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