1 /*
2 * Copyright (c) 1997, 2024, 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 #define RANGEFMT "[" PTR_FORMAT " - " PTR_FORMAT "), (" SIZE_FORMAT " bytes)"
383 #define RANGEFMTARGS(p1, size) p2i(p1), p2i(p1 + size), size
384
385 inline const char* exact_unit_for_byte_size(size_t s) {
386 #ifdef _LP64
387 if (s >= G && (s % G) == 0) {
388 return "G";
389 }
390 #endif
391 if (s >= M && (s % M) == 0) {
392 return "M";
393 }
394 if (s >= K && (s % K) == 0) {
395 return "K";
396 }
397 return "B";
398 }
399
400 inline size_t byte_size_in_exact_unit(size_t s) {
401 #ifdef _LP64
402 if (s >= G && (s % G) == 0) {
403 return s / G;
404 }
405 #endif
406 if (s >= M && (s % M) == 0) {
407 return s / M;
408 }
409 if (s >= K && (s % K) == 0) {
410 return s / K;
411 }
412 return s;
413 }
414
415 #define EXACTFMT SIZE_FORMAT "%s"
416 #define EXACTFMTARGS(s) byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
417
418 // Memory size transition formatting.
419
420 #define HEAP_CHANGE_FORMAT "%s: " SIZE_FORMAT "K(" SIZE_FORMAT "K)->" SIZE_FORMAT "K(" SIZE_FORMAT "K)"
421
422 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
423 (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
424
425 //----------------------------------------------------------------------------------------------------
426 // VM type definitions
427
428 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
429 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
430
431 typedef intptr_t intx;
432 typedef uintptr_t uintx;
433
434 const intx min_intx = (intx)1 << (sizeof(intx)*BitsPerByte-1);
435 const intx max_intx = (uintx)min_intx - 1;
436 const uintx max_uintx = (uintx)-1;
437
438 // Table of values:
439 // sizeof intx 4 8
440 // min_intx 0x80000000 0x8000000000000000
441 // max_intx 0x7FFFFFFF 0x7FFFFFFFFFFFFFFF
442 // max_uintx 0xFFFFFFFF 0xFFFFFFFFFFFFFFFF
443
444 typedef unsigned int uint; NEEDS_CLEANUP
445
446 //----------------------------------------------------------------------------------------------------
447 // Java type definitions
448
449 // All kinds of 'plain' byte addresses
450 typedef signed char s_char;
451 typedef unsigned char u_char;
452 typedef u_char* address;
453
454 // Pointer subtraction.
455 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
456 // the range we might need to find differences from one end of the heap
457 // to the other.
458 // A typical use might be:
459 // if (pointer_delta(end(), top()) >= size) {
460 // // enough room for an object of size
461 // ...
462 // and then additions like
463 // ... top() + size ...
464 // are safe because we know that top() is at least size below end().
465 inline size_t pointer_delta(const volatile void* left,
466 const volatile void* right,
467 size_t element_size) {
468 assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
469 return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
470 }
471
472 // A version specialized for HeapWord*'s.
473 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
474 return pointer_delta(left, right, sizeof(HeapWord));
475 }
476 // A version specialized for MetaWord*'s.
477 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
478 return pointer_delta(left, right, sizeof(MetaWord));
479 }
480
481 // pointer_delta_as_int is called to do pointer subtraction for nearby pointers that
482 // returns a non-negative int, usually used as a size of a code buffer range.
483 // This scales to sizeof(T).
484 template <typename T>
485 inline int pointer_delta_as_int(const volatile T* left, const volatile T* right) {
486 size_t delta = pointer_delta(left, right, sizeof(T));
487 assert(delta <= size_t(INT_MAX), "pointer delta out of range: %zu", delta);
488 return static_cast<int>(delta);
489 }
490
491 //
492 // ANSI C++ does not allow casting from one pointer type to a function pointer
493 // directly without at best a warning. This macro accomplishes it silently
494 // In every case that is present at this point the value be cast is a pointer
495 // to a C linkage function. In some case the type used for the cast reflects
496 // that linkage and a picky compiler would not complain. In other cases because
497 // there is no convenient place to place a typedef with extern C linkage (i.e
498 // a platform dependent header file) it doesn't. At this point no compiler seems
499 // picky enough to catch these instances (which are few). It is possible that
500 // using templates could fix these for all cases. This use of templates is likely
501 // so far from the middle of the road that it is likely to be problematic in
502 // many C++ compilers.
503 //
504 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
505 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((uintptr_t)(func_ptr)))
506
507 // Need the correct linkage to call qsort without warnings
508 extern "C" {
509 typedef int (*_sort_Fn)(const void *, const void *);
510 }
511
512 // Additional Java basic types
513
514 typedef uint8_t jubyte;
515 typedef uint16_t jushort;
516 typedef uint32_t juint;
517 typedef uint64_t julong;
518
519 // Unsigned byte types for os and stream.hpp
520
521 // Unsigned one, two, four and eight byte quantities used for describing
522 // the .class file format. See JVM book chapter 4.
523
524 typedef jubyte u1;
525 typedef jushort u2;
526 typedef juint u4;
527 typedef julong u8;
528
529 const jubyte max_jubyte = (jubyte)-1; // 0xFF largest jubyte
530 const jushort max_jushort = (jushort)-1; // 0xFFFF largest jushort
531 const juint max_juint = (juint)-1; // 0xFFFFFFFF largest juint
532 const julong max_julong = (julong)-1; // 0xFF....FF largest julong
533
534 typedef jbyte s1;
535 typedef jshort s2;
536 typedef jint s4;
537 typedef jlong s8;
538
539 const jbyte min_jbyte = -(1 << 7); // smallest jbyte
540 const jbyte max_jbyte = (1 << 7) - 1; // largest jbyte
541 const jshort min_jshort = -(1 << 15); // smallest jshort
542 const jshort max_jshort = (1 << 15) - 1; // largest jshort
543
544 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
545 const jint max_jint = (juint)min_jint - 1; // 0x7FFFFFFF == largest jint
546
547 const jint min_jintFloat = (jint)(0x00000001);
548 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
549 const jint max_jintFloat = (jint)(0x7f7fffff);
550 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
551
552 //----------------------------------------------------------------------------------------------------
553 // JVM spec restrictions
554
555 const int max_method_code_size = 64*K - 1; // JVM spec, 2nd ed. section 4.8.1 (p.134)
556
557 //----------------------------------------------------------------------------------------------------
558 // old CDS options
559 extern bool RequireSharedSpaces;
560 extern "C" {
561 // Make sure UseSharedSpaces is accessible to the serviceability agent.
562 extern JNIEXPORT jboolean UseSharedSpaces;
563 }
564
565 //----------------------------------------------------------------------------------------------------
566 // Object alignment, in units of HeapWords.
567 //
568 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
569 // reference fields can be naturally aligned.
570
571 extern int MinObjAlignment;
572 extern int MinObjAlignmentInBytes;
573 extern int MinObjAlignmentInBytesMask;
574
575 extern int LogMinObjAlignment;
576 extern int LogMinObjAlignmentInBytes;
577
578 // Maximal size of heap where unscaled compression can be used. Also upper bound
579 // for heap placement: 4GB.
580 const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
581 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
582 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
583 extern uint64_t OopEncodingHeapMax;
584
585 // Machine dependent stuff
586
587 #include CPU_HEADER(globalDefinitions)
588
589 // The maximum size of the code cache. Can be overridden by targets.
590 #ifndef CODE_CACHE_SIZE_LIMIT
591 #define CODE_CACHE_SIZE_LIMIT (2*G)
592 #endif
593
594 // Allow targets to reduce the default size of the code cache.
595 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
596
597 // To assure the IRIW property on processors that are not multiple copy
598 // atomic, sync instructions must be issued between volatile reads to
599 // assure their ordering, instead of after volatile stores.
600 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
601 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
602 #ifdef CPU_MULTI_COPY_ATOMIC
603 // Not needed.
604 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
605 #else
606 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
607 // Final decision is subject to JEP 188: Java Memory Model Update.
608 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
609 #endif
610
611 // The expected size in bytes of a cache line.
612 #ifndef DEFAULT_CACHE_LINE_SIZE
613 #error "Platform should define DEFAULT_CACHE_LINE_SIZE"
614 #endif
615
616 // The default padding size for data structures to avoid false sharing.
617 #ifndef DEFAULT_PADDING_SIZE
618 #error "Platform should define DEFAULT_PADDING_SIZE"
619 #endif
620
621
622 //----------------------------------------------------------------------------------------------------
623 // Miscellaneous
624
625 // 6302670 Eliminate Hotspot __fabsf dependency
626 // All fabs() callers should call this function instead, which will implicitly
627 // convert the operand to double, avoiding a dependency on __fabsf which
628 // doesn't exist in early versions of Solaris 8.
629 inline double fabsd(double value) {
630 return fabs(value);
631 }
632
633 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
634 // is zero, return 0.0.
635 template<typename T>
636 inline double percent_of(T numerator, T denominator) {
637 return denominator != 0 ? (double)numerator / (double)denominator * 100.0 : 0.0;
638 }
639
640 //----------------------------------------------------------------------------------------------------
641 // Special casts
642 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
643 typedef union {
644 jfloat f;
645 jint i;
646 } FloatIntConv;
647
648 typedef union {
649 jdouble d;
650 jlong l;
651 julong ul;
652 } DoubleLongConv;
653
654 inline jint jint_cast (jfloat x) { return ((FloatIntConv*)&x)->i; }
655 inline jfloat jfloat_cast (jint x) { return ((FloatIntConv*)&x)->f; }
656
657 inline jlong jlong_cast (jdouble x) { return ((DoubleLongConv*)&x)->l; }
658 inline julong julong_cast (jdouble x) { return ((DoubleLongConv*)&x)->ul; }
659 inline jdouble jdouble_cast (jlong x) { return ((DoubleLongConv*)&x)->d; }
660
661 inline jint low (jlong value) { return jint(value); }
662 inline jint high(jlong value) { return jint(value >> 32); }
663
664 // the fancy casts are a hopefully portable way
665 // to do unsigned 32 to 64 bit type conversion
666 inline void set_low (jlong* value, jint low ) { *value &= (jlong)0xffffffff << 32;
667 *value |= (jlong)(julong)(juint)low; }
668
669 inline void set_high(jlong* value, jint high) { *value &= (jlong)(julong)(juint)0xffffffff;
670 *value |= (jlong)high << 32; }
671
672 inline jlong jlong_from(jint h, jint l) {
673 jlong result = 0; // initialization to avoid warning
674 set_high(&result, h);
675 set_low(&result, l);
676 return result;
677 }
678
679 union jlong_accessor {
680 jint words[2];
681 jlong long_value;
682 };
683
684 void basic_types_init(); // cannot define here; uses assert
685
686
687 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
688 enum BasicType : u1 {
689 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
690 T_BOOLEAN = JVM_T_BOOLEAN,
691 T_CHAR = JVM_T_CHAR,
692 T_FLOAT = JVM_T_FLOAT,
693 T_DOUBLE = JVM_T_DOUBLE,
694 T_BYTE = JVM_T_BYTE,
695 T_SHORT = JVM_T_SHORT,
696 T_INT = JVM_T_INT,
697 T_LONG = JVM_T_LONG,
698 // The remaining values are not part of any standard.
699 // T_OBJECT and T_VOID denote two more semantic choices
700 // for method return values.
701 // T_OBJECT and T_ARRAY describe signature syntax.
702 // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
703 // internal references within the JVM as if they were Java
704 // types in their own right.
705 T_OBJECT = 12,
706 T_ARRAY = 13,
707 T_VOID = 14,
708 T_ADDRESS = 15,
709 T_NARROWOOP = 16,
710 T_METADATA = 17,
711 T_NARROWKLASS = 18,
712 T_CONFLICT = 19, // for stack value type with conflicting contents
713 T_ILLEGAL = 99
714 };
715
716 #define SIGNATURE_TYPES_DO(F, N) \
717 F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N) \
718 F(JVM_SIGNATURE_CHAR, T_CHAR, N) \
719 F(JVM_SIGNATURE_FLOAT, T_FLOAT, N) \
720 F(JVM_SIGNATURE_DOUBLE, T_DOUBLE, N) \
721 F(JVM_SIGNATURE_BYTE, T_BYTE, N) \
722 F(JVM_SIGNATURE_SHORT, T_SHORT, N) \
723 F(JVM_SIGNATURE_INT, T_INT, N) \
724 F(JVM_SIGNATURE_LONG, T_LONG, N) \
725 F(JVM_SIGNATURE_CLASS, T_OBJECT, N) \
726 F(JVM_SIGNATURE_ARRAY, T_ARRAY, N) \
727 F(JVM_SIGNATURE_VOID, T_VOID, N) \
728 /*end*/
729
730 inline bool is_java_type(BasicType t) {
731 return T_BOOLEAN <= t && t <= T_VOID;
732 }
733
734 inline bool is_java_primitive(BasicType t) {
735 return T_BOOLEAN <= t && t <= T_LONG;
736 }
737
738 inline bool is_subword_type(BasicType t) {
739 // these guys are processed exactly like T_INT in calling sequences:
740 return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
741 }
742
743 inline bool is_signed_subword_type(BasicType t) {
744 return (t == T_BYTE || t == T_SHORT);
745 }
746
747 inline bool is_unsigned_subword_type(BasicType t) {
748 return (t == T_BOOLEAN || t == T_CHAR);
749 }
750
751 inline bool is_double_word_type(BasicType t) {
752 return (t == T_DOUBLE || t == T_LONG);
753 }
754
755 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
756 return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
757 }
758
759 inline bool is_integral_type(BasicType t) {
760 return is_subword_type(t) || t == T_INT || t == T_LONG;
761 }
762
763 inline bool is_non_subword_integral_type(BasicType t) {
764 return t == T_INT || t == T_LONG;
765 }
766
767 inline bool is_floating_point_type(BasicType t) {
768 return (t == T_FLOAT || t == T_DOUBLE);
769 }
770
771 extern char type2char_tab[T_CONFLICT+1]; // Map a BasicType to a jchar
772 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
773 extern int type2size[T_CONFLICT+1]; // Map BasicType to result stack elements
774 extern const char* type2name_tab[T_CONFLICT+1]; // Map a BasicType to a char*
775 extern BasicType name2type(const char* name);
776
777 const char* type2name(BasicType t);
778
779 inline jlong max_signed_integer(BasicType bt) {
780 if (bt == T_INT) {
781 return max_jint;
782 }
783 assert(bt == T_LONG, "unsupported");
784 return max_jlong;
785 }
786
787 inline jlong min_signed_integer(BasicType bt) {
788 if (bt == T_INT) {
789 return min_jint;
790 }
791 assert(bt == T_LONG, "unsupported");
792 return min_jlong;
793 }
794
795 // Auxiliary math routines
796 // least common multiple
797 extern size_t lcm(size_t a, size_t b);
798
799
800 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
801 enum BasicTypeSize {
802 T_BOOLEAN_size = 1,
803 T_CHAR_size = 1,
804 T_FLOAT_size = 1,
805 T_DOUBLE_size = 2,
806 T_BYTE_size = 1,
807 T_SHORT_size = 1,
808 T_INT_size = 1,
809 T_LONG_size = 2,
810 T_OBJECT_size = 1,
811 T_ARRAY_size = 1,
812 T_NARROWOOP_size = 1,
813 T_NARROWKLASS_size = 1,
814 T_VOID_size = 0
815 };
816
817 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
818 inline int parameter_type_word_count(BasicType t) {
819 if (is_double_word_type(t)) return 2;
820 assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
821 assert(type2size[t] == 1, "must be");
822 return 1;
823 }
824
825 // maps a BasicType to its instance field storage type:
826 // all sub-word integral types are widened to T_INT
827 extern BasicType type2field[T_CONFLICT+1];
828 extern BasicType type2wfield[T_CONFLICT+1];
829
830
831 // size in bytes
832 enum ArrayElementSize {
833 T_BOOLEAN_aelem_bytes = 1,
834 T_CHAR_aelem_bytes = 2,
835 T_FLOAT_aelem_bytes = 4,
836 T_DOUBLE_aelem_bytes = 8,
837 T_BYTE_aelem_bytes = 1,
838 T_SHORT_aelem_bytes = 2,
839 T_INT_aelem_bytes = 4,
840 T_LONG_aelem_bytes = 8,
841 #ifdef _LP64
842 T_OBJECT_aelem_bytes = 8,
843 T_ARRAY_aelem_bytes = 8,
844 #else
845 T_OBJECT_aelem_bytes = 4,
846 T_ARRAY_aelem_bytes = 4,
847 #endif
848 T_NARROWOOP_aelem_bytes = 4,
849 T_NARROWKLASS_aelem_bytes = 4,
850 T_VOID_aelem_bytes = 0
851 };
852
853 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
854 #ifdef ASSERT
855 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
856 #else
857 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
858 #endif
859
860 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
861 return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
862 }
863
864 // JavaValue serves as a container for arbitrary Java values.
865
866 class JavaValue {
867
868 public:
869 typedef union JavaCallValue {
870 jfloat f;
871 jdouble d;
872 jint i;
873 jlong l;
874 jobject h;
875 oopDesc* o;
876 } JavaCallValue;
877
878 private:
879 BasicType _type;
880 JavaCallValue _value;
881
882 public:
883 JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
884
885 JavaValue(jfloat value) {
886 _type = T_FLOAT;
887 _value.f = value;
888 }
889
890 JavaValue(jdouble value) {
891 _type = T_DOUBLE;
892 _value.d = value;
893 }
894
895 jfloat get_jfloat() const { return _value.f; }
896 jdouble get_jdouble() const { return _value.d; }
897 jint get_jint() const { return _value.i; }
898 jlong get_jlong() const { return _value.l; }
899 jobject get_jobject() const { return _value.h; }
900 oopDesc* get_oop() const { return _value.o; }
901 JavaCallValue* get_value_addr() { return &_value; }
902 BasicType get_type() const { return _type; }
903
904 void set_jfloat(jfloat f) { _value.f = f;}
905 void set_jdouble(jdouble d) { _value.d = d;}
906 void set_jint(jint i) { _value.i = i;}
907 void set_jlong(jlong l) { _value.l = l;}
908 void set_jobject(jobject h) { _value.h = h;}
909 void set_oop(oopDesc* o) { _value.o = o;}
910 void set_type(BasicType t) { _type = t; }
911
912 jboolean get_jboolean() const { return (jboolean) (_value.i);}
913 jbyte get_jbyte() const { return (jbyte) (_value.i);}
914 jchar get_jchar() const { return (jchar) (_value.i);}
915 jshort get_jshort() const { return (jshort) (_value.i);}
916
917 };
918
919
920 // TosState describes the top-of-stack state before and after the execution of
921 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
922 // registers. The TosState corresponds to the 'machine representation' of this cached
923 // value. There's 4 states corresponding to the JAVA types int, long, float & double
924 // as well as a 5th state in case the top-of-stack value is actually on the top
925 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
926 // state when it comes to machine representation but is used separately for (oop)
927 // type specific operations (e.g. verification code).
928
929 enum TosState { // describes the tos cache contents
930 btos = 0, // byte, bool tos cached
931 ztos = 1, // byte, bool tos cached
932 ctos = 2, // char tos cached
933 stos = 3, // short tos cached
934 itos = 4, // int tos cached
935 ltos = 5, // long tos cached
936 ftos = 6, // float tos cached
937 dtos = 7, // double tos cached
938 atos = 8, // object cached
939 vtos = 9, // tos not cached
940 number_of_states,
941 ilgl // illegal state: should not occur
942 };
943
944
945 inline TosState as_TosState(BasicType type) {
946 switch (type) {
947 case T_BYTE : return btos;
948 case T_BOOLEAN: return ztos;
949 case T_CHAR : return ctos;
950 case T_SHORT : return stos;
951 case T_INT : return itos;
952 case T_LONG : return ltos;
953 case T_FLOAT : return ftos;
954 case T_DOUBLE : return dtos;
955 case T_VOID : return vtos;
956 case T_ARRAY : // fall through
957 case T_OBJECT : return atos;
958 default : return ilgl;
959 }
960 }
961
962 inline BasicType as_BasicType(TosState state) {
963 switch (state) {
964 case btos : return T_BYTE;
965 case ztos : return T_BOOLEAN;
966 case ctos : return T_CHAR;
967 case stos : return T_SHORT;
968 case itos : return T_INT;
969 case ltos : return T_LONG;
970 case ftos : return T_FLOAT;
971 case dtos : return T_DOUBLE;
972 case atos : return T_OBJECT;
973 case vtos : return T_VOID;
974 default : return T_ILLEGAL;
975 }
976 }
977
978
979 // Helper function to convert BasicType info into TosState
980 // Note: Cannot define here as it uses global constant at the time being.
981 TosState as_TosState(BasicType type);
982
983
984 // JavaThreadState keeps track of which part of the code a thread is executing in. This
985 // information is needed by the safepoint code.
986 //
987 // There are 4 essential states:
988 //
989 // _thread_new : Just started, but not executed init. code yet (most likely still in OS init code)
990 // _thread_in_native : In native code. This is a safepoint region, since all oops will be in jobject handles
991 // _thread_in_vm : Executing in the vm
992 // _thread_in_Java : Executing either interpreted or compiled Java code (or could be in a stub)
993 //
994 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
995 // a transition from one state to another. These extra states makes it possible for the safepoint code to
996 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
997 //
998 // Given a state, the xxxx_trans state can always be found by adding 1.
999 //
1000 enum JavaThreadState {
1001 _thread_uninitialized = 0, // should never happen (missing initialization)
1002 _thread_new = 2, // just starting up, i.e., in process of being initialized
1003 _thread_new_trans = 3, // corresponding transition state (not used, included for completeness)
1004 _thread_in_native = 4, // running in native code
1005 _thread_in_native_trans = 5, // corresponding transition state
1006 _thread_in_vm = 6, // running in VM
1007 _thread_in_vm_trans = 7, // corresponding transition state
1008 _thread_in_Java = 8, // running in Java or in stub code
1009 _thread_in_Java_trans = 9, // corresponding transition state (not used, included for completeness)
1010 _thread_blocked = 10, // blocked in vm
1011 _thread_blocked_trans = 11, // corresponding transition state
1012 _thread_max_state = 12 // maximum thread state+1 - used for statistics allocation
1013 };
1014
1015 enum LockingMode {
1016 // Use only heavy monitors for locking
1017 LM_MONITOR = 0,
1018 // Legacy stack-locking, with monitors as 2nd tier
1019 LM_LEGACY = 1,
1020 // New lightweight locking, with monitors as 2nd tier
1021 LM_LIGHTWEIGHT = 2
1022 };
1023
1024 //----------------------------------------------------------------------------------------------------
1025 // Special constants for debugging
1026
1027 const jint badInt = -3; // generic "bad int" value
1028 const intptr_t badAddressVal = -2; // generic "bad address" value
1029 const intptr_t badOopVal = -1; // generic "bad oop" value
1030 const intptr_t badHeapOopVal = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1031 const int badStackSegVal = 0xCA; // value used to zap stack segments
1032 const int badHandleValue = 0xBC; // value used to zap vm handle area
1033 const int badResourceValue = 0xAB; // value used to zap resource area
1034 const int freeBlockPad = 0xBA; // value used to pad freed blocks.
1035 const int uninitBlockPad = 0xF1; // value used to zap newly malloc'd blocks.
1036 const juint uninitMetaWordVal = 0xf7f7f7f7; // value used to zap newly allocated metachunk
1037 const jubyte heapPaddingByteVal = 0xBD; // value used to zap object padding in the heap
1038 const juint badHeapWordVal = 0xBAADBABE; // value used to zap heap after GC
1039 const int badCodeHeapNewVal = 0xCC; // value used to zap Code heap at allocation
1040 const int badCodeHeapFreeVal = 0xDD; // value used to zap Code heap at deallocation
1041 const intptr_t badDispHeaderDeopt = 0xDE0BD000; // value to fill unused displaced header during deoptimization
1042 const intptr_t badDispHeaderOSR = 0xDEAD05A0; // value to fill unused displaced header during OSR
1043
1044 // (These must be implemented as #defines because C++ compilers are
1045 // not obligated to inline non-integral constants!)
1046 #define badAddress ((address)::badAddressVal)
1047 #define badHeapWord (::badHeapWordVal)
1048
1049 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1050 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1051
1052 //----------------------------------------------------------------------------------------------------
1053 // Utility functions for bitfield manipulations
1054
1055 const intptr_t AllBits = ~0; // all bits set in a word
1056 const intptr_t NoBits = 0; // no bits set in a word
1057 const jlong NoLongBits = 0; // no bits set in a long
1058 const intptr_t OneBit = 1; // only right_most bit set in a word
1059
1060 // get a word with the n.th or the right-most or left-most n bits set
1061 // (note: #define used only so that they can be used in enum constant definitions)
1062 #define nth_bit(n) (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1063 #define right_n_bits(n) (nth_bit(n) - 1)
1064
1065 // bit-operations using a mask m
1066 inline void set_bits (intptr_t& x, intptr_t m) { x |= m; }
1067 inline void clear_bits (intptr_t& x, intptr_t m) { x &= ~m; }
1068 inline intptr_t mask_bits (intptr_t x, intptr_t m) { return x & m; }
1069 inline jlong mask_long_bits (jlong x, jlong m) { return x & m; }
1070 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1071
1072 // bit-operations using the n.th bit
1073 inline void set_nth_bit(intptr_t& x, int n) { set_bits (x, nth_bit(n)); }
1074 inline void clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1075 inline bool is_set_nth_bit(intptr_t x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1076
1077 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1078 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1079 return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1080 }
1081
1082
1083 //----------------------------------------------------------------------------------------------------
1084 // Utility functions for integers
1085
1086 // Avoid use of global min/max macros which may cause unwanted double
1087 // evaluation of arguments.
1088 #ifdef max
1089 #undef max
1090 #endif
1091
1092 #ifdef min
1093 #undef min
1094 #endif
1095
1096 // It is necessary to use templates here. Having normal overloaded
1097 // functions does not work because it is necessary to provide both 32-
1098 // and 64-bit overloaded functions, which does not work, and having
1099 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1100 // will be even more error-prone than macros.
1101 template<class T> constexpr T MAX2(T a, T b) { return (a > b) ? a : b; }
1102 template<class T> constexpr T MIN2(T a, T b) { return (a < b) ? a : b; }
1103 template<class T> constexpr T MAX3(T a, T b, T c) { return MAX2(MAX2(a, b), c); }
1104 template<class T> constexpr T MIN3(T a, T b, T c) { return MIN2(MIN2(a, b), c); }
1105 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1106 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1107
1108 template<class T> inline T ABS(T x) { return (x > 0) ? x : -x; }
1109
1110 // Return the given value clamped to the range [min ... max]
1111 template<typename T>
1112 inline T clamp(T value, T min, T max) {
1113 assert(min <= max, "must be");
1114 return MIN2(MAX2(value, min), max);
1115 }
1116
1117 inline bool is_odd (intx x) { return x & 1; }
1118 inline bool is_even(intx x) { return !is_odd(x); }
1119
1120 // abs methods which cannot overflow and so are well-defined across
1121 // the entire domain of integer types.
1122 static inline unsigned int uabs(unsigned int n) {
1123 union {
1124 unsigned int result;
1125 int value;
1126 };
1127 result = n;
1128 if (value < 0) result = 0-result;
1129 return result;
1130 }
1131 static inline julong uabs(julong n) {
1132 union {
1133 julong result;
1134 jlong value;
1135 };
1136 result = n;
1137 if (value < 0) result = 0-result;
1138 return result;
1139 }
1140 static inline julong uabs(jlong n) { return uabs((julong)n); }
1141 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1142
1143 // "to" should be greater than "from."
1144 inline size_t byte_size(void* from, void* to) {
1145 return pointer_delta(to, from, sizeof(char));
1146 }
1147
1148 // Pack and extract shorts to/from ints:
1149
1150 inline u2 extract_low_short_from_int(u4 x) {
1151 return u2(x & 0xffff);
1152 }
1153
1154 inline u2 extract_high_short_from_int(u4 x) {
1155 return u2((x >> 16) & 0xffff);
1156 }
1157
1158 inline int build_int_from_shorts( u2 low, u2 high ) {
1159 return ((int)((unsigned int)high << 16) | (unsigned int)low);
1160 }
1161
1162 // swap a & b
1163 template<class T> static void swap(T& a, T& b) {
1164 T tmp = a;
1165 a = b;
1166 b = tmp;
1167 }
1168
1169 // array_size_impl is a function that takes a reference to T[N] and
1170 // returns a reference to char[N]. It is not ODR-used, so not defined.
1171 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1172
1173 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1174
1175 //----------------------------------------------------------------------------------------------------
1176 // Sum and product which can never overflow: they wrap, just like the
1177 // Java operations. Note that we don't intend these to be used for
1178 // general-purpose arithmetic: their purpose is to emulate Java
1179 // operations.
1180
1181 // The goal of this code to avoid undefined or implementation-defined
1182 // behavior. The use of an lvalue to reference cast is explicitly
1183 // permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1184 // 15 in C++03]
1185 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1186 inline TYPE NAME (TYPE in1, TYPE in2) { \
1187 UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1188 ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1189 return reinterpret_cast<TYPE&>(ures); \
1190 }
1191
1192 JAVA_INTEGER_OP(+, java_add, jint, juint)
1193 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1194 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1195 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1196 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1197 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1198
1199 inline jint java_negate(jint v) { return java_subtract((jint) 0, v); }
1200 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1201
1202 #undef JAVA_INTEGER_OP
1203
1204 // Provide integer shift operations with Java semantics. No overflow
1205 // issues - left shifts simply discard shifted out bits. No undefined
1206 // behavior for large or negative shift quantities; instead the actual
1207 // shift distance is the argument modulo the lhs value's size in bits.
1208 // No undefined or implementation defined behavior for shifting negative
1209 // values; left shift discards bits, right shift sign extends. We use
1210 // the same safe conversion technique as above for java_add and friends.
1211 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE) \
1212 inline TYPE NAME (TYPE lhs, jint rhs) { \
1213 const uint rhs_mask = (sizeof(TYPE) * 8) - 1; \
1214 STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63); \
1215 XTYPE xres = static_cast<XTYPE>(lhs); \
1216 xres OP ## = (rhs & rhs_mask); \
1217 return reinterpret_cast<TYPE&>(xres); \
1218 }
1219
1220 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1221 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1222
1223 // For signed shift right, assume C++ implementation >> sign extends.
1224 //
1225 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1226 // and a negative value, the resulting value is implementation-defined."
1227 //
1228 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1229 // requiring two's-complement behavior.
1230 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1231 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1232 // The corresponding C++20 text is "Right-shift on signed integral types is an
1233 // arithmetic right shift, which performs sign-extension."
1234 //
1235 // As discussed in the two's complement proposal, all known modern C++ compilers
1236 // already behave that way. And it is unlikely any would go off and do something
1237 // different now, with C++20 tightening things up.
1238 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1239 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1240 // For >>> use C++ unsigned >>.
1241 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1242 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1243
1244 #undef JAVA_INTEGER_SHIFT_OP
1245
1246 //----------------------------------------------------------------------------------------------------
1247 // The goal of this code is to provide saturating operations for int/uint.
1248 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1249 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1250 inline int NAME (TYPE1 in1, TYPE2 in2) { \
1251 jlong res = static_cast<jlong>(in1); \
1252 res OP ## = static_cast<jlong>(in2); \
1253 if (res > max_jint) { \
1254 res = max_jint; \
1255 } else if (res < min_jint) { \
1256 res = min_jint; \
1257 } \
1258 return static_cast<int>(res); \
1259 }
1260
1261 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1262 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1263 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1264 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1265
1266 #undef SATURATED_INTEGER_OP
1267
1268 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1269 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1270 const uint64_t x1 = x >> 32u;
1271 const uint64_t x2 = x & 0xFFFFFFFF;
1272 const uint64_t y1 = y >> 32u;
1273 const uint64_t y2 = y & 0xFFFFFFFF;
1274 const uint64_t z2 = x2 * y2;
1275 const uint64_t t = x1 * y2 + (z2 >> 32u);
1276 uint64_t z1 = t & 0xFFFFFFFF;
1277 const uint64_t z0 = t >> 32u;
1278 z1 += x2 * y1;
1279
1280 return x1 * y1 + z0 + (z1 >> 32u);
1281 }
1282
1283 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1284 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1285 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1286 const jlong x1 = java_shift_right((jlong)x, 32);
1287 const jlong x2 = x & 0xFFFFFFFF;
1288 const jlong y1 = java_shift_right((jlong)y, 32);
1289 const jlong y2 = y & 0xFFFFFFFF;
1290
1291 const uint64_t z2 = (uint64_t)x2 * y2;
1292 const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1293 int64_t z1 = t & 0xFFFFFFFF;
1294 const int64_t z0 = java_shift_right((jlong)t, 32);
1295 z1 += x2 * y1;
1296
1297 return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1298 }
1299
1300 // Dereference vptr
1301 // All C++ compilers that we know of have the vtbl pointer in the first
1302 // word. If there are exceptions, this function needs to be made compiler
1303 // specific.
1304 static inline void* dereference_vptr(const void* addr) {
1305 return *(void**)addr;
1306 }
1307
1308 //----------------------------------------------------------------------------------------------------
1309 // String type aliases used by command line flag declarations and
1310 // processing utilities.
1311
1312 typedef const char* ccstr;
1313 typedef const char* ccstrlist; // represents string arguments which accumulate
1314
1315 //----------------------------------------------------------------------------------------------------
1316 // Default hash/equals functions used by ResourceHashtable
1317
1318 template<typename K> unsigned primitive_hash(const K& k) {
1319 unsigned hash = (unsigned)((uintptr_t)k);
1320 return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1321 }
1322
1323 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1324 return k0 == k1;
1325 }
1326
1327 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1328 return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1329 }
1330
1331 //----------------------------------------------------------------------------------------------------
1332
1333 // Allow use of C++ thread_local when approved - see JDK-8282469.
1334 #define APPROVED_CPP_THREAD_LOCAL thread_local
1335
1336 // Converts any type T to a reference type.
1337 template<typename T>
1338 std::add_rvalue_reference_t<T> declval() noexcept;
1339
1340 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1341 // handled.
1342 bool IEEE_subnormal_handling_OK();
1343
1344 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP