1 /*
2 * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
26 #define SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
27
28 #include "classfile_constants.h"
29 #include "cppstdlib/cstddef.hpp"
30 #include "cppstdlib/limits.hpp"
31 #include "cppstdlib/type_traits.hpp"
32 #include "utilities/checkedCast.hpp"
33 #include "utilities/compilerWarnings.hpp"
34 #include "utilities/debug.hpp"
35 #include "utilities/forbiddenFunctions.hpp"
36 #include "utilities/macros.hpp"
37
38 #include COMPILER_HEADER(utilities/globalDefinitions)
39
40 #include <cstdint>
41
42 class oopDesc;
43
44 // Defaults for macros that might be defined per compiler.
45 #ifndef NOINLINE
46 #define NOINLINE
47 #endif
48 #ifndef ALWAYSINLINE
49 #define ALWAYSINLINE inline
50 #endif
51
52 #ifndef ATTRIBUTE_ALIGNED
53 #define ATTRIBUTE_ALIGNED(x) alignas(x)
54 #endif
55
56 #ifndef ATTRIBUTE_FLATTEN
57 #define ATTRIBUTE_FLATTEN
58 #endif
59
60 // These are #defines to selectively turn on/off the Print(Opto)Assembly
61 // capabilities. Choices should be led by a tradeoff between
62 // code size and improved supportability.
63 // if PRINT_ASSEMBLY then PRINT_ABSTRACT_ASSEMBLY must be true as well
64 // to have a fallback in case hsdis is not available.
65 #if defined(PRODUCT)
66 #define SUPPORT_ABSTRACT_ASSEMBLY
67 #define SUPPORT_ASSEMBLY
68 #undef SUPPORT_OPTO_ASSEMBLY // Can't activate. In PRODUCT, many dump methods are missing.
69 #undef SUPPORT_DATA_STRUCTS // Of limited use. In PRODUCT, many print methods are empty.
70 #else
71 #define SUPPORT_ABSTRACT_ASSEMBLY
72 #define SUPPORT_ASSEMBLY
73 #define SUPPORT_OPTO_ASSEMBLY
74 #define SUPPORT_DATA_STRUCTS
75 #endif
76 #if defined(SUPPORT_ASSEMBLY) && !defined(SUPPORT_ABSTRACT_ASSEMBLY)
77 #define SUPPORT_ABSTRACT_ASSEMBLY
78 #endif
79
80 // This file holds all globally used constants & types, class (forward)
81 // declarations and a few frequently used utility functions.
82
83 // Declare the named class to be noncopyable. This macro must be followed by
84 // a semi-colon. The macro provides deleted declarations for the class's copy
85 // constructor and assignment operator. Because these operations are deleted,
86 // they cannot be defined and potential callers will fail to compile.
87 #define NONCOPYABLE(C) C(C const&) = delete; C& operator=(C const&) = delete /* next token must be ; */
88
89 // offset_of was a workaround for UB with offsetof uses that are no longer an
90 // issue. This can be removed once all uses have been converted.
91 #define offset_of(klass, field) offsetof(klass, field)
92
93 //----------------------------------------------------------------------------------------------------
94 // Printf-style formatters for fixed- and variable-width types as pointers and
95 // integers. These are derived from the definitions in inttypes.h. If the platform
96 // doesn't provide appropriate definitions, they should be provided in
97 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
98
99 // Guide to the suffixes used in the format specifiers for integers:
100 // - print the decimal value: 745565
101 // _X - print as hexadecimal, without leading 0s: 0x12345
102 // _X_0 - print as hexadecimal, with leading 0s: 0x00012345
103 // _W(w) - prints w sized string with the given value right
104 // adjusted. Use -w to print left adjusted.
105 // _0 - print as hexadecimal, with leading 0s, without 0x prefix: 0012345
106 //
107 // Note that the PTR format specifiers print using 0x with leading zeros,
108 // just like the _X_0 version for integers.
109
110 // Format 8-bit quantities.
111 #define INT8_FORMAT_X_0 "0x%02" PRIx8
112 #define UINT8_FORMAT_X_0 "0x%02" PRIx8
113
114 // Format 16-bit quantities.
115 #define INT16_FORMAT_X_0 "0x%04" PRIx16
116 #define UINT16_FORMAT_X_0 "0x%04" PRIx16
117
118 // Format 32-bit quantities.
119 #define INT32_FORMAT "%" PRId32
120 #define INT32_FORMAT_X "0x%" PRIx32
121 #define INT32_FORMAT_X_0 "0x%08" PRIx32
122 #define INT32_FORMAT_W(width) "%" #width PRId32
123 #define UINT32_FORMAT "%" PRIu32
124 #define UINT32_FORMAT_X "0x%" PRIx32
125 #define UINT32_FORMAT_X_0 "0x%08" PRIx32
126 #define UINT32_FORMAT_W(width) "%" #width PRIu32
127
128 // Format 64-bit quantities.
129 #define INT64_FORMAT "%" PRId64
130 #define INT64_PLUS_FORMAT "%+" PRId64
131 #define INT64_FORMAT_X "0x%" PRIx64
132 #define INT64_FORMAT_X_0 "0x%016" PRIx64
133 #define INT64_FORMAT_W(width) "%" #width PRId64
134 #define UINT64_FORMAT "%" PRIu64
135 #define UINT64_FORMAT_X "0x%" PRIx64
136 #define UINT64_FORMAT_X_0 "0x%016" PRIx64
137 #define UINT64_FORMAT_W(width) "%" #width PRIu64
138 #define UINT64_FORMAT_0 "%016" PRIx64
139 #define PHYS_MEM_TYPE_FORMAT "%" PRIu64
140
141 // Format jlong, if necessary
142 #ifndef JLONG_FORMAT
143 #define JLONG_FORMAT INT64_FORMAT
144 #endif
145 #ifndef JLONG_FORMAT_W
146 #define JLONG_FORMAT_W(width) INT64_FORMAT_W(width)
147 #endif
148 #ifndef JULONG_FORMAT
149 #define JULONG_FORMAT UINT64_FORMAT
150 #endif
151 #ifndef JULONG_FORMAT_X
152 #define JULONG_FORMAT_X UINT64_FORMAT_X
153 #endif
154 #ifndef JULONG_FORMAT_W
155 #define JULONG_FORMAT_W(width) UINT64_FORMAT_W(width)
156 #endif
157
158 // Format pointers and padded integral values which change size between 32- and 64-bit.
159 #ifdef _LP64
160 #define INTPTR_FORMAT "0x%016" PRIxPTR
161 #define PTR_FORMAT "0x%016" PRIxPTR
162 #define UINTX_FORMAT_X_0 "0x%016" PRIxPTR
163 #define SIZE_FORMAT_X_0 "0x%016" PRIxPTR
164 #else // !_LP64
165 #define INTPTR_FORMAT "0x%08" PRIxPTR
166 #define PTR_FORMAT "0x%08" PRIxPTR
167 #define UINTX_FORMAT_X_0 "0x%08" PRIxPTR
168 #define SIZE_FORMAT_X_0 "0x%08" PRIxPTR
169 #endif // _LP64
170
171
172 template<size_t N>
173 constexpr auto sizeof_auto_impl() {
174 if constexpr (N <= std::numeric_limits<uint8_t>::max()) return uint8_t(N);
175 else if constexpr (N <= std::numeric_limits<uint16_t>::max()) return uint16_t(N);
176 else if constexpr (N <= std::numeric_limits<uint32_t>::max()) return uint32_t(N);
177 else return uint64_t(N);
178 }
179
180 // Yields the size (in bytes) of the operand, using the smallest
181 // unsigned type that can represent the size value. The operand may be
182 // an expression, which is an unevaluated operand, or it may be a
183 // type. All of the restrictions for sizeof operands apply to the
184 // operand. The result is a constant expression.
185 //
186 // Example of correct usage of sizeof/sizeof_auto:
187 // // this will wrap using sizeof_auto, use sizeof to ensure computation using size_t
188 // size_t size = std::numeric_limits<uint32_t>::max() * sizeof(uint16_t);
189 // // implicit narrowing conversion or compiler warning/error using stricter compiler flags when using sizeof
190 // int count = 42 / sizeof_auto(uint16_t);
191
192 #define sizeof_auto(...) sizeof_auto_impl<sizeof(__VA_ARGS__)>()
193
194 // Convert pointer to intptr_t, for use in printing pointers.
195 inline intptr_t p2i(const volatile void* p) {
196 return (intptr_t) p;
197 }
198
199 // Convert pointer to uintptr_t
200 inline uintptr_t p2u(const volatile void* p) {
201 return (uintptr_t) p;
202 }
203
204 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
205
206 //----------------------------------------------------------------------------------------------------
207 // Constants
208
209 const int LogBytesPerShort = 1;
210 const int LogBytesPerInt = 2;
211 #ifdef _LP64
212 constexpr int LogBytesPerWord = 3;
213 #else
214 constexpr int LogBytesPerWord = 2;
215 #endif
216 const int LogBytesPerLong = 3;
217
218 const int BytesPerShort = 1 << LogBytesPerShort;
219 const int BytesPerInt = 1 << LogBytesPerInt;
220 const int BytesPerWord = 1 << LogBytesPerWord;
221 const int BytesPerLong = 1 << LogBytesPerLong;
222
223 constexpr int LogBitsPerByte = 3;
224 const int LogBitsPerShort = LogBitsPerByte + LogBytesPerShort;
225 const int LogBitsPerInt = LogBitsPerByte + LogBytesPerInt;
226 constexpr int LogBitsPerWord = LogBitsPerByte + LogBytesPerWord;
227 const int LogBitsPerLong = LogBitsPerByte + LogBytesPerLong;
228
229 const int BitsPerByte = 1 << LogBitsPerByte;
230 const int BitsPerShort = 1 << LogBitsPerShort;
231 const int BitsPerInt = 1 << LogBitsPerInt;
232 constexpr int BitsPerWord = 1 << LogBitsPerWord;
233 const int BitsPerLong = 1 << LogBitsPerLong;
234
235 const int WordAlignmentMask = (1 << LogBytesPerWord) - 1;
236 const int LongAlignmentMask = (1 << LogBytesPerLong) - 1;
237
238 const int oopSize = sizeof(char*); // Full-width oop
239 extern int heapOopSize; // Oop within a java object
240 const int wordSize = sizeof(char*);
241 const int longSize = sizeof(jlong);
242 const int jintSize = sizeof(jint);
243 const int size_tSize = sizeof(size_t);
244
245 const int BytesPerOop = BytesPerWord; // Full-width oop
246
247 extern int LogBytesPerHeapOop; // Oop within a java object
248 extern int LogBitsPerHeapOop;
249 extern int BytesPerHeapOop;
250 extern int BitsPerHeapOop;
251
252 const int BitsPerJavaInteger = 32;
253 const int BitsPerJavaLong = 64;
254 const int BitsPerSize_t = size_tSize * BitsPerByte;
255
256 // Size of a char[] needed to represent a jint as a string in decimal.
257 const int jintAsStringSize = 12;
258
259 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
260 // We require that object sizes be measured in units of heap words (e.g.
261 // pointer-sized values), so that given HeapWord* hw,
262 // hw += oop(hw)->foo();
263 // works, where foo is a method (like size or scavenge) that returns the
264 // object size.
265 class HeapWordImpl; // Opaque, never defined.
266 typedef HeapWordImpl* HeapWord;
267
268 // Analogous opaque struct for metadata allocated from metaspaces.
269 class MetaWordImpl; // Opaque, never defined.
270 typedef MetaWordImpl* MetaWord;
271
272 // HeapWordSize must be 2^LogHeapWordSize.
273 const int HeapWordSize = sizeof(HeapWord);
274 #ifdef _LP64
275 const int LogHeapWordSize = 3;
276 #else
277 const int LogHeapWordSize = 2;
278 #endif
279 const int HeapWordsPerLong = BytesPerLong / HeapWordSize;
280 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
281
282 // The minimum number of native machine words necessary to contain "byte_size"
283 // bytes.
284 inline size_t heap_word_size(size_t byte_size) {
285 return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
286 }
287
288 inline jfloat jfloat_cast(jint x);
289 inline jdouble jdouble_cast(jlong x);
290
291 //-------------------------------------------
292 // Constant for jlong (standardized by C++11)
293
294 // Build a 64bit integer constant
295 #define CONST64(x) (x ## LL)
296 #define UCONST64(x) (x ## ULL)
297
298 const jlong min_jlong = CONST64(0x8000000000000000);
299 const jlong max_jlong = CONST64(0x7fffffffffffffff);
300
301 // for timer info max values which include all bits, 0xffffffffffffffff
302 const jlong all_bits_jlong = ~jlong(0);
303
304 //-------------------------------------------
305 // Constant for jdouble
306 const jlong min_jlongDouble = CONST64(0x0000000000000001);
307 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
308 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
309 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
310
311 const size_t K = 1024;
312 const size_t M = K*K;
313 const size_t G = M*K;
314
315 // Constants for converting from a base unit to milli-base units. For
316 // example from seconds to milliseconds and microseconds
317
318 const int MILLIUNITS = 1000; // milli units per base unit
319 const int MICROUNITS = 1000000; // micro units per base unit
320 const int NANOUNITS = 1000000000; // nano units per base unit
321 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
322
323 const jlong NANOSECS_PER_SEC = CONST64(1000000000);
324 const jint NANOSECS_PER_MILLISEC = 1000000;
325
326
327 // Unit conversion functions
328 // The caller is responsible for considering overflow.
329
330 inline int64_t nanos_to_millis(int64_t nanos) {
331 return nanos / NANOUNITS_PER_MILLIUNIT;
332 }
333 inline int64_t millis_to_nanos(int64_t millis) {
334 return millis * NANOUNITS_PER_MILLIUNIT;
335 }
336
337 // Proper units routines try to maintain at least three significant digits.
338 // In worst case, it would print five significant digits with lower prefix.
339 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
340 // and therefore we need to be careful.
341
342 inline const char* proper_unit_for_byte_size(size_t s) {
343 #ifdef _LP64
344 if (s >= 100*G) {
345 return "G";
346 }
347 #endif
348 if (s >= 100*M) {
349 return "M";
350 } else if (s >= 100*K) {
351 return "K";
352 } else {
353 return "B";
354 }
355 }
356
357 template <class T>
358 inline T byte_size_in_proper_unit(T s) {
359 #ifdef _LP64
360 if (s >= 100*G) {
361 return (T)(s/G);
362 }
363 #endif
364 if (s >= 100*M) {
365 return (T)(s/M);
366 } else if (s >= 100*K) {
367 return (T)(s/K);
368 } else {
369 return s;
370 }
371 }
372
373 #define PROPERFMT "%zu%s"
374 #define PROPERFMTARGS(s) byte_size_in_proper_unit<size_t>(s), proper_unit_for_byte_size(s)
375
376 // Printing a range, with start and bytes given
377 #define RANGEFMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
378 #define RANGEFMTARGS(p1, size) p2i(p1), p2i(p1 + size), size
379
380 // Printing a range, with start and end given
381 #define RANGE2FMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
382 #define RANGE2FMTARGS(p1, p2) p2i(p1), p2i(p2), ((uintptr_t)p2 - (uintptr_t)p1)
383
384 inline const char* exact_unit_for_byte_size(size_t s) {
385 #ifdef _LP64
386 if (s >= G && (s % G) == 0) {
387 return "G";
388 }
389 #endif
390 if (s >= M && (s % M) == 0) {
391 return "M";
392 }
393 if (s >= K && (s % K) == 0) {
394 return "K";
395 }
396 return "B";
397 }
398
399 inline size_t byte_size_in_exact_unit(size_t s) {
400 #ifdef _LP64
401 if (s >= G && (s % G) == 0) {
402 return s / G;
403 }
404 #endif
405 if (s >= M && (s % M) == 0) {
406 return s / M;
407 }
408 if (s >= K && (s % K) == 0) {
409 return s / K;
410 }
411 return s;
412 }
413
414 #define EXACTFMT "%zu%s"
415 #define EXACTFMTARGS(s) byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
416
417 // Memory size transition formatting.
418
419 #define HEAP_CHANGE_FORMAT "%s: %zuK(%zuK)->%zuK(%zuK)"
420
421 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
422 (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
423
424 //----------------------------------------------------------------------------------------------------
425 // VM type definitions
426
427 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
428 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
429
430 typedef intptr_t intx;
431 typedef uintptr_t uintx;
432
433 const intx min_intx = (intx)1 << (sizeof(intx)*BitsPerByte-1);
434 const intx max_intx = (uintx)min_intx - 1;
435 const uintx max_uintx = (uintx)-1;
436
437 // Table of values:
438 // sizeof intx 4 8
439 // min_intx 0x80000000 0x8000000000000000
440 // max_intx 0x7FFFFFFF 0x7FFFFFFFFFFFFFFF
441 // max_uintx 0xFFFFFFFF 0xFFFFFFFFFFFFFFFF
442
443 typedef unsigned int uint; NEEDS_CLEANUP
444
445 // This typedef is to address the issue of running a 32-bit VM. In this case the amount
446 // of physical memory may not fit in size_t, so we have to have a larger type. Once 32-bit
447 // is deprecated, one can use size_t.
448 typedef uint64_t physical_memory_size_type;
449
450 //----------------------------------------------------------------------------------------------------
451 // Java type definitions
452
453 // All kinds of 'plain' byte addresses
454 typedef signed char s_char;
455 typedef unsigned char u_char;
456 typedef u_char* address;
457 typedef const u_char* const_address;
458
459 // Pointer subtraction, calculating high - low. Asserts on underflow.
460 //
461 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
462 // the range we might need to find differences from one end of the heap
463 // to the other.
464 // A typical use might be:
465 // if (pointer_delta(end(), top()) >= size) {
466 // // enough room for an object of size
467 // ...
468 // and then additions like
469 // ... top() + size ...
470 // are safe because we know that top() is at least size below end().
471 inline size_t pointer_delta(const volatile void* high,
472 const volatile void* low,
473 size_t element_size) {
474 assert(high >= low, "avoid underflow - high address: " PTR_FORMAT " low address: " PTR_FORMAT, p2i(high), p2i(low));
475 return (((uintptr_t) high) - ((uintptr_t) low)) / element_size;
476 }
477
478 // A version specialized for HeapWord*'s.
479 inline size_t pointer_delta(const HeapWord* high, const HeapWord* low) {
480 return pointer_delta(high, low, sizeof(HeapWord));
481 }
482 // A version specialized for MetaWord*'s.
483 inline size_t pointer_delta(const MetaWord* high, const MetaWord* low) {
484 return pointer_delta(high, low, sizeof(MetaWord));
485 }
486
487 // pointer_delta_as_int is called to do pointer subtraction for nearby pointers that
488 // returns a non-negative int, usually used as a size of a code buffer range.
489 // This scales to sizeof(T).
490 template <typename T>
491 inline int pointer_delta_as_int(const volatile T* high, const volatile T* low) {
492 size_t delta = pointer_delta(high, low, sizeof(T));
493 assert(delta <= size_t(INT_MAX), "pointer delta out of range: %zu", delta);
494 return static_cast<int>(delta);
495 }
496
497 //
498 // ANSI C++ does not allow casting from one pointer type to a function pointer
499 // directly without at best a warning. This macro accomplishes it silently
500 // In every case that is present at this point the value be cast is a pointer
501 // to a C linkage function. In some case the type used for the cast reflects
502 // that linkage and a picky compiler would not complain. In other cases because
503 // there is no convenient place to place a typedef with extern C linkage (i.e
504 // a platform dependent header file) it doesn't. At this point no compiler seems
505 // picky enough to catch these instances (which are few). It is possible that
506 // using templates could fix these for all cases. This use of templates is likely
507 // so far from the middle of the road that it is likely to be problematic in
508 // many C++ compilers.
509 //
510 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
511 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((uintptr_t)(func_ptr)))
512
513 // Need the correct linkage to call qsort without warnings
514 extern "C" {
515 typedef int (*_sort_Fn)(const void *, const void *);
516 }
517
518 // Additional Java basic types
519
520 typedef uint8_t jubyte;
521 typedef uint16_t jushort;
522 typedef uint32_t juint;
523 typedef uint64_t julong;
524
525 // Unsigned byte types for os and stream.hpp
526
527 // Unsigned one, two, four and eight byte quantities used for describing
528 // the .class file format. See JVM book chapter 4.
529
530 typedef jubyte u1;
531 typedef jushort u2;
532 typedef juint u4;
533 typedef julong u8;
534
535 const jubyte max_jubyte = (jubyte)-1; // 0xFF largest jubyte
536 const jushort max_jushort = (jushort)-1; // 0xFFFF largest jushort
537 const juint max_juint = (juint)-1; // 0xFFFFFFFF largest juint
538 const julong max_julong = (julong)-1; // 0xFF....FF largest julong
539
540 typedef jbyte s1;
541 typedef jshort s2;
542 typedef jint s4;
543 typedef jlong s8;
544
545 const jbyte min_jbyte = -(1 << 7); // smallest jbyte
546 const jbyte max_jbyte = (1 << 7) - 1; // largest jbyte
547 const jshort min_jshort = -(1 << 15); // smallest jshort
548 const jshort max_jshort = (1 << 15) - 1; // largest jshort
549
550 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
551 const jint max_jint = (juint)min_jint - 1; // 0x7FFFFFFF == largest jint
552
553 const jint min_jintFloat = (jint)(0x00000001);
554 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
555 const jint max_jintFloat = (jint)(0x7f7fffff);
556 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
557
558 const jshort max_jfloat16 = 31743;
559 const jshort min_jfloat16 = 1;
560 const jshort one_jfloat16 = 15360;
561 const jshort pos_inf_jfloat16 = 31744;
562 const jshort neg_inf_jfloat16 = -1024;
563 // A named constant for the integral representation of a Java null.
564 const intptr_t NULL_WORD = 0;
565
566 //----------------------------------------------------------------------------------------------------
567 // JVM spec restrictions
568
569 const int max_method_code_size = 64*K - 1; // JVM spec, 2nd ed. section 4.8.1 (p.134)
570 const int max_method_parameter_length = 255; // JVM spec, 22nd ed. section 4.3.3 (p.83)
571
572 //----------------------------------------------------------------------------------------------------
573 // old CDS options
574 extern bool RequireSharedSpaces;
575 extern "C" {
576 // Make sure UseSharedSpaces is accessible to the serviceability agent.
577 extern JNIEXPORT jboolean UseSharedSpaces;
578 }
579
580 //----------------------------------------------------------------------------------------------------
581 // Object alignment, in units of HeapWords.
582 //
583 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
584 // reference fields can be naturally aligned.
585
586 extern int MinObjAlignment;
587 extern int MinObjAlignmentInBytes;
588 extern int MinObjAlignmentInBytesMask;
589
590 extern int LogMinObjAlignment;
591 extern int LogMinObjAlignmentInBytes;
592
593 // Maximal size of heap where unscaled compression can be used. Also upper bound
594 // for heap placement: 4GB.
595 const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
596 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
597 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
598 extern uint64_t OopEncodingHeapMax;
599
600 // Machine dependent stuff
601
602 #include CPU_HEADER(globalDefinitions)
603
604 // The maximum size of the code cache. Can be overridden by targets.
605 #ifndef CODE_CACHE_SIZE_LIMIT
606 #define CODE_CACHE_SIZE_LIMIT (2*G)
607 #endif
608
609 // Allow targets to reduce the default size of the code cache.
610 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
611
612 // To assure the IRIW property on processors that are not multiple copy
613 // atomic, sync instructions must be issued between volatile reads to
614 // assure their ordering, instead of after volatile stores.
615 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
616 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
617 #ifdef CPU_MULTI_COPY_ATOMIC
618 // Not needed.
619 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
620 #else
621 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
622 // Final decision is subject to JEP 188: Java Memory Model Update.
623 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
624 #endif
625
626 // The expected size in bytes of a cache line.
627 #ifndef DEFAULT_CACHE_LINE_SIZE
628 #error "Platform should define DEFAULT_CACHE_LINE_SIZE"
629 #endif
630
631 // The default padding size for data structures to avoid false sharing.
632 #ifndef DEFAULT_PADDING_SIZE
633 #error "Platform should define DEFAULT_PADDING_SIZE"
634 #endif
635
636
637 //----------------------------------------------------------------------------------------------------
638 // Miscellaneous
639
640 // 6302670 Eliminate Hotspot __fabsf dependency
641 // All fabs() callers should call this function instead, which will implicitly
642 // convert the operand to double, avoiding a dependency on __fabsf which
643 // doesn't exist in early versions of Solaris 8.
644 inline double fabsd(double value) {
645 return fabs(value);
646 }
647
648 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
649 // is zero, return 0.0.
650 template<typename T>
651 inline double percent_of(T numerator, T denominator) {
652 return denominator != 0 ? (double)numerator / (double)denominator * 100.0 : 0.0;
653 }
654
655 //----------------------------------------------------------------------------------------------------
656 // Special casts
657 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
658 typedef union {
659 jfloat f;
660 jint i;
661 } FloatIntConv;
662
663 typedef union {
664 jdouble d;
665 jlong l;
666 julong ul;
667 } DoubleLongConv;
668
669 inline jint jint_cast (jfloat x) { return ((FloatIntConv*)&x)->i; }
670 inline jfloat jfloat_cast (jint x) { return ((FloatIntConv*)&x)->f; }
671
672 inline jlong jlong_cast (jdouble x) { return ((DoubleLongConv*)&x)->l; }
673 inline julong julong_cast (jdouble x) { return ((DoubleLongConv*)&x)->ul; }
674 inline jdouble jdouble_cast (jlong x) { return ((DoubleLongConv*)&x)->d; }
675
676 inline jint low (jlong value) { return jint(value); }
677 inline jint high(jlong value) { return jint(value >> 32); }
678
679 inline jlong jlong_from(jint h, jint l) {
680 // First cast jint values to juint, so cast to julong will zero-extend.
681 julong high = (julong)(juint)h << 32;
682 julong low = (julong)(juint)l;
683 return (jlong)(high | low);
684 }
685
686 union jlong_accessor {
687 jint words[2];
688 jlong long_value;
689 };
690
691 void basic_types_init(); // cannot define here; uses assert
692
693
694 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
695 enum BasicType : u1 {
696 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
697 T_BOOLEAN = JVM_T_BOOLEAN,
698 T_CHAR = JVM_T_CHAR,
699 T_FLOAT = JVM_T_FLOAT,
700 T_DOUBLE = JVM_T_DOUBLE,
701 T_BYTE = JVM_T_BYTE,
702 T_SHORT = JVM_T_SHORT,
703 T_INT = JVM_T_INT,
704 T_LONG = JVM_T_LONG,
705 // The remaining values are not part of any standard.
706 // T_OBJECT and T_VOID denote two more semantic choices
707 // for method return values.
708 // T_OBJECT and T_ARRAY describe signature syntax.
709 // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
710 // internal references within the JVM as if they were Java
711 // types in their own right.
712 T_OBJECT = 12,
713 T_ARRAY = 13,
714 T_VOID = 14,
715 T_ADDRESS = 15,
716 T_NARROWOOP = 16,
717 T_METADATA = 17,
718 T_NARROWKLASS = 18,
719 T_CONFLICT = 19, // for stack value type with conflicting contents
720 T_ILLEGAL = 99
721 };
722
723 #define SIGNATURE_TYPES_DO(F, N) \
724 F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N) \
725 F(JVM_SIGNATURE_CHAR, T_CHAR, N) \
726 F(JVM_SIGNATURE_FLOAT, T_FLOAT, N) \
727 F(JVM_SIGNATURE_DOUBLE, T_DOUBLE, N) \
728 F(JVM_SIGNATURE_BYTE, T_BYTE, N) \
729 F(JVM_SIGNATURE_SHORT, T_SHORT, N) \
730 F(JVM_SIGNATURE_INT, T_INT, N) \
731 F(JVM_SIGNATURE_LONG, T_LONG, N) \
732 F(JVM_SIGNATURE_CLASS, T_OBJECT, N) \
733 F(JVM_SIGNATURE_ARRAY, T_ARRAY, N) \
734 F(JVM_SIGNATURE_VOID, T_VOID, N) \
735 /*end*/
736
737 inline bool is_java_type(BasicType t) {
738 return T_BOOLEAN <= t && t <= T_VOID;
739 }
740
741 inline bool is_java_primitive(BasicType t) {
742 return T_BOOLEAN <= t && t <= T_LONG;
743 }
744
745 inline bool is_subword_type(BasicType t) {
746 // these guys are processed exactly like T_INT in calling sequences:
747 return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
748 }
749
750 inline bool is_signed_subword_type(BasicType t) {
751 return (t == T_BYTE || t == T_SHORT);
752 }
753
754 inline bool is_unsigned_subword_type(BasicType t) {
755 return (t == T_BOOLEAN || t == T_CHAR);
756 }
757
758 inline bool is_double_word_type(BasicType t) {
759 return (t == T_DOUBLE || t == T_LONG);
760 }
761
762 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
763 return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
764 }
765
766 inline bool is_integral_type(BasicType t) {
767 return is_subword_type(t) || t == T_INT || t == T_LONG;
768 }
769
770 inline bool is_non_subword_integral_type(BasicType t) {
771 return t == T_INT || t == T_LONG;
772 }
773
774 inline bool is_floating_point_type(BasicType t) {
775 return (t == T_FLOAT || t == T_DOUBLE);
776 }
777
778 extern char type2char_tab[T_CONFLICT+1]; // Map a BasicType to a jchar
779 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
780 extern int type2size[T_CONFLICT+1]; // Map BasicType to result stack elements
781 extern const char* type2name_tab[T_CONFLICT+1]; // Map a BasicType to a char*
782 extern BasicType name2type(const char* name);
783
784 const char* type2name(BasicType t);
785
786 inline jlong max_signed_integer(BasicType bt) {
787 if (bt == T_INT) {
788 return max_jint;
789 }
790 assert(bt == T_LONG, "unsupported");
791 return max_jlong;
792 }
793
794 inline jlong min_signed_integer(BasicType bt) {
795 if (bt == T_INT) {
796 return min_jint;
797 }
798 assert(bt == T_LONG, "unsupported");
799 return min_jlong;
800 }
801
802 inline julong max_unsigned_integer(BasicType bt) {
803 if (bt == T_INT) {
804 return max_juint;
805 }
806 assert(bt == T_LONG, "unsupported");
807 return max_julong;
808 }
809
810 inline uint bits_per_java_integer(BasicType bt) {
811 if (bt == T_INT) {
812 return BitsPerJavaInteger;
813 }
814 assert(bt == T_LONG, "int or long only");
815 return BitsPerJavaLong;
816 }
817
818 // Auxiliary math routines
819 // least common multiple
820 extern size_t lcm(size_t a, size_t b);
821
822
823 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
824 enum BasicTypeSize {
825 T_BOOLEAN_size = 1,
826 T_CHAR_size = 1,
827 T_FLOAT_size = 1,
828 T_DOUBLE_size = 2,
829 T_BYTE_size = 1,
830 T_SHORT_size = 1,
831 T_INT_size = 1,
832 T_LONG_size = 2,
833 T_OBJECT_size = 1,
834 T_ARRAY_size = 1,
835 T_NARROWOOP_size = 1,
836 T_NARROWKLASS_size = 1,
837 T_VOID_size = 0
838 };
839
840 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
841 inline int parameter_type_word_count(BasicType t) {
842 if (is_double_word_type(t)) return 2;
843 assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
844 assert(type2size[t] == 1, "must be");
845 return 1;
846 }
847
848 // maps a BasicType to its instance field storage type:
849 // all sub-word integral types are widened to T_INT
850 extern BasicType type2field[T_CONFLICT+1];
851 extern BasicType type2wfield[T_CONFLICT+1];
852
853
854 // size in bytes
855 enum ArrayElementSize {
856 T_BOOLEAN_aelem_bytes = 1,
857 T_CHAR_aelem_bytes = 2,
858 T_FLOAT_aelem_bytes = 4,
859 T_DOUBLE_aelem_bytes = 8,
860 T_BYTE_aelem_bytes = 1,
861 T_SHORT_aelem_bytes = 2,
862 T_INT_aelem_bytes = 4,
863 T_LONG_aelem_bytes = 8,
864 #ifdef _LP64
865 T_OBJECT_aelem_bytes = 8,
866 T_ARRAY_aelem_bytes = 8,
867 #else
868 T_OBJECT_aelem_bytes = 4,
869 T_ARRAY_aelem_bytes = 4,
870 #endif
871 T_NARROWOOP_aelem_bytes = 4,
872 T_NARROWKLASS_aelem_bytes = 4,
873 T_VOID_aelem_bytes = 0
874 };
875
876 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
877 #ifdef ASSERT
878 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
879 #else
880 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
881 #endif
882
883 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
884 return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
885 }
886
887 // JavaValue serves as a container for arbitrary Java values.
888
889 class JavaValue {
890
891 public:
892 typedef union JavaCallValue {
893 jfloat f;
894 jdouble d;
895 jint i;
896 jlong l;
897 jobject h;
898 oopDesc* o;
899 } JavaCallValue;
900
901 private:
902 BasicType _type;
903 JavaCallValue _value;
904
905 public:
906 JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
907
908 JavaValue(jfloat value) {
909 _type = T_FLOAT;
910 _value.f = value;
911 }
912
913 JavaValue(jdouble value) {
914 _type = T_DOUBLE;
915 _value.d = value;
916 }
917
918 jfloat get_jfloat() const { return _value.f; }
919 jdouble get_jdouble() const { return _value.d; }
920 jint get_jint() const { return _value.i; }
921 jlong get_jlong() const { return _value.l; }
922 jobject get_jobject() const { return _value.h; }
923 oopDesc* get_oop() const { return _value.o; }
924 JavaCallValue* get_value_addr() { return &_value; }
925 BasicType get_type() const { return _type; }
926
927 void set_jfloat(jfloat f) { _value.f = f;}
928 void set_jdouble(jdouble d) { _value.d = d;}
929 void set_jint(jint i) { _value.i = i;}
930 void set_jshort(jshort i) { _value.i = i;}
931 void set_jlong(jlong l) { _value.l = l;}
932 void set_jobject(jobject h) { _value.h = h;}
933 void set_oop(oopDesc* o) { _value.o = o;}
934 void set_type(BasicType t) { _type = t; }
935
936 jboolean get_jboolean() const { return (jboolean) (_value.i);}
937 jbyte get_jbyte() const { return (jbyte) (_value.i);}
938 jchar get_jchar() const { return (jchar) (_value.i);}
939 jshort get_jshort() const { return (jshort) (_value.i);}
940
941 };
942
943
944 // TosState describes the top-of-stack state before and after the execution of
945 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
946 // registers. The TosState corresponds to the 'machine representation' of this cached
947 // value. There's 4 states corresponding to the JAVA types int, long, float & double
948 // as well as a 5th state in case the top-of-stack value is actually on the top
949 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
950 // state when it comes to machine representation but is used separately for (oop)
951 // type specific operations (e.g. verification code).
952
953 enum TosState { // describes the tos cache contents
954 btos = 0, // byte, bool tos cached
955 ztos = 1, // byte, bool tos cached
956 ctos = 2, // char tos cached
957 stos = 3, // short tos cached
958 itos = 4, // int tos cached
959 ltos = 5, // long tos cached
960 ftos = 6, // float tos cached
961 dtos = 7, // double tos cached
962 atos = 8, // object cached
963 vtos = 9, // tos not cached
964 number_of_states,
965 ilgl // illegal state: should not occur
966 };
967
968
969 inline TosState as_TosState(BasicType type) {
970 switch (type) {
971 case T_BYTE : return btos;
972 case T_BOOLEAN: return ztos;
973 case T_CHAR : return ctos;
974 case T_SHORT : return stos;
975 case T_INT : return itos;
976 case T_LONG : return ltos;
977 case T_FLOAT : return ftos;
978 case T_DOUBLE : return dtos;
979 case T_VOID : return vtos;
980 case T_ARRAY : // fall through
981 case T_OBJECT : return atos;
982 default : return ilgl;
983 }
984 }
985
986 inline BasicType as_BasicType(TosState state) {
987 switch (state) {
988 case btos : return T_BYTE;
989 case ztos : return T_BOOLEAN;
990 case ctos : return T_CHAR;
991 case stos : return T_SHORT;
992 case itos : return T_INT;
993 case ltos : return T_LONG;
994 case ftos : return T_FLOAT;
995 case dtos : return T_DOUBLE;
996 case atos : return T_OBJECT;
997 case vtos : return T_VOID;
998 default : return T_ILLEGAL;
999 }
1000 }
1001
1002
1003 // Helper function to convert BasicType info into TosState
1004 // Note: Cannot define here as it uses global constant at the time being.
1005 TosState as_TosState(BasicType type);
1006
1007
1008 // JavaThreadState keeps track of which part of the code a thread is executing in. This
1009 // information is needed by the safepoint code.
1010 //
1011 // There are 4 essential states:
1012 //
1013 // _thread_new : Just started, but not executed init. code yet (most likely still in OS init code)
1014 // _thread_in_native : In native code. This is a safepoint region, since all oops will be in jobject handles
1015 // _thread_in_vm : Executing in the vm
1016 // _thread_in_Java : Executing either interpreted or compiled Java code (or could be in a stub)
1017 //
1018 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1019 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1020 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1021 //
1022 // Given a state, the xxxx_trans state can always be found by adding 1.
1023 //
1024 enum JavaThreadState {
1025 _thread_uninitialized = 0, // should never happen (missing initialization)
1026 _thread_new = 2, // just starting up, i.e., in process of being initialized
1027 _thread_new_trans = 3, // corresponding transition state (not used, included for completeness)
1028 _thread_in_native = 4, // running in native code
1029 _thread_in_native_trans = 5, // corresponding transition state
1030 _thread_in_vm = 6, // running in VM
1031 _thread_in_vm_trans = 7, // corresponding transition state
1032 _thread_in_Java = 8, // running in Java or in stub code
1033 _thread_in_Java_trans = 9, // corresponding transition state (not used, included for completeness)
1034 _thread_blocked = 10, // blocked in vm
1035 _thread_blocked_trans = 11, // corresponding transition state
1036 _thread_max_state = 12 // maximum thread state+1 - used for statistics allocation
1037 };
1038
1039 //----------------------------------------------------------------------------------------------------
1040 // Special constants for debugging
1041
1042 const jint badInt = -3; // generic "bad int" value
1043 const intptr_t badAddressVal = -2; // generic "bad address" value
1044 const intptr_t badOopVal = -1; // generic "bad oop" value
1045 const intptr_t badHeapOopVal = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1046 const int badStackSegVal = 0xCA; // value used to zap stack segments
1047 const int badHandleValue = 0xBC; // value used to zap vm handle area
1048 const int badResourceValue = 0xAB; // value used to zap resource area
1049 const int freeBlockPad = 0xBA; // value used to pad freed blocks.
1050 const int uninitBlockPad = 0xF1; // value used to zap newly malloc'd blocks.
1051 const juint uninitMetaWordVal = 0xf7f7f7f7; // value used to zap newly allocated metachunk
1052 const jubyte heapPaddingByteVal = 0xBD; // value used to zap object padding in the heap
1053 const juint badHeapWordVal = 0xBAADBABE; // value used to zap heap after GC
1054 const int badCodeHeapNewVal = 0xCC; // value used to zap Code heap at allocation
1055 const int badCodeHeapFreeVal = 0xDD; // value used to zap Code heap at deallocation
1056 const intptr_t badDispHeaderDeopt = 0xDE0BD000; // value to fill unused displaced header during deoptimization
1057 const intptr_t badDispHeaderOSR = 0xDEAD05A0; // value to fill unused displaced header during OSR
1058
1059 // (These must be implemented as #defines because C++ compilers are
1060 // not obligated to inline non-integral constants!)
1061 #define badAddress ((address)::badAddressVal)
1062 #define badHeapWord (::badHeapWordVal)
1063
1064 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1065 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1066
1067 //----------------------------------------------------------------------------------------------------
1068 // Utility functions for bitfield manipulations
1069
1070 const intptr_t AllBits = ~0; // all bits set in a word
1071 const intptr_t NoBits = 0; // no bits set in a word
1072 const jlong NoLongBits = 0; // no bits set in a long
1073 const intptr_t OneBit = 1; // only right_most bit set in a word
1074
1075 // Return a value of type T with the n.th bit set and all other bits zero.
1076 // T must be an integral or enum type. n must be non-negative. If n is at
1077 // least the bitwise size of T then all bits in the result are zero.
1078 template<typename T = intptr_t>
1079 constexpr T nth_bit(int n) {
1080 assert(n >= 0, "n must be non-negative");
1081 using U = std::make_unsigned_t<T>;
1082 constexpr size_t size = sizeof(U) * BitsPerByte;
1083 return T((size_t(n) >= size) ? U(0) : (U(1) << n));
1084 }
1085
1086 // Return a value of type T with all bits below the n.th bit set and all
1087 // other bits zero. T must be an integral or enum type. n must be
1088 // non-negative. If n is at least the bitwise size of T then all bits in
1089 // the result are set.
1090 template<typename T = intptr_t>
1091 constexpr T right_n_bits(int n) {
1092 assert(n >= 0, "n must be non-negative");
1093 using U = std::make_unsigned_t<T>;
1094 return T(nth_bit<U>(n) - 1);
1095 }
1096
1097 // bit-operations using a mask m
1098 inline void set_bits (intptr_t& x, intptr_t m) { x |= m; }
1099 inline void clear_bits (intptr_t& x, intptr_t m) { x &= ~m; }
1100 inline intptr_t mask_bits (intptr_t x, intptr_t m) { return x & m; }
1101 inline jlong mask_long_bits (jlong x, jlong m) { return x & m; }
1102 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1103
1104 // bit-operations using the n.th bit
1105 inline void set_nth_bit(intptr_t& x, int n) { set_bits (x, nth_bit(n)); }
1106 inline void clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1107 inline bool is_set_nth_bit(intptr_t x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1108
1109 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1110 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1111 return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1112 }
1113
1114
1115 //----------------------------------------------------------------------------------------------------
1116 // Utility functions for integers
1117
1118 // Avoid use of global min/max macros which may cause unwanted double
1119 // evaluation of arguments.
1120 #ifdef max
1121 #undef max
1122 #endif
1123
1124 #ifdef min
1125 #undef min
1126 #endif
1127
1128 // It is necessary to use templates here. Having normal overloaded
1129 // functions does not work because it is necessary to provide both 32-
1130 // and 64-bit overloaded functions, which does not work, and having
1131 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1132 // will be even more error-prone than macros.
1133 template<class T> constexpr T MAX2(T a, T b) { return (a > b) ? a : b; }
1134 template<class T> constexpr T MIN2(T a, T b) { return (a < b) ? a : b; }
1135 template<class T> constexpr T MAX3(T a, T b, T c) { return MAX2(MAX2(a, b), c); }
1136 template<class T> constexpr T MIN3(T a, T b, T c) { return MIN2(MIN2(a, b), c); }
1137 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1138 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1139
1140 #define ABS(x) asserted_abs(x, __FILE__, __LINE__)
1141
1142 template<class T> inline T asserted_abs(T x, const char* file, int line) {
1143 bool valid_arg = !(std::is_integral<T>::value && x == std::numeric_limits<T>::min());
1144 #ifdef ASSERT
1145 if (!valid_arg) {
1146 report_vm_error(file, line, "ABS: argument should not allow overflow");
1147 }
1148 #endif
1149 // Prevent exposure to UB by checking valid_arg here as well.
1150 return (x < 0 && valid_arg) ? -x : x;
1151 }
1152
1153 // Return the given value clamped to the range [min ... max]
1154 template<typename T>
1155 inline T clamp(T value, T min, T max) {
1156 assert(min <= max, "must be");
1157 return MIN2(MAX2(value, min), max);
1158 }
1159
1160 inline bool is_odd (intx x) { return x & 1; }
1161 inline bool is_even(intx x) { return !is_odd(x); }
1162
1163 // abs methods which cannot overflow and so are well-defined across
1164 // the entire domain of integer types.
1165 static inline unsigned int g_uabs(unsigned int n) {
1166 union {
1167 unsigned int result;
1168 int value;
1169 };
1170 result = n;
1171 if (value < 0) result = 0-result;
1172 return result;
1173 }
1174 static inline julong g_uabs(julong n) {
1175 union {
1176 julong result;
1177 jlong value;
1178 };
1179 result = n;
1180 if (value < 0) result = 0-result;
1181 return result;
1182 }
1183 static inline julong g_uabs(jlong n) { return g_uabs((julong)n); }
1184 static inline unsigned int g_uabs(int n) { return g_uabs((unsigned int)n); }
1185
1186 // "to" should be greater than "from."
1187 inline size_t byte_size(void* from, void* to) {
1188 return pointer_delta(to, from, sizeof(char));
1189 }
1190
1191 // Pack and extract shorts to/from ints:
1192
1193 inline u2 extract_low_short_from_int(u4 x) {
1194 return u2(x & 0xffff);
1195 }
1196
1197 inline u2 extract_high_short_from_int(u4 x) {
1198 return u2((x >> 16) & 0xffff);
1199 }
1200
1201 inline int build_int_from_shorts( u2 low, u2 high ) {
1202 return ((int)((unsigned int)high << 16) | (unsigned int)low);
1203 }
1204
1205 // swap a & b
1206 template<class T> static void swap(T& a, T& b) {
1207 T tmp = a;
1208 a = b;
1209 b = tmp;
1210 }
1211
1212 // array_size_impl is a function that takes a reference to T[N] and
1213 // returns a reference to char[N]. It is not ODR-used, so not defined.
1214 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1215
1216 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1217
1218 //----------------------------------------------------------------------------------------------------
1219 // Sum and product which can never overflow: they wrap, just like the
1220 // Java operations. Note that we don't intend these to be used for
1221 // general-purpose arithmetic: their purpose is to emulate Java
1222 // operations.
1223
1224 // The goal of this code to avoid undefined or implementation-defined
1225 // behavior. The use of an lvalue to reference cast is explicitly
1226 // permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1227 // 15 in C++03]
1228 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1229 inline TYPE NAME (TYPE in1, TYPE in2) { \
1230 UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1231 ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1232 return reinterpret_cast<TYPE&>(ures); \
1233 }
1234
1235 JAVA_INTEGER_OP(+, java_add, jint, juint)
1236 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1237 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1238 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1239 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1240 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1241
1242 inline jint java_negate(jint v) { return java_subtract((jint) 0, v); }
1243 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1244
1245 #undef JAVA_INTEGER_OP
1246
1247 // Provide integer shift operations with Java semantics. No overflow
1248 // issues - left shifts simply discard shifted out bits. No undefined
1249 // behavior for large or negative shift quantities; instead the actual
1250 // shift distance is the argument modulo the lhs value's size in bits.
1251 // No undefined or implementation defined behavior for shifting negative
1252 // values; left shift discards bits, right shift sign extends. We use
1253 // the same safe conversion technique as above for java_add and friends.
1254 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE) \
1255 inline TYPE NAME (TYPE lhs, jint rhs) { \
1256 const uint rhs_mask = (sizeof(TYPE) * 8) - 1; \
1257 STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63); \
1258 XTYPE xres = static_cast<XTYPE>(lhs); \
1259 xres OP ## = (rhs & rhs_mask); \
1260 return reinterpret_cast<TYPE&>(xres); \
1261 }
1262
1263 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1264 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1265
1266 // For signed shift right, assume C++ implementation >> sign extends.
1267 //
1268 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1269 // and a negative value, the resulting value is implementation-defined."
1270 //
1271 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1272 // requiring two's-complement behavior.
1273 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1274 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1275 // The corresponding C++20 text is "Right-shift on signed integral types is an
1276 // arithmetic right shift, which performs sign-extension."
1277 //
1278 // As discussed in the two's complement proposal, all known modern C++ compilers
1279 // already behave that way. And it is unlikely any would go off and do something
1280 // different now, with C++20 tightening things up.
1281 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1282 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1283 // For >>> use C++ unsigned >>.
1284 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1285 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1286
1287 #undef JAVA_INTEGER_SHIFT_OP
1288
1289 inline jlong java_negate(jlong v, BasicType bt) {
1290 if (bt == T_INT) {
1291 return java_negate(checked_cast<jint>(v));
1292 }
1293 assert(bt == T_LONG, "int or long only");
1294 return java_negate(v);
1295 }
1296
1297 // Some convenient bit shift operations that accepts a BasicType as the last
1298 // argument. These avoid potential mistakes with overloaded functions only
1299 // distinguished by lhs argument type.
1300 #define JAVA_INTEGER_SHIFT_BASIC_TYPE(FUNC) \
1301 inline jlong FUNC(jlong lhs, jint rhs, BasicType bt) { \
1302 if (bt == T_INT) { \
1303 return FUNC(checked_cast<jint>(lhs), rhs); \
1304 } \
1305 assert(bt == T_LONG, "unsupported basic type"); \
1306 return FUNC(lhs, rhs); \
1307 }
1308
1309 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_left)
1310 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_right)
1311 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_right_unsigned)
1312
1313 #undef JAVA_INTERGER_SHIFT_BASIC_TYPE
1314
1315 //----------------------------------------------------------------------------------------------------
1316 // The goal of this code is to provide saturating operations for int/uint.
1317 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1318 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1319 inline int NAME (TYPE1 in1, TYPE2 in2) { \
1320 jlong res = static_cast<jlong>(in1); \
1321 res OP ## = static_cast<jlong>(in2); \
1322 if (res > max_jint) { \
1323 res = max_jint; \
1324 } else if (res < min_jint) { \
1325 res = min_jint; \
1326 } \
1327 return static_cast<int>(res); \
1328 }
1329
1330 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1331 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1332 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1333 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1334
1335 #undef SATURATED_INTEGER_OP
1336
1337 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1338 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1339 const uint64_t x1 = x >> 32u;
1340 const uint64_t x2 = x & 0xFFFFFFFF;
1341 const uint64_t y1 = y >> 32u;
1342 const uint64_t y2 = y & 0xFFFFFFFF;
1343 const uint64_t z2 = x2 * y2;
1344 const uint64_t t = x1 * y2 + (z2 >> 32u);
1345 uint64_t z1 = t & 0xFFFFFFFF;
1346 const uint64_t z0 = t >> 32u;
1347 z1 += x2 * y1;
1348
1349 return x1 * y1 + z0 + (z1 >> 32u);
1350 }
1351
1352 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1353 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1354 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1355 const jlong x1 = java_shift_right((jlong)x, 32);
1356 const jlong x2 = x & 0xFFFFFFFF;
1357 const jlong y1 = java_shift_right((jlong)y, 32);
1358 const jlong y2 = y & 0xFFFFFFFF;
1359
1360 const uint64_t z2 = (uint64_t)x2 * y2;
1361 const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1362 int64_t z1 = t & 0xFFFFFFFF;
1363 const int64_t z0 = java_shift_right((jlong)t, 32);
1364 z1 += x2 * y1;
1365
1366 return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1367 }
1368
1369 // Dereference vptr
1370 // All C++ compilers that we know of have the vtbl pointer in the first
1371 // word. If there are exceptions, this function needs to be made compiler
1372 // specific.
1373 static inline void* dereference_vptr(const void* addr) {
1374 return *(void**)addr;
1375 }
1376
1377 //----------------------------------------------------------------------------------------------------
1378 // String type aliases used by command line flag declarations and
1379 // processing utilities.
1380
1381 typedef const char* ccstr;
1382 typedef const char* ccstrlist; // represents string arguments which accumulate
1383
1384 //----------------------------------------------------------------------------------------------------
1385 // Default hash/equals functions used by HashTable
1386
1387 template<typename K> unsigned primitive_hash(const K& k) {
1388 unsigned hash = (unsigned)((uintptr_t)k);
1389 return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1390 }
1391
1392 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1393 return k0 == k1;
1394 }
1395
1396 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1397 return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1398 }
1399
1400 //----------------------------------------------------------------------------------------------------
1401
1402 // Allow use of C++ thread_local when approved - see JDK-8282469.
1403 #define APPROVED_CPP_THREAD_LOCAL thread_local
1404
1405 // Converts any type T to a reference type.
1406 template<typename T>
1407 std::add_rvalue_reference_t<T> declval() noexcept;
1408
1409 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1410 // handled.
1411 bool IEEE_subnormal_handling_OK();
1412
1413 //----------------------------------------------------------------------------------------------------
1414 // Forbid using the global allocator by HotSpot code.
1415 //
1416 // This is a subset of allocator and deallocator functions. These are
1417 // implicitly declared in all translation units, without needing to include
1418 // <new>; see C++17 6.7.4. This isn't even the full set of those; implicit
1419 // declarations involving std::align_val_t are not covered here, since that
1420 // type is defined in <new>. A translation unit that doesn't include <new> is
1421 // still likely to include this file. See cppstdlib/new.hpp for more details.
1422 #ifndef HOTSPOT_GTEST
1423
1424 [[deprecated]] void* operator new(std::size_t);
1425 [[deprecated]] void operator delete(void*) noexcept;
1426 [[deprecated]] void operator delete(void*, std::size_t) noexcept;
1427
1428 [[deprecated]] void* operator new[](std::size_t);
1429 [[deprecated]] void operator delete[](void*) noexcept;
1430 [[deprecated]] void operator delete[](void*, std::size_t) noexcept;
1431
1432 #endif // HOTSPOT_GTEST
1433
1434 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP