
415 #define HEAP_CHANGE_FORMAT "%s: " SIZE_FORMAT "K(" SIZE_FORMAT "K)->" SIZE_FORMAT "K(" SIZE_FORMAT "K)"
416
417 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
418 (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
419
420 //----------------------------------------------------------------------------------------------------
421 // VM type definitions
422
423 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
424 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
425
426 typedef intptr_t intx;
427 typedef uintptr_t uintx;
428
429 const intx min_intx = (intx)1 << (sizeof(intx)*BitsPerByte-1);
430 const intx max_intx = (uintx)min_intx - 1;
431 const uintx max_uintx = (uintx)-1;
432
433 // Table of values:
434 // sizeof intx 4 8
435 // min_intx 0x80000000 0x8000000000000000
436 // max_intx 0x7FFFFFFF 0x7FFFFFFFFFFFFFFF
437 // max_uintx 0xFFFFFFFF 0xFFFFFFFFFFFFFFFF
438
439 typedef unsigned int uint; NEEDS_CLEANUP
440
441
442 //----------------------------------------------------------------------------------------------------
443 // Java type definitions
444
445 // All kinds of 'plain' byte addresses
446 typedef signed char s_char;
447 typedef unsigned char u_char;
448 typedef u_char* address;
449 typedef uintptr_t address_word; // unsigned integer which will hold a pointer
450 // except for some implementations of a C++
451 // linkage pointer to function. Should never
452 // need one of those to be placed in this
453 // type anyway.
454
455 // Utility functions to "portably" (?) bit twiddle pointers
456 // Where portable means keep ANSI C++ compilers quiet
457
458 inline address set_address_bits(address x, int m) { return address(intptr_t(x) | m); }
459 inline address clear_address_bits(address x, int m) { return address(intptr_t(x) & ~m); }
460
461 // Utility functions to "portably" make cast to/from function pointers.
462
463 inline address_word mask_address_bits(address x, int m) { return address_word(x) & m; }
464 inline address_word castable_address(address x) { return address_word(x) ; }
465 inline address_word castable_address(void* x) { return address_word(x) ; }
466
467 // Pointer subtraction.
468 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
469 // the range we might need to find differences from one end of the heap
470 // to the other.
471 // A typical use might be:
472 // if (pointer_delta(end(), top()) >= size) {
473 // // enough room for an object of size
474 // ...
475 // and then additions like
476 // ... top() + size ...
477 // are safe because we know that top() is at least size below end().
478 inline size_t pointer_delta(const volatile void* left,
479 const volatile void* right,
480 size_t element_size) {
481 assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
482 return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
483 }
484
485 // A version specialized for HeapWord*'s.
486 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
487 return pointer_delta(left, right, sizeof(HeapWord));
488 }
489 // A version specialized for MetaWord*'s.
490 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
491 return pointer_delta(left, right, sizeof(MetaWord));
492 }
493
494 //
495 // ANSI C++ does not allow casting from one pointer type to a function pointer
496 // directly without at best a warning. This macro accomplishes it silently
497 // In every case that is present at this point the value be cast is a pointer
498 // to a C linkage function. In some case the type used for the cast reflects
499 // that linkage and a picky compiler would not complain. In other cases because
500 // there is no convenient place to place a typedef with extern C linkage (i.e
501 // a platform dependent header file) it doesn't. At this point no compiler seems
502 // picky enough to catch these instances (which are few). It is possible that
503 // using templates could fix these for all cases. This use of templates is likely
504 // so far from the middle of the road that it is likely to be problematic in
505 // many C++ compilers.
506 //
507 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
508 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((address_word)(func_ptr)))
509
510 // In many places we've added C-style casts to silence compiler
511 // warnings, for example when truncating a size_t to an int when we
512 // know the size_t is a small struct. Such casts are risky because
513 // they effectively disable useful compiler warnings. We can make our
514 // lives safer with this function, which ensures that any cast is
515 // reversible without loss of information. It doesn't check
516 // everything: it isn't intended to make sure that pointer types are
517 // compatible, for example.
518 template <typename T2, typename T1>
519 T2 checked_cast(T1 thing) {
520 T2 result = static_cast<T2>(thing);
521 assert(static_cast<T1>(result) == thing, "must be");
522 return result;
523 }
524
525 // Need the correct linkage to call qsort without warnings
526 extern "C" {
527 typedef int (*_sort_Fn)(const void *, const void *);
528 }
529
530 // Additional Java basic types
531
532 typedef uint8_t jubyte;
533 typedef uint16_t jushort;
534 typedef uint32_t juint;
535 typedef uint64_t julong;
536
537 // Unsigned byte types for os and stream.hpp
538
539 // Unsigned one, two, four and eight byte quantities used for describing
540 // the .class file format. See JVM book chapter 4.
541
542 typedef jubyte u1;
543 typedef jushort u2;
544 typedef juint u4;
545 typedef julong u8;
546
547 const jubyte max_jubyte = (jubyte)-1; // 0xFF largest jubyte
548 const jushort max_jushort = (jushort)-1; // 0xFFFF largest jushort
549 const juint max_juint = (juint)-1; // 0xFFFFFFFF largest juint
550 const julong max_julong = (julong)-1; // 0xFF....FF largest julong
551
552 typedef jbyte s1;
553 typedef jshort s2;
554 typedef jint s4;
555 typedef jlong s8;
556
557 const jbyte min_jbyte = -(1 << 7); // smallest jbyte
558 const jbyte max_jbyte = (1 << 7) - 1; // largest jbyte
559 const jshort min_jshort = -(1 << 15); // smallest jshort
560 const jshort max_jshort = (1 << 15) - 1; // largest jshort
561
562 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
563 const jint max_jint = (juint)min_jint - 1; // 0x7FFFFFFF == largest jint
564
565 const jint min_jintFloat = (jint)(0x00000001);
566 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
567 const jint max_jintFloat = (jint)(0x7f7fffff);
568 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
569
570 //----------------------------------------------------------------------------------------------------
571 // JVM spec restrictions
572
573 const int max_method_code_size = 64*K - 1; // JVM spec, 2nd ed. section 4.8.1 (p.134)
574
575 //----------------------------------------------------------------------------------------------------
576 // old CDS options
577 extern bool DumpSharedSpaces;
578 extern bool DynamicDumpSharedSpaces;
579 extern bool RequireSharedSpaces;
580 extern "C" {
581 // Make sure UseSharedSpaces is accessible to the serviceability agent.
582 extern JNIEXPORT jboolean UseSharedSpaces;
583 }
584
585 //----------------------------------------------------------------------------------------------------
586 // Object alignment, in units of HeapWords.
587 //
588 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
589 // reference fields can be naturally aligned.
590
591 extern int MinObjAlignment;
592 extern int MinObjAlignmentInBytes;
593 extern int MinObjAlignmentInBytesMask;
594
595 extern int LogMinObjAlignment;
596 extern int LogMinObjAlignmentInBytes;
597
598 const int LogKlassAlignmentInBytes = 3;
599 const int LogKlassAlignment = LogKlassAlignmentInBytes - LogHeapWordSize;
600 const int KlassAlignmentInBytes = 1 << LogKlassAlignmentInBytes;
601 const int KlassAlignment = KlassAlignmentInBytes / HeapWordSize;
602
603 // Maximal size of heap where unscaled compression can be used. Also upper bound
604 // for heap placement: 4GB.
605 const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
606 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
607 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
608 extern uint64_t OopEncodingHeapMax;
609
610 // Maximal size of compressed class space. Above this limit compression is not possible.
611 // Also upper bound for placement of zero based class space. (Class space is further limited
612 // to be < 3G, see arguments.cpp.)
613 const uint64_t KlassEncodingMetaspaceMax = (uint64_t(max_juint) + 1) << LogKlassAlignmentInBytes;
614
615 // Machine dependent stuff
616
617 // The maximum size of the code cache. Can be overridden by targets.
618 #define CODE_CACHE_SIZE_LIMIT (2*G)
619 // Allow targets to reduce the default size of the code cache.
620 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
621
622 #include CPU_HEADER(globalDefinitions)
623
624 // To assure the IRIW property on processors that are not multiple copy
625 // atomic, sync instructions must be issued between volatile reads to
626 // assure their ordering, instead of after volatile stores.
627 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
628 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
629 #ifdef CPU_MULTI_COPY_ATOMIC
630 // Not needed.
631 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
632 #else
633 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
634 // Final decision is subject to JEP 188: Java Memory Model Update.
635 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
636 #endif
637
638 // The expected size in bytes of a cache line, used to pad data structures.
639 #ifndef DEFAULT_CACHE_LINE_SIZE
640 #define DEFAULT_CACHE_LINE_SIZE 64
641 #endif
642
643
644 //----------------------------------------------------------------------------------------------------
645 // Utility macros for compilers
646 // used to silence compiler warnings
647
648 #define Unused_Variable(var) var
649
650
651 //----------------------------------------------------------------------------------------------------
652 // Miscellaneous
653
654 // 6302670 Eliminate Hotspot __fabsf dependency
655 // All fabs() callers should call this function instead, which will implicitly
656 // convert the operand to double, avoiding a dependency on __fabsf which
657 // doesn't exist in early versions of Solaris 8.
658 inline double fabsd(double value) {
659 return fabs(value);
660 }
661
662 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
663 // is zero, return 0.0.
664 template<typename T>
665 inline double percent_of(T numerator, T denominator) {
666 return denominator != 0 ? (double)numerator / denominator * 100.0 : 0.0;
667 }
668
669 //----------------------------------------------------------------------------------------------------
670 // Special casts
671 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
672 typedef union {
673 jfloat f;
674 jint i;
675 } FloatIntConv;
676
677 typedef union {
678 jdouble d;
679 jlong l;
680 julong ul;
681 } DoubleLongConv;
682
683 inline jint jint_cast (jfloat x) { return ((FloatIntConv*)&x)->i; }
684 inline jfloat jfloat_cast (jint x) { return ((FloatIntConv*)&x)->f; }
685
686 inline jlong jlong_cast (jdouble x) { return ((DoubleLongConv*)&x)->l; }
687 inline julong julong_cast (jdouble x) { return ((DoubleLongConv*)&x)->ul; }
688 inline jdouble jdouble_cast (jlong x) { return ((DoubleLongConv*)&x)->d; }
689
690 inline jint low (jlong value) { return jint(value); }
691 inline jint high(jlong value) { return jint(value >> 32); }
692
693 // the fancy casts are a hopefully portable way
694 // to do unsigned 32 to 64 bit type conversion
695 inline void set_low (jlong* value, jint low ) { *value &= (jlong)0xffffffff << 32;
696 *value |= (jlong)(julong)(juint)low; }
697
698 inline void set_high(jlong* value, jint high) { *value &= (jlong)(julong)(juint)0xffffffff;
699 *value |= (jlong)high << 32; }
700
701 inline jlong jlong_from(jint h, jint l) {
702 jlong result = 0; // initialization to avoid warning
703 set_high(&result, h);
704 set_low(&result, l);
705 return result;
706 }
707
708 union jlong_accessor {
709 jint words[2];
710 jlong long_value;
711 };
712
713 void basic_types_init(); // cannot define here; uses assert
714
715
716 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
717 enum BasicType {
718 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
719 T_BOOLEAN = JVM_T_BOOLEAN,
720 T_CHAR = JVM_T_CHAR,
721 T_FLOAT = JVM_T_FLOAT,
722 T_DOUBLE = JVM_T_DOUBLE,
723 T_BYTE = JVM_T_BYTE,
724 T_SHORT = JVM_T_SHORT,
725 T_INT = JVM_T_INT,
726 T_LONG = JVM_T_LONG,
727 // The remaining values are not part of any standard.
728 // T_OBJECT and T_VOID denote two more semantic choices
729 // for method return values.
730 // T_OBJECT and T_ARRAY describe signature syntax.
731 // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
732 // internal references within the JVM as if they were Java
733 // types in their own right.
734 T_OBJECT = 12,
735 T_ARRAY = 13,
736 T_VOID = 14,
737 T_ADDRESS = 15,
738 T_NARROWOOP = 16,
739 T_METADATA = 17,
740 T_NARROWKLASS = 18,
741 T_CONFLICT = 19, // for stack value type with conflicting contents
742 T_ILLEGAL = 99
743 };
744
745 #define SIGNATURE_TYPES_DO(F, N) \
746 F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N) \
747 F(JVM_SIGNATURE_CHAR, T_CHAR, N) \
748 F(JVM_SIGNATURE_FLOAT, T_FLOAT, N) \
749 F(JVM_SIGNATURE_DOUBLE, T_DOUBLE, N) \
750 F(JVM_SIGNATURE_BYTE, T_BYTE, N) \
751 F(JVM_SIGNATURE_SHORT, T_SHORT, N) \
752 F(JVM_SIGNATURE_INT, T_INT, N) \
753 F(JVM_SIGNATURE_LONG, T_LONG, N) \
754 F(JVM_SIGNATURE_CLASS, T_OBJECT, N) \
755 F(JVM_SIGNATURE_ARRAY, T_ARRAY, N) \
756 F(JVM_SIGNATURE_VOID, T_VOID, N) \
757 /*end*/
758
759 inline bool is_java_type(BasicType t) {
760 return T_BOOLEAN <= t && t <= T_VOID;
761 }
762
763 inline bool is_java_primitive(BasicType t) {
764 return T_BOOLEAN <= t && t <= T_LONG;
765 }
766
767 inline bool is_subword_type(BasicType t) {
768 // these guys are processed exactly like T_INT in calling sequences:
769 return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
770 }
771
772 inline bool is_signed_subword_type(BasicType t) {
773 return (t == T_BYTE || t == T_SHORT);
774 }
775
776 inline bool is_unsigned_subword_type(BasicType t) {
777 return (t == T_BOOLEAN || t == T_CHAR);
778 }
779
780 inline bool is_double_word_type(BasicType t) {
781 return (t == T_DOUBLE || t == T_LONG);
782 }
783
784 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
785 return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
786 }
787
788 inline bool is_integral_type(BasicType t) {
789 return is_subword_type(t) || t == T_INT || t == T_LONG;
790 }
791
792 inline bool is_non_subword_integral_type(BasicType t) {
793 return t == T_INT || t == T_LONG;
794 }
795
796 inline bool is_floating_point_type(BasicType t) {
797 return (t == T_FLOAT || t == T_DOUBLE);
798 }
799
800 extern char type2char_tab[T_CONFLICT+1]; // Map a BasicType to a jchar
801 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
802 extern int type2size[T_CONFLICT+1]; // Map BasicType to result stack elements
803 extern const char* type2name_tab[T_CONFLICT+1]; // Map a BasicType to a char*
804 extern BasicType name2type(const char* name);
805
806 const char* type2name(BasicType t);
807
808 inline jlong max_signed_integer(BasicType bt) {
809 if (bt == T_INT) {
810 return max_jint;
811 }
812 assert(bt == T_LONG, "unsupported");
813 return max_jlong;
814 }
815
816 inline jlong min_signed_integer(BasicType bt) {
817 if (bt == T_INT) {
818 return min_jint;
819 }
820 assert(bt == T_LONG, "unsupported");
821 return min_jlong;
822 }
823
824 // Auxiliary math routines
825 // least common multiple
826 extern size_t lcm(size_t a, size_t b);
827
828
829 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
830 enum BasicTypeSize {
831 T_BOOLEAN_size = 1,
832 T_CHAR_size = 1,
833 T_FLOAT_size = 1,
834 T_DOUBLE_size = 2,
835 T_BYTE_size = 1,
836 T_SHORT_size = 1,
837 T_INT_size = 1,
838 T_LONG_size = 2,
839 T_OBJECT_size = 1,
840 T_ARRAY_size = 1,
841 T_NARROWOOP_size = 1,
842 T_NARROWKLASS_size = 1,
843 T_VOID_size = 0
844 };
845
846 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
847 inline int parameter_type_word_count(BasicType t) {
848 if (is_double_word_type(t)) return 2;
849 assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
850 assert(type2size[t] == 1, "must be");
851 return 1;
852 }
853
854 // maps a BasicType to its instance field storage type:
855 // all sub-word integral types are widened to T_INT
856 extern BasicType type2field[T_CONFLICT+1];
857 extern BasicType type2wfield[T_CONFLICT+1];
858
859
860 // size in bytes
861 enum ArrayElementSize {
862 T_BOOLEAN_aelem_bytes = 1,
863 T_CHAR_aelem_bytes = 2,
864 T_FLOAT_aelem_bytes = 4,
865 T_DOUBLE_aelem_bytes = 8,
866 T_BYTE_aelem_bytes = 1,
867 T_SHORT_aelem_bytes = 2,
868 T_INT_aelem_bytes = 4,
869 T_LONG_aelem_bytes = 8,
870 #ifdef _LP64
871 T_OBJECT_aelem_bytes = 8,
872 T_ARRAY_aelem_bytes = 8,
873 #else
874 T_OBJECT_aelem_bytes = 4,
875 T_ARRAY_aelem_bytes = 4,
876 #endif
877 T_NARROWOOP_aelem_bytes = 4,
878 T_NARROWKLASS_aelem_bytes = 4,
879 T_VOID_aelem_bytes = 0
880 };
881
882 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
883 #ifdef ASSERT
884 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
885 #else
886 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
887 #endif
888
889 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
890 return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
891 }
892
893 // JavaValue serves as a container for arbitrary Java values.
894
895 class JavaValue {
896
897 public:
898 typedef union JavaCallValue {
899 jfloat f;
900 jdouble d;
901 jint i;
902 jlong l;
903 jobject h;
904 oopDesc* o;
905 } JavaCallValue;
906
907 private:
908 BasicType _type;
909 JavaCallValue _value;
910
911 public:
912 JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
913
914 JavaValue(jfloat value) {
915 _type = T_FLOAT;
916 _value.f = value;
917 }
918
919 JavaValue(jdouble value) {
920 _type = T_DOUBLE;
921 _value.d = value;
922 }
923
924 jfloat get_jfloat() const { return _value.f; }
925 jdouble get_jdouble() const { return _value.d; }
926 jint get_jint() const { return _value.i; }
927 jlong get_jlong() const { return _value.l; }
928 jobject get_jobject() const { return _value.h; }
929 oopDesc* get_oop() const { return _value.o; }
930 JavaCallValue* get_value_addr() { return &_value; }
931 BasicType get_type() const { return _type; }
932
933 void set_jfloat(jfloat f) { _value.f = f;}
934 void set_jdouble(jdouble d) { _value.d = d;}
935 void set_jint(jint i) { _value.i = i;}
936 void set_jlong(jlong l) { _value.l = l;}
937 void set_jobject(jobject h) { _value.h = h;}
938 void set_oop(oopDesc* o) { _value.o = o;}
939 void set_type(BasicType t) { _type = t; }
940
941 jboolean get_jboolean() const { return (jboolean) (_value.i);}
942 jbyte get_jbyte() const { return (jbyte) (_value.i);}
943 jchar get_jchar() const { return (jchar) (_value.i);}
944 jshort get_jshort() const { return (jshort) (_value.i);}
945
946 };
947
948
949 // TosState describes the top-of-stack state before and after the execution of
950 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
951 // registers. The TosState corresponds to the 'machine representation' of this cached
952 // value. There's 4 states corresponding to the JAVA types int, long, float & double
953 // as well as a 5th state in case the top-of-stack value is actually on the top
954 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
955 // state when it comes to machine representation but is used separately for (oop)
956 // type specific operations (e.g. verification code).
957
958 enum TosState { // describes the tos cache contents
959 btos = 0, // byte, bool tos cached
960 ztos = 1, // byte, bool tos cached
961 ctos = 2, // char tos cached
962 stos = 3, // short tos cached
963 itos = 4, // int tos cached
964 ltos = 5, // long tos cached
965 ftos = 6, // float tos cached
966 dtos = 7, // double tos cached
967 atos = 8, // object cached
968 vtos = 9, // tos not cached
969 number_of_states,
970 ilgl // illegal state: should not occur
971 };
972
973
974 inline TosState as_TosState(BasicType type) {
975 switch (type) {
976 case T_BYTE : return btos;
977 case T_BOOLEAN: return ztos;
978 case T_CHAR : return ctos;
979 case T_SHORT : return stos;
980 case T_INT : return itos;
981 case T_LONG : return ltos;
982 case T_FLOAT : return ftos;
983 case T_DOUBLE : return dtos;
984 case T_VOID : return vtos;
985 case T_ARRAY : // fall through
986 case T_OBJECT : return atos;
987 default : return ilgl;
988 }
989 }
990
991 inline BasicType as_BasicType(TosState state) {
992 switch (state) {
993 case btos : return T_BYTE;
994 case ztos : return T_BOOLEAN;
995 case ctos : return T_CHAR;
996 case stos : return T_SHORT;
997 case itos : return T_INT;
998 case ltos : return T_LONG;
999 case ftos : return T_FLOAT;
1000 case dtos : return T_DOUBLE;
1001 case atos : return T_OBJECT;
1002 case vtos : return T_VOID;
1003 default : return T_ILLEGAL;
1004 }
1005 }
1006
1007
1008 // Helper function to convert BasicType info into TosState
1009 // Note: Cannot define here as it uses global constant at the time being.
1010 TosState as_TosState(BasicType type);
1011
1012
1013 // JavaThreadState keeps track of which part of the code a thread is executing in. This
1014 // information is needed by the safepoint code.
1015 //
1016 // There are 4 essential states:
1017 //
1018 // _thread_new : Just started, but not executed init. code yet (most likely still in OS init code)
1019 // _thread_in_native : In native code. This is a safepoint region, since all oops will be in jobject handles
1020 // _thread_in_vm : Executing in the vm
1021 // _thread_in_Java : Executing either interpreted or compiled Java code (or could be in a stub)
1022 //
1023 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1024 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1025 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1026 //
1027 // Given a state, the xxxx_trans state can always be found by adding 1.
1028 //
1029 enum JavaThreadState {
1030 _thread_uninitialized = 0, // should never happen (missing initialization)
1031 _thread_new = 2, // just starting up, i.e., in process of being initialized
1032 _thread_new_trans = 3, // corresponding transition state (not used, included for completeness)
1033 _thread_in_native = 4, // running in native code
1034 _thread_in_native_trans = 5, // corresponding transition state
1035 _thread_in_vm = 6, // running in VM
1036 _thread_in_vm_trans = 7, // corresponding transition state
1037 _thread_in_Java = 8, // running in Java or in stub code
1038 _thread_in_Java_trans = 9, // corresponding transition state (not used, included for completeness)
1039 _thread_blocked = 10, // blocked in vm
1040 _thread_blocked_trans = 11, // corresponding transition state
1041 _thread_max_state = 12 // maximum thread state+1 - used for statistics allocation
1042 };
1043
1044 //----------------------------------------------------------------------------------------------------
1045 // Special constants for debugging
1046
1047 const jint badInt = -3; // generic "bad int" value
1048 const intptr_t badAddressVal = -2; // generic "bad address" value
1049 const intptr_t badOopVal = -1; // generic "bad oop" value
1050 const intptr_t badHeapOopVal = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1051 const int badStackSegVal = 0xCA; // value used to zap stack segments
1052 const int badHandleValue = 0xBC; // value used to zap vm handle area
1053 const int badResourceValue = 0xAB; // value used to zap resource area
1054 const int freeBlockPad = 0xBA; // value used to pad freed blocks.
1055 const int uninitBlockPad = 0xF1; // value used to zap newly malloc'd blocks.
1056 const juint uninitMetaWordVal= 0xf7f7f7f7; // value used to zap newly allocated metachunk
1057 const juint badHeapWordVal = 0xBAADBABE; // value used to zap heap after GC
1058 const juint badMetaWordVal = 0xBAADFADE; // value used to zap metadata heap after GC
1059 const int badCodeHeapNewVal= 0xCC; // value used to zap Code heap at allocation
1060 const int badCodeHeapFreeVal = 0xDD; // value used to zap Code heap at deallocation
1061
1062
1063 // (These must be implemented as #defines because C++ compilers are
1064 // not obligated to inline non-integral constants!)
1065 #define badAddress ((address)::badAddressVal)
1066 #define badHeapWord (::badHeapWordVal)
1067
1068 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1069 #define TASKQUEUE_SIZE (NOT_LP64(1<<14) LP64_ONLY(1<<17))
1070
1071 //----------------------------------------------------------------------------------------------------
1072 // Utility functions for bitfield manipulations
1073
1074 const intptr_t AllBits = ~0; // all bits set in a word
1075 const intptr_t NoBits = 0; // no bits set in a word
1076 const jlong NoLongBits = 0; // no bits set in a long
1077 const intptr_t OneBit = 1; // only right_most bit set in a word
1078
1079 // get a word with the n.th or the right-most or left-most n bits set
1080 // (note: #define used only so that they can be used in enum constant definitions)
1081 #define nth_bit(n) (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1082 #define right_n_bits(n) (nth_bit(n) - 1)
1083
1084 // bit-operations using a mask m
1085 inline void set_bits (intptr_t& x, intptr_t m) { x |= m; }
1086 inline void clear_bits (intptr_t& x, intptr_t m) { x &= ~m; }
1087 inline intptr_t mask_bits (intptr_t x, intptr_t m) { return x & m; }
1088 inline jlong mask_long_bits (jlong x, jlong m) { return x & m; }
1089 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1090
1091 // bit-operations using the n.th bit
1092 inline void set_nth_bit(intptr_t& x, int n) { set_bits (x, nth_bit(n)); }
1093 inline void clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1094 inline bool is_set_nth_bit(intptr_t x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1095
1096 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1097 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1098 return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1099 }
1100
1101
1102 //----------------------------------------------------------------------------------------------------
1103 // Utility functions for integers
1104
1105 // Avoid use of global min/max macros which may cause unwanted double
1106 // evaluation of arguments.
1107 #ifdef max
1108 #undef max
1109 #endif
1110
1111 #ifdef min
1112 #undef min
1113 #endif
1114
1115 // It is necessary to use templates here. Having normal overloaded
1116 // functions does not work because it is necessary to provide both 32-
1117 // and 64-bit overloaded functions, which does not work, and having
1118 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1119 // will be even more error-prone than macros.
1120 template<class T> constexpr T MAX2(T a, T b) { return (a > b) ? a : b; }
1121 template<class T> constexpr T MIN2(T a, T b) { return (a < b) ? a : b; }
1122 template<class T> constexpr T MAX3(T a, T b, T c) { return MAX2(MAX2(a, b), c); }
1123 template<class T> constexpr T MIN3(T a, T b, T c) { return MIN2(MIN2(a, b), c); }
1124 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1125 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1126
1127 template<class T> inline T ABS(T x) { return (x > 0) ? x : -x; }
1128
1129 // Return the given value clamped to the range [min ... max]
1130 template<typename T>
1131 inline T clamp(T value, T min, T max) {
1132 assert(min <= max, "must be");
1133 return MIN2(MAX2(value, min), max);
1134 }
1135
1136 inline bool is_odd (intx x) { return x & 1; }
1137 inline bool is_even(intx x) { return !is_odd(x); }
1138
1139 // abs methods which cannot overflow and so are well-defined across
1140 // the entire domain of integer types.
1141 static inline unsigned int uabs(unsigned int n) {
1142 union {
1143 unsigned int result;
1144 int value;
1145 };
1146 result = n;
1147 if (value < 0) result = 0-result;
1148 return result;
1149 }
1150 static inline julong uabs(julong n) {
1151 union {
1152 julong result;
1153 jlong value;
1154 };
1155 result = n;
1156 if (value < 0) result = 0-result;
1157 return result;
1158 }
1159 static inline julong uabs(jlong n) { return uabs((julong)n); }
1160 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1161
1162 // "to" should be greater than "from."
1163 inline intx byte_size(void* from, void* to) {
1164 return (address)to - (address)from;
1165 }
1166
1167 // Pack and extract shorts to/from ints:
1168
1169 inline int extract_low_short_from_int(jint x) {
1170 return x & 0xffff;
1171 }
1172
1173 inline int extract_high_short_from_int(jint x) {
1174 return (x >> 16) & 0xffff;
1175 }
1176
1177 inline int build_int_from_shorts( jushort low, jushort high ) {
1178 return ((int)((unsigned int)high << 16) | (unsigned int)low);
1179 }
1180
1181 // swap a & b
1182 template<class T> static void swap(T& a, T& b) {
1183 T tmp = a;
1184 a = b;
1185 b = tmp;
1186 }
1187
1188 // array_size_impl is a function that takes a reference to T[N] and
1189 // returns a reference to char[N]. It is not ODR-used, so not defined.
1190 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1191
1192 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1193
1194 //----------------------------------------------------------------------------------------------------
1195 // Sum and product which can never overflow: they wrap, just like the
1196 // Java operations. Note that we don't intend these to be used for
1197 // general-purpose arithmetic: their purpose is to emulate Java
1198 // operations.
1199
1200 // The goal of this code to avoid undefined or implementation-defined
1201 // behavior. The use of an lvalue to reference cast is explicitly
1202 // permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1203 // 15 in C++03]
1204 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1205 inline TYPE NAME (TYPE in1, TYPE in2) { \
1206 UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1207 ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1208 return reinterpret_cast<TYPE&>(ures); \
1209 }
1210
1211 JAVA_INTEGER_OP(+, java_add, jint, juint)
1212 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1213 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1214 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1215 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1216 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1217
1218 #undef JAVA_INTEGER_OP
1219
1220 // Provide integer shift operations with Java semantics. No overflow
1221 // issues - left shifts simply discard shifted out bits. No undefined
1222 // behavior for large or negative shift quantities; instead the actual
1223 // shift distance is the argument modulo the lhs value's size in bits.
1224 // No undefined or implementation defined behavior for shifting negative
1225 // values; left shift discards bits, right shift sign extends. We use
1226 // the same safe conversion technique as above for java_add and friends.
1227 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE) \
1228 inline TYPE NAME (TYPE lhs, jint rhs) { \
1229 const uint rhs_mask = (sizeof(TYPE) * 8) - 1; \
1230 STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63); \
1231 XTYPE xres = static_cast<XTYPE>(lhs); \
1232 xres OP ## = (rhs & rhs_mask); \
1233 return reinterpret_cast<TYPE&>(xres); \
1234 }
1235
1236 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1237 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1238 // For signed shift right, assume C++ implementation >> sign extends.
1239 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1240 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1241 // For >>> use C++ unsigned >>.
1242 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1243 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1244
1245 #undef JAVA_INTEGER_SHIFT_OP
1246
1247 //----------------------------------------------------------------------------------------------------
1248 // The goal of this code is to provide saturating operations for int/uint.
1249 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1250 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1251 inline int NAME (TYPE1 in1, TYPE2 in2) { \
1252 jlong res = static_cast<jlong>(in1); \
1253 res OP ## = static_cast<jlong>(in2); \
1254 if (res > max_jint) { \
1255 res = max_jint; \
1256 } else if (res < min_jint) { \
1257 res = min_jint; \
1258 } \
1259 return static_cast<int>(res); \
1260 }
1261
1262 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1263 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1264 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1265 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1266
1267 #undef SATURATED_INTEGER_OP
1268
1269 // Dereference vptr
1270 // All C++ compilers that we know of have the vtbl pointer in the first
1271 // word. If there are exceptions, this function needs to be made compiler
1272 // specific.
1273 static inline void* dereference_vptr(const void* addr) {
1274 return *(void**)addr;
1275 }
1276
1277 //----------------------------------------------------------------------------------------------------
1278 // String type aliases used by command line flag declarations and
1279 // processing utilities.
1280
1281 typedef const char* ccstr;
1282 typedef const char* ccstrlist; // represents string arguments which accumulate
1283
1284 //----------------------------------------------------------------------------------------------------
1285 // Default hash/equals functions used by ResourceHashtable
1286
1287 template<typename K> unsigned primitive_hash(const K& k) {
1288 unsigned hash = (unsigned)((uintptr_t)k);
1289 return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1290 }
1291
1292 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1293 return k0 == k1;
1294 }
1295
1296 //----------------------------------------------------------------------------------------------------
1297
1298 // Allow use of C++ thread_local when approved - see JDK-8282469.
1299 #define APPROVED_CPP_THREAD_LOCAL thread_local
1300
1301 // Converts any type T to a reference type.
1302 template<typename T>
1303 std::add_rvalue_reference_t<T> declval() noexcept;
1304
1305 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP