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 "utilities/compilerWarnings.hpp"
29 #include "utilities/debug.hpp"
30 #include "utilities/macros.hpp"
31
32 // Get constants like JVM_T_CHAR and JVM_SIGNATURE_INT, before pulling in <jvm.h>.
33 #include "classfile_constants.h"
34
35 #include COMPILER_HEADER(utilities/globalDefinitions)
36
37 #include <cstddef>
38 #include <cstdint>
39 #include <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
90 //----------------------------------------------------------------------------------------------------
91 // Printf-style formatters for fixed- and variable-width types as pointers and
92 // integers. These are derived from the definitions in inttypes.h. If the platform
93 // doesn't provide appropriate definitions, they should be provided in
94 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
95
96 // Guide to the suffixes used in the format specifiers for integers:
97 // - print the decimal value: 745565
98 // _X - print as hexadecimal, without leading 0s: 0x12345
99 // _X_0 - print as hexadecimal, with leading 0s: 0x00012345
100 // _W(w) - prints w sized string with the given value right
101 // adjusted. Use -w to print left adjusted.
102 // _0 - print as hexadecimal, with leading 0s, without 0x prefix: 0012345
103 //
104 // Note that the PTR format specifiers print using 0x with leading zeros,
105 // just like the _X_0 version for integers.
106
107 // Format 8-bit quantities.
108 #define INT8_FORMAT_X_0 "0x%02" PRIx8
109 #define UINT8_FORMAT_X_0 "0x%02" PRIx8
110
111 // Format 16-bit quantities.
112 #define INT16_FORMAT_X_0 "0x%04" PRIx16
113 #define UINT16_FORMAT_X_0 "0x%04" PRIx16
114
115 // Format 32-bit quantities.
116 #define INT32_FORMAT "%" PRId32
117 #define INT32_FORMAT_X "0x%" PRIx32
118 #define INT32_FORMAT_X_0 "0x%08" PRIx32
119 #define INT32_FORMAT_W(width) "%" #width PRId32
120 #define UINT32_FORMAT "%" PRIu32
121 #define UINT32_FORMAT_X "0x%" PRIx32
122 #define UINT32_FORMAT_X_0 "0x%08" PRIx32
123 #define UINT32_FORMAT_W(width) "%" #width PRIu32
124
125 // Format 64-bit quantities.
126 #define INT64_FORMAT "%" PRId64
127 #define INT64_PLUS_FORMAT "%+" PRId64
128 #define INT64_FORMAT_X "0x%" PRIx64
129 #define INT64_FORMAT_X_0 "0x%016" PRIx64
130 #define INT64_FORMAT_W(width) "%" #width PRId64
131 #define UINT64_FORMAT "%" PRIu64
132 #define UINT64_FORMAT_X "0x%" PRIx64
133 #define UINT64_FORMAT_X_0 "0x%016" PRIx64
134 #define UINT64_FORMAT_W(width) "%" #width PRIu64
135 #define UINT64_FORMAT_0 "%016" PRIx64
136
137 // Format jlong, if necessary
138 #ifndef JLONG_FORMAT
139 #define JLONG_FORMAT INT64_FORMAT
140 #endif
141 #ifndef JLONG_FORMAT_W
142 #define JLONG_FORMAT_W(width) INT64_FORMAT_W(width)
143 #endif
144 #ifndef JULONG_FORMAT
145 #define JULONG_FORMAT UINT64_FORMAT
146 #endif
147 #ifndef JULONG_FORMAT_X
148 #define JULONG_FORMAT_X UINT64_FORMAT_X
149 #endif
150
151 // Format pointers and padded integral values which change size between 32- and 64-bit.
152 #ifdef _LP64
153 #define INTPTR_FORMAT "0x%016" PRIxPTR
154 #define PTR_FORMAT "0x%016" PRIxPTR
155 #define UINTX_FORMAT_X_0 "0x%016" PRIxPTR
156 #define SIZE_FORMAT_X_0 "0x%016" PRIxPTR
157 #else // !_LP64
158 #define INTPTR_FORMAT "0x%08" PRIxPTR
159 #define PTR_FORMAT "0x%08" PRIxPTR
160 #define UINTX_FORMAT_X_0 "0x%08" PRIxPTR
161 #define SIZE_FORMAT_X_0 "0x%08" PRIxPTR
162 #endif // _LP64
163
164 // Convert pointer to intptr_t, for use in printing pointers.
165 inline intptr_t p2i(const volatile void* p) {
166 return (intptr_t) p;
167 }
168
169 // Convert pointer to uintptr_t
170 inline uintptr_t p2u(const volatile void* p) {
171 return (uintptr_t) p;
172 }
173
174 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
175
176 //----------------------------------------------------------------------------------------------------
177 // Forbid the use of various C library functions.
178 // Some of these have os:: replacements that should normally be used instead.
179 // Others are considered security concerns, with preferred alternatives.
180
181 FORBID_C_FUNCTION(void exit(int), "use os::exit");
182 FORBID_C_FUNCTION(void _exit(int), "use os::exit");
183 FORBID_C_FUNCTION(char* strerror(int), "use os::strerror");
184 FORBID_C_FUNCTION(char* strtok(char*, const char*), "use strtok_r");
185 FORBID_C_FUNCTION(int sprintf(char*, const char*, ...), "use os::snprintf");
186 FORBID_C_FUNCTION(int vsprintf(char*, const char*, va_list), "use os::vsnprintf");
187 FORBID_C_FUNCTION(int vsnprintf(char*, size_t, const char*, va_list), "use os::vsnprintf");
188
189 // All of the following functions return raw C-heap pointers (sometimes as an option, e.g. realpath or getwd)
190 // or, in case of free(), take raw C-heap pointers. Don't use them unless you are really sure you must.
191 FORBID_C_FUNCTION(void* malloc(size_t size), "use os::malloc");
192 FORBID_C_FUNCTION(void* calloc(size_t nmemb, size_t size), "use os::malloc and zero out manually");
193 FORBID_C_FUNCTION(void free(void *ptr), "use os::free");
194 FORBID_C_FUNCTION(void* realloc(void *ptr, size_t size), "use os::realloc");
195 FORBID_C_FUNCTION(char* strdup(const char *s), "use os::strdup");
196 FORBID_C_FUNCTION(char* strndup(const char *s, size_t n), "don't use");
197 FORBID_C_FUNCTION(int posix_memalign(void **memptr, size_t alignment, size_t size), "don't use");
198 FORBID_C_FUNCTION(void* aligned_alloc(size_t alignment, size_t size), "don't use");
199 FORBID_C_FUNCTION(char* realpath(const char* path, char* resolved_path), "use os::realpath");
200 FORBID_C_FUNCTION(char* get_current_dir_name(void), "use os::get_current_directory()");
201 FORBID_C_FUNCTION(char* getwd(char *buf), "use os::get_current_directory()");
202 FORBID_C_FUNCTION(wchar_t* wcsdup(const wchar_t *s), "don't use");
203 FORBID_C_FUNCTION(void* reallocf(void *ptr, size_t size), "don't use");
204
205 //----------------------------------------------------------------------------------------------------
206 // Constants
207
208 const int LogBytesPerShort = 1;
209 const int LogBytesPerInt = 2;
210 #ifdef _LP64
211 constexpr int LogBytesPerWord = 3;
212 #else
213 constexpr int LogBytesPerWord = 2;
214 #endif
215 const int LogBytesPerLong = 3;
216
217 const int BytesPerShort = 1 << LogBytesPerShort;
218 const int BytesPerInt = 1 << LogBytesPerInt;
219 const int BytesPerWord = 1 << LogBytesPerWord;
220 const int BytesPerLong = 1 << LogBytesPerLong;
221
222 constexpr int LogBitsPerByte = 3;
223 const int LogBitsPerShort = LogBitsPerByte + LogBytesPerShort;
224 const int LogBitsPerInt = LogBitsPerByte + LogBytesPerInt;
225 constexpr int LogBitsPerWord = LogBitsPerByte + LogBytesPerWord;
226 const int LogBitsPerLong = LogBitsPerByte + LogBytesPerLong;
227
228 const int BitsPerByte = 1 << LogBitsPerByte;
229 const int BitsPerShort = 1 << LogBitsPerShort;
230 const int BitsPerInt = 1 << LogBitsPerInt;
231 constexpr int BitsPerWord = 1 << LogBitsPerWord;
232 const int BitsPerLong = 1 << LogBitsPerLong;
233
234 const int WordAlignmentMask = (1 << LogBytesPerWord) - 1;
235 const int LongAlignmentMask = (1 << LogBytesPerLong) - 1;
236
237 const int oopSize = sizeof(char*); // Full-width oop
238 extern int heapOopSize; // Oop within a java object
239 const int wordSize = sizeof(char*);
240 const int longSize = sizeof(jlong);
241 const int jintSize = sizeof(jint);
242 const int size_tSize = sizeof(size_t);
243
244 const int BytesPerOop = BytesPerWord; // Full-width oop
245
246 extern int LogBytesPerHeapOop; // Oop within a java object
247 extern int LogBitsPerHeapOop;
248 extern int BytesPerHeapOop;
249 extern int BitsPerHeapOop;
250
251 const int BitsPerJavaInteger = 32;
252 const int BitsPerJavaLong = 64;
253 const int BitsPerSize_t = size_tSize * BitsPerByte;
254
255 // Size of a char[] needed to represent a jint as a string in decimal.
256 const int jintAsStringSize = 12;
257
258 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
259 // We require that object sizes be measured in units of heap words (e.g.
260 // pointer-sized values), so that given HeapWord* hw,
261 // hw += oop(hw)->foo();
262 // works, where foo is a method (like size or scavenge) that returns the
263 // object size.
264 class HeapWordImpl; // Opaque, never defined.
265 typedef HeapWordImpl* HeapWord;
266
267 // Analogous opaque struct for metadata allocated from metaspaces.
268 class MetaWordImpl; // Opaque, never defined.
269 typedef MetaWordImpl* MetaWord;
270
271 // HeapWordSize must be 2^LogHeapWordSize.
272 const int HeapWordSize = sizeof(HeapWord);
273 #ifdef _LP64
274 const int LogHeapWordSize = 3;
275 #else
276 const int LogHeapWordSize = 2;
277 #endif
278 const int HeapWordsPerLong = BytesPerLong / HeapWordSize;
279 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
280
281 // The minimum number of native machine words necessary to contain "byte_size"
282 // bytes.
283 inline size_t heap_word_size(size_t byte_size) {
284 return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
285 }
286
287 inline jfloat jfloat_cast(jint x);
288 inline jdouble jdouble_cast(jlong x);
289
290 //-------------------------------------------
291 // Constant for jlong (standardized by C++11)
292
293 // Build a 64bit integer constant
294 #define CONST64(x) (x ## LL)
295 #define UCONST64(x) (x ## ULL)
296
297 const jlong min_jlong = CONST64(0x8000000000000000);
298 const jlong max_jlong = CONST64(0x7fffffffffffffff);
299
300 //-------------------------------------------
301 // Constant for jdouble
302 const jlong min_jlongDouble = CONST64(0x0000000000000001);
303 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
304 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
305 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
306
307 const size_t K = 1024;
308 const size_t M = K*K;
309 const size_t G = M*K;
310 const size_t HWperKB = K / sizeof(HeapWord);
311
312 // Constants for converting from a base unit to milli-base units. For
313 // example from seconds to milliseconds and microseconds
314
315 const int MILLIUNITS = 1000; // milli units per base unit
316 const int MICROUNITS = 1000000; // micro units per base unit
317 const int NANOUNITS = 1000000000; // nano units per base unit
318 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
319
320 const jlong NANOSECS_PER_SEC = CONST64(1000000000);
321 const jint NANOSECS_PER_MILLISEC = 1000000;
322
323
324 // Unit conversion functions
325 // The caller is responsible for considering overflow.
326
327 inline int64_t nanos_to_millis(int64_t nanos) {
328 return nanos / NANOUNITS_PER_MILLIUNIT;
329 }
330 inline int64_t millis_to_nanos(int64_t millis) {
331 return millis * NANOUNITS_PER_MILLIUNIT;
332 }
333
334 // Proper units routines try to maintain at least three significant digits.
335 // In worst case, it would print five significant digits with lower prefix.
336 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
337 // and therefore we need to be careful.
338
339 inline const char* proper_unit_for_byte_size(size_t s) {
340 #ifdef _LP64
341 if (s >= 100*G) {
342 return "G";
343 }
344 #endif
345 if (s >= 100*M) {
346 return "M";
347 } else if (s >= 100*K) {
348 return "K";
349 } else {
350 return "B";
351 }
352 }
353
354 template <class T>
355 inline T byte_size_in_proper_unit(T s) {
356 #ifdef _LP64
357 if (s >= 100*G) {
358 return (T)(s/G);
359 }
360 #endif
361 if (s >= 100*M) {
362 return (T)(s/M);
363 } else if (s >= 100*K) {
364 return (T)(s/K);
365 } else {
366 return s;
367 }
368 }
369
370 #define PROPERFMT "%zu%s"
371 #define PROPERFMTARGS(s) byte_size_in_proper_unit(s), proper_unit_for_byte_size(s)
372
373 // Printing a range, with start and bytes given
374 #define RANGEFMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
375 #define RANGEFMTARGS(p1, size) p2i(p1), p2i(p1 + size), size
376
377 // Printing a range, with start and end given
378 #define RANGE2FMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
379 #define RANGE2FMTARGS(p1, p2) p2i(p1), p2i(p2), ((uintptr_t)p2 - (uintptr_t)p1)
380
381 inline const char* exact_unit_for_byte_size(size_t s) {
382 #ifdef _LP64
383 if (s >= G && (s % G) == 0) {
384 return "G";
385 }
386 #endif
387 if (s >= M && (s % M) == 0) {
388 return "M";
389 }
390 if (s >= K && (s % K) == 0) {
391 return "K";
392 }
393 return "B";
394 }
395
396 inline size_t byte_size_in_exact_unit(size_t s) {
397 #ifdef _LP64
398 if (s >= G && (s % G) == 0) {
399 return s / G;
400 }
401 #endif
402 if (s >= M && (s % M) == 0) {
403 return s / M;
404 }
405 if (s >= K && (s % K) == 0) {
406 return s / K;
407 }
408 return s;
409 }
410
411 #define EXACTFMT "%zu%s"
412 #define EXACTFMTARGS(s) byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
413
414 // Memory size transition formatting.
415
416 #define HEAP_CHANGE_FORMAT "%s: %zuK(%zuK)->%zuK(%zuK)"
417
418 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
419 (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
420
421 //----------------------------------------------------------------------------------------------------
422 // VM type definitions
423
424 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
425 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
426
427 typedef intptr_t intx;
428 typedef uintptr_t uintx;
429
430 const intx min_intx = (intx)1 << (sizeof(intx)*BitsPerByte-1);
431 const intx max_intx = (uintx)min_intx - 1;
432 const uintx max_uintx = (uintx)-1;
433
434 // Table of values:
435 // sizeof intx 4 8
436 // min_intx 0x80000000 0x8000000000000000
437 // max_intx 0x7FFFFFFF 0x7FFFFFFFFFFFFFFF
438 // max_uintx 0xFFFFFFFF 0xFFFFFFFFFFFFFFFF
439
440 typedef unsigned int uint; NEEDS_CLEANUP
441
442 //----------------------------------------------------------------------------------------------------
443 // Java type definitions
444
445 // All kinds of 'plain' byte addresses
446 typedef signed char s_char;
447 typedef unsigned char u_char;
448 typedef u_char* address;
449 typedef const u_char* const_address;
450
451 // Pointer subtraction.
452 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
453 // the range we might need to find differences from one end of the heap
454 // to the other.
455 // A typical use might be:
456 // if (pointer_delta(end(), top()) >= size) {
457 // // enough room for an object of size
458 // ...
459 // and then additions like
460 // ... top() + size ...
461 // are safe because we know that top() is at least size below end().
462 inline size_t pointer_delta(const volatile void* left,
463 const volatile void* right,
464 size_t element_size) {
465 assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
466 return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
467 }
468
469 // A version specialized for HeapWord*'s.
470 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
471 return pointer_delta(left, right, sizeof(HeapWord));
472 }
473 // A version specialized for MetaWord*'s.
474 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
475 return pointer_delta(left, right, sizeof(MetaWord));
476 }
477
478 // pointer_delta_as_int is called to do pointer subtraction for nearby pointers that
479 // returns a non-negative int, usually used as a size of a code buffer range.
480 // This scales to sizeof(T).
481 template <typename T>
482 inline int pointer_delta_as_int(const volatile T* left, const volatile T* right) {
483 size_t delta = pointer_delta(left, right, sizeof(T));
484 assert(delta <= size_t(INT_MAX), "pointer delta out of range: %zu", delta);
485 return static_cast<int>(delta);
486 }
487
488 //
489 // ANSI C++ does not allow casting from one pointer type to a function pointer
490 // directly without at best a warning. This macro accomplishes it silently
491 // In every case that is present at this point the value be cast is a pointer
492 // to a C linkage function. In some case the type used for the cast reflects
493 // that linkage and a picky compiler would not complain. In other cases because
494 // there is no convenient place to place a typedef with extern C linkage (i.e
495 // a platform dependent header file) it doesn't. At this point no compiler seems
496 // picky enough to catch these instances (which are few). It is possible that
497 // using templates could fix these for all cases. This use of templates is likely
498 // so far from the middle of the road that it is likely to be problematic in
499 // many C++ compilers.
500 //
501 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
502 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((uintptr_t)(func_ptr)))
503
504 // Need the correct linkage to call qsort without warnings
505 extern "C" {
506 typedef int (*_sort_Fn)(const void *, const void *);
507 }
508
509 // Additional Java basic types
510
511 typedef uint8_t jubyte;
512 typedef uint16_t jushort;
513 typedef uint32_t juint;
514 typedef uint64_t julong;
515
516 // Unsigned byte types for os and stream.hpp
517
518 // Unsigned one, two, four and eight byte quantities used for describing
519 // the .class file format. See JVM book chapter 4.
520
521 typedef jubyte u1;
522 typedef jushort u2;
523 typedef juint u4;
524 typedef julong u8;
525
526 const jubyte max_jubyte = (jubyte)-1; // 0xFF largest jubyte
527 const jushort max_jushort = (jushort)-1; // 0xFFFF largest jushort
528 const juint max_juint = (juint)-1; // 0xFFFFFFFF largest juint
529 const julong max_julong = (julong)-1; // 0xFF....FF largest julong
530
531 typedef jbyte s1;
532 typedef jshort s2;
533 typedef jint s4;
534 typedef jlong s8;
535
536 const jbyte min_jbyte = -(1 << 7); // smallest jbyte
537 const jbyte max_jbyte = (1 << 7) - 1; // largest jbyte
538 const jshort min_jshort = -(1 << 15); // smallest jshort
539 const jshort max_jshort = (1 << 15) - 1; // largest jshort
540
541 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
542 const jint max_jint = (juint)min_jint - 1; // 0x7FFFFFFF == largest jint
543
544 const jint min_jintFloat = (jint)(0x00000001);
545 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
546 const jint max_jintFloat = (jint)(0x7f7fffff);
547 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
548
549 const jshort max_jfloat16 = 31743;
550 const jshort min_jfloat16 = 1;
551 const jshort one_jfloat16 = 15360;
552 const jshort pos_inf_jfloat16 = 31744;
553 const jshort neg_inf_jfloat16 = -1024;
554 // A named constant for the integral representation of a Java null.
555 const intptr_t NULL_WORD = 0;
556
557 //----------------------------------------------------------------------------------------------------
558 // JVM spec restrictions
559
560 const int max_method_code_size = 64*K - 1; // JVM spec, 2nd ed. section 4.8.1 (p.134)
561
562 //----------------------------------------------------------------------------------------------------
563 // old CDS options
564 extern bool RequireSharedSpaces;
565 extern "C" {
566 // Make sure UseSharedSpaces is accessible to the serviceability agent.
567 extern JNIEXPORT jboolean UseSharedSpaces;
568 }
569
570 //----------------------------------------------------------------------------------------------------
571 // Object alignment, in units of HeapWords.
572 //
573 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
574 // reference fields can be naturally aligned.
575
576 extern int MinObjAlignment;
577 extern int MinObjAlignmentInBytes;
578 extern int MinObjAlignmentInBytesMask;
579
580 extern int LogMinObjAlignment;
581 extern int LogMinObjAlignmentInBytes;
582
583 // Maximal size of heap where unscaled compression can be used. Also upper bound
584 // for heap placement: 4GB.
585 const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
586 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
587 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
588 extern uint64_t OopEncodingHeapMax;
589
590 // Machine dependent stuff
591
592 #include CPU_HEADER(globalDefinitions)
593
594 // The maximum size of the code cache. Can be overridden by targets.
595 #ifndef CODE_CACHE_SIZE_LIMIT
596 #define CODE_CACHE_SIZE_LIMIT (2*G)
597 #endif
598
599 // Allow targets to reduce the default size of the code cache.
600 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
601
602 // To assure the IRIW property on processors that are not multiple copy
603 // atomic, sync instructions must be issued between volatile reads to
604 // assure their ordering, instead of after volatile stores.
605 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
606 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
607 #ifdef CPU_MULTI_COPY_ATOMIC
608 // Not needed.
609 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
610 #else
611 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
612 // Final decision is subject to JEP 188: Java Memory Model Update.
613 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
614 #endif
615
616 // The expected size in bytes of a cache line.
617 #ifndef DEFAULT_CACHE_LINE_SIZE
618 #error "Platform should define DEFAULT_CACHE_LINE_SIZE"
619 #endif
620
621 // The default padding size for data structures to avoid false sharing.
622 #ifndef DEFAULT_PADDING_SIZE
623 #error "Platform should define DEFAULT_PADDING_SIZE"
624 #endif
625
626
627 //----------------------------------------------------------------------------------------------------
628 // Miscellaneous
629
630 // 6302670 Eliminate Hotspot __fabsf dependency
631 // All fabs() callers should call this function instead, which will implicitly
632 // convert the operand to double, avoiding a dependency on __fabsf which
633 // doesn't exist in early versions of Solaris 8.
634 inline double fabsd(double value) {
635 return fabs(value);
636 }
637
638 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
639 // is zero, return 0.0.
640 template<typename T>
641 inline double percent_of(T numerator, T denominator) {
642 return denominator != 0 ? (double)numerator / (double)denominator * 100.0 : 0.0;
643 }
644
645 //----------------------------------------------------------------------------------------------------
646 // Special casts
647 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
648 typedef union {
649 jfloat f;
650 jint i;
651 } FloatIntConv;
652
653 typedef union {
654 jdouble d;
655 jlong l;
656 julong ul;
657 } DoubleLongConv;
658
659 inline jint jint_cast (jfloat x) { return ((FloatIntConv*)&x)->i; }
660 inline jfloat jfloat_cast (jint x) { return ((FloatIntConv*)&x)->f; }
661
662 inline jlong jlong_cast (jdouble x) { return ((DoubleLongConv*)&x)->l; }
663 inline julong julong_cast (jdouble x) { return ((DoubleLongConv*)&x)->ul; }
664 inline jdouble jdouble_cast (jlong x) { return ((DoubleLongConv*)&x)->d; }
665
666 inline jint low (jlong value) { return jint(value); }
667 inline jint high(jlong value) { return jint(value >> 32); }
668
669 // the fancy casts are a hopefully portable way
670 // to do unsigned 32 to 64 bit type conversion
671 inline void set_low (jlong* value, jint low ) { *value &= (jlong)0xffffffff << 32;
672 *value |= (jlong)(julong)(juint)low; }
673
674 inline void set_high(jlong* value, jint high) { *value &= (jlong)(julong)(juint)0xffffffff;
675 *value |= (jlong)high << 32; }
676
677 inline jlong jlong_from(jint h, jint l) {
678 jlong result = 0; // initialization to avoid warning
679 set_high(&result, h);
680 set_low(&result, l);
681 return result;
682 }
683
684 union jlong_accessor {
685 jint words[2];
686 jlong long_value;
687 };
688
689 void basic_types_init(); // cannot define here; uses assert
690
691
692 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
693 enum BasicType : u1 {
694 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
695 T_BOOLEAN = JVM_T_BOOLEAN,
696 T_CHAR = JVM_T_CHAR,
697 T_FLOAT = JVM_T_FLOAT,
698 T_DOUBLE = JVM_T_DOUBLE,
699 T_BYTE = JVM_T_BYTE,
700 T_SHORT = JVM_T_SHORT,
701 T_INT = JVM_T_INT,
702 T_LONG = JVM_T_LONG,
703 // The remaining values are not part of any standard.
704 // T_OBJECT and T_VOID denote two more semantic choices
705 // for method return values.
706 // T_OBJECT and T_ARRAY describe signature syntax.
707 // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
708 // internal references within the JVM as if they were Java
709 // types in their own right.
710 T_OBJECT = 12,
711 T_ARRAY = 13,
712 T_VOID = 14,
713 T_ADDRESS = 15,
714 T_NARROWOOP = 16,
715 T_METADATA = 17,
716 T_NARROWKLASS = 18,
717 T_CONFLICT = 19, // for stack value type with conflicting contents
718 T_ILLEGAL = 99
719 };
720
721 #define SIGNATURE_TYPES_DO(F, N) \
722 F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N) \
723 F(JVM_SIGNATURE_CHAR, T_CHAR, N) \
724 F(JVM_SIGNATURE_FLOAT, T_FLOAT, N) \
725 F(JVM_SIGNATURE_DOUBLE, T_DOUBLE, N) \
726 F(JVM_SIGNATURE_BYTE, T_BYTE, N) \
727 F(JVM_SIGNATURE_SHORT, T_SHORT, N) \
728 F(JVM_SIGNATURE_INT, T_INT, N) \
729 F(JVM_SIGNATURE_LONG, T_LONG, N) \
730 F(JVM_SIGNATURE_CLASS, T_OBJECT, N) \
731 F(JVM_SIGNATURE_ARRAY, T_ARRAY, N) \
732 F(JVM_SIGNATURE_VOID, T_VOID, N) \
733 /*end*/
734
735 inline bool is_java_type(BasicType t) {
736 return T_BOOLEAN <= t && t <= T_VOID;
737 }
738
739 inline bool is_java_primitive(BasicType t) {
740 return T_BOOLEAN <= t && t <= T_LONG;
741 }
742
743 inline bool is_subword_type(BasicType t) {
744 // these guys are processed exactly like T_INT in calling sequences:
745 return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
746 }
747
748 inline bool is_signed_subword_type(BasicType t) {
749 return (t == T_BYTE || t == T_SHORT);
750 }
751
752 inline bool is_unsigned_subword_type(BasicType t) {
753 return (t == T_BOOLEAN || t == T_CHAR);
754 }
755
756 inline bool is_double_word_type(BasicType t) {
757 return (t == T_DOUBLE || t == T_LONG);
758 }
759
760 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
761 return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
762 }
763
764 inline bool is_integral_type(BasicType t) {
765 return is_subword_type(t) || t == T_INT || t == T_LONG;
766 }
767
768 inline bool is_non_subword_integral_type(BasicType t) {
769 return t == T_INT || t == T_LONG;
770 }
771
772 inline bool is_floating_point_type(BasicType t) {
773 return (t == T_FLOAT || t == T_DOUBLE);
774 }
775
776 extern char type2char_tab[T_CONFLICT+1]; // Map a BasicType to a jchar
777 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
778 extern int type2size[T_CONFLICT+1]; // Map BasicType to result stack elements
779 extern const char* type2name_tab[T_CONFLICT+1]; // Map a BasicType to a char*
780 extern BasicType name2type(const char* name);
781
782 const char* type2name(BasicType t);
783
784 inline jlong max_signed_integer(BasicType bt) {
785 if (bt == T_INT) {
786 return max_jint;
787 }
788 assert(bt == T_LONG, "unsupported");
789 return max_jlong;
790 }
791
792 inline jlong min_signed_integer(BasicType bt) {
793 if (bt == T_INT) {
794 return min_jint;
795 }
796 assert(bt == T_LONG, "unsupported");
797 return min_jlong;
798 }
799
800 // Auxiliary math routines
801 // least common multiple
802 extern size_t lcm(size_t a, size_t b);
803
804
805 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
806 enum BasicTypeSize {
807 T_BOOLEAN_size = 1,
808 T_CHAR_size = 1,
809 T_FLOAT_size = 1,
810 T_DOUBLE_size = 2,
811 T_BYTE_size = 1,
812 T_SHORT_size = 1,
813 T_INT_size = 1,
814 T_LONG_size = 2,
815 T_OBJECT_size = 1,
816 T_ARRAY_size = 1,
817 T_NARROWOOP_size = 1,
818 T_NARROWKLASS_size = 1,
819 T_VOID_size = 0
820 };
821
822 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
823 inline int parameter_type_word_count(BasicType t) {
824 if (is_double_word_type(t)) return 2;
825 assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
826 assert(type2size[t] == 1, "must be");
827 return 1;
828 }
829
830 // maps a BasicType to its instance field storage type:
831 // all sub-word integral types are widened to T_INT
832 extern BasicType type2field[T_CONFLICT+1];
833 extern BasicType type2wfield[T_CONFLICT+1];
834
835
836 // size in bytes
837 enum ArrayElementSize {
838 T_BOOLEAN_aelem_bytes = 1,
839 T_CHAR_aelem_bytes = 2,
840 T_FLOAT_aelem_bytes = 4,
841 T_DOUBLE_aelem_bytes = 8,
842 T_BYTE_aelem_bytes = 1,
843 T_SHORT_aelem_bytes = 2,
844 T_INT_aelem_bytes = 4,
845 T_LONG_aelem_bytes = 8,
846 #ifdef _LP64
847 T_OBJECT_aelem_bytes = 8,
848 T_ARRAY_aelem_bytes = 8,
849 #else
850 T_OBJECT_aelem_bytes = 4,
851 T_ARRAY_aelem_bytes = 4,
852 #endif
853 T_NARROWOOP_aelem_bytes = 4,
854 T_NARROWKLASS_aelem_bytes = 4,
855 T_VOID_aelem_bytes = 0
856 };
857
858 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
859 #ifdef ASSERT
860 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
861 #else
862 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
863 #endif
864
865 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
866 return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
867 }
868
869 // JavaValue serves as a container for arbitrary Java values.
870
871 class JavaValue {
872
873 public:
874 typedef union JavaCallValue {
875 jfloat f;
876 jdouble d;
877 jint i;
878 jlong l;
879 jobject h;
880 oopDesc* o;
881 } JavaCallValue;
882
883 private:
884 BasicType _type;
885 JavaCallValue _value;
886
887 public:
888 JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
889
890 JavaValue(jfloat value) {
891 _type = T_FLOAT;
892 _value.f = value;
893 }
894
895 JavaValue(jdouble value) {
896 _type = T_DOUBLE;
897 _value.d = value;
898 }
899
900 jfloat get_jfloat() const { return _value.f; }
901 jdouble get_jdouble() const { return _value.d; }
902 jint get_jint() const { return _value.i; }
903 jlong get_jlong() const { return _value.l; }
904 jobject get_jobject() const { return _value.h; }
905 oopDesc* get_oop() const { return _value.o; }
906 JavaCallValue* get_value_addr() { return &_value; }
907 BasicType get_type() const { return _type; }
908
909 void set_jfloat(jfloat f) { _value.f = f;}
910 void set_jdouble(jdouble d) { _value.d = d;}
911 void set_jint(jint i) { _value.i = i;}
912 void set_jshort(jshort i) { _value.i = i;}
913 void set_jlong(jlong l) { _value.l = l;}
914 void set_jobject(jobject h) { _value.h = h;}
915 void set_oop(oopDesc* o) { _value.o = o;}
916 void set_type(BasicType t) { _type = t; }
917
918 jboolean get_jboolean() const { return (jboolean) (_value.i);}
919 jbyte get_jbyte() const { return (jbyte) (_value.i);}
920 jchar get_jchar() const { return (jchar) (_value.i);}
921 jshort get_jshort() const { return (jshort) (_value.i);}
922
923 };
924
925
926 // TosState describes the top-of-stack state before and after the execution of
927 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
928 // registers. The TosState corresponds to the 'machine representation' of this cached
929 // value. There's 4 states corresponding to the JAVA types int, long, float & double
930 // as well as a 5th state in case the top-of-stack value is actually on the top
931 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
932 // state when it comes to machine representation but is used separately for (oop)
933 // type specific operations (e.g. verification code).
934
935 enum TosState { // describes the tos cache contents
936 btos = 0, // byte, bool tos cached
937 ztos = 1, // byte, bool tos cached
938 ctos = 2, // char tos cached
939 stos = 3, // short tos cached
940 itos = 4, // int tos cached
941 ltos = 5, // long tos cached
942 ftos = 6, // float tos cached
943 dtos = 7, // double tos cached
944 atos = 8, // object cached
945 vtos = 9, // tos not cached
946 number_of_states,
947 ilgl // illegal state: should not occur
948 };
949
950
951 inline TosState as_TosState(BasicType type) {
952 switch (type) {
953 case T_BYTE : return btos;
954 case T_BOOLEAN: return ztos;
955 case T_CHAR : return ctos;
956 case T_SHORT : return stos;
957 case T_INT : return itos;
958 case T_LONG : return ltos;
959 case T_FLOAT : return ftos;
960 case T_DOUBLE : return dtos;
961 case T_VOID : return vtos;
962 case T_ARRAY : // fall through
963 case T_OBJECT : return atos;
964 default : return ilgl;
965 }
966 }
967
968 inline BasicType as_BasicType(TosState state) {
969 switch (state) {
970 case btos : return T_BYTE;
971 case ztos : return T_BOOLEAN;
972 case ctos : return T_CHAR;
973 case stos : return T_SHORT;
974 case itos : return T_INT;
975 case ltos : return T_LONG;
976 case ftos : return T_FLOAT;
977 case dtos : return T_DOUBLE;
978 case atos : return T_OBJECT;
979 case vtos : return T_VOID;
980 default : return T_ILLEGAL;
981 }
982 }
983
984
985 // Helper function to convert BasicType info into TosState
986 // Note: Cannot define here as it uses global constant at the time being.
987 TosState as_TosState(BasicType type);
988
989
990 // JavaThreadState keeps track of which part of the code a thread is executing in. This
991 // information is needed by the safepoint code.
992 //
993 // There are 4 essential states:
994 //
995 // _thread_new : Just started, but not executed init. code yet (most likely still in OS init code)
996 // _thread_in_native : In native code. This is a safepoint region, since all oops will be in jobject handles
997 // _thread_in_vm : Executing in the vm
998 // _thread_in_Java : Executing either interpreted or compiled Java code (or could be in a stub)
999 //
1000 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1001 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1002 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1003 //
1004 // Given a state, the xxxx_trans state can always be found by adding 1.
1005 //
1006 enum JavaThreadState {
1007 _thread_uninitialized = 0, // should never happen (missing initialization)
1008 _thread_new = 2, // just starting up, i.e., in process of being initialized
1009 _thread_new_trans = 3, // corresponding transition state (not used, included for completeness)
1010 _thread_in_native = 4, // running in native code
1011 _thread_in_native_trans = 5, // corresponding transition state
1012 _thread_in_vm = 6, // running in VM
1013 _thread_in_vm_trans = 7, // corresponding transition state
1014 _thread_in_Java = 8, // running in Java or in stub code
1015 _thread_in_Java_trans = 9, // corresponding transition state (not used, included for completeness)
1016 _thread_blocked = 10, // blocked in vm
1017 _thread_blocked_trans = 11, // corresponding transition state
1018 _thread_max_state = 12 // maximum thread state+1 - used for statistics allocation
1019 };
1020
1021 enum LockingMode {
1022 // Use only heavy monitors for locking
1023 LM_MONITOR = 0,
1024 // Legacy stack-locking, with monitors as 2nd tier
1025 LM_LEGACY = 1,
1026 // New lightweight locking, with monitors as 2nd tier
1027 LM_LIGHTWEIGHT = 2
1028 };
1029
1030 //----------------------------------------------------------------------------------------------------
1031 // Special constants for debugging
1032
1033 const jint badInt = -3; // generic "bad int" value
1034 const intptr_t badAddressVal = -2; // generic "bad address" value
1035 const intptr_t badOopVal = -1; // generic "bad oop" value
1036 const intptr_t badHeapOopVal = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1037 const int badStackSegVal = 0xCA; // value used to zap stack segments
1038 const int badHandleValue = 0xBC; // value used to zap vm handle area
1039 const int badResourceValue = 0xAB; // value used to zap resource area
1040 const int freeBlockPad = 0xBA; // value used to pad freed blocks.
1041 const int uninitBlockPad = 0xF1; // value used to zap newly malloc'd blocks.
1042 const juint uninitMetaWordVal = 0xf7f7f7f7; // value used to zap newly allocated metachunk
1043 const jubyte heapPaddingByteVal = 0xBD; // value used to zap object padding in the heap
1044 const juint badHeapWordVal = 0xBAADBABE; // value used to zap heap after GC
1045 const int badCodeHeapNewVal = 0xCC; // value used to zap Code heap at allocation
1046 const int badCodeHeapFreeVal = 0xDD; // value used to zap Code heap at deallocation
1047 const intptr_t badDispHeaderDeopt = 0xDE0BD000; // value to fill unused displaced header during deoptimization
1048 const intptr_t badDispHeaderOSR = 0xDEAD05A0; // value to fill unused displaced header during OSR
1049
1050 // (These must be implemented as #defines because C++ compilers are
1051 // not obligated to inline non-integral constants!)
1052 #define badAddress ((address)::badAddressVal)
1053 #define badHeapWord (::badHeapWordVal)
1054
1055 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1056 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1057
1058 //----------------------------------------------------------------------------------------------------
1059 // Utility functions for bitfield manipulations
1060
1061 const intptr_t AllBits = ~0; // all bits set in a word
1062 const intptr_t NoBits = 0; // no bits set in a word
1063 const jlong NoLongBits = 0; // no bits set in a long
1064 const intptr_t OneBit = 1; // only right_most bit set in a word
1065
1066 // get a word with the n.th or the right-most or left-most n bits set
1067 // (note: #define used only so that they can be used in enum constant definitions)
1068 #define nth_bit(n) (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1069 #define right_n_bits(n) (nth_bit(n) - 1)
1070
1071 // bit-operations using a mask m
1072 inline void set_bits (intptr_t& x, intptr_t m) { x |= m; }
1073 inline void clear_bits (intptr_t& x, intptr_t m) { x &= ~m; }
1074 inline intptr_t mask_bits (intptr_t x, intptr_t m) { return x & m; }
1075 inline jlong mask_long_bits (jlong x, jlong m) { return x & m; }
1076 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1077
1078 // bit-operations using the n.th bit
1079 inline void set_nth_bit(intptr_t& x, int n) { set_bits (x, nth_bit(n)); }
1080 inline void clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1081 inline bool is_set_nth_bit(intptr_t x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1082
1083 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1084 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1085 return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1086 }
1087
1088
1089 //----------------------------------------------------------------------------------------------------
1090 // Utility functions for integers
1091
1092 // Avoid use of global min/max macros which may cause unwanted double
1093 // evaluation of arguments.
1094 #ifdef max
1095 #undef max
1096 #endif
1097
1098 #ifdef min
1099 #undef min
1100 #endif
1101
1102 // It is necessary to use templates here. Having normal overloaded
1103 // functions does not work because it is necessary to provide both 32-
1104 // and 64-bit overloaded functions, which does not work, and having
1105 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1106 // will be even more error-prone than macros.
1107 template<class T> constexpr T MAX2(T a, T b) { return (a > b) ? a : b; }
1108 template<class T> constexpr T MIN2(T a, T b) { return (a < b) ? a : b; }
1109 template<class T> constexpr T MAX3(T a, T b, T c) { return MAX2(MAX2(a, b), c); }
1110 template<class T> constexpr T MIN3(T a, T b, T c) { return MIN2(MIN2(a, b), c); }
1111 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1112 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1113
1114 #define ABS(x) asserted_abs(x, __FILE__, __LINE__)
1115
1116 template<class T> inline T asserted_abs(T x, const char* file, int line) {
1117 bool valid_arg = !(std::is_integral<T>::value && x == std::numeric_limits<T>::min());
1118 #ifdef ASSERT
1119 if (!valid_arg) {
1120 report_vm_error(file, line, "ABS: argument should not allow overflow");
1121 }
1122 #endif
1123 // Prevent exposure to UB by checking valid_arg here as well.
1124 return (x < 0 && valid_arg) ? -x : x;
1125 }
1126
1127 // Return the given value clamped to the range [min ... max]
1128 template<typename T>
1129 inline T clamp(T value, T min, T max) {
1130 assert(min <= max, "must be");
1131 return MIN2(MAX2(value, min), max);
1132 }
1133
1134 inline bool is_odd (intx x) { return x & 1; }
1135 inline bool is_even(intx x) { return !is_odd(x); }
1136
1137 // abs methods which cannot overflow and so are well-defined across
1138 // the entire domain of integer types.
1139 static inline unsigned int uabs(unsigned int n) {
1140 union {
1141 unsigned int result;
1142 int value;
1143 };
1144 result = n;
1145 if (value < 0) result = 0-result;
1146 return result;
1147 }
1148 static inline julong uabs(julong n) {
1149 union {
1150 julong result;
1151 jlong value;
1152 };
1153 result = n;
1154 if (value < 0) result = 0-result;
1155 return result;
1156 }
1157 static inline julong uabs(jlong n) { return uabs((julong)n); }
1158 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1159
1160 // "to" should be greater than "from."
1161 inline size_t byte_size(void* from, void* to) {
1162 return pointer_delta(to, from, sizeof(char));
1163 }
1164
1165 // Pack and extract shorts to/from ints:
1166
1167 inline u2 extract_low_short_from_int(u4 x) {
1168 return u2(x & 0xffff);
1169 }
1170
1171 inline u2 extract_high_short_from_int(u4 x) {
1172 return u2((x >> 16) & 0xffff);
1173 }
1174
1175 inline int build_int_from_shorts( u2 low, u2 high ) {
1176 return ((int)((unsigned int)high << 16) | (unsigned int)low);
1177 }
1178
1179 // swap a & b
1180 template<class T> static void swap(T& a, T& b) {
1181 T tmp = a;
1182 a = b;
1183 b = tmp;
1184 }
1185
1186 // array_size_impl is a function that takes a reference to T[N] and
1187 // returns a reference to char[N]. It is not ODR-used, so not defined.
1188 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1189
1190 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1191
1192 //----------------------------------------------------------------------------------------------------
1193 // Sum and product which can never overflow: they wrap, just like the
1194 // Java operations. Note that we don't intend these to be used for
1195 // general-purpose arithmetic: their purpose is to emulate Java
1196 // operations.
1197
1198 // The goal of this code to avoid undefined or implementation-defined
1199 // behavior. The use of an lvalue to reference cast is explicitly
1200 // permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1201 // 15 in C++03]
1202 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1203 inline TYPE NAME (TYPE in1, TYPE in2) { \
1204 UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1205 ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1206 return reinterpret_cast<TYPE&>(ures); \
1207 }
1208
1209 JAVA_INTEGER_OP(+, java_add, jint, juint)
1210 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1211 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1212 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1213 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1214 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1215
1216 inline jint java_negate(jint v) { return java_subtract((jint) 0, v); }
1217 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1218
1219 #undef JAVA_INTEGER_OP
1220
1221 // Provide integer shift operations with Java semantics. No overflow
1222 // issues - left shifts simply discard shifted out bits. No undefined
1223 // behavior for large or negative shift quantities; instead the actual
1224 // shift distance is the argument modulo the lhs value's size in bits.
1225 // No undefined or implementation defined behavior for shifting negative
1226 // values; left shift discards bits, right shift sign extends. We use
1227 // the same safe conversion technique as above for java_add and friends.
1228 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE) \
1229 inline TYPE NAME (TYPE lhs, jint rhs) { \
1230 const uint rhs_mask = (sizeof(TYPE) * 8) - 1; \
1231 STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63); \
1232 XTYPE xres = static_cast<XTYPE>(lhs); \
1233 xres OP ## = (rhs & rhs_mask); \
1234 return reinterpret_cast<TYPE&>(xres); \
1235 }
1236
1237 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1238 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1239
1240 // For signed shift right, assume C++ implementation >> sign extends.
1241 //
1242 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1243 // and a negative value, the resulting value is implementation-defined."
1244 //
1245 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1246 // requiring two's-complement behavior.
1247 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1248 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1249 // The corresponding C++20 text is "Right-shift on signed integral types is an
1250 // arithmetic right shift, which performs sign-extension."
1251 //
1252 // As discussed in the two's complement proposal, all known modern C++ compilers
1253 // already behave that way. And it is unlikely any would go off and do something
1254 // different now, with C++20 tightening things up.
1255 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1256 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1257 // For >>> use C++ unsigned >>.
1258 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1259 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1260
1261 #undef JAVA_INTEGER_SHIFT_OP
1262
1263 //----------------------------------------------------------------------------------------------------
1264 // The goal of this code is to provide saturating operations for int/uint.
1265 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1266 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1267 inline int NAME (TYPE1 in1, TYPE2 in2) { \
1268 jlong res = static_cast<jlong>(in1); \
1269 res OP ## = static_cast<jlong>(in2); \
1270 if (res > max_jint) { \
1271 res = max_jint; \
1272 } else if (res < min_jint) { \
1273 res = min_jint; \
1274 } \
1275 return static_cast<int>(res); \
1276 }
1277
1278 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1279 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1280 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1281 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1282
1283 #undef SATURATED_INTEGER_OP
1284
1285 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1286 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1287 const uint64_t x1 = x >> 32u;
1288 const uint64_t x2 = x & 0xFFFFFFFF;
1289 const uint64_t y1 = y >> 32u;
1290 const uint64_t y2 = y & 0xFFFFFFFF;
1291 const uint64_t z2 = x2 * y2;
1292 const uint64_t t = x1 * y2 + (z2 >> 32u);
1293 uint64_t z1 = t & 0xFFFFFFFF;
1294 const uint64_t z0 = t >> 32u;
1295 z1 += x2 * y1;
1296
1297 return x1 * y1 + z0 + (z1 >> 32u);
1298 }
1299
1300 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1301 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1302 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1303 const jlong x1 = java_shift_right((jlong)x, 32);
1304 const jlong x2 = x & 0xFFFFFFFF;
1305 const jlong y1 = java_shift_right((jlong)y, 32);
1306 const jlong y2 = y & 0xFFFFFFFF;
1307
1308 const uint64_t z2 = (uint64_t)x2 * y2;
1309 const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1310 int64_t z1 = t & 0xFFFFFFFF;
1311 const int64_t z0 = java_shift_right((jlong)t, 32);
1312 z1 += x2 * y1;
1313
1314 return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1315 }
1316
1317 // Dereference vptr
1318 // All C++ compilers that we know of have the vtbl pointer in the first
1319 // word. If there are exceptions, this function needs to be made compiler
1320 // specific.
1321 static inline void* dereference_vptr(const void* addr) {
1322 return *(void**)addr;
1323 }
1324
1325 //----------------------------------------------------------------------------------------------------
1326 // String type aliases used by command line flag declarations and
1327 // processing utilities.
1328
1329 typedef const char* ccstr;
1330 typedef const char* ccstrlist; // represents string arguments which accumulate
1331
1332 //----------------------------------------------------------------------------------------------------
1333 // Default hash/equals functions used by ResourceHashtable
1334
1335 template<typename K> unsigned primitive_hash(const K& k) {
1336 unsigned hash = (unsigned)((uintptr_t)k);
1337 return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1338 }
1339
1340 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1341 return k0 == k1;
1342 }
1343
1344 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1345 return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1346 }
1347
1348 //----------------------------------------------------------------------------------------------------
1349
1350 // Allow use of C++ thread_local when approved - see JDK-8282469.
1351 #define APPROVED_CPP_THREAD_LOCAL thread_local
1352
1353 // Converts any type T to a reference type.
1354 template<typename T>
1355 std::add_rvalue_reference_t<T> declval() noexcept;
1356
1357 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1358 // handled.
1359 bool IEEE_subnormal_handling_OK();
1360
1361 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP