1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
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 "classfile_constants.h"
29 #include "utilities/compilerWarnings.hpp"
30 #include "utilities/debug.hpp"
31 #include "utilities/forbiddenFunctions.hpp"
32 #include "utilities/macros.hpp"
33
34 #include COMPILER_HEADER(utilities/globalDefinitions)
35
36 #include <cstddef>
37 #include <cstdint>
38 #include <limits>
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) alignas(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 // _0 - print as hexadecimal, with leading 0s, without 0x prefix: 0012345
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 #define UINT64_FORMAT_0 "%016" PRIx64
135
136 // Format jlong, if necessary
137 #ifndef JLONG_FORMAT
138 #define JLONG_FORMAT INT64_FORMAT
139 #endif
140 #ifndef JLONG_FORMAT_W
141 #define JLONG_FORMAT_W(width) INT64_FORMAT_W(width)
142 #endif
143 #ifndef JULONG_FORMAT
144 #define JULONG_FORMAT UINT64_FORMAT
145 #endif
146 #ifndef JULONG_FORMAT_X
147 #define JULONG_FORMAT_X UINT64_FORMAT_X
148 #endif
149 #ifndef JULONG_FORMAT_W
150 #define JULONG_FORMAT_W(width) UINT64_FORMAT_W(width)
151 #endif
152
153 // Format pointers and padded integral values which change size between 32- and 64-bit.
154 #ifdef _LP64
155 #define INTPTR_FORMAT "0x%016" PRIxPTR
156 #define PTR_FORMAT "0x%016" PRIxPTR
157 #define UINTX_FORMAT_X_0 "0x%016" PRIxPTR
158 #define SIZE_FORMAT_X_0 "0x%016" PRIxPTR
159 #else // !_LP64
160 #define INTPTR_FORMAT "0x%08" PRIxPTR
161 #define PTR_FORMAT "0x%08" PRIxPTR
162 #define UINTX_FORMAT_X_0 "0x%08" PRIxPTR
163 #define SIZE_FORMAT_X_0 "0x%08" PRIxPTR
164 #endif // _LP64
165
166 // Convert pointer to intptr_t, for use in printing pointers.
167 inline intptr_t p2i(const volatile void* p) {
168 return (intptr_t) p;
169 }
170
171 // Convert pointer to uintptr_t
172 inline uintptr_t p2u(const volatile void* p) {
173 return (uintptr_t) p;
174 }
175
176 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
177
178 //----------------------------------------------------------------------------------------------------
179 // Constants
180
181 const int LogBytesPerShort = 1;
182 const int LogBytesPerInt = 2;
183 #ifdef _LP64
184 constexpr int LogBytesPerWord = 3;
185 #else
186 constexpr int LogBytesPerWord = 2;
187 #endif
188 const int LogBytesPerLong = 3;
189
190 const int BytesPerShort = 1 << LogBytesPerShort;
191 const int BytesPerInt = 1 << LogBytesPerInt;
192 const int BytesPerWord = 1 << LogBytesPerWord;
193 const int BytesPerLong = 1 << LogBytesPerLong;
194
195 constexpr int LogBitsPerByte = 3;
196 const int LogBitsPerShort = LogBitsPerByte + LogBytesPerShort;
197 const int LogBitsPerInt = LogBitsPerByte + LogBytesPerInt;
198 constexpr int LogBitsPerWord = LogBitsPerByte + LogBytesPerWord;
199 const int LogBitsPerLong = LogBitsPerByte + LogBytesPerLong;
200
201 const int BitsPerByte = 1 << LogBitsPerByte;
202 const int BitsPerShort = 1 << LogBitsPerShort;
203 const int BitsPerInt = 1 << LogBitsPerInt;
204 constexpr int BitsPerWord = 1 << LogBitsPerWord;
205 const int BitsPerLong = 1 << LogBitsPerLong;
206
207 const int WordAlignmentMask = (1 << LogBytesPerWord) - 1;
208 const int LongAlignmentMask = (1 << LogBytesPerLong) - 1;
209
210 const int oopSize = sizeof(char*); // Full-width oop
211 extern int heapOopSize; // Oop within a java object
212 const int wordSize = sizeof(char*);
213 const int longSize = sizeof(jlong);
214 const int jintSize = sizeof(jint);
215 const int size_tSize = sizeof(size_t);
216
217 const int BytesPerOop = BytesPerWord; // Full-width oop
218
219 extern int LogBytesPerHeapOop; // Oop within a java object
220 extern int LogBitsPerHeapOop;
221 extern int BytesPerHeapOop;
222 extern int BitsPerHeapOop;
223
224 const int BitsPerJavaInteger = 32;
225 const int BitsPerJavaLong = 64;
226 const int BitsPerSize_t = size_tSize * BitsPerByte;
227
228 // Size of a char[] needed to represent a jint as a string in decimal.
229 const int jintAsStringSize = 12;
230
231 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
232 // We require that object sizes be measured in units of heap words (e.g.
233 // pointer-sized values), so that given HeapWord* hw,
234 // hw += oop(hw)->foo();
235 // works, where foo is a method (like size or scavenge) that returns the
236 // object size.
237 class HeapWordImpl; // Opaque, never defined.
238 typedef HeapWordImpl* HeapWord;
239
240 // Analogous opaque struct for metadata allocated from metaspaces.
241 class MetaWordImpl; // Opaque, never defined.
242 typedef MetaWordImpl* MetaWord;
243
244 // HeapWordSize must be 2^LogHeapWordSize.
245 const int HeapWordSize = sizeof(HeapWord);
246 #ifdef _LP64
247 const int LogHeapWordSize = 3;
248 #else
249 const int LogHeapWordSize = 2;
250 #endif
251 const int HeapWordsPerLong = BytesPerLong / HeapWordSize;
252 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
253
254 // The minimum number of native machine words necessary to contain "byte_size"
255 // bytes.
256 inline size_t heap_word_size(size_t byte_size) {
257 return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
258 }
259
260 inline jfloat jfloat_cast(jint x);
261 inline jdouble jdouble_cast(jlong x);
262
263 //-------------------------------------------
264 // Constant for jlong (standardized by C++11)
265
266 // Build a 64bit integer constant
267 #define CONST64(x) (x ## LL)
268 #define UCONST64(x) (x ## ULL)
269
270 const jlong min_jlong = CONST64(0x8000000000000000);
271 const jlong max_jlong = CONST64(0x7fffffffffffffff);
272
273 // for timer info max values which include all bits, 0xffffffffffffffff
274 const jlong all_bits_jlong = ~jlong(0);
275
276 //-------------------------------------------
277 // Constant for jdouble
278 const jlong min_jlongDouble = CONST64(0x0000000000000001);
279 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
280 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
281 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
282
283 const size_t K = 1024;
284 const size_t M = K*K;
285 const size_t G = M*K;
286
287 // Constants for converting from a base unit to milli-base units. For
288 // example from seconds to milliseconds and microseconds
289
290 const int MILLIUNITS = 1000; // milli units per base unit
291 const int MICROUNITS = 1000000; // micro units per base unit
292 const int NANOUNITS = 1000000000; // nano units per base unit
293 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
294
295 const jlong NANOSECS_PER_SEC = CONST64(1000000000);
296 const jint NANOSECS_PER_MILLISEC = 1000000;
297
298
299 // Unit conversion functions
300 // The caller is responsible for considering overflow.
301
302 inline int64_t nanos_to_millis(int64_t nanos) {
303 return nanos / NANOUNITS_PER_MILLIUNIT;
304 }
305 inline int64_t millis_to_nanos(int64_t millis) {
306 return millis * NANOUNITS_PER_MILLIUNIT;
307 }
308
309 // Proper units routines try to maintain at least three significant digits.
310 // In worst case, it would print five significant digits with lower prefix.
311 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
312 // and therefore we need to be careful.
313
314 inline const char* proper_unit_for_byte_size(size_t s) {
315 #ifdef _LP64
316 if (s >= 100*G) {
317 return "G";
318 }
319 #endif
320 if (s >= 100*M) {
321 return "M";
322 } else if (s >= 100*K) {
323 return "K";
324 } else {
325 return "B";
326 }
327 }
328
329 template <class T>
330 inline T byte_size_in_proper_unit(T s) {
331 #ifdef _LP64
332 if (s >= 100*G) {
333 return (T)(s/G);
334 }
335 #endif
336 if (s >= 100*M) {
337 return (T)(s/M);
338 } else if (s >= 100*K) {
339 return (T)(s/K);
340 } else {
341 return s;
342 }
343 }
344
345 #define PROPERFMT "%zu%s"
346 #define PROPERFMTARGS(s) byte_size_in_proper_unit<size_t>(s), proper_unit_for_byte_size(s)
347
348 // Printing a range, with start and bytes given
349 #define RANGEFMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
350 #define RANGEFMTARGS(p1, size) p2i(p1), p2i(p1 + size), size
351
352 // Printing a range, with start and end given
353 #define RANGE2FMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
354 #define RANGE2FMTARGS(p1, p2) p2i(p1), p2i(p2), ((uintptr_t)p2 - (uintptr_t)p1)
355
356 inline const char* exact_unit_for_byte_size(size_t s) {
357 #ifdef _LP64
358 if (s >= G && (s % G) == 0) {
359 return "G";
360 }
361 #endif
362 if (s >= M && (s % M) == 0) {
363 return "M";
364 }
365 if (s >= K && (s % K) == 0) {
366 return "K";
367 }
368 return "B";
369 }
370
371 inline size_t byte_size_in_exact_unit(size_t s) {
372 #ifdef _LP64
373 if (s >= G && (s % G) == 0) {
374 return s / G;
375 }
376 #endif
377 if (s >= M && (s % M) == 0) {
378 return s / M;
379 }
380 if (s >= K && (s % K) == 0) {
381 return s / K;
382 }
383 return s;
384 }
385
386 #define EXACTFMT "%zu%s"
387 #define EXACTFMTARGS(s) byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
388
389 // Memory size transition formatting.
390
391 #define HEAP_CHANGE_FORMAT "%s: %zuK(%zuK)->%zuK(%zuK)"
392
393 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
394 (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
395
396 //----------------------------------------------------------------------------------------------------
397 // VM type definitions
398
399 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
400 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
401
402 typedef intptr_t intx;
403 typedef uintptr_t uintx;
404
405 const intx min_intx = (intx)1 << (sizeof(intx)*BitsPerByte-1);
406 const intx max_intx = (uintx)min_intx - 1;
407 const uintx max_uintx = (uintx)-1;
408
409 // Table of values:
410 // sizeof intx 4 8
411 // min_intx 0x80000000 0x8000000000000000
412 // max_intx 0x7FFFFFFF 0x7FFFFFFFFFFFFFFF
413 // max_uintx 0xFFFFFFFF 0xFFFFFFFFFFFFFFFF
414
415 typedef unsigned int uint; NEEDS_CLEANUP
416
417 //----------------------------------------------------------------------------------------------------
418 // Java type definitions
419
420 // All kinds of 'plain' byte addresses
421 typedef signed char s_char;
422 typedef unsigned char u_char;
423 typedef u_char* address;
424 typedef const u_char* const_address;
425
426 // Pointer subtraction.
427 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
428 // the range we might need to find differences from one end of the heap
429 // to the other.
430 // A typical use might be:
431 // if (pointer_delta(end(), top()) >= size) {
432 // // enough room for an object of size
433 // ...
434 // and then additions like
435 // ... top() + size ...
436 // are safe because we know that top() is at least size below end().
437 inline size_t pointer_delta(const volatile void* left,
438 const volatile void* right,
439 size_t element_size) {
440 assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
441 return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
442 }
443
444 // A version specialized for HeapWord*'s.
445 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
446 return pointer_delta(left, right, sizeof(HeapWord));
447 }
448 // A version specialized for MetaWord*'s.
449 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
450 return pointer_delta(left, right, sizeof(MetaWord));
451 }
452
453 // pointer_delta_as_int is called to do pointer subtraction for nearby pointers that
454 // returns a non-negative int, usually used as a size of a code buffer range.
455 // This scales to sizeof(T).
456 template <typename T>
457 inline int pointer_delta_as_int(const volatile T* left, const volatile T* right) {
458 size_t delta = pointer_delta(left, right, sizeof(T));
459 assert(delta <= size_t(INT_MAX), "pointer delta out of range: %zu", delta);
460 return static_cast<int>(delta);
461 }
462
463 //
464 // ANSI C++ does not allow casting from one pointer type to a function pointer
465 // directly without at best a warning. This macro accomplishes it silently
466 // In every case that is present at this point the value be cast is a pointer
467 // to a C linkage function. In some case the type used for the cast reflects
468 // that linkage and a picky compiler would not complain. In other cases because
469 // there is no convenient place to place a typedef with extern C linkage (i.e
470 // a platform dependent header file) it doesn't. At this point no compiler seems
471 // picky enough to catch these instances (which are few). It is possible that
472 // using templates could fix these for all cases. This use of templates is likely
473 // so far from the middle of the road that it is likely to be problematic in
474 // many C++ compilers.
475 //
476 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
477 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((uintptr_t)(func_ptr)))
478
479 // Need the correct linkage to call qsort without warnings
480 extern "C" {
481 typedef int (*_sort_Fn)(const void *, const void *);
482 }
483
484 // Additional Java basic types
485
486 typedef uint8_t jubyte;
487 typedef uint16_t jushort;
488 typedef uint32_t juint;
489 typedef uint64_t julong;
490
491 // Unsigned byte types for os and stream.hpp
492
493 // Unsigned one, two, four and eight byte quantities used for describing
494 // the .class file format. See JVM book chapter 4.
495
496 typedef jubyte u1;
497 typedef jushort u2;
498 typedef juint u4;
499 typedef julong u8;
500
501 const jubyte max_jubyte = (jubyte)-1; // 0xFF largest jubyte
502 const jushort max_jushort = (jushort)-1; // 0xFFFF largest jushort
503 const juint max_juint = (juint)-1; // 0xFFFFFFFF largest juint
504 const julong max_julong = (julong)-1; // 0xFF....FF largest julong
505
506 typedef jbyte s1;
507 typedef jshort s2;
508 typedef jint s4;
509 typedef jlong s8;
510
511 const jbyte min_jbyte = -(1 << 7); // smallest jbyte
512 const jbyte max_jbyte = (1 << 7) - 1; // largest jbyte
513 const jshort min_jshort = -(1 << 15); // smallest jshort
514 const jshort max_jshort = (1 << 15) - 1; // largest jshort
515
516 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
517 const jint max_jint = (juint)min_jint - 1; // 0x7FFFFFFF == largest jint
518
519 const jint min_jintFloat = (jint)(0x00000001);
520 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
521 const jint max_jintFloat = (jint)(0x7f7fffff);
522 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
523
524 const jshort max_jfloat16 = 31743;
525 const jshort min_jfloat16 = 1;
526 const jshort one_jfloat16 = 15360;
527 const jshort pos_inf_jfloat16 = 31744;
528 const jshort neg_inf_jfloat16 = -1024;
529 // A named constant for the integral representation of a Java null.
530 const intptr_t NULL_WORD = 0;
531
532 //----------------------------------------------------------------------------------------------------
533 // JVM spec restrictions
534
535 const int max_method_code_size = 64*K - 1; // JVM spec, 2nd ed. section 4.8.1 (p.134)
536
537 //----------------------------------------------------------------------------------------------------
538 // old CDS options
539 extern bool RequireSharedSpaces;
540 extern "C" {
541 // Make sure UseSharedSpaces is accessible to the serviceability agent.
542 extern JNIEXPORT jboolean UseSharedSpaces;
543 }
544
545 //----------------------------------------------------------------------------------------------------
546 // Object alignment, in units of HeapWords.
547 //
548 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
549 // reference fields can be naturally aligned.
550
551 extern int MinObjAlignment;
552 extern int MinObjAlignmentInBytes;
553 extern int MinObjAlignmentInBytesMask;
554
555 extern int LogMinObjAlignment;
556 extern int LogMinObjAlignmentInBytes;
557
558 // Maximal size of heap where unscaled compression can be used. Also upper bound
559 // for heap placement: 4GB.
560 const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
561 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
562 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
563 extern uint64_t OopEncodingHeapMax;
564
565 // Machine dependent stuff
566
567 #include CPU_HEADER(globalDefinitions)
568
569 // The maximum size of the code cache. Can be overridden by targets.
570 #ifndef CODE_CACHE_SIZE_LIMIT
571 #define CODE_CACHE_SIZE_LIMIT (2*G)
572 #endif
573
574 // Allow targets to reduce the default size of the code cache.
575 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
576
577 // To assure the IRIW property on processors that are not multiple copy
578 // atomic, sync instructions must be issued between volatile reads to
579 // assure their ordering, instead of after volatile stores.
580 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
581 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
582 #ifdef CPU_MULTI_COPY_ATOMIC
583 // Not needed.
584 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
585 #else
586 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
587 // Final decision is subject to JEP 188: Java Memory Model Update.
588 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
589 #endif
590
591 // The expected size in bytes of a cache line.
592 #ifndef DEFAULT_CACHE_LINE_SIZE
593 #error "Platform should define DEFAULT_CACHE_LINE_SIZE"
594 #endif
595
596 // The default padding size for data structures to avoid false sharing.
597 #ifndef DEFAULT_PADDING_SIZE
598 #error "Platform should define DEFAULT_PADDING_SIZE"
599 #endif
600
601
602 //----------------------------------------------------------------------------------------------------
603 // Prototyping
604 // "Code Missing Here" macro, un-define when integrating back from prototyping stage and break
605 // compilation on purpose (i.e. "forget me not")
606 #define PROTOTYPE
607 #ifdef PROTOTYPE
608 #define CMH(m)
609 #endif
610
611 //----------------------------------------------------------------------------------------------------
612 // Miscellaneous
613
614 // 6302670 Eliminate Hotspot __fabsf dependency
615 // All fabs() callers should call this function instead, which will implicitly
616 // convert the operand to double, avoiding a dependency on __fabsf which
617 // doesn't exist in early versions of Solaris 8.
618 inline double fabsd(double value) {
619 return fabs(value);
620 }
621
622 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
623 // is zero, return 0.0.
624 template<typename T>
625 inline double percent_of(T numerator, T denominator) {
626 return denominator != 0 ? (double)numerator / (double)denominator * 100.0 : 0.0;
627 }
628
629 //----------------------------------------------------------------------------------------------------
630 // Special casts
631 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
632 typedef union {
633 jfloat f;
634 jint i;
635 } FloatIntConv;
636
637 typedef union {
638 jdouble d;
639 jlong l;
640 julong ul;
641 } DoubleLongConv;
642
643 inline jint jint_cast (jfloat x) { return ((FloatIntConv*)&x)->i; }
644 inline jfloat jfloat_cast (jint x) { return ((FloatIntConv*)&x)->f; }
645
646 inline jlong jlong_cast (jdouble x) { return ((DoubleLongConv*)&x)->l; }
647 inline julong julong_cast (jdouble x) { return ((DoubleLongConv*)&x)->ul; }
648 inline jdouble jdouble_cast (jlong x) { return ((DoubleLongConv*)&x)->d; }
649
650 inline jint low (jlong value) { return jint(value); }
651 inline jint high(jlong value) { return jint(value >> 32); }
652
653 // the fancy casts are a hopefully portable way
654 // to do unsigned 32 to 64 bit type conversion
655 inline void set_low (jlong* value, jint low ) { *value &= (jlong)0xffffffff << 32;
656 *value |= (jlong)(julong)(juint)low; }
657
658 inline void set_high(jlong* value, jint high) { *value &= (jlong)(julong)(juint)0xffffffff;
659 *value |= (jlong)high << 32; }
660
661 inline jlong jlong_from(jint h, jint l) {
662 jlong result = 0; // initialization to avoid warning
663 set_high(&result, h);
664 set_low(&result, l);
665 return result;
666 }
667
668 union jlong_accessor {
669 jint words[2];
670 jlong long_value;
671 };
672
673 void basic_types_init(); // cannot define here; uses assert
674
675
676 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
677 enum BasicType : u1 {
678 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
679 T_BOOLEAN = JVM_T_BOOLEAN,
680 T_CHAR = JVM_T_CHAR,
681 T_FLOAT = JVM_T_FLOAT,
682 T_DOUBLE = JVM_T_DOUBLE,
683 T_BYTE = JVM_T_BYTE,
684 T_SHORT = JVM_T_SHORT,
685 T_INT = JVM_T_INT,
686 T_LONG = JVM_T_LONG,
687 // The remaining values are not part of any standard.
688 // T_OBJECT and T_VOID denote two more semantic choices
689 // for method return values.
690 // T_OBJECT and T_ARRAY describe signature syntax.
691 // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
692 // internal references within the JVM as if they were Java
693 // types in their own right.
694 T_OBJECT = 12,
695 T_ARRAY = 13,
696 T_VOID = 14,
697 T_FLAT_ELEMENT = 15, // Not a true BasicType, only used in layout helpers of flat arrays
698 T_ADDRESS = 16,
699 T_NARROWOOP = 17,
700 T_METADATA = 18,
701 T_NARROWKLASS = 19,
702 T_CONFLICT = 20, // for stack value type with conflicting contents
703 T_ILLEGAL = 99
704 };
705
706 #define SIGNATURE_TYPES_DO(F, N) \
707 F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N) \
708 F(JVM_SIGNATURE_CHAR, T_CHAR, N) \
709 F(JVM_SIGNATURE_FLOAT, T_FLOAT, N) \
710 F(JVM_SIGNATURE_DOUBLE, T_DOUBLE, N) \
711 F(JVM_SIGNATURE_BYTE, T_BYTE, N) \
712 F(JVM_SIGNATURE_SHORT, T_SHORT, N) \
713 F(JVM_SIGNATURE_INT, T_INT, N) \
714 F(JVM_SIGNATURE_LONG, T_LONG, N) \
715 F(JVM_SIGNATURE_CLASS, T_OBJECT, N) \
716 F(JVM_SIGNATURE_ARRAY, T_ARRAY, N) \
717 F(JVM_SIGNATURE_VOID, T_VOID, N) \
718 /*end*/
719
720 inline bool is_java_type(BasicType t) {
721 return T_BOOLEAN <= t && t <= T_VOID;
722 }
723
724 inline bool is_java_primitive(BasicType t) {
725 return T_BOOLEAN <= t && t <= T_LONG;
726 }
727
728 inline bool is_subword_type(BasicType t) {
729 // these guys are processed exactly like T_INT in calling sequences:
730 return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
731 }
732
733 inline bool is_signed_subword_type(BasicType t) {
734 return (t == T_BYTE || t == T_SHORT);
735 }
736
737 inline bool is_unsigned_subword_type(BasicType t) {
738 return (t == T_BOOLEAN || t == T_CHAR);
739 }
740
741 inline bool is_double_word_type(BasicType t) {
742 return (t == T_DOUBLE || t == T_LONG);
743 }
744
745 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
746 assert(t != T_FLAT_ELEMENT, ""); // Strong assert to detect misuses of T_FLAT_ELEMENT
747 return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
748 }
749
750 inline bool is_integral_type(BasicType t) {
751 return is_subword_type(t) || t == T_INT || t == T_LONG;
752 }
753
754 inline bool is_non_subword_integral_type(BasicType t) {
755 return t == T_INT || t == T_LONG;
756 }
757
758 inline bool is_floating_point_type(BasicType t) {
759 return (t == T_FLOAT || t == T_DOUBLE);
760 }
761
762 extern char type2char_tab[T_CONFLICT+1]; // Map a BasicType to a jchar
763 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
764 extern int type2size[T_CONFLICT+1]; // Map BasicType to result stack elements
765 extern const char* type2name_tab[T_CONFLICT+1]; // Map a BasicType to a char*
766 extern BasicType name2type(const char* name);
767
768 const char* type2name(BasicType t);
769
770 inline jlong max_signed_integer(BasicType bt) {
771 if (bt == T_INT) {
772 return max_jint;
773 }
774 assert(bt == T_LONG, "unsupported");
775 return max_jlong;
776 }
777
778 inline jlong min_signed_integer(BasicType bt) {
779 if (bt == T_INT) {
780 return min_jint;
781 }
782 assert(bt == T_LONG, "unsupported");
783 return min_jlong;
784 }
785
786 inline julong max_unsigned_integer(BasicType bt) {
787 if (bt == T_INT) {
788 return max_juint;
789 }
790 assert(bt == T_LONG, "unsupported");
791 return max_julong;
792 }
793
794 inline uint bits_per_java_integer(BasicType bt) {
795 if (bt == T_INT) {
796 return BitsPerJavaInteger;
797 }
798 assert(bt == T_LONG, "int or long only");
799 return BitsPerJavaLong;
800 }
801
802 // Auxiliary math routines
803 // least common multiple
804 extern size_t lcm(size_t a, size_t b);
805
806
807 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
808 enum BasicTypeSize {
809 T_BOOLEAN_size = 1,
810 T_CHAR_size = 1,
811 T_FLOAT_size = 1,
812 T_DOUBLE_size = 2,
813 T_BYTE_size = 1,
814 T_SHORT_size = 1,
815 T_INT_size = 1,
816 T_LONG_size = 2,
817 T_OBJECT_size = 1,
818 T_ARRAY_size = 1,
819 T_NARROWOOP_size = 1,
820 T_NARROWKLASS_size = 1,
821 T_VOID_size = 0,
822 T_FLAT_ELEMENT_size = 0
823 };
824
825 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
826 inline int parameter_type_word_count(BasicType t) {
827 if (is_double_word_type(t)) return 2;
828 assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
829 assert(type2size[t] == 1, "must be");
830 return 1;
831 }
832
833 // maps a BasicType to its instance field storage type:
834 // all sub-word integral types are widened to T_INT
835 extern BasicType type2field[T_CONFLICT+1];
836 extern BasicType type2wfield[T_CONFLICT+1];
837
838
839 // size in bytes
840 enum ArrayElementSize {
841 T_BOOLEAN_aelem_bytes = 1,
842 T_CHAR_aelem_bytes = 2,
843 T_FLOAT_aelem_bytes = 4,
844 T_DOUBLE_aelem_bytes = 8,
845 T_BYTE_aelem_bytes = 1,
846 T_SHORT_aelem_bytes = 2,
847 T_INT_aelem_bytes = 4,
848 T_LONG_aelem_bytes = 8,
849 #ifdef _LP64
850 T_OBJECT_aelem_bytes = 8,
851 T_ARRAY_aelem_bytes = 8,
852 #else
853 T_OBJECT_aelem_bytes = 4,
854 T_ARRAY_aelem_bytes = 4,
855 #endif
856 T_NARROWOOP_aelem_bytes = 4,
857 T_NARROWKLASS_aelem_bytes = 4,
858 T_VOID_aelem_bytes = 0,
859 T_FLAT_ELEMENT_aelem_bytes = 0
860 };
861
862 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
863 #ifdef ASSERT
864 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
865 #else
866 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
867 #endif
868
869 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
870 return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
871 }
872
873 // JavaValue serves as a container for arbitrary Java values.
874
875 class JavaValue {
876
877 public:
878 typedef union JavaCallValue {
879 jfloat f;
880 jdouble d;
881 jint i;
882 jlong l;
883 jobject h;
884 oopDesc* o;
885 } JavaCallValue;
886
887 private:
888 BasicType _type;
889 JavaCallValue _value;
890
891 public:
892 JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
893
894 JavaValue(jfloat value) {
895 _type = T_FLOAT;
896 _value.f = value;
897 }
898
899 JavaValue(jdouble value) {
900 _type = T_DOUBLE;
901 _value.d = value;
902 }
903
904 jfloat get_jfloat() const { return _value.f; }
905 jdouble get_jdouble() const { return _value.d; }
906 jint get_jint() const { return _value.i; }
907 jlong get_jlong() const { return _value.l; }
908 jobject get_jobject() const { return _value.h; }
909 oopDesc* get_oop() const { return _value.o; }
910 JavaCallValue* get_value_addr() { return &_value; }
911 BasicType get_type() const { return _type; }
912
913 void set_jfloat(jfloat f) { _value.f = f;}
914 void set_jdouble(jdouble d) { _value.d = d;}
915 void set_jint(jint i) { _value.i = i;}
916 void set_jshort(jshort i) { _value.i = i;}
917 void set_jlong(jlong l) { _value.l = l;}
918 void set_jobject(jobject h) { _value.h = h;}
919 void set_oop(oopDesc* o) { _value.o = o;}
920 void set_type(BasicType t) { _type = t; }
921
922 jboolean get_jboolean() const { return (jboolean) (_value.i);}
923 jbyte get_jbyte() const { return (jbyte) (_value.i);}
924 jchar get_jchar() const { return (jchar) (_value.i);}
925 jshort get_jshort() const { return (jshort) (_value.i);}
926
927 };
928
929
930 // TosState describes the top-of-stack state before and after the execution of
931 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
932 // registers. The TosState corresponds to the 'machine representation' of this cached
933 // value. There's 4 states corresponding to the JAVA types int, long, float & double
934 // as well as a 5th state in case the top-of-stack value is actually on the top
935 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
936 // state when it comes to machine representation but is used separately for (oop)
937 // type specific operations (e.g. verification code).
938
939 enum TosState { // describes the tos cache contents
940 btos = 0, // byte, bool tos cached
941 ztos = 1, // byte, bool tos cached
942 ctos = 2, // char tos cached
943 stos = 3, // short tos cached
944 itos = 4, // int tos cached
945 ltos = 5, // long tos cached
946 ftos = 6, // float tos cached
947 dtos = 7, // double tos cached
948 atos = 8, // object cached
949 vtos = 9, // tos not cached,
950 number_of_states,
951 ilgl // illegal state: should not occur
952 };
953
954
955 inline TosState as_TosState(BasicType type) {
956 switch (type) {
957 case T_BYTE : return btos;
958 case T_BOOLEAN: return ztos;
959 case T_CHAR : return ctos;
960 case T_SHORT : return stos;
961 case T_INT : return itos;
962 case T_LONG : return ltos;
963 case T_FLOAT : return ftos;
964 case T_DOUBLE : return dtos;
965 case T_VOID : return vtos;
966 case T_ARRAY : // fall through
967 case T_OBJECT : return atos;
968 default : return ilgl;
969 }
970 }
971
972 inline BasicType as_BasicType(TosState state) {
973 switch (state) {
974 case btos : return T_BYTE;
975 case ztos : return T_BOOLEAN;
976 case ctos : return T_CHAR;
977 case stos : return T_SHORT;
978 case itos : return T_INT;
979 case ltos : return T_LONG;
980 case ftos : return T_FLOAT;
981 case dtos : return T_DOUBLE;
982 case atos : return T_OBJECT;
983 case vtos : return T_VOID;
984 default : return T_ILLEGAL;
985 }
986 }
987
988
989 // Helper function to convert BasicType info into TosState
990 // Note: Cannot define here as it uses global constant at the time being.
991 TosState as_TosState(BasicType type);
992
993
994 // JavaThreadState keeps track of which part of the code a thread is executing in. This
995 // information is needed by the safepoint code.
996 //
997 // There are 4 essential states:
998 //
999 // _thread_new : Just started, but not executed init. code yet (most likely still in OS init code)
1000 // _thread_in_native : In native code. This is a safepoint region, since all oops will be in jobject handles
1001 // _thread_in_vm : Executing in the vm
1002 // _thread_in_Java : Executing either interpreted or compiled Java code (or could be in a stub)
1003 //
1004 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1005 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1006 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1007 //
1008 // Given a state, the xxxx_trans state can always be found by adding 1.
1009 //
1010 enum JavaThreadState {
1011 _thread_uninitialized = 0, // should never happen (missing initialization)
1012 _thread_new = 2, // just starting up, i.e., in process of being initialized
1013 _thread_new_trans = 3, // corresponding transition state (not used, included for completeness)
1014 _thread_in_native = 4, // running in native code
1015 _thread_in_native_trans = 5, // corresponding transition state
1016 _thread_in_vm = 6, // running in VM
1017 _thread_in_vm_trans = 7, // corresponding transition state
1018 _thread_in_Java = 8, // running in Java or in stub code
1019 _thread_in_Java_trans = 9, // corresponding transition state (not used, included for completeness)
1020 _thread_blocked = 10, // blocked in vm
1021 _thread_blocked_trans = 11, // corresponding transition state
1022 _thread_max_state = 12 // maximum thread state+1 - used for statistics allocation
1023 };
1024
1025 enum LockingMode {
1026 // Use only heavy monitors for locking
1027 LM_MONITOR = 0,
1028 // Legacy stack-locking, with monitors as 2nd tier
1029 LM_LEGACY = 1,
1030 // New lightweight locking, with monitors as 2nd tier
1031 LM_LIGHTWEIGHT = 2
1032 };
1033
1034 extern const int LockingMode;
1035
1036 //----------------------------------------------------------------------------------------------------
1037 // Special constants for debugging
1038
1039 const jint badInt = -3; // generic "bad int" value
1040 const intptr_t badAddressVal = -2; // generic "bad address" value
1041 const intptr_t badOopVal = -1; // generic "bad oop" value
1042 const intptr_t badHeapOopVal = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1043 const int badStackSegVal = 0xCA; // value used to zap stack segments
1044 const int badHandleValue = 0xBC; // value used to zap vm handle area
1045 const int badResourceValue = 0xAB; // value used to zap resource area
1046 const int freeBlockPad = 0xBA; // value used to pad freed blocks.
1047 const int uninitBlockPad = 0xF1; // value used to zap newly malloc'd blocks.
1048 const juint uninitMetaWordVal = 0xf7f7f7f7; // value used to zap newly allocated metachunk
1049 const jubyte heapPaddingByteVal = 0xBD; // value used to zap object padding in the heap
1050 const juint badHeapWordVal = 0xBAADBABE; // value used to zap heap after GC
1051 const int badCodeHeapNewVal = 0xCC; // value used to zap Code heap at allocation
1052 const int badCodeHeapFreeVal = 0xDD; // value used to zap Code heap at deallocation
1053 const intptr_t badDispHeaderDeopt = 0xDE0BD000; // value to fill unused displaced header during deoptimization
1054 const intptr_t badDispHeaderOSR = 0xDEAD05A0; // value to fill unused displaced header during OSR
1055
1056 // (These must be implemented as #defines because C++ compilers are
1057 // not obligated to inline non-integral constants!)
1058 #define badAddress ((address)::badAddressVal)
1059 #define badHeapWord (::badHeapWordVal)
1060
1061 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1062 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1063
1064 //----------------------------------------------------------------------------------------------------
1065 // Utility functions for bitfield manipulations
1066
1067 const intptr_t AllBits = ~0; // all bits set in a word
1068 const intptr_t NoBits = 0; // no bits set in a word
1069 const jlong NoLongBits = 0; // no bits set in a long
1070 const intptr_t OneBit = 1; // only right_most bit set in a word
1071
1072 // get a word with the n.th or the right-most or left-most n bits set
1073 // (note: #define used only so that they can be used in enum constant definitions)
1074 #define nth_bit(n) (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1075 #define right_n_bits(n) (nth_bit(n) - 1)
1076
1077 // same as nth_bit(n), but allows handing in a type as template parameter. Allows
1078 // us to use nth_bit with 64-bit types on 32-bit platforms
1079 template<class T> inline T nth_bit_typed(int n) {
1080 return ((T)1) << n;
1081 }
1082 template<class T> inline T right_n_bits_typed(int n) {
1083 return nth_bit_typed<T>(n) - 1;
1084 }
1085
1086 // bit-operations using a mask m
1087 inline void set_bits (intptr_t& x, intptr_t m) { x |= m; }
1088 inline void clear_bits (intptr_t& x, intptr_t m) { x &= ~m; }
1089 inline intptr_t mask_bits (intptr_t x, intptr_t m) { return x & m; }
1090 inline jlong mask_long_bits (jlong x, jlong m) { return x & m; }
1091 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1092
1093 // bit-operations using the n.th bit
1094 inline void set_nth_bit(intptr_t& x, int n) { set_bits (x, nth_bit(n)); }
1095 inline void clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1096 inline bool is_set_nth_bit(intptr_t x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1097
1098 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1099 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1100 return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1101 }
1102
1103
1104 //----------------------------------------------------------------------------------------------------
1105 // Utility functions for integers
1106
1107 // Avoid use of global min/max macros which may cause unwanted double
1108 // evaluation of arguments.
1109 #ifdef max
1110 #undef max
1111 #endif
1112
1113 #ifdef min
1114 #undef min
1115 #endif
1116
1117 // It is necessary to use templates here. Having normal overloaded
1118 // functions does not work because it is necessary to provide both 32-
1119 // and 64-bit overloaded functions, which does not work, and having
1120 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1121 // will be even more error-prone than macros.
1122 template<class T> constexpr T MAX2(T a, T b) { return (a > b) ? a : b; }
1123 template<class T> constexpr T MIN2(T a, T b) { return (a < b) ? a : b; }
1124 template<class T> constexpr T MAX3(T a, T b, T c) { return MAX2(MAX2(a, b), c); }
1125 template<class T> constexpr T MIN3(T a, T b, T c) { return MIN2(MIN2(a, b), c); }
1126 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1127 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1128
1129 #define ABS(x) asserted_abs(x, __FILE__, __LINE__)
1130
1131 template<class T> inline T asserted_abs(T x, const char* file, int line) {
1132 bool valid_arg = !(std::is_integral<T>::value && x == std::numeric_limits<T>::min());
1133 #ifdef ASSERT
1134 if (!valid_arg) {
1135 report_vm_error(file, line, "ABS: argument should not allow overflow");
1136 }
1137 #endif
1138 // Prevent exposure to UB by checking valid_arg here as well.
1139 return (x < 0 && valid_arg) ? -x : x;
1140 }
1141
1142 // Return the given value clamped to the range [min ... max]
1143 template<typename T>
1144 inline T clamp(T value, T min, T max) {
1145 assert(min <= max, "must be");
1146 return MIN2(MAX2(value, min), max);
1147 }
1148
1149 inline bool is_odd (intx x) { return x & 1; }
1150 inline bool is_even(intx x) { return !is_odd(x); }
1151
1152 // abs methods which cannot overflow and so are well-defined across
1153 // the entire domain of integer types.
1154 static inline unsigned int g_uabs(unsigned int n) {
1155 union {
1156 unsigned int result;
1157 int value;
1158 };
1159 result = n;
1160 if (value < 0) result = 0-result;
1161 return result;
1162 }
1163 static inline julong g_uabs(julong n) {
1164 union {
1165 julong result;
1166 jlong value;
1167 };
1168 result = n;
1169 if (value < 0) result = 0-result;
1170 return result;
1171 }
1172 static inline julong g_uabs(jlong n) { return g_uabs((julong)n); }
1173 static inline unsigned int g_uabs(int n) { return g_uabs((unsigned int)n); }
1174
1175 // "to" should be greater than "from."
1176 inline size_t byte_size(void* from, void* to) {
1177 return pointer_delta(to, from, sizeof(char));
1178 }
1179
1180 // Pack and extract shorts to/from ints:
1181
1182 inline u2 extract_low_short_from_int(u4 x) {
1183 return u2(x & 0xffff);
1184 }
1185
1186 inline u2 extract_high_short_from_int(u4 x) {
1187 return u2((x >> 16) & 0xffff);
1188 }
1189
1190 inline int build_int_from_shorts( u2 low, u2 high ) {
1191 return ((int)((unsigned int)high << 16) | (unsigned int)low);
1192 }
1193
1194 // swap a & b
1195 template<class T> static void swap(T& a, T& b) {
1196 T tmp = a;
1197 a = b;
1198 b = tmp;
1199 }
1200
1201 // array_size_impl is a function that takes a reference to T[N] and
1202 // returns a reference to char[N]. It is not ODR-used, so not defined.
1203 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1204
1205 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1206
1207 //----------------------------------------------------------------------------------------------------
1208 // Sum and product which can never overflow: they wrap, just like the
1209 // Java operations. Note that we don't intend these to be used for
1210 // general-purpose arithmetic: their purpose is to emulate Java
1211 // operations.
1212
1213 // The goal of this code to avoid undefined or implementation-defined
1214 // behavior. The use of an lvalue to reference cast is explicitly
1215 // permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1216 // 15 in C++03]
1217 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1218 inline TYPE NAME (TYPE in1, TYPE in2) { \
1219 UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1220 ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1221 return reinterpret_cast<TYPE&>(ures); \
1222 }
1223
1224 JAVA_INTEGER_OP(+, java_add, jint, juint)
1225 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1226 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1227 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1228 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1229 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1230
1231 inline jint java_negate(jint v) { return java_subtract((jint) 0, v); }
1232 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1233
1234 #undef JAVA_INTEGER_OP
1235
1236 // Provide integer shift operations with Java semantics. No overflow
1237 // issues - left shifts simply discard shifted out bits. No undefined
1238 // behavior for large or negative shift quantities; instead the actual
1239 // shift distance is the argument modulo the lhs value's size in bits.
1240 // No undefined or implementation defined behavior for shifting negative
1241 // values; left shift discards bits, right shift sign extends. We use
1242 // the same safe conversion technique as above for java_add and friends.
1243 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE) \
1244 inline TYPE NAME (TYPE lhs, jint rhs) { \
1245 const uint rhs_mask = (sizeof(TYPE) * 8) - 1; \
1246 STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63); \
1247 XTYPE xres = static_cast<XTYPE>(lhs); \
1248 xres OP ## = (rhs & rhs_mask); \
1249 return reinterpret_cast<TYPE&>(xres); \
1250 }
1251
1252 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1253 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1254
1255 // For signed shift right, assume C++ implementation >> sign extends.
1256 //
1257 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1258 // and a negative value, the resulting value is implementation-defined."
1259 //
1260 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1261 // requiring two's-complement behavior.
1262 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1263 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1264 // The corresponding C++20 text is "Right-shift on signed integral types is an
1265 // arithmetic right shift, which performs sign-extension."
1266 //
1267 // As discussed in the two's complement proposal, all known modern C++ compilers
1268 // already behave that way. And it is unlikely any would go off and do something
1269 // different now, with C++20 tightening things up.
1270 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1271 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1272 // For >>> use C++ unsigned >>.
1273 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1274 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1275
1276 #undef JAVA_INTEGER_SHIFT_OP
1277
1278 //----------------------------------------------------------------------------------------------------
1279 // The goal of this code is to provide saturating operations for int/uint.
1280 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1281 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1282 inline int NAME (TYPE1 in1, TYPE2 in2) { \
1283 jlong res = static_cast<jlong>(in1); \
1284 res OP ## = static_cast<jlong>(in2); \
1285 if (res > max_jint) { \
1286 res = max_jint; \
1287 } else if (res < min_jint) { \
1288 res = min_jint; \
1289 } \
1290 return static_cast<int>(res); \
1291 }
1292
1293 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1294 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1295 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1296 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1297
1298 #undef SATURATED_INTEGER_OP
1299
1300 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1301 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1302 const uint64_t x1 = x >> 32u;
1303 const uint64_t x2 = x & 0xFFFFFFFF;
1304 const uint64_t y1 = y >> 32u;
1305 const uint64_t y2 = y & 0xFFFFFFFF;
1306 const uint64_t z2 = x2 * y2;
1307 const uint64_t t = x1 * y2 + (z2 >> 32u);
1308 uint64_t z1 = t & 0xFFFFFFFF;
1309 const uint64_t z0 = t >> 32u;
1310 z1 += x2 * y1;
1311
1312 return x1 * y1 + z0 + (z1 >> 32u);
1313 }
1314
1315 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1316 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1317 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1318 const jlong x1 = java_shift_right((jlong)x, 32);
1319 const jlong x2 = x & 0xFFFFFFFF;
1320 const jlong y1 = java_shift_right((jlong)y, 32);
1321 const jlong y2 = y & 0xFFFFFFFF;
1322
1323 const uint64_t z2 = (uint64_t)x2 * y2;
1324 const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1325 int64_t z1 = t & 0xFFFFFFFF;
1326 const int64_t z0 = java_shift_right((jlong)t, 32);
1327 z1 += x2 * y1;
1328
1329 return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1330 }
1331
1332 // Dereference vptr
1333 // All C++ compilers that we know of have the vtbl pointer in the first
1334 // word. If there are exceptions, this function needs to be made compiler
1335 // specific.
1336 static inline void* dereference_vptr(const void* addr) {
1337 return *(void**)addr;
1338 }
1339
1340 //----------------------------------------------------------------------------------------------------
1341 // String type aliases used by command line flag declarations and
1342 // processing utilities.
1343
1344 typedef const char* ccstr;
1345 typedef const char* ccstrlist; // represents string arguments which accumulate
1346
1347 //----------------------------------------------------------------------------------------------------
1348 // Default hash/equals functions used by HashTable
1349
1350 template<typename K> unsigned primitive_hash(const K& k) {
1351 unsigned hash = (unsigned)((uintptr_t)k);
1352 return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1353 }
1354
1355 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1356 return k0 == k1;
1357 }
1358
1359 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1360 return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1361 }
1362
1363 //----------------------------------------------------------------------------------------------------
1364
1365 // Allow use of C++ thread_local when approved - see JDK-8282469.
1366 #define APPROVED_CPP_THREAD_LOCAL thread_local
1367
1368 // Converts any type T to a reference type.
1369 template<typename T>
1370 std::add_rvalue_reference_t<T> declval() noexcept;
1371
1372 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1373 // handled.
1374 bool IEEE_subnormal_handling_OK();
1375
1376 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP