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/checkedCast.hpp"
30 #include "utilities/compilerWarnings.hpp"
31 #include "utilities/debug.hpp"
32 #include "utilities/forbiddenFunctions.hpp"
33 #include "utilities/macros.hpp"
34
35 #include COMPILER_HEADER(utilities/globalDefinitions)
36
37 #include <cstddef>
38 #include <cstdint>
39 #include <limits>
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 // offset_of was a workaround for UB with offsetof uses that are no longer an
90 // issue. This can be removed once all uses have been converted.
91 #define offset_of(klass, field) offsetof(klass, field)
92
93 //----------------------------------------------------------------------------------------------------
94 // Printf-style formatters for fixed- and variable-width types as pointers and
95 // integers. These are derived from the definitions in inttypes.h. If the platform
96 // doesn't provide appropriate definitions, they should be provided in
97 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
98
99 // Guide to the suffixes used in the format specifiers for integers:
100 // - print the decimal value: 745565
101 // _X - print as hexadecimal, without leading 0s: 0x12345
102 // _X_0 - print as hexadecimal, with leading 0s: 0x00012345
103 // _W(w) - prints w sized string with the given value right
104 // adjusted. Use -w to print left adjusted.
105 // _0 - print as hexadecimal, with leading 0s, without 0x prefix: 0012345
106 //
107 // Note that the PTR format specifiers print using 0x with leading zeros,
108 // just like the _X_0 version for integers.
109
110 // Format 8-bit quantities.
111 #define INT8_FORMAT_X_0 "0x%02" PRIx8
112 #define UINT8_FORMAT_X_0 "0x%02" PRIx8
113
114 // Format 16-bit quantities.
115 #define INT16_FORMAT_X_0 "0x%04" PRIx16
116 #define UINT16_FORMAT_X_0 "0x%04" PRIx16
117
118 // Format 32-bit quantities.
119 #define INT32_FORMAT "%" PRId32
120 #define INT32_FORMAT_X "0x%" PRIx32
121 #define INT32_FORMAT_X_0 "0x%08" PRIx32
122 #define INT32_FORMAT_W(width) "%" #width PRId32
123 #define UINT32_FORMAT "%" PRIu32
124 #define UINT32_FORMAT_X "0x%" PRIx32
125 #define UINT32_FORMAT_X_0 "0x%08" PRIx32
126 #define UINT32_FORMAT_W(width) "%" #width PRIu32
127
128 // Format 64-bit quantities.
129 #define INT64_FORMAT "%" PRId64
130 #define INT64_PLUS_FORMAT "%+" PRId64
131 #define INT64_FORMAT_X "0x%" PRIx64
132 #define INT64_FORMAT_X_0 "0x%016" PRIx64
133 #define INT64_FORMAT_W(width) "%" #width PRId64
134 #define UINT64_FORMAT "%" PRIu64
135 #define UINT64_FORMAT_X "0x%" PRIx64
136 #define UINT64_FORMAT_X_0 "0x%016" PRIx64
137 #define UINT64_FORMAT_W(width) "%" #width PRIu64
138 #define UINT64_FORMAT_0 "%016" PRIx64
139 #define PHYS_MEM_TYPE_FORMAT "%" PRIu64
140
141 // Format jlong, if necessary
142 #ifndef JLONG_FORMAT
143 #define JLONG_FORMAT INT64_FORMAT
144 #endif
145 #ifndef JLONG_FORMAT_W
146 #define JLONG_FORMAT_W(width) INT64_FORMAT_W(width)
147 #endif
148 #ifndef JULONG_FORMAT
149 #define JULONG_FORMAT UINT64_FORMAT
150 #endif
151 #ifndef JULONG_FORMAT_X
152 #define JULONG_FORMAT_X UINT64_FORMAT_X
153 #endif
154 #ifndef JULONG_FORMAT_W
155 #define JULONG_FORMAT_W(width) UINT64_FORMAT_W(width)
156 #endif
157
158 // Format pointers and padded integral values which change size between 32- and 64-bit.
159 #ifdef _LP64
160 #define INTPTR_FORMAT "0x%016" PRIxPTR
161 #define PTR_FORMAT "0x%016" PRIxPTR
162 #define UINTX_FORMAT_X_0 "0x%016" PRIxPTR
163 #define SIZE_FORMAT_X_0 "0x%016" PRIxPTR
164 #else // !_LP64
165 #define INTPTR_FORMAT "0x%08" PRIxPTR
166 #define PTR_FORMAT "0x%08" PRIxPTR
167 #define UINTX_FORMAT_X_0 "0x%08" PRIxPTR
168 #define SIZE_FORMAT_X_0 "0x%08" PRIxPTR
169 #endif // _LP64
170
171 // Convert pointer to intptr_t, for use in printing pointers.
172 inline intptr_t p2i(const volatile void* p) {
173 return (intptr_t) p;
174 }
175
176 // Convert pointer to uintptr_t
177 inline uintptr_t p2u(const volatile void* p) {
178 return (uintptr_t) p;
179 }
180
181 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
182
183 //----------------------------------------------------------------------------------------------------
184 // Constants
185
186 const int LogBytesPerShort = 1;
187 const int LogBytesPerInt = 2;
188 #ifdef _LP64
189 constexpr int LogBytesPerWord = 3;
190 #else
191 constexpr int LogBytesPerWord = 2;
192 #endif
193 const int LogBytesPerLong = 3;
194
195 const int BytesPerShort = 1 << LogBytesPerShort;
196 const int BytesPerInt = 1 << LogBytesPerInt;
197 const int BytesPerWord = 1 << LogBytesPerWord;
198 const int BytesPerLong = 1 << LogBytesPerLong;
199
200 constexpr int LogBitsPerByte = 3;
201 const int LogBitsPerShort = LogBitsPerByte + LogBytesPerShort;
202 const int LogBitsPerInt = LogBitsPerByte + LogBytesPerInt;
203 constexpr int LogBitsPerWord = LogBitsPerByte + LogBytesPerWord;
204 const int LogBitsPerLong = LogBitsPerByte + LogBytesPerLong;
205
206 const int BitsPerByte = 1 << LogBitsPerByte;
207 const int BitsPerShort = 1 << LogBitsPerShort;
208 const int BitsPerInt = 1 << LogBitsPerInt;
209 constexpr int BitsPerWord = 1 << LogBitsPerWord;
210 const int BitsPerLong = 1 << LogBitsPerLong;
211
212 const int WordAlignmentMask = (1 << LogBytesPerWord) - 1;
213 const int LongAlignmentMask = (1 << LogBytesPerLong) - 1;
214
215 const int oopSize = sizeof(char*); // Full-width oop
216 extern int heapOopSize; // Oop within a java object
217 const int wordSize = sizeof(char*);
218 const int longSize = sizeof(jlong);
219 const int jintSize = sizeof(jint);
220 const int size_tSize = sizeof(size_t);
221
222 const int BytesPerOop = BytesPerWord; // Full-width oop
223
224 extern int LogBytesPerHeapOop; // Oop within a java object
225 extern int LogBitsPerHeapOop;
226 extern int BytesPerHeapOop;
227 extern int BitsPerHeapOop;
228
229 const int BitsPerJavaInteger = 32;
230 const int BitsPerJavaLong = 64;
231 const int BitsPerSize_t = size_tSize * BitsPerByte;
232
233 // Size of a char[] needed to represent a jint as a string in decimal.
234 const int jintAsStringSize = 12;
235
236 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
237 // We require that object sizes be measured in units of heap words (e.g.
238 // pointer-sized values), so that given HeapWord* hw,
239 // hw += oop(hw)->foo();
240 // works, where foo is a method (like size or scavenge) that returns the
241 // object size.
242 class HeapWordImpl; // Opaque, never defined.
243 typedef HeapWordImpl* HeapWord;
244
245 // Analogous opaque struct for metadata allocated from metaspaces.
246 class MetaWordImpl; // Opaque, never defined.
247 typedef MetaWordImpl* MetaWord;
248
249 // HeapWordSize must be 2^LogHeapWordSize.
250 const int HeapWordSize = sizeof(HeapWord);
251 #ifdef _LP64
252 const int LogHeapWordSize = 3;
253 #else
254 const int LogHeapWordSize = 2;
255 #endif
256 const int HeapWordsPerLong = BytesPerLong / HeapWordSize;
257 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
258
259 // The minimum number of native machine words necessary to contain "byte_size"
260 // bytes.
261 inline size_t heap_word_size(size_t byte_size) {
262 return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
263 }
264
265 inline jfloat jfloat_cast(jint x);
266 inline jdouble jdouble_cast(jlong x);
267
268 //-------------------------------------------
269 // Constant for jlong (standardized by C++11)
270
271 // Build a 64bit integer constant
272 #define CONST64(x) (x ## LL)
273 #define UCONST64(x) (x ## ULL)
274
275 const jlong min_jlong = CONST64(0x8000000000000000);
276 const jlong max_jlong = CONST64(0x7fffffffffffffff);
277
278 // for timer info max values which include all bits, 0xffffffffffffffff
279 const jlong all_bits_jlong = ~jlong(0);
280
281 //-------------------------------------------
282 // Constant for jdouble
283 const jlong min_jlongDouble = CONST64(0x0000000000000001);
284 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
285 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
286 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
287
288 const size_t K = 1024;
289 const size_t M = K*K;
290 const size_t G = M*K;
291
292 // Constants for converting from a base unit to milli-base units. For
293 // example from seconds to milliseconds and microseconds
294
295 const int MILLIUNITS = 1000; // milli units per base unit
296 const int MICROUNITS = 1000000; // micro units per base unit
297 const int NANOUNITS = 1000000000; // nano units per base unit
298 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
299
300 const jlong NANOSECS_PER_SEC = CONST64(1000000000);
301 const jint NANOSECS_PER_MILLISEC = 1000000;
302
303
304 // Unit conversion functions
305 // The caller is responsible for considering overflow.
306
307 inline int64_t nanos_to_millis(int64_t nanos) {
308 return nanos / NANOUNITS_PER_MILLIUNIT;
309 }
310 inline int64_t millis_to_nanos(int64_t millis) {
311 return millis * NANOUNITS_PER_MILLIUNIT;
312 }
313
314 // Proper units routines try to maintain at least three significant digits.
315 // In worst case, it would print five significant digits with lower prefix.
316 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
317 // and therefore we need to be careful.
318
319 inline const char* proper_unit_for_byte_size(size_t s) {
320 #ifdef _LP64
321 if (s >= 100*G) {
322 return "G";
323 }
324 #endif
325 if (s >= 100*M) {
326 return "M";
327 } else if (s >= 100*K) {
328 return "K";
329 } else {
330 return "B";
331 }
332 }
333
334 template <class T>
335 inline T byte_size_in_proper_unit(T s) {
336 #ifdef _LP64
337 if (s >= 100*G) {
338 return (T)(s/G);
339 }
340 #endif
341 if (s >= 100*M) {
342 return (T)(s/M);
343 } else if (s >= 100*K) {
344 return (T)(s/K);
345 } else {
346 return s;
347 }
348 }
349
350 #define PROPERFMT "%zu%s"
351 #define PROPERFMTARGS(s) byte_size_in_proper_unit<size_t>(s), proper_unit_for_byte_size(s)
352
353 // Printing a range, with start and bytes given
354 #define RANGEFMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
355 #define RANGEFMTARGS(p1, size) p2i(p1), p2i(p1 + size), size
356
357 // Printing a range, with start and end given
358 #define RANGE2FMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
359 #define RANGE2FMTARGS(p1, p2) p2i(p1), p2i(p2), ((uintptr_t)p2 - (uintptr_t)p1)
360
361 inline const char* exact_unit_for_byte_size(size_t s) {
362 #ifdef _LP64
363 if (s >= G && (s % G) == 0) {
364 return "G";
365 }
366 #endif
367 if (s >= M && (s % M) == 0) {
368 return "M";
369 }
370 if (s >= K && (s % K) == 0) {
371 return "K";
372 }
373 return "B";
374 }
375
376 inline size_t byte_size_in_exact_unit(size_t s) {
377 #ifdef _LP64
378 if (s >= G && (s % G) == 0) {
379 return s / G;
380 }
381 #endif
382 if (s >= M && (s % M) == 0) {
383 return s / M;
384 }
385 if (s >= K && (s % K) == 0) {
386 return s / K;
387 }
388 return s;
389 }
390
391 #define EXACTFMT "%zu%s"
392 #define EXACTFMTARGS(s) byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
393
394 // Memory size transition formatting.
395
396 #define HEAP_CHANGE_FORMAT "%s: %zuK(%zuK)->%zuK(%zuK)"
397
398 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
399 (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
400
401 //----------------------------------------------------------------------------------------------------
402 // VM type definitions
403
404 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
405 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
406
407 typedef intptr_t intx;
408 typedef uintptr_t uintx;
409
410 const intx min_intx = (intx)1 << (sizeof(intx)*BitsPerByte-1);
411 const intx max_intx = (uintx)min_intx - 1;
412 const uintx max_uintx = (uintx)-1;
413
414 // Table of values:
415 // sizeof intx 4 8
416 // min_intx 0x80000000 0x8000000000000000
417 // max_intx 0x7FFFFFFF 0x7FFFFFFFFFFFFFFF
418 // max_uintx 0xFFFFFFFF 0xFFFFFFFFFFFFFFFF
419
420 typedef unsigned int uint; NEEDS_CLEANUP
421
422 // This typedef is to address the issue of running a 32-bit VM. In this case the amount
423 // of physical memory may not fit in size_t, so we have to have a larger type. Once 32-bit
424 // is deprecated, one can use size_t.
425 typedef uint64_t physical_memory_size_type;
426
427 //----------------------------------------------------------------------------------------------------
428 // Java type definitions
429
430 // All kinds of 'plain' byte addresses
431 typedef signed char s_char;
432 typedef unsigned char u_char;
433 typedef u_char* address;
434 typedef const u_char* const_address;
435
436 // Pointer subtraction.
437 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
438 // the range we might need to find differences from one end of the heap
439 // to the other.
440 // A typical use might be:
441 // if (pointer_delta(end(), top()) >= size) {
442 // // enough room for an object of size
443 // ...
444 // and then additions like
445 // ... top() + size ...
446 // are safe because we know that top() is at least size below end().
447 inline size_t pointer_delta(const volatile void* left,
448 const volatile void* right,
449 size_t element_size) {
450 assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
451 return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
452 }
453
454 // A version specialized for HeapWord*'s.
455 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
456 return pointer_delta(left, right, sizeof(HeapWord));
457 }
458 // A version specialized for MetaWord*'s.
459 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
460 return pointer_delta(left, right, sizeof(MetaWord));
461 }
462
463 // pointer_delta_as_int is called to do pointer subtraction for nearby pointers that
464 // returns a non-negative int, usually used as a size of a code buffer range.
465 // This scales to sizeof(T).
466 template <typename T>
467 inline int pointer_delta_as_int(const volatile T* left, const volatile T* right) {
468 size_t delta = pointer_delta(left, right, sizeof(T));
469 assert(delta <= size_t(INT_MAX), "pointer delta out of range: %zu", delta);
470 return static_cast<int>(delta);
471 }
472
473 //
474 // ANSI C++ does not allow casting from one pointer type to a function pointer
475 // directly without at best a warning. This macro accomplishes it silently
476 // In every case that is present at this point the value be cast is a pointer
477 // to a C linkage function. In some case the type used for the cast reflects
478 // that linkage and a picky compiler would not complain. In other cases because
479 // there is no convenient place to place a typedef with extern C linkage (i.e
480 // a platform dependent header file) it doesn't. At this point no compiler seems
481 // picky enough to catch these instances (which are few). It is possible that
482 // using templates could fix these for all cases. This use of templates is likely
483 // so far from the middle of the road that it is likely to be problematic in
484 // many C++ compilers.
485 //
486 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
487 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((uintptr_t)(func_ptr)))
488
489 // Need the correct linkage to call qsort without warnings
490 extern "C" {
491 typedef int (*_sort_Fn)(const void *, const void *);
492 }
493
494 // Additional Java basic types
495
496 typedef uint8_t jubyte;
497 typedef uint16_t jushort;
498 typedef uint32_t juint;
499 typedef uint64_t julong;
500
501 // Unsigned byte types for os and stream.hpp
502
503 // Unsigned one, two, four and eight byte quantities used for describing
504 // the .class file format. See JVM book chapter 4.
505
506 typedef jubyte u1;
507 typedef jushort u2;
508 typedef juint u4;
509 typedef julong u8;
510
511 const jubyte max_jubyte = (jubyte)-1; // 0xFF largest jubyte
512 const jushort max_jushort = (jushort)-1; // 0xFFFF largest jushort
513 const juint max_juint = (juint)-1; // 0xFFFFFFFF largest juint
514 const julong max_julong = (julong)-1; // 0xFF....FF largest julong
515
516 typedef jbyte s1;
517 typedef jshort s2;
518 typedef jint s4;
519 typedef jlong s8;
520
521 const jbyte min_jbyte = -(1 << 7); // smallest jbyte
522 const jbyte max_jbyte = (1 << 7) - 1; // largest jbyte
523 const jshort min_jshort = -(1 << 15); // smallest jshort
524 const jshort max_jshort = (1 << 15) - 1; // largest jshort
525
526 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
527 const jint max_jint = (juint)min_jint - 1; // 0x7FFFFFFF == largest jint
528
529 const jint min_jintFloat = (jint)(0x00000001);
530 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
531 const jint max_jintFloat = (jint)(0x7f7fffff);
532 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
533
534 const jshort max_jfloat16 = 31743;
535 const jshort min_jfloat16 = 1;
536 const jshort one_jfloat16 = 15360;
537 const jshort pos_inf_jfloat16 = 31744;
538 const jshort neg_inf_jfloat16 = -1024;
539 // A named constant for the integral representation of a Java null.
540 const intptr_t NULL_WORD = 0;
541
542 //----------------------------------------------------------------------------------------------------
543 // JVM spec restrictions
544
545 const int max_method_code_size = 64*K - 1; // JVM spec, 2nd ed. section 4.8.1 (p.134)
546 const int max_method_parameter_length = 255; // JVM spec, 22nd ed. section 4.3.3 (p.83)
547
548 //----------------------------------------------------------------------------------------------------
549 // old CDS options
550 extern bool RequireSharedSpaces;
551 extern "C" {
552 // Make sure UseSharedSpaces is accessible to the serviceability agent.
553 extern JNIEXPORT jboolean UseSharedSpaces;
554 }
555
556 //----------------------------------------------------------------------------------------------------
557 // Object alignment, in units of HeapWords.
558 //
559 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
560 // reference fields can be naturally aligned.
561
562 extern int MinObjAlignment;
563 extern int MinObjAlignmentInBytes;
564 extern int MinObjAlignmentInBytesMask;
565
566 extern int LogMinObjAlignment;
567 extern int LogMinObjAlignmentInBytes;
568
569 // Maximal size of heap where unscaled compression can be used. Also upper bound
570 // for heap placement: 4GB.
571 const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
572 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
573 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
574 extern uint64_t OopEncodingHeapMax;
575
576 // Machine dependent stuff
577
578 #include CPU_HEADER(globalDefinitions)
579
580 // The maximum size of the code cache. Can be overridden by targets.
581 #ifndef CODE_CACHE_SIZE_LIMIT
582 #define CODE_CACHE_SIZE_LIMIT (2*G)
583 #endif
584
585 // Allow targets to reduce the default size of the code cache.
586 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
587
588 // To assure the IRIW property on processors that are not multiple copy
589 // atomic, sync instructions must be issued between volatile reads to
590 // assure their ordering, instead of after volatile stores.
591 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
592 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
593 #ifdef CPU_MULTI_COPY_ATOMIC
594 // Not needed.
595 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
596 #else
597 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
598 // Final decision is subject to JEP 188: Java Memory Model Update.
599 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
600 #endif
601
602 // The expected size in bytes of a cache line.
603 #ifndef DEFAULT_CACHE_LINE_SIZE
604 #error "Platform should define DEFAULT_CACHE_LINE_SIZE"
605 #endif
606
607 // The default padding size for data structures to avoid false sharing.
608 #ifndef DEFAULT_PADDING_SIZE
609 #error "Platform should define DEFAULT_PADDING_SIZE"
610 #endif
611
612
613 //----------------------------------------------------------------------------------------------------
614 // Miscellaneous
615
616 // 6302670 Eliminate Hotspot __fabsf dependency
617 // All fabs() callers should call this function instead, which will implicitly
618 // convert the operand to double, avoiding a dependency on __fabsf which
619 // doesn't exist in early versions of Solaris 8.
620 inline double fabsd(double value) {
621 return fabs(value);
622 }
623
624 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
625 // is zero, return 0.0.
626 template<typename T>
627 inline double percent_of(T numerator, T denominator) {
628 return denominator != 0 ? (double)numerator / (double)denominator * 100.0 : 0.0;
629 }
630
631 //----------------------------------------------------------------------------------------------------
632 // Special casts
633 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
634 typedef union {
635 jfloat f;
636 jint i;
637 } FloatIntConv;
638
639 typedef union {
640 jdouble d;
641 jlong l;
642 julong ul;
643 } DoubleLongConv;
644
645 inline jint jint_cast (jfloat x) { return ((FloatIntConv*)&x)->i; }
646 inline jfloat jfloat_cast (jint x) { return ((FloatIntConv*)&x)->f; }
647
648 inline jlong jlong_cast (jdouble x) { return ((DoubleLongConv*)&x)->l; }
649 inline julong julong_cast (jdouble x) { return ((DoubleLongConv*)&x)->ul; }
650 inline jdouble jdouble_cast (jlong x) { return ((DoubleLongConv*)&x)->d; }
651
652 inline jint low (jlong value) { return jint(value); }
653 inline jint high(jlong value) { return jint(value >> 32); }
654
655 inline jlong jlong_from(jint h, jint l) {
656 // First cast jint values to juint, so cast to julong will zero-extend.
657 julong high = (julong)(juint)h << 32;
658 julong low = (julong)(juint)l;
659 return (jlong)(high | low);
660 }
661
662 union jlong_accessor {
663 jint words[2];
664 jlong long_value;
665 };
666
667 void basic_types_init(); // cannot define here; uses assert
668
669
670 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
671 enum BasicType : u1 {
672 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
673 T_BOOLEAN = JVM_T_BOOLEAN,
674 T_CHAR = JVM_T_CHAR,
675 T_FLOAT = JVM_T_FLOAT,
676 T_DOUBLE = JVM_T_DOUBLE,
677 T_BYTE = JVM_T_BYTE,
678 T_SHORT = JVM_T_SHORT,
679 T_INT = JVM_T_INT,
680 T_LONG = JVM_T_LONG,
681 // The remaining values are not part of any standard.
682 // T_OBJECT and T_VOID denote two more semantic choices
683 // for method return values.
684 // T_OBJECT and T_ARRAY describe signature syntax.
685 // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
686 // internal references within the JVM as if they were Java
687 // types in their own right.
688 T_OBJECT = 12,
689 T_ARRAY = 13,
690 T_VOID = 14,
691 T_ADDRESS = 15,
692 T_NARROWOOP = 16,
693 T_METADATA = 17,
694 T_NARROWKLASS = 18,
695 T_CONFLICT = 19, // for stack value type with conflicting contents
696 T_ILLEGAL = 99
697 };
698
699 #define SIGNATURE_TYPES_DO(F, N) \
700 F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N) \
701 F(JVM_SIGNATURE_CHAR, T_CHAR, N) \
702 F(JVM_SIGNATURE_FLOAT, T_FLOAT, N) \
703 F(JVM_SIGNATURE_DOUBLE, T_DOUBLE, N) \
704 F(JVM_SIGNATURE_BYTE, T_BYTE, N) \
705 F(JVM_SIGNATURE_SHORT, T_SHORT, N) \
706 F(JVM_SIGNATURE_INT, T_INT, N) \
707 F(JVM_SIGNATURE_LONG, T_LONG, N) \
708 F(JVM_SIGNATURE_CLASS, T_OBJECT, N) \
709 F(JVM_SIGNATURE_ARRAY, T_ARRAY, N) \
710 F(JVM_SIGNATURE_VOID, T_VOID, N) \
711 /*end*/
712
713 inline bool is_java_type(BasicType t) {
714 return T_BOOLEAN <= t && t <= T_VOID;
715 }
716
717 inline bool is_java_primitive(BasicType t) {
718 return T_BOOLEAN <= t && t <= T_LONG;
719 }
720
721 inline bool is_subword_type(BasicType t) {
722 // these guys are processed exactly like T_INT in calling sequences:
723 return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
724 }
725
726 inline bool is_signed_subword_type(BasicType t) {
727 return (t == T_BYTE || t == T_SHORT);
728 }
729
730 inline bool is_unsigned_subword_type(BasicType t) {
731 return (t == T_BOOLEAN || t == T_CHAR);
732 }
733
734 inline bool is_double_word_type(BasicType t) {
735 return (t == T_DOUBLE || t == T_LONG);
736 }
737
738 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
739 return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
740 }
741
742 inline bool is_integral_type(BasicType t) {
743 return is_subword_type(t) || t == T_INT || t == T_LONG;
744 }
745
746 inline bool is_non_subword_integral_type(BasicType t) {
747 return t == T_INT || t == T_LONG;
748 }
749
750 inline bool is_floating_point_type(BasicType t) {
751 return (t == T_FLOAT || t == T_DOUBLE);
752 }
753
754 extern char type2char_tab[T_CONFLICT+1]; // Map a BasicType to a jchar
755 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
756 extern int type2size[T_CONFLICT+1]; // Map BasicType to result stack elements
757 extern const char* type2name_tab[T_CONFLICT+1]; // Map a BasicType to a char*
758 extern BasicType name2type(const char* name);
759
760 const char* type2name(BasicType t);
761
762 inline jlong max_signed_integer(BasicType bt) {
763 if (bt == T_INT) {
764 return max_jint;
765 }
766 assert(bt == T_LONG, "unsupported");
767 return max_jlong;
768 }
769
770 inline jlong min_signed_integer(BasicType bt) {
771 if (bt == T_INT) {
772 return min_jint;
773 }
774 assert(bt == T_LONG, "unsupported");
775 return min_jlong;
776 }
777
778 inline julong max_unsigned_integer(BasicType bt) {
779 if (bt == T_INT) {
780 return max_juint;
781 }
782 assert(bt == T_LONG, "unsupported");
783 return max_julong;
784 }
785
786 inline uint bits_per_java_integer(BasicType bt) {
787 if (bt == T_INT) {
788 return BitsPerJavaInteger;
789 }
790 assert(bt == T_LONG, "int or long only");
791 return BitsPerJavaLong;
792 }
793
794 // Auxiliary math routines
795 // least common multiple
796 extern size_t lcm(size_t a, size_t b);
797
798
799 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
800 enum BasicTypeSize {
801 T_BOOLEAN_size = 1,
802 T_CHAR_size = 1,
803 T_FLOAT_size = 1,
804 T_DOUBLE_size = 2,
805 T_BYTE_size = 1,
806 T_SHORT_size = 1,
807 T_INT_size = 1,
808 T_LONG_size = 2,
809 T_OBJECT_size = 1,
810 T_ARRAY_size = 1,
811 T_NARROWOOP_size = 1,
812 T_NARROWKLASS_size = 1,
813 T_VOID_size = 0
814 };
815
816 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
817 inline int parameter_type_word_count(BasicType t) {
818 if (is_double_word_type(t)) return 2;
819 assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
820 assert(type2size[t] == 1, "must be");
821 return 1;
822 }
823
824 // maps a BasicType to its instance field storage type:
825 // all sub-word integral types are widened to T_INT
826 extern BasicType type2field[T_CONFLICT+1];
827 extern BasicType type2wfield[T_CONFLICT+1];
828
829
830 // size in bytes
831 enum ArrayElementSize {
832 T_BOOLEAN_aelem_bytes = 1,
833 T_CHAR_aelem_bytes = 2,
834 T_FLOAT_aelem_bytes = 4,
835 T_DOUBLE_aelem_bytes = 8,
836 T_BYTE_aelem_bytes = 1,
837 T_SHORT_aelem_bytes = 2,
838 T_INT_aelem_bytes = 4,
839 T_LONG_aelem_bytes = 8,
840 #ifdef _LP64
841 T_OBJECT_aelem_bytes = 8,
842 T_ARRAY_aelem_bytes = 8,
843 #else
844 T_OBJECT_aelem_bytes = 4,
845 T_ARRAY_aelem_bytes = 4,
846 #endif
847 T_NARROWOOP_aelem_bytes = 4,
848 T_NARROWKLASS_aelem_bytes = 4,
849 T_VOID_aelem_bytes = 0
850 };
851
852 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
853 #ifdef ASSERT
854 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
855 #else
856 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
857 #endif
858
859 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
860 return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
861 }
862
863 // JavaValue serves as a container for arbitrary Java values.
864
865 class JavaValue {
866
867 public:
868 typedef union JavaCallValue {
869 jfloat f;
870 jdouble d;
871 jint i;
872 jlong l;
873 jobject h;
874 oopDesc* o;
875 } JavaCallValue;
876
877 private:
878 BasicType _type;
879 JavaCallValue _value;
880
881 public:
882 JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
883
884 JavaValue(jfloat value) {
885 _type = T_FLOAT;
886 _value.f = value;
887 }
888
889 JavaValue(jdouble value) {
890 _type = T_DOUBLE;
891 _value.d = value;
892 }
893
894 jfloat get_jfloat() const { return _value.f; }
895 jdouble get_jdouble() const { return _value.d; }
896 jint get_jint() const { return _value.i; }
897 jlong get_jlong() const { return _value.l; }
898 jobject get_jobject() const { return _value.h; }
899 oopDesc* get_oop() const { return _value.o; }
900 JavaCallValue* get_value_addr() { return &_value; }
901 BasicType get_type() const { return _type; }
902
903 void set_jfloat(jfloat f) { _value.f = f;}
904 void set_jdouble(jdouble d) { _value.d = d;}
905 void set_jint(jint i) { _value.i = i;}
906 void set_jshort(jshort 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 //----------------------------------------------------------------------------------------------------
1016 // Special constants for debugging
1017
1018 const jint badInt = -3; // generic "bad int" value
1019 const intptr_t badAddressVal = -2; // generic "bad address" value
1020 const intptr_t badOopVal = -1; // generic "bad oop" value
1021 const intptr_t badHeapOopVal = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1022 const int badStackSegVal = 0xCA; // value used to zap stack segments
1023 const int badHandleValue = 0xBC; // value used to zap vm handle area
1024 const int badResourceValue = 0xAB; // value used to zap resource area
1025 const int freeBlockPad = 0xBA; // value used to pad freed blocks.
1026 const int uninitBlockPad = 0xF1; // value used to zap newly malloc'd blocks.
1027 const juint uninitMetaWordVal = 0xf7f7f7f7; // value used to zap newly allocated metachunk
1028 const jubyte heapPaddingByteVal = 0xBD; // value used to zap object padding in the heap
1029 const juint badHeapWordVal = 0xBAADBABE; // value used to zap heap after GC
1030 const int badCodeHeapNewVal = 0xCC; // value used to zap Code heap at allocation
1031 const int badCodeHeapFreeVal = 0xDD; // value used to zap Code heap at deallocation
1032 const intptr_t badDispHeaderDeopt = 0xDE0BD000; // value to fill unused displaced header during deoptimization
1033 const intptr_t badDispHeaderOSR = 0xDEAD05A0; // value to fill unused displaced header during OSR
1034
1035 // (These must be implemented as #defines because C++ compilers are
1036 // not obligated to inline non-integral constants!)
1037 #define badAddress ((address)::badAddressVal)
1038 #define badHeapWord (::badHeapWordVal)
1039
1040 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1041 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1042
1043 //----------------------------------------------------------------------------------------------------
1044 // Utility functions for bitfield manipulations
1045
1046 const intptr_t AllBits = ~0; // all bits set in a word
1047 const intptr_t NoBits = 0; // no bits set in a word
1048 const jlong NoLongBits = 0; // no bits set in a long
1049 const intptr_t OneBit = 1; // only right_most bit set in a word
1050
1051 // get a word with the n.th or the right-most or left-most n bits set
1052 // (note: #define used only so that they can be used in enum constant definitions)
1053 #define nth_bit(n) (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1054 #define right_n_bits(n) (nth_bit(n) - 1)
1055
1056 // same as nth_bit(n), but allows handing in a type as template parameter. Allows
1057 // us to use nth_bit with 64-bit types on 32-bit platforms
1058 template<class T> inline T nth_bit_typed(int n) {
1059 return ((T)1) << n;
1060 }
1061 template<class T> inline T right_n_bits_typed(int n) {
1062 return nth_bit_typed<T>(n) - 1;
1063 }
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 #define ABS(x) asserted_abs(x, __FILE__, __LINE__)
1109
1110 template<class T> inline T asserted_abs(T x, const char* file, int line) {
1111 bool valid_arg = !(std::is_integral<T>::value && x == std::numeric_limits<T>::min());
1112 #ifdef ASSERT
1113 if (!valid_arg) {
1114 report_vm_error(file, line, "ABS: argument should not allow overflow");
1115 }
1116 #endif
1117 // Prevent exposure to UB by checking valid_arg here as well.
1118 return (x < 0 && valid_arg) ? -x : x;
1119 }
1120
1121 // Return the given value clamped to the range [min ... max]
1122 template<typename T>
1123 inline T clamp(T value, T min, T max) {
1124 assert(min <= max, "must be");
1125 return MIN2(MAX2(value, min), max);
1126 }
1127
1128 inline bool is_odd (intx x) { return x & 1; }
1129 inline bool is_even(intx x) { return !is_odd(x); }
1130
1131 // abs methods which cannot overflow and so are well-defined across
1132 // the entire domain of integer types.
1133 static inline unsigned int g_uabs(unsigned int n) {
1134 union {
1135 unsigned int result;
1136 int value;
1137 };
1138 result = n;
1139 if (value < 0) result = 0-result;
1140 return result;
1141 }
1142 static inline julong g_uabs(julong n) {
1143 union {
1144 julong result;
1145 jlong value;
1146 };
1147 result = n;
1148 if (value < 0) result = 0-result;
1149 return result;
1150 }
1151 static inline julong g_uabs(jlong n) { return g_uabs((julong)n); }
1152 static inline unsigned int g_uabs(int n) { return g_uabs((unsigned int)n); }
1153
1154 // "to" should be greater than "from."
1155 inline size_t byte_size(void* from, void* to) {
1156 return pointer_delta(to, from, sizeof(char));
1157 }
1158
1159 // Pack and extract shorts to/from ints:
1160
1161 inline u2 extract_low_short_from_int(u4 x) {
1162 return u2(x & 0xffff);
1163 }
1164
1165 inline u2 extract_high_short_from_int(u4 x) {
1166 return u2((x >> 16) & 0xffff);
1167 }
1168
1169 inline int build_int_from_shorts( u2 low, u2 high ) {
1170 return ((int)((unsigned int)high << 16) | (unsigned int)low);
1171 }
1172
1173 // swap a & b
1174 template<class T> static void swap(T& a, T& b) {
1175 T tmp = a;
1176 a = b;
1177 b = tmp;
1178 }
1179
1180 // array_size_impl is a function that takes a reference to T[N] and
1181 // returns a reference to char[N]. It is not ODR-used, so not defined.
1182 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1183
1184 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1185
1186 //----------------------------------------------------------------------------------------------------
1187 // Sum and product which can never overflow: they wrap, just like the
1188 // Java operations. Note that we don't intend these to be used for
1189 // general-purpose arithmetic: their purpose is to emulate Java
1190 // operations.
1191
1192 // The goal of this code to avoid undefined or implementation-defined
1193 // behavior. The use of an lvalue to reference cast is explicitly
1194 // permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1195 // 15 in C++03]
1196 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1197 inline TYPE NAME (TYPE in1, TYPE in2) { \
1198 UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1199 ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1200 return reinterpret_cast<TYPE&>(ures); \
1201 }
1202
1203 JAVA_INTEGER_OP(+, java_add, jint, juint)
1204 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1205 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1206 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1207 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1208 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1209
1210 inline jint java_negate(jint v) { return java_subtract((jint) 0, v); }
1211 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1212
1213 #undef JAVA_INTEGER_OP
1214
1215 // Provide integer shift operations with Java semantics. No overflow
1216 // issues - left shifts simply discard shifted out bits. No undefined
1217 // behavior for large or negative shift quantities; instead the actual
1218 // shift distance is the argument modulo the lhs value's size in bits.
1219 // No undefined or implementation defined behavior for shifting negative
1220 // values; left shift discards bits, right shift sign extends. We use
1221 // the same safe conversion technique as above for java_add and friends.
1222 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE) \
1223 inline TYPE NAME (TYPE lhs, jint rhs) { \
1224 const uint rhs_mask = (sizeof(TYPE) * 8) - 1; \
1225 STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63); \
1226 XTYPE xres = static_cast<XTYPE>(lhs); \
1227 xres OP ## = (rhs & rhs_mask); \
1228 return reinterpret_cast<TYPE&>(xres); \
1229 }
1230
1231 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1232 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1233
1234 // For signed shift right, assume C++ implementation >> sign extends.
1235 //
1236 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1237 // and a negative value, the resulting value is implementation-defined."
1238 //
1239 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1240 // requiring two's-complement behavior.
1241 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1242 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1243 // The corresponding C++20 text is "Right-shift on signed integral types is an
1244 // arithmetic right shift, which performs sign-extension."
1245 //
1246 // As discussed in the two's complement proposal, all known modern C++ compilers
1247 // already behave that way. And it is unlikely any would go off and do something
1248 // different now, with C++20 tightening things up.
1249 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1250 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1251 // For >>> use C++ unsigned >>.
1252 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1253 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1254
1255 #undef JAVA_INTEGER_SHIFT_OP
1256
1257 inline jlong java_negate(jlong v, BasicType bt) {
1258 if (bt == T_INT) {
1259 return java_negate(checked_cast<jint>(v));
1260 }
1261 assert(bt == T_LONG, "int or long only");
1262 return java_negate(v);
1263 }
1264
1265 // Some convenient bit shift operations that accepts a BasicType as the last
1266 // argument. These avoid potential mistakes with overloaded functions only
1267 // distinguished by lhs argument type.
1268 #define JAVA_INTEGER_SHIFT_BASIC_TYPE(FUNC) \
1269 inline jlong FUNC(jlong lhs, jint rhs, BasicType bt) { \
1270 if (bt == T_INT) { \
1271 return FUNC(checked_cast<jint>(lhs), rhs); \
1272 } \
1273 assert(bt == T_LONG, "unsupported basic type"); \
1274 return FUNC(lhs, rhs); \
1275 }
1276
1277 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_left)
1278 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_right)
1279 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_right_unsigned)
1280
1281 #undef JAVA_INTERGER_SHIFT_BASIC_TYPE
1282
1283 //----------------------------------------------------------------------------------------------------
1284 // The goal of this code is to provide saturating operations for int/uint.
1285 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1286 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1287 inline int NAME (TYPE1 in1, TYPE2 in2) { \
1288 jlong res = static_cast<jlong>(in1); \
1289 res OP ## = static_cast<jlong>(in2); \
1290 if (res > max_jint) { \
1291 res = max_jint; \
1292 } else if (res < min_jint) { \
1293 res = min_jint; \
1294 } \
1295 return static_cast<int>(res); \
1296 }
1297
1298 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1299 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1300 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1301 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1302
1303 #undef SATURATED_INTEGER_OP
1304
1305 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1306 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1307 const uint64_t x1 = x >> 32u;
1308 const uint64_t x2 = x & 0xFFFFFFFF;
1309 const uint64_t y1 = y >> 32u;
1310 const uint64_t y2 = y & 0xFFFFFFFF;
1311 const uint64_t z2 = x2 * y2;
1312 const uint64_t t = x1 * y2 + (z2 >> 32u);
1313 uint64_t z1 = t & 0xFFFFFFFF;
1314 const uint64_t z0 = t >> 32u;
1315 z1 += x2 * y1;
1316
1317 return x1 * y1 + z0 + (z1 >> 32u);
1318 }
1319
1320 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1321 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1322 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1323 const jlong x1 = java_shift_right((jlong)x, 32);
1324 const jlong x2 = x & 0xFFFFFFFF;
1325 const jlong y1 = java_shift_right((jlong)y, 32);
1326 const jlong y2 = y & 0xFFFFFFFF;
1327
1328 const uint64_t z2 = (uint64_t)x2 * y2;
1329 const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1330 int64_t z1 = t & 0xFFFFFFFF;
1331 const int64_t z0 = java_shift_right((jlong)t, 32);
1332 z1 += x2 * y1;
1333
1334 return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1335 }
1336
1337 // Dereference vptr
1338 // All C++ compilers that we know of have the vtbl pointer in the first
1339 // word. If there are exceptions, this function needs to be made compiler
1340 // specific.
1341 static inline void* dereference_vptr(const void* addr) {
1342 return *(void**)addr;
1343 }
1344
1345 //----------------------------------------------------------------------------------------------------
1346 // String type aliases used by command line flag declarations and
1347 // processing utilities.
1348
1349 typedef const char* ccstr;
1350 typedef const char* ccstrlist; // represents string arguments which accumulate
1351
1352 //----------------------------------------------------------------------------------------------------
1353 // Default hash/equals functions used by HashTable
1354
1355 template<typename K> unsigned primitive_hash(const K& k) {
1356 unsigned hash = (unsigned)((uintptr_t)k);
1357 return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1358 }
1359
1360 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1361 return k0 == k1;
1362 }
1363
1364 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1365 return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1366 }
1367
1368 //----------------------------------------------------------------------------------------------------
1369
1370 // Allow use of C++ thread_local when approved - see JDK-8282469.
1371 #define APPROVED_CPP_THREAD_LOCAL thread_local
1372
1373 // Converts any type T to a reference type.
1374 template<typename T>
1375 std::add_rvalue_reference_t<T> declval() noexcept;
1376
1377 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1378 // handled.
1379 bool IEEE_subnormal_handling_OK();
1380
1381 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP