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 // Prototyping
639 // "Code Missing Here" macro, un-define when integrating back from prototyping stage and break
640 // compilation on purpose (i.e. "forget me not")
641 #define PROTOTYPE
642 #ifdef PROTOTYPE
643 #define CMH(m)
644 #endif
645
646 //----------------------------------------------------------------------------------------------------
647 // Miscellaneous
648
649 // 6302670 Eliminate Hotspot __fabsf dependency
650 // All fabs() callers should call this function instead, which will implicitly
651 // convert the operand to double, avoiding a dependency on __fabsf which
652 // doesn't exist in early versions of Solaris 8.
653 inline double fabsd(double value) {
654 return fabs(value);
655 }
656
657 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
658 // is zero, return 0.0.
659 template<typename T>
660 inline double percent_of(T numerator, T denominator) {
661 return denominator != 0 ? (double)numerator / (double)denominator * 100.0 : 0.0;
662 }
663
664 //----------------------------------------------------------------------------------------------------
665 // Special casts
666 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
667 typedef union {
668 jfloat f;
669 jint i;
670 } FloatIntConv;
671
672 typedef union {
673 jdouble d;
674 jlong l;
675 julong ul;
676 } DoubleLongConv;
677
678 inline jint jint_cast (jfloat x) { return ((FloatIntConv*)&x)->i; }
679 inline jfloat jfloat_cast (jint x) { return ((FloatIntConv*)&x)->f; }
680
681 inline jlong jlong_cast (jdouble x) { return ((DoubleLongConv*)&x)->l; }
682 inline julong julong_cast (jdouble x) { return ((DoubleLongConv*)&x)->ul; }
683 inline jdouble jdouble_cast (jlong x) { return ((DoubleLongConv*)&x)->d; }
684
685 inline jint low (jlong value) { return jint(value); }
686 inline jint high(jlong value) { return jint(value >> 32); }
687
688 inline jlong jlong_from(jint h, jint l) {
689 // First cast jint values to juint, so cast to julong will zero-extend.
690 julong high = (julong)(juint)h << 32;
691 julong low = (julong)(juint)l;
692 return (jlong)(high | low);
693 }
694
695 union jlong_accessor {
696 jint words[2];
697 jlong long_value;
698 };
699
700 void basic_types_init(); // cannot define here; uses assert
701
702
703 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
704 enum BasicType : u1 {
705 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
706 T_BOOLEAN = JVM_T_BOOLEAN,
707 T_CHAR = JVM_T_CHAR,
708 T_FLOAT = JVM_T_FLOAT,
709 T_DOUBLE = JVM_T_DOUBLE,
710 T_BYTE = JVM_T_BYTE,
711 T_SHORT = JVM_T_SHORT,
712 T_INT = JVM_T_INT,
713 T_LONG = JVM_T_LONG,
714 // The remaining values are not part of any standard.
715 // T_OBJECT and T_VOID denote two more semantic choices
716 // for method return values.
717 // T_OBJECT and T_ARRAY describe signature syntax.
718 // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
719 // internal references within the JVM as if they were Java
720 // types in their own right.
721 T_OBJECT = 12,
722 T_ARRAY = 13,
723 T_VOID = 14,
724 T_FLAT_ELEMENT = 15, // Not a true BasicType, only used in layout helpers of flat arrays
725 T_ADDRESS = 16,
726 T_NARROWOOP = 17,
727 T_METADATA = 18,
728 T_NARROWKLASS = 19,
729 T_CONFLICT = 20, // for stack value type with conflicting contents
730 T_ILLEGAL = 99
731 };
732
733 #define SIGNATURE_TYPES_DO(F, N) \
734 F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N) \
735 F(JVM_SIGNATURE_CHAR, T_CHAR, N) \
736 F(JVM_SIGNATURE_FLOAT, T_FLOAT, N) \
737 F(JVM_SIGNATURE_DOUBLE, T_DOUBLE, N) \
738 F(JVM_SIGNATURE_BYTE, T_BYTE, N) \
739 F(JVM_SIGNATURE_SHORT, T_SHORT, N) \
740 F(JVM_SIGNATURE_INT, T_INT, N) \
741 F(JVM_SIGNATURE_LONG, T_LONG, N) \
742 F(JVM_SIGNATURE_CLASS, T_OBJECT, N) \
743 F(JVM_SIGNATURE_ARRAY, T_ARRAY, N) \
744 F(JVM_SIGNATURE_VOID, T_VOID, N) \
745 /*end*/
746
747 inline bool is_java_type(BasicType t) {
748 return T_BOOLEAN <= t && t <= T_VOID;
749 }
750
751 inline bool is_java_primitive(BasicType t) {
752 return T_BOOLEAN <= t && t <= T_LONG;
753 }
754
755 inline bool is_subword_type(BasicType t) {
756 // these guys are processed exactly like T_INT in calling sequences:
757 return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
758 }
759
760 inline bool is_signed_subword_type(BasicType t) {
761 return (t == T_BYTE || t == T_SHORT);
762 }
763
764 inline bool is_unsigned_subword_type(BasicType t) {
765 return (t == T_BOOLEAN || t == T_CHAR);
766 }
767
768 inline bool is_double_word_type(BasicType t) {
769 return (t == T_DOUBLE || t == T_LONG);
770 }
771
772 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
773 assert(t != T_FLAT_ELEMENT, ""); // Strong assert to detect misuses of T_FLAT_ELEMENT
774 return (t == T_OBJECT || t == T_ARRAY || (include_narrow_oop && t == T_NARROWOOP));
775 }
776
777 inline bool is_integral_type(BasicType t) {
778 return is_subword_type(t) || t == T_INT || t == T_LONG;
779 }
780
781 inline bool is_non_subword_integral_type(BasicType t) {
782 return t == T_INT || t == T_LONG;
783 }
784
785 inline bool is_floating_point_type(BasicType t) {
786 return (t == T_FLOAT || t == T_DOUBLE);
787 }
788
789 extern char type2char_tab[T_CONFLICT+1]; // Map a BasicType to a jchar
790 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
791 extern int type2size[T_CONFLICT+1]; // Map BasicType to result stack elements
792 extern const char* type2name_tab[T_CONFLICT+1]; // Map a BasicType to a char*
793 extern BasicType name2type(const char* name);
794
795 const char* type2name(BasicType t);
796
797 inline jlong max_signed_integer(BasicType bt) {
798 if (bt == T_INT) {
799 return max_jint;
800 }
801 assert(bt == T_LONG, "unsupported");
802 return max_jlong;
803 }
804
805 inline jlong min_signed_integer(BasicType bt) {
806 if (bt == T_INT) {
807 return min_jint;
808 }
809 assert(bt == T_LONG, "unsupported");
810 return min_jlong;
811 }
812
813 inline julong max_unsigned_integer(BasicType bt) {
814 if (bt == T_INT) {
815 return max_juint;
816 }
817 assert(bt == T_LONG, "unsupported");
818 return max_julong;
819 }
820
821 inline uint bits_per_java_integer(BasicType bt) {
822 if (bt == T_INT) {
823 return BitsPerJavaInteger;
824 }
825 assert(bt == T_LONG, "int or long only");
826 return BitsPerJavaLong;
827 }
828
829 // Auxiliary math routines
830 // least common multiple
831 extern size_t lcm(size_t a, size_t b);
832
833
834 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
835 enum BasicTypeSize {
836 T_BOOLEAN_size = 1,
837 T_CHAR_size = 1,
838 T_FLOAT_size = 1,
839 T_DOUBLE_size = 2,
840 T_BYTE_size = 1,
841 T_SHORT_size = 1,
842 T_INT_size = 1,
843 T_LONG_size = 2,
844 T_OBJECT_size = 1,
845 T_ARRAY_size = 1,
846 T_NARROWOOP_size = 1,
847 T_NARROWKLASS_size = 1,
848 T_VOID_size = 0,
849 T_FLAT_ELEMENT_size = 0
850 };
851
852 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
853 inline int parameter_type_word_count(BasicType t) {
854 if (is_double_word_type(t)) return 2;
855 assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
856 assert(type2size[t] == 1, "must be");
857 return 1;
858 }
859
860 // maps a BasicType to its instance field storage type:
861 // all sub-word integral types are widened to T_INT
862 extern BasicType type2field[T_CONFLICT+1];
863 extern BasicType type2wfield[T_CONFLICT+1];
864
865
866 // size in bytes
867 enum ArrayElementSize {
868 T_BOOLEAN_aelem_bytes = 1,
869 T_CHAR_aelem_bytes = 2,
870 T_FLOAT_aelem_bytes = 4,
871 T_DOUBLE_aelem_bytes = 8,
872 T_BYTE_aelem_bytes = 1,
873 T_SHORT_aelem_bytes = 2,
874 T_INT_aelem_bytes = 4,
875 T_LONG_aelem_bytes = 8,
876 #ifdef _LP64
877 T_OBJECT_aelem_bytes = 8,
878 T_ARRAY_aelem_bytes = 8,
879 #else
880 T_OBJECT_aelem_bytes = 4,
881 T_ARRAY_aelem_bytes = 4,
882 #endif
883 T_NARROWOOP_aelem_bytes = 4,
884 T_NARROWKLASS_aelem_bytes = 4,
885 T_VOID_aelem_bytes = 0,
886 T_FLAT_ELEMENT_aelem_bytes = 0
887 };
888
889 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
890 #ifdef ASSERT
891 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
892 #else
893 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
894 #endif
895
896 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
897 return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
898 }
899
900 // JavaValue serves as a container for arbitrary Java values.
901
902 class JavaValue {
903
904 public:
905 typedef union JavaCallValue {
906 jfloat f;
907 jdouble d;
908 jint i;
909 jlong l;
910 jobject h;
911 oopDesc* o;
912 } JavaCallValue;
913
914 private:
915 BasicType _type;
916 JavaCallValue _value;
917
918 public:
919 JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
920
921 JavaValue(jfloat value) {
922 _type = T_FLOAT;
923 _value.f = value;
924 }
925
926 JavaValue(jdouble value) {
927 _type = T_DOUBLE;
928 _value.d = value;
929 }
930
931 jfloat get_jfloat() const { return _value.f; }
932 jdouble get_jdouble() const { return _value.d; }
933 jint get_jint() const { return _value.i; }
934 jlong get_jlong() const { return _value.l; }
935 jobject get_jobject() const { return _value.h; }
936 oopDesc* get_oop() const { return _value.o; }
937 JavaCallValue* get_value_addr() { return &_value; }
938 BasicType get_type() const { return _type; }
939
940 void set_jfloat(jfloat f) { _value.f = f;}
941 void set_jdouble(jdouble d) { _value.d = d;}
942 void set_jint(jint i) { _value.i = i;}
943 void set_jshort(jshort i) { _value.i = i;}
944 void set_jlong(jlong l) { _value.l = l;}
945 void set_jobject(jobject h) { _value.h = h;}
946 void set_oop(oopDesc* o) { _value.o = o;}
947 void set_type(BasicType t) { _type = t; }
948
949 jboolean get_jboolean() const { return (jboolean) (_value.i);}
950 jbyte get_jbyte() const { return (jbyte) (_value.i);}
951 jchar get_jchar() const { return (jchar) (_value.i);}
952 jshort get_jshort() const { return (jshort) (_value.i);}
953
954 };
955
956
957 // TosState describes the top-of-stack state before and after the execution of
958 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
959 // registers. The TosState corresponds to the 'machine representation' of this cached
960 // value. There's 4 states corresponding to the JAVA types int, long, float & double
961 // as well as a 5th state in case the top-of-stack value is actually on the top
962 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
963 // state when it comes to machine representation but is used separately for (oop)
964 // type specific operations (e.g. verification code).
965
966 enum TosState { // describes the tos cache contents
967 btos = 0, // byte, bool tos cached
968 ztos = 1, // byte, bool tos cached
969 ctos = 2, // char tos cached
970 stos = 3, // short tos cached
971 itos = 4, // int tos cached
972 ltos = 5, // long tos cached
973 ftos = 6, // float tos cached
974 dtos = 7, // double tos cached
975 atos = 8, // object cached
976 vtos = 9, // tos not cached,
977 number_of_states,
978 ilgl // illegal state: should not occur
979 };
980
981
982 inline TosState as_TosState(BasicType type) {
983 switch (type) {
984 case T_BYTE : return btos;
985 case T_BOOLEAN: return ztos;
986 case T_CHAR : return ctos;
987 case T_SHORT : return stos;
988 case T_INT : return itos;
989 case T_LONG : return ltos;
990 case T_FLOAT : return ftos;
991 case T_DOUBLE : return dtos;
992 case T_VOID : return vtos;
993 case T_ARRAY : // fall through
994 case T_OBJECT : return atos;
995 default : return ilgl;
996 }
997 }
998
999 inline BasicType as_BasicType(TosState state) {
1000 switch (state) {
1001 case btos : return T_BYTE;
1002 case ztos : return T_BOOLEAN;
1003 case ctos : return T_CHAR;
1004 case stos : return T_SHORT;
1005 case itos : return T_INT;
1006 case ltos : return T_LONG;
1007 case ftos : return T_FLOAT;
1008 case dtos : return T_DOUBLE;
1009 case atos : return T_OBJECT;
1010 case vtos : return T_VOID;
1011 default : return T_ILLEGAL;
1012 }
1013 }
1014
1015
1016 // Helper function to convert BasicType info into TosState
1017 // Note: Cannot define here as it uses global constant at the time being.
1018 TosState as_TosState(BasicType type);
1019
1020
1021 // JavaThreadState keeps track of which part of the code a thread is executing in. This
1022 // information is needed by the safepoint code.
1023 //
1024 // There are 4 essential states:
1025 //
1026 // _thread_new : Just started, but not executed init. code yet (most likely still in OS init code)
1027 // _thread_in_native : In native code. This is a safepoint region, since all oops will be in jobject handles
1028 // _thread_in_vm : Executing in the vm
1029 // _thread_in_Java : Executing either interpreted or compiled Java code (or could be in a stub)
1030 //
1031 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1032 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1033 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1034 //
1035 // Given a state, the xxxx_trans state can always be found by adding 1.
1036 //
1037 enum JavaThreadState {
1038 _thread_uninitialized = 0, // should never happen (missing initialization)
1039 _thread_new = 2, // just starting up, i.e., in process of being initialized
1040 _thread_new_trans = 3, // corresponding transition state (not used, included for completeness)
1041 _thread_in_native = 4, // running in native code
1042 _thread_in_native_trans = 5, // corresponding transition state
1043 _thread_in_vm = 6, // running in VM
1044 _thread_in_vm_trans = 7, // corresponding transition state
1045 _thread_in_Java = 8, // running in Java or in stub code
1046 _thread_in_Java_trans = 9, // corresponding transition state (not used, included for completeness)
1047 _thread_blocked = 10, // blocked in vm
1048 _thread_blocked_trans = 11, // corresponding transition state
1049 _thread_max_state = 12 // maximum thread state+1 - used for statistics allocation
1050 };
1051
1052 //----------------------------------------------------------------------------------------------------
1053 // Special constants for debugging
1054
1055 const jint badInt = -3; // generic "bad int" value
1056 const intptr_t badAddressVal = -2; // generic "bad address" value
1057 const intptr_t badOopVal = -1; // generic "bad oop" value
1058 const intptr_t badHeapOopVal = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1059 const int badStackSegVal = 0xCA; // value used to zap stack segments
1060 const int badHandleValue = 0xBC; // value used to zap vm handle area
1061 const int badResourceValue = 0xAB; // value used to zap resource area
1062 const int freeBlockPad = 0xBA; // value used to pad freed blocks.
1063 const int uninitBlockPad = 0xF1; // value used to zap newly malloc'd blocks.
1064 const juint uninitMetaWordVal = 0xf7f7f7f7; // value used to zap newly allocated metachunk
1065 const jubyte heapPaddingByteVal = 0xBD; // value used to zap object padding in the heap
1066 const juint badHeapWordVal = 0xBAADBABE; // value used to zap heap after GC
1067 const int badCodeHeapNewVal = 0xCC; // value used to zap Code heap at allocation
1068 const int badCodeHeapFreeVal = 0xDD; // value used to zap Code heap at deallocation
1069 const intptr_t badDispHeaderDeopt = 0xDE0BD000; // value to fill unused displaced header during deoptimization
1070 const intptr_t badDispHeaderOSR = 0xDEAD05A0; // value to fill unused displaced header during OSR
1071 const juint badRegWordVal = 0xDEADDA7A; // value used to zap registers
1072
1073 // (These must be implemented as #defines because C++ compilers are
1074 // not obligated to inline non-integral constants!)
1075 #define badAddress ((address)::badAddressVal)
1076 #define badHeapWord (::badHeapWordVal)
1077
1078 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1079 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1080
1081 //----------------------------------------------------------------------------------------------------
1082 // Utility functions for bitfield manipulations
1083
1084 const intptr_t AllBits = ~0; // all bits set in a word
1085 const intptr_t NoBits = 0; // no bits set in a word
1086 const jlong NoLongBits = 0; // no bits set in a long
1087 const intptr_t OneBit = 1; // only right_most bit set in a word
1088
1089 // get a word with the n.th or the right-most or left-most n bits set
1090 // (note: #define used only so that they can be used in enum constant definitions)
1091 #define nth_bit(n) (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1092 #define right_n_bits(n) (nth_bit(n) - 1)
1093
1094 // same as nth_bit(n), but allows handing in a type as template parameter. Allows
1095 // us to use nth_bit with 64-bit types on 32-bit platforms
1096 template<class T> inline T nth_bit_typed(int n) {
1097 return ((T)1) << n;
1098 }
1099 template<class T> inline T right_n_bits_typed(int n) {
1100 return nth_bit_typed<T>(n) - 1;
1101 }
1102
1103 // bit-operations using a mask m
1104 inline void set_bits (intptr_t& x, intptr_t m) { x |= m; }
1105 inline void clear_bits (intptr_t& x, intptr_t m) { x &= ~m; }
1106 inline intptr_t mask_bits (intptr_t x, intptr_t m) { return x & m; }
1107 inline jlong mask_long_bits (jlong x, jlong m) { return x & m; }
1108 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1109
1110 // bit-operations using the n.th bit
1111 inline void set_nth_bit(intptr_t& x, int n) { set_bits (x, nth_bit(n)); }
1112 inline void clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1113 inline bool is_set_nth_bit(intptr_t x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1114
1115 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1116 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1117 return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1118 }
1119
1120
1121 //----------------------------------------------------------------------------------------------------
1122 // Utility functions for integers
1123
1124 // Avoid use of global min/max macros which may cause unwanted double
1125 // evaluation of arguments.
1126 #ifdef max
1127 #undef max
1128 #endif
1129
1130 #ifdef min
1131 #undef min
1132 #endif
1133
1134 // It is necessary to use templates here. Having normal overloaded
1135 // functions does not work because it is necessary to provide both 32-
1136 // and 64-bit overloaded functions, which does not work, and having
1137 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1138 // will be even more error-prone than macros.
1139 template<class T> constexpr T MAX2(T a, T b) { return (a > b) ? a : b; }
1140 template<class T> constexpr T MIN2(T a, T b) { return (a < b) ? a : b; }
1141 template<class T> constexpr T MAX3(T a, T b, T c) { return MAX2(MAX2(a, b), c); }
1142 template<class T> constexpr T MIN3(T a, T b, T c) { return MIN2(MIN2(a, b), c); }
1143 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1144 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1145
1146 #define ABS(x) asserted_abs(x, __FILE__, __LINE__)
1147
1148 template<class T> inline T asserted_abs(T x, const char* file, int line) {
1149 bool valid_arg = !(std::is_integral<T>::value && x == std::numeric_limits<T>::min());
1150 #ifdef ASSERT
1151 if (!valid_arg) {
1152 report_vm_error(file, line, "ABS: argument should not allow overflow");
1153 }
1154 #endif
1155 // Prevent exposure to UB by checking valid_arg here as well.
1156 return (x < 0 && valid_arg) ? -x : x;
1157 }
1158
1159 // Return the given value clamped to the range [min ... max]
1160 template<typename T>
1161 inline T clamp(T value, T min, T max) {
1162 assert(min <= max, "must be");
1163 return MIN2(MAX2(value, min), max);
1164 }
1165
1166 inline bool is_odd (intx x) { return x & 1; }
1167 inline bool is_even(intx x) { return !is_odd(x); }
1168
1169 // abs methods which cannot overflow and so are well-defined across
1170 // the entire domain of integer types.
1171 static inline unsigned int g_uabs(unsigned int n) {
1172 union {
1173 unsigned int result;
1174 int value;
1175 };
1176 result = n;
1177 if (value < 0) result = 0-result;
1178 return result;
1179 }
1180 static inline julong g_uabs(julong n) {
1181 union {
1182 julong result;
1183 jlong value;
1184 };
1185 result = n;
1186 if (value < 0) result = 0-result;
1187 return result;
1188 }
1189 static inline julong g_uabs(jlong n) { return g_uabs((julong)n); }
1190 static inline unsigned int g_uabs(int n) { return g_uabs((unsigned int)n); }
1191
1192 // "to" should be greater than "from."
1193 inline size_t byte_size(void* from, void* to) {
1194 return pointer_delta(to, from, sizeof(char));
1195 }
1196
1197 // Pack and extract shorts to/from ints:
1198
1199 inline u2 extract_low_short_from_int(u4 x) {
1200 return u2(x & 0xffff);
1201 }
1202
1203 inline u2 extract_high_short_from_int(u4 x) {
1204 return u2((x >> 16) & 0xffff);
1205 }
1206
1207 inline int build_int_from_shorts( u2 low, u2 high ) {
1208 return ((int)((unsigned int)high << 16) | (unsigned int)low);
1209 }
1210
1211 // swap a & b
1212 template<class T> static void swap(T& a, T& b) {
1213 T tmp = a;
1214 a = b;
1215 b = tmp;
1216 }
1217
1218 // array_size_impl is a function that takes a reference to T[N] and
1219 // returns a reference to char[N]. It is not ODR-used, so not defined.
1220 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1221
1222 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1223
1224 //----------------------------------------------------------------------------------------------------
1225 // Sum and product which can never overflow: they wrap, just like the
1226 // Java operations. Note that we don't intend these to be used for
1227 // general-purpose arithmetic: their purpose is to emulate Java
1228 // operations.
1229
1230 // The goal of this code to avoid undefined or implementation-defined
1231 // behavior. The use of an lvalue to reference cast is explicitly
1232 // permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1233 // 15 in C++03]
1234 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1235 inline TYPE NAME (TYPE in1, TYPE in2) { \
1236 UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1237 ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1238 return reinterpret_cast<TYPE&>(ures); \
1239 }
1240
1241 JAVA_INTEGER_OP(+, java_add, jint, juint)
1242 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1243 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1244 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1245 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1246 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1247
1248 inline jint java_negate(jint v) { return java_subtract((jint) 0, v); }
1249 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1250
1251 #undef JAVA_INTEGER_OP
1252
1253 // Provide integer shift operations with Java semantics. No overflow
1254 // issues - left shifts simply discard shifted out bits. No undefined
1255 // behavior for large or negative shift quantities; instead the actual
1256 // shift distance is the argument modulo the lhs value's size in bits.
1257 // No undefined or implementation defined behavior for shifting negative
1258 // values; left shift discards bits, right shift sign extends. We use
1259 // the same safe conversion technique as above for java_add and friends.
1260 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE) \
1261 inline TYPE NAME (TYPE lhs, jint rhs) { \
1262 const uint rhs_mask = (sizeof(TYPE) * 8) - 1; \
1263 STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63); \
1264 XTYPE xres = static_cast<XTYPE>(lhs); \
1265 xres OP ## = (rhs & rhs_mask); \
1266 return reinterpret_cast<TYPE&>(xres); \
1267 }
1268
1269 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1270 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1271
1272 // For signed shift right, assume C++ implementation >> sign extends.
1273 //
1274 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1275 // and a negative value, the resulting value is implementation-defined."
1276 //
1277 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1278 // requiring two's-complement behavior.
1279 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1280 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1281 // The corresponding C++20 text is "Right-shift on signed integral types is an
1282 // arithmetic right shift, which performs sign-extension."
1283 //
1284 // As discussed in the two's complement proposal, all known modern C++ compilers
1285 // already behave that way. And it is unlikely any would go off and do something
1286 // different now, with C++20 tightening things up.
1287 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1288 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1289 // For >>> use C++ unsigned >>.
1290 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1291 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1292
1293 #undef JAVA_INTEGER_SHIFT_OP
1294
1295 inline jlong java_negate(jlong v, BasicType bt) {
1296 if (bt == T_INT) {
1297 return java_negate(checked_cast<jint>(v));
1298 }
1299 assert(bt == T_LONG, "int or long only");
1300 return java_negate(v);
1301 }
1302
1303 // Some convenient bit shift operations that accepts a BasicType as the last
1304 // argument. These avoid potential mistakes with overloaded functions only
1305 // distinguished by lhs argument type.
1306 #define JAVA_INTEGER_SHIFT_BASIC_TYPE(FUNC) \
1307 inline jlong FUNC(jlong lhs, jint rhs, BasicType bt) { \
1308 if (bt == T_INT) { \
1309 return FUNC(checked_cast<jint>(lhs), rhs); \
1310 } \
1311 assert(bt == T_LONG, "unsupported basic type"); \
1312 return FUNC(lhs, rhs); \
1313 }
1314
1315 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_left)
1316 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_right)
1317 JAVA_INTEGER_SHIFT_BASIC_TYPE(java_shift_right_unsigned)
1318
1319 #undef JAVA_INTERGER_SHIFT_BASIC_TYPE
1320
1321 //----------------------------------------------------------------------------------------------------
1322 // The goal of this code is to provide saturating operations for int/uint.
1323 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1324 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1325 inline int NAME (TYPE1 in1, TYPE2 in2) { \
1326 jlong res = static_cast<jlong>(in1); \
1327 res OP ## = static_cast<jlong>(in2); \
1328 if (res > max_jint) { \
1329 res = max_jint; \
1330 } else if (res < min_jint) { \
1331 res = min_jint; \
1332 } \
1333 return static_cast<int>(res); \
1334 }
1335
1336 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1337 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1338 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1339 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1340
1341 #undef SATURATED_INTEGER_OP
1342
1343 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1344 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1345 const uint64_t x1 = x >> 32u;
1346 const uint64_t x2 = x & 0xFFFFFFFF;
1347 const uint64_t y1 = y >> 32u;
1348 const uint64_t y2 = y & 0xFFFFFFFF;
1349 const uint64_t z2 = x2 * y2;
1350 const uint64_t t = x1 * y2 + (z2 >> 32u);
1351 uint64_t z1 = t & 0xFFFFFFFF;
1352 const uint64_t z0 = t >> 32u;
1353 z1 += x2 * y1;
1354
1355 return x1 * y1 + z0 + (z1 >> 32u);
1356 }
1357
1358 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1359 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1360 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1361 const jlong x1 = java_shift_right((jlong)x, 32);
1362 const jlong x2 = x & 0xFFFFFFFF;
1363 const jlong y1 = java_shift_right((jlong)y, 32);
1364 const jlong y2 = y & 0xFFFFFFFF;
1365
1366 const uint64_t z2 = (uint64_t)x2 * y2;
1367 const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1368 int64_t z1 = t & 0xFFFFFFFF;
1369 const int64_t z0 = java_shift_right((jlong)t, 32);
1370 z1 += x2 * y1;
1371
1372 return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1373 }
1374
1375 // Dereference vptr
1376 // All C++ compilers that we know of have the vtbl pointer in the first
1377 // word. If there are exceptions, this function needs to be made compiler
1378 // specific.
1379 static inline void* dereference_vptr(const void* addr) {
1380 return *(void**)addr;
1381 }
1382
1383 //----------------------------------------------------------------------------------------------------
1384 // String type aliases used by command line flag declarations and
1385 // processing utilities.
1386
1387 typedef const char* ccstr;
1388 typedef const char* ccstrlist; // represents string arguments which accumulate
1389
1390 //----------------------------------------------------------------------------------------------------
1391 // Default hash/equals functions used by HashTable
1392
1393 template<typename K> unsigned primitive_hash(const K& k) {
1394 unsigned hash = (unsigned)((uintptr_t)k);
1395 return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1396 }
1397
1398 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1399 return k0 == k1;
1400 }
1401
1402 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1403 return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1404 }
1405
1406 //----------------------------------------------------------------------------------------------------
1407
1408 // Allow use of C++ thread_local when approved - see JDK-8282469.
1409 #define APPROVED_CPP_THREAD_LOCAL thread_local
1410
1411 // Converts any type T to a reference type.
1412 template<typename T>
1413 std::add_rvalue_reference_t<T> declval() noexcept;
1414
1415 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1416 // handled.
1417 bool IEEE_subnormal_handling_OK();
1418
1419 //----------------------------------------------------------------------------------------------------
1420 // Forbid using the global allocator by HotSpot code.
1421 //
1422 // This is a subset of allocator and deallocator functions. These are
1423 // implicitly declared in all translation units, without needing to include
1424 // <new>; see C++17 6.7.4. This isn't even the full set of those; implicit
1425 // declarations involving std::align_val_t are not covered here, since that
1426 // type is defined in <new>. A translation unit that doesn't include <new> is
1427 // still likely to include this file. See cppstdlib/new.hpp for more details.
1428 #ifndef HOTSPOT_GTEST
1429
1430 [[deprecated]] void* operator new(std::size_t);
1431 [[deprecated]] void operator delete(void*) noexcept;
1432 [[deprecated]] void operator delete(void*, std::size_t) noexcept;
1433
1434 [[deprecated]] void* operator new[](std::size_t);
1435 [[deprecated]] void operator delete[](void*) noexcept;
1436 [[deprecated]] void operator delete[](void*, std::size_t) noexcept;
1437
1438 #endif // HOTSPOT_GTEST
1439
1440 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP