1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
26 #define SHARE_UTILITIES_GLOBALDEFINITIONS_HPP
27
28 #include "utilities/compilerWarnings.hpp"
29 #include "utilities/debug.hpp"
30 #include "utilities/macros.hpp"
31
32 // Get constants like JVM_T_CHAR and JVM_SIGNATURE_INT, before pulling in <jvm.h>.
33 #include "classfile_constants.h"
34
35 #include COMPILER_HEADER(utilities/globalDefinitions)
36
37 #include <cstddef>
38 #include <cstdint>
39 #include <limits>
40 #include <type_traits>
41
42 class oopDesc;
43
44 // Defaults for macros that might be defined per compiler.
45 #ifndef NOINLINE
46 #define NOINLINE
47 #endif
48 #ifndef ALWAYSINLINE
49 #define ALWAYSINLINE inline
50 #endif
51
52 #ifndef ATTRIBUTE_ALIGNED
53 #define ATTRIBUTE_ALIGNED(x) alignas(x)
54 #endif
55
56 #ifndef ATTRIBUTE_FLATTEN
57 #define ATTRIBUTE_FLATTEN
58 #endif
59
60 // These are #defines to selectively turn on/off the Print(Opto)Assembly
61 // capabilities. Choices should be led by a tradeoff between
62 // code size and improved supportability.
63 // if PRINT_ASSEMBLY then PRINT_ABSTRACT_ASSEMBLY must be true as well
64 // to have a fallback in case hsdis is not available.
65 #if defined(PRODUCT)
66 #define SUPPORT_ABSTRACT_ASSEMBLY
67 #define SUPPORT_ASSEMBLY
68 #undef SUPPORT_OPTO_ASSEMBLY // Can't activate. In PRODUCT, many dump methods are missing.
69 #undef SUPPORT_DATA_STRUCTS // Of limited use. In PRODUCT, many print methods are empty.
70 #else
71 #define SUPPORT_ABSTRACT_ASSEMBLY
72 #define SUPPORT_ASSEMBLY
73 #define SUPPORT_OPTO_ASSEMBLY
74 #define SUPPORT_DATA_STRUCTS
75 #endif
76 #if defined(SUPPORT_ASSEMBLY) && !defined(SUPPORT_ABSTRACT_ASSEMBLY)
77 #define SUPPORT_ABSTRACT_ASSEMBLY
78 #endif
79
80 // This file holds all globally used constants & types, class (forward)
81 // declarations and a few frequently used utility functions.
82
83 // Declare the named class to be noncopyable. This macro must be followed by
84 // a semi-colon. The macro provides deleted declarations for the class's copy
85 // constructor and assignment operator. Because these operations are deleted,
86 // they cannot be defined and potential callers will fail to compile.
87 #define NONCOPYABLE(C) C(C const&) = delete; C& operator=(C const&) = delete /* next token must be ; */
88
89
90 //----------------------------------------------------------------------------------------------------
91 // Printf-style formatters for fixed- and variable-width types as pointers and
92 // integers. These are derived from the definitions in inttypes.h. If the platform
93 // doesn't provide appropriate definitions, they should be provided in
94 // the compiler-specific definitions file (e.g., globalDefinitions_gcc.hpp)
95
96 // Guide to the suffixes used in the format specifiers for integers:
97 // - print the decimal value: 745565
98 // _X - print as hexadecimal, without leading 0s: 0x12345
99 // _X_0 - print as hexadecimal, with leading 0s: 0x00012345
100 // _W(w) - prints w sized string with the given value right
101 // adjusted. Use -w to print left adjusted.
102 // _0 - print as hexadecimal, with leading 0s, without 0x prefix: 0012345
103 //
104 // Note that the PTR format specifiers print using 0x with leading zeros,
105 // just like the _X_0 version for integers.
106
107 // Format 8-bit quantities.
108 #define INT8_FORMAT_X_0 "0x%02" PRIx8
109 #define UINT8_FORMAT_X_0 "0x%02" PRIx8
110
111 // Format 16-bit quantities.
112 #define INT16_FORMAT_X_0 "0x%04" PRIx16
113 #define UINT16_FORMAT_X_0 "0x%04" PRIx16
114
115 // Format 32-bit quantities.
116 #define INT32_FORMAT "%" PRId32
117 #define INT32_FORMAT_X "0x%" PRIx32
118 #define INT32_FORMAT_X_0 "0x%08" PRIx32
119 #define INT32_FORMAT_W(width) "%" #width PRId32
120 #define UINT32_FORMAT "%" PRIu32
121 #define UINT32_FORMAT_X "0x%" PRIx32
122 #define UINT32_FORMAT_X_0 "0x%08" PRIx32
123 #define UINT32_FORMAT_W(width) "%" #width PRIu32
124
125 // Format 64-bit quantities.
126 #define INT64_FORMAT "%" PRId64
127 #define INT64_PLUS_FORMAT "%+" PRId64
128 #define INT64_FORMAT_X "0x%" PRIx64
129 #define INT64_FORMAT_X_0 "0x%016" PRIx64
130 #define INT64_FORMAT_W(width) "%" #width PRId64
131 #define UINT64_FORMAT "%" PRIu64
132 #define UINT64_FORMAT_X "0x%" PRIx64
133 #define UINT64_FORMAT_X_0 "0x%016" PRIx64
134 #define UINT64_FORMAT_W(width) "%" #width PRIu64
135 #define UINT64_FORMAT_0 "%016" PRIx64
136
137 // Format jlong, if necessary
138 #ifndef JLONG_FORMAT
139 #define JLONG_FORMAT INT64_FORMAT
140 #endif
141 #ifndef JLONG_FORMAT_W
142 #define JLONG_FORMAT_W(width) INT64_FORMAT_W(width)
143 #endif
144 #ifndef JULONG_FORMAT
145 #define JULONG_FORMAT UINT64_FORMAT
146 #endif
147 #ifndef JULONG_FORMAT_X
148 #define JULONG_FORMAT_X UINT64_FORMAT_X
149 #endif
150
151 // Format pointers and padded integral values which change size between 32- and 64-bit.
152 #ifdef _LP64
153 #define INTPTR_FORMAT "0x%016" PRIxPTR
154 #define PTR_FORMAT "0x%016" PRIxPTR
155 #define UINTX_FORMAT_X_0 "0x%016" PRIxPTR
156 #define SIZE_FORMAT_X_0 "0x%016" PRIxPTR
157 #else // !_LP64
158 #define INTPTR_FORMAT "0x%08" PRIxPTR
159 #define PTR_FORMAT "0x%08" PRIxPTR
160 #define UINTX_FORMAT_X_0 "0x%08" PRIxPTR
161 #define SIZE_FORMAT_X_0 "0x%08" PRIxPTR
162 #endif // _LP64
163
164 // Convert pointer to intptr_t, for use in printing pointers.
165 inline intptr_t p2i(const volatile void* p) {
166 return (intptr_t) p;
167 }
168
169 // Convert pointer to uintptr_t
170 inline uintptr_t p2u(const volatile void* p) {
171 return (uintptr_t) p;
172 }
173
174 #define BOOL_TO_STR(_b_) ((_b_) ? "true" : "false")
175
176 //----------------------------------------------------------------------------------------------------
177 // Forbid the use of various C library functions.
178 // Some of these have os:: replacements that should normally be used instead.
179 // Others are considered security concerns, with preferred alternatives.
180
181 FORBID_C_FUNCTION(void exit(int), "use os::exit");
182 FORBID_C_FUNCTION(void _exit(int), "use os::exit");
183 FORBID_C_FUNCTION(char* strerror(int), "use os::strerror");
184 FORBID_C_FUNCTION(char* strtok(char*, const char*), "use strtok_r");
185 FORBID_C_FUNCTION(int sprintf(char*, const char*, ...), "use os::snprintf");
186 FORBID_C_FUNCTION(int vsprintf(char*, const char*, va_list), "use os::vsnprintf");
187 FORBID_C_FUNCTION(int vsnprintf(char*, size_t, const char*, va_list), "use os::vsnprintf");
188
189 // All of the following functions return raw C-heap pointers (sometimes as an option, e.g. realpath or getwd)
190 // or, in case of free(), take raw C-heap pointers. Don't use them unless you are really sure you must.
191 FORBID_C_FUNCTION(void* malloc(size_t size), "use os::malloc");
192 FORBID_C_FUNCTION(void* calloc(size_t nmemb, size_t size), "use os::malloc and zero out manually");
193 FORBID_C_FUNCTION(void free(void *ptr), "use os::free");
194 FORBID_C_FUNCTION(void* realloc(void *ptr, size_t size), "use os::realloc");
195 FORBID_C_FUNCTION(char* strdup(const char *s), "use os::strdup");
196 FORBID_C_FUNCTION(char* strndup(const char *s, size_t n), "don't use");
197 FORBID_C_FUNCTION(int posix_memalign(void **memptr, size_t alignment, size_t size), "don't use");
198 FORBID_C_FUNCTION(void* aligned_alloc(size_t alignment, size_t size), "don't use");
199 FORBID_C_FUNCTION(char* realpath(const char* path, char* resolved_path), "use os::realpath");
200 FORBID_C_FUNCTION(char* get_current_dir_name(void), "use os::get_current_directory()");
201 FORBID_C_FUNCTION(char* getwd(char *buf), "use os::get_current_directory()");
202 FORBID_C_FUNCTION(wchar_t* wcsdup(const wchar_t *s), "don't use");
203 FORBID_C_FUNCTION(void* reallocf(void *ptr, size_t size), "don't use");
204
205 //----------------------------------------------------------------------------------------------------
206 // Constants
207
208 const int LogBytesPerShort = 1;
209 const int LogBytesPerInt = 2;
210 #ifdef _LP64
211 constexpr int LogBytesPerWord = 3;
212 #else
213 constexpr int LogBytesPerWord = 2;
214 #endif
215 const int LogBytesPerLong = 3;
216
217 const int BytesPerShort = 1 << LogBytesPerShort;
218 const int BytesPerInt = 1 << LogBytesPerInt;
219 const int BytesPerWord = 1 << LogBytesPerWord;
220 const int BytesPerLong = 1 << LogBytesPerLong;
221
222 constexpr int LogBitsPerByte = 3;
223 const int LogBitsPerShort = LogBitsPerByte + LogBytesPerShort;
224 const int LogBitsPerInt = LogBitsPerByte + LogBytesPerInt;
225 constexpr int LogBitsPerWord = LogBitsPerByte + LogBytesPerWord;
226 const int LogBitsPerLong = LogBitsPerByte + LogBytesPerLong;
227
228 const int BitsPerByte = 1 << LogBitsPerByte;
229 const int BitsPerShort = 1 << LogBitsPerShort;
230 const int BitsPerInt = 1 << LogBitsPerInt;
231 constexpr int BitsPerWord = 1 << LogBitsPerWord;
232 const int BitsPerLong = 1 << LogBitsPerLong;
233
234 const int WordAlignmentMask = (1 << LogBytesPerWord) - 1;
235 const int LongAlignmentMask = (1 << LogBytesPerLong) - 1;
236
237 const int oopSize = sizeof(char*); // Full-width oop
238 extern int heapOopSize; // Oop within a java object
239 const int wordSize = sizeof(char*);
240 const int longSize = sizeof(jlong);
241 const int jintSize = sizeof(jint);
242 const int size_tSize = sizeof(size_t);
243
244 const int BytesPerOop = BytesPerWord; // Full-width oop
245
246 extern int LogBytesPerHeapOop; // Oop within a java object
247 extern int LogBitsPerHeapOop;
248 extern int BytesPerHeapOop;
249 extern int BitsPerHeapOop;
250
251 const int BitsPerJavaInteger = 32;
252 const int BitsPerJavaLong = 64;
253 const int BitsPerSize_t = size_tSize * BitsPerByte;
254
255 // Size of a char[] needed to represent a jint as a string in decimal.
256 const int jintAsStringSize = 12;
257
258 // An opaque type, so that HeapWord* can be a generic pointer into the heap.
259 // We require that object sizes be measured in units of heap words (e.g.
260 // pointer-sized values), so that given HeapWord* hw,
261 // hw += oop(hw)->foo();
262 // works, where foo is a method (like size or scavenge) that returns the
263 // object size.
264 class HeapWordImpl; // Opaque, never defined.
265 typedef HeapWordImpl* HeapWord;
266
267 // Analogous opaque struct for metadata allocated from metaspaces.
268 class MetaWordImpl; // Opaque, never defined.
269 typedef MetaWordImpl* MetaWord;
270
271 // HeapWordSize must be 2^LogHeapWordSize.
272 const int HeapWordSize = sizeof(HeapWord);
273 #ifdef _LP64
274 const int LogHeapWordSize = 3;
275 #else
276 const int LogHeapWordSize = 2;
277 #endif
278 const int HeapWordsPerLong = BytesPerLong / HeapWordSize;
279 const int LogHeapWordsPerLong = LogBytesPerLong - LogHeapWordSize;
280
281 // The minimum number of native machine words necessary to contain "byte_size"
282 // bytes.
283 inline size_t heap_word_size(size_t byte_size) {
284 return (byte_size + (HeapWordSize-1)) >> LogHeapWordSize;
285 }
286
287 inline jfloat jfloat_cast(jint x);
288 inline jdouble jdouble_cast(jlong x);
289
290 //-------------------------------------------
291 // Constant for jlong (standardized by C++11)
292
293 // Build a 64bit integer constant
294 #define CONST64(x) (x ## LL)
295 #define UCONST64(x) (x ## ULL)
296
297 const jlong min_jlong = CONST64(0x8000000000000000);
298 const jlong max_jlong = CONST64(0x7fffffffffffffff);
299
300 //-------------------------------------------
301 // Constant for jdouble
302 const jlong min_jlongDouble = CONST64(0x0000000000000001);
303 const jdouble min_jdouble = jdouble_cast(min_jlongDouble);
304 const jlong max_jlongDouble = CONST64(0x7fefffffffffffff);
305 const jdouble max_jdouble = jdouble_cast(max_jlongDouble);
306
307 const size_t K = 1024;
308 const size_t M = K*K;
309 const size_t G = M*K;
310
311 // Constants for converting from a base unit to milli-base units. For
312 // example from seconds to milliseconds and microseconds
313
314 const int MILLIUNITS = 1000; // milli units per base unit
315 const int MICROUNITS = 1000000; // micro units per base unit
316 const int NANOUNITS = 1000000000; // nano units per base unit
317 const int NANOUNITS_PER_MILLIUNIT = NANOUNITS / MILLIUNITS;
318
319 const jlong NANOSECS_PER_SEC = CONST64(1000000000);
320 const jint NANOSECS_PER_MILLISEC = 1000000;
321
322
323 // Unit conversion functions
324 // The caller is responsible for considering overflow.
325
326 inline int64_t nanos_to_millis(int64_t nanos) {
327 return nanos / NANOUNITS_PER_MILLIUNIT;
328 }
329 inline int64_t millis_to_nanos(int64_t millis) {
330 return millis * NANOUNITS_PER_MILLIUNIT;
331 }
332
333 // Proper units routines try to maintain at least three significant digits.
334 // In worst case, it would print five significant digits with lower prefix.
335 // G is close to MAX_SIZE on 32-bit platforms, so its product can easily overflow,
336 // and therefore we need to be careful.
337
338 inline const char* proper_unit_for_byte_size(size_t s) {
339 #ifdef _LP64
340 if (s >= 100*G) {
341 return "G";
342 }
343 #endif
344 if (s >= 100*M) {
345 return "M";
346 } else if (s >= 100*K) {
347 return "K";
348 } else {
349 return "B";
350 }
351 }
352
353 template <class T>
354 inline T byte_size_in_proper_unit(T s) {
355 #ifdef _LP64
356 if (s >= 100*G) {
357 return (T)(s/G);
358 }
359 #endif
360 if (s >= 100*M) {
361 return (T)(s/M);
362 } else if (s >= 100*K) {
363 return (T)(s/K);
364 } else {
365 return s;
366 }
367 }
368
369 #define PROPERFMT "%zu%s"
370 #define PROPERFMTARGS(s) byte_size_in_proper_unit(s), proper_unit_for_byte_size(s)
371
372 // Printing a range, with start and bytes given
373 #define RANGEFMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
374 #define RANGEFMTARGS(p1, size) p2i(p1), p2i(p1 + size), size
375
376 // Printing a range, with start and end given
377 #define RANGE2FMT "[" PTR_FORMAT " - " PTR_FORMAT "), (%zu bytes)"
378 #define RANGE2FMTARGS(p1, p2) p2i(p1), p2i(p2), ((uintptr_t)p2 - (uintptr_t)p1)
379
380 inline const char* exact_unit_for_byte_size(size_t s) {
381 #ifdef _LP64
382 if (s >= G && (s % G) == 0) {
383 return "G";
384 }
385 #endif
386 if (s >= M && (s % M) == 0) {
387 return "M";
388 }
389 if (s >= K && (s % K) == 0) {
390 return "K";
391 }
392 return "B";
393 }
394
395 inline size_t byte_size_in_exact_unit(size_t s) {
396 #ifdef _LP64
397 if (s >= G && (s % G) == 0) {
398 return s / G;
399 }
400 #endif
401 if (s >= M && (s % M) == 0) {
402 return s / M;
403 }
404 if (s >= K && (s % K) == 0) {
405 return s / K;
406 }
407 return s;
408 }
409
410 #define EXACTFMT "%zu%s"
411 #define EXACTFMTARGS(s) byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
412
413 // Memory size transition formatting.
414
415 #define HEAP_CHANGE_FORMAT "%s: %zuK(%zuK)->%zuK(%zuK)"
416
417 #define HEAP_CHANGE_FORMAT_ARGS(_name_, _prev_used_, _prev_capacity_, _used_, _capacity_) \
418 (_name_), (_prev_used_) / K, (_prev_capacity_) / K, (_used_) / K, (_capacity_) / K
419
420 //----------------------------------------------------------------------------------------------------
421 // VM type definitions
422
423 // intx and uintx are the 'extended' int and 'extended' unsigned int types;
424 // they are 32bit wide on a 32-bit platform, and 64bit wide on a 64bit platform.
425
426 typedef intptr_t intx;
427 typedef uintptr_t uintx;
428
429 const intx min_intx = (intx)1 << (sizeof(intx)*BitsPerByte-1);
430 const intx max_intx = (uintx)min_intx - 1;
431 const uintx max_uintx = (uintx)-1;
432
433 // Table of values:
434 // sizeof intx 4 8
435 // min_intx 0x80000000 0x8000000000000000
436 // max_intx 0x7FFFFFFF 0x7FFFFFFFFFFFFFFF
437 // max_uintx 0xFFFFFFFF 0xFFFFFFFFFFFFFFFF
438
439 typedef unsigned int uint; NEEDS_CLEANUP
440
441 //----------------------------------------------------------------------------------------------------
442 // Java type definitions
443
444 // All kinds of 'plain' byte addresses
445 typedef signed char s_char;
446 typedef unsigned char u_char;
447 typedef u_char* address;
448 typedef const u_char* const_address;
449
450 // Pointer subtraction.
451 // The idea here is to avoid ptrdiff_t, which is signed and so doesn't have
452 // the range we might need to find differences from one end of the heap
453 // to the other.
454 // A typical use might be:
455 // if (pointer_delta(end(), top()) >= size) {
456 // // enough room for an object of size
457 // ...
458 // and then additions like
459 // ... top() + size ...
460 // are safe because we know that top() is at least size below end().
461 inline size_t pointer_delta(const volatile void* left,
462 const volatile void* right,
463 size_t element_size) {
464 assert(left >= right, "avoid underflow - left: " PTR_FORMAT " right: " PTR_FORMAT, p2i(left), p2i(right));
465 return (((uintptr_t) left) - ((uintptr_t) right)) / element_size;
466 }
467
468 // A version specialized for HeapWord*'s.
469 inline size_t pointer_delta(const HeapWord* left, const HeapWord* right) {
470 return pointer_delta(left, right, sizeof(HeapWord));
471 }
472 // A version specialized for MetaWord*'s.
473 inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
474 return pointer_delta(left, right, sizeof(MetaWord));
475 }
476
477 // pointer_delta_as_int is called to do pointer subtraction for nearby pointers that
478 // returns a non-negative int, usually used as a size of a code buffer range.
479 // This scales to sizeof(T).
480 template <typename T>
481 inline int pointer_delta_as_int(const volatile T* left, const volatile T* right) {
482 size_t delta = pointer_delta(left, right, sizeof(T));
483 assert(delta <= size_t(INT_MAX), "pointer delta out of range: %zu", delta);
484 return static_cast<int>(delta);
485 }
486
487 //
488 // ANSI C++ does not allow casting from one pointer type to a function pointer
489 // directly without at best a warning. This macro accomplishes it silently
490 // In every case that is present at this point the value be cast is a pointer
491 // to a C linkage function. In some case the type used for the cast reflects
492 // that linkage and a picky compiler would not complain. In other cases because
493 // there is no convenient place to place a typedef with extern C linkage (i.e
494 // a platform dependent header file) it doesn't. At this point no compiler seems
495 // picky enough to catch these instances (which are few). It is possible that
496 // using templates could fix these for all cases. This use of templates is likely
497 // so far from the middle of the road that it is likely to be problematic in
498 // many C++ compilers.
499 //
500 #define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
501 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((uintptr_t)(func_ptr)))
502
503 // Need the correct linkage to call qsort without warnings
504 extern "C" {
505 typedef int (*_sort_Fn)(const void *, const void *);
506 }
507
508 // Additional Java basic types
509
510 typedef uint8_t jubyte;
511 typedef uint16_t jushort;
512 typedef uint32_t juint;
513 typedef uint64_t julong;
514
515 // Unsigned byte types for os and stream.hpp
516
517 // Unsigned one, two, four and eight byte quantities used for describing
518 // the .class file format. See JVM book chapter 4.
519
520 typedef jubyte u1;
521 typedef jushort u2;
522 typedef juint u4;
523 typedef julong u8;
524
525 const jubyte max_jubyte = (jubyte)-1; // 0xFF largest jubyte
526 const jushort max_jushort = (jushort)-1; // 0xFFFF largest jushort
527 const juint max_juint = (juint)-1; // 0xFFFFFFFF largest juint
528 const julong max_julong = (julong)-1; // 0xFF....FF largest julong
529
530 typedef jbyte s1;
531 typedef jshort s2;
532 typedef jint s4;
533 typedef jlong s8;
534
535 const jbyte min_jbyte = -(1 << 7); // smallest jbyte
536 const jbyte max_jbyte = (1 << 7) - 1; // largest jbyte
537 const jshort min_jshort = -(1 << 15); // smallest jshort
538 const jshort max_jshort = (1 << 15) - 1; // largest jshort
539
540 const jint min_jint = (jint)1 << (sizeof(jint)*BitsPerByte-1); // 0x80000000 == smallest jint
541 const jint max_jint = (juint)min_jint - 1; // 0x7FFFFFFF == largest jint
542
543 const jint min_jintFloat = (jint)(0x00000001);
544 const jfloat min_jfloat = jfloat_cast(min_jintFloat);
545 const jint max_jintFloat = (jint)(0x7f7fffff);
546 const jfloat max_jfloat = jfloat_cast(max_jintFloat);
547
548 const jshort max_jfloat16 = 31743;
549 const jshort min_jfloat16 = 1;
550 const jshort one_jfloat16 = 15360;
551 const jshort pos_inf_jfloat16 = 31744;
552 const jshort neg_inf_jfloat16 = -1024;
553 // A named constant for the integral representation of a Java null.
554 const intptr_t NULL_WORD = 0;
555
556 //----------------------------------------------------------------------------------------------------
557 // JVM spec restrictions
558
559 const int max_method_code_size = 64*K - 1; // JVM spec, 2nd ed. section 4.8.1 (p.134)
560
561 //----------------------------------------------------------------------------------------------------
562 // old CDS options
563 extern bool RequireSharedSpaces;
564 extern "C" {
565 // Make sure UseSharedSpaces is accessible to the serviceability agent.
566 extern JNIEXPORT jboolean UseSharedSpaces;
567 }
568
569 //----------------------------------------------------------------------------------------------------
570 // Object alignment, in units of HeapWords.
571 //
572 // Minimum is max(BytesPerLong, BytesPerDouble, BytesPerOop) / HeapWordSize, so jlong, jdouble and
573 // reference fields can be naturally aligned.
574
575 extern int MinObjAlignment;
576 extern int MinObjAlignmentInBytes;
577 extern int MinObjAlignmentInBytesMask;
578
579 extern int LogMinObjAlignment;
580 extern int LogMinObjAlignmentInBytes;
581
582 // Maximal size of heap where unscaled compression can be used. Also upper bound
583 // for heap placement: 4GB.
584 const uint64_t UnscaledOopHeapMax = (uint64_t(max_juint) + 1);
585 // Maximal size of heap where compressed oops can be used. Also upper bound for heap
586 // placement for zero based compression algorithm: UnscaledOopHeapMax << LogMinObjAlignmentInBytes.
587 extern uint64_t OopEncodingHeapMax;
588
589 // Machine dependent stuff
590
591 #include CPU_HEADER(globalDefinitions)
592
593 // The maximum size of the code cache. Can be overridden by targets.
594 #ifndef CODE_CACHE_SIZE_LIMIT
595 #define CODE_CACHE_SIZE_LIMIT (2*G)
596 #endif
597
598 // Allow targets to reduce the default size of the code cache.
599 #define CODE_CACHE_DEFAULT_LIMIT CODE_CACHE_SIZE_LIMIT
600
601 // To assure the IRIW property on processors that are not multiple copy
602 // atomic, sync instructions must be issued between volatile reads to
603 // assure their ordering, instead of after volatile stores.
604 // (See "A Tutorial Introduction to the ARM and POWER Relaxed Memory Models"
605 // by Luc Maranget, Susmit Sarkar and Peter Sewell, INRIA/Cambridge)
606 #ifdef CPU_MULTI_COPY_ATOMIC
607 // Not needed.
608 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
609 #else
610 // From all non-multi-copy-atomic architectures, only PPC64 supports IRIW at the moment.
611 // Final decision is subject to JEP 188: Java Memory Model Update.
612 const bool support_IRIW_for_not_multiple_copy_atomic_cpu = PPC64_ONLY(true) NOT_PPC64(false);
613 #endif
614
615 // The expected size in bytes of a cache line.
616 #ifndef DEFAULT_CACHE_LINE_SIZE
617 #error "Platform should define DEFAULT_CACHE_LINE_SIZE"
618 #endif
619
620 // The default padding size for data structures to avoid false sharing.
621 #ifndef DEFAULT_PADDING_SIZE
622 #error "Platform should define DEFAULT_PADDING_SIZE"
623 #endif
624
625
626 //----------------------------------------------------------------------------------------------------
627 // Prototyping
628 // "Code Missing Here" macro, un-define when integrating back from prototyping stage and break
629 // compilation on purpose (i.e. "forget me not")
630 #define PROTOTYPE
631 #ifdef PROTOTYPE
632 #define CMH(m)
633 #endif
634
635 //----------------------------------------------------------------------------------------------------
636 // Miscellaneous
637
638 // 6302670 Eliminate Hotspot __fabsf dependency
639 // All fabs() callers should call this function instead, which will implicitly
640 // convert the operand to double, avoiding a dependency on __fabsf which
641 // doesn't exist in early versions of Solaris 8.
642 inline double fabsd(double value) {
643 return fabs(value);
644 }
645
646 // Returns numerator/denominator as percentage value from 0 to 100. If denominator
647 // is zero, return 0.0.
648 template<typename T>
649 inline double percent_of(T numerator, T denominator) {
650 return denominator != 0 ? (double)numerator / (double)denominator * 100.0 : 0.0;
651 }
652
653 //----------------------------------------------------------------------------------------------------
654 // Special casts
655 // Cast floats into same-size integers and vice-versa w/o changing bit-pattern
656 typedef union {
657 jfloat f;
658 jint i;
659 } FloatIntConv;
660
661 typedef union {
662 jdouble d;
663 jlong l;
664 julong ul;
665 } DoubleLongConv;
666
667 inline jint jint_cast (jfloat x) { return ((FloatIntConv*)&x)->i; }
668 inline jfloat jfloat_cast (jint x) { return ((FloatIntConv*)&x)->f; }
669
670 inline jlong jlong_cast (jdouble x) { return ((DoubleLongConv*)&x)->l; }
671 inline julong julong_cast (jdouble x) { return ((DoubleLongConv*)&x)->ul; }
672 inline jdouble jdouble_cast (jlong x) { return ((DoubleLongConv*)&x)->d; }
673
674 inline jint low (jlong value) { return jint(value); }
675 inline jint high(jlong value) { return jint(value >> 32); }
676
677 // the fancy casts are a hopefully portable way
678 // to do unsigned 32 to 64 bit type conversion
679 inline void set_low (jlong* value, jint low ) { *value &= (jlong)0xffffffff << 32;
680 *value |= (jlong)(julong)(juint)low; }
681
682 inline void set_high(jlong* value, jint high) { *value &= (jlong)(julong)(juint)0xffffffff;
683 *value |= (jlong)high << 32; }
684
685 inline jlong jlong_from(jint h, jint l) {
686 jlong result = 0; // initialization to avoid warning
687 set_high(&result, h);
688 set_low(&result, l);
689 return result;
690 }
691
692 union jlong_accessor {
693 jint words[2];
694 jlong long_value;
695 };
696
697 void basic_types_init(); // cannot define here; uses assert
698
699
700 // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/runtime/BasicType.java
701 enum BasicType : u1 {
702 // The values T_BOOLEAN..T_LONG (4..11) are derived from the JVMS.
703 T_BOOLEAN = JVM_T_BOOLEAN,
704 T_CHAR = JVM_T_CHAR,
705 T_FLOAT = JVM_T_FLOAT,
706 T_DOUBLE = JVM_T_DOUBLE,
707 T_BYTE = JVM_T_BYTE,
708 T_SHORT = JVM_T_SHORT,
709 T_INT = JVM_T_INT,
710 T_LONG = JVM_T_LONG,
711 // The remaining values are not part of any standard.
712 // T_OBJECT and T_VOID denote two more semantic choices
713 // for method return values.
714 // T_OBJECT and T_ARRAY describe signature syntax.
715 // T_ADDRESS, T_METADATA, T_NARROWOOP, T_NARROWKLASS describe
716 // internal references within the JVM as if they were Java
717 // types in their own right.
718 T_OBJECT = 12,
719 T_ARRAY = 13,
720 T_FLAT_ELEMENT = 14, // Not a true BasicType, only use in headers of flat arrays
721 T_VOID = 15,
722 T_ADDRESS = 16,
723 T_NARROWOOP = 17,
724 T_METADATA = 18,
725 T_NARROWKLASS = 19,
726 T_CONFLICT = 20, // for stack value type with conflicting contents
727 T_ILLEGAL = 99
728 };
729
730 #define SIGNATURE_TYPES_DO(F, N) \
731 F(JVM_SIGNATURE_BOOLEAN, T_BOOLEAN, N) \
732 F(JVM_SIGNATURE_CHAR, T_CHAR, N) \
733 F(JVM_SIGNATURE_FLOAT, T_FLOAT, N) \
734 F(JVM_SIGNATURE_DOUBLE, T_DOUBLE, N) \
735 F(JVM_SIGNATURE_BYTE, T_BYTE, N) \
736 F(JVM_SIGNATURE_SHORT, T_SHORT, N) \
737 F(JVM_SIGNATURE_INT, T_INT, N) \
738 F(JVM_SIGNATURE_LONG, T_LONG, N) \
739 F(JVM_SIGNATURE_CLASS, T_OBJECT, N) \
740 F(JVM_SIGNATURE_ARRAY, T_ARRAY, N) \
741 F(JVM_SIGNATURE_FLAT_ELEMENT, T_FLAT_ELEMENT, N) \
742 F(JVM_SIGNATURE_VOID, T_VOID, N) \
743 /*end*/
744
745 inline bool is_java_type(BasicType t) {
746 return T_BOOLEAN <= t && t <= T_VOID;
747 }
748
749 inline bool is_java_primitive(BasicType t) {
750 return T_BOOLEAN <= t && t <= T_LONG;
751 }
752
753 inline bool is_subword_type(BasicType t) {
754 // these guys are processed exactly like T_INT in calling sequences:
755 return (t == T_BOOLEAN || t == T_CHAR || t == T_BYTE || t == T_SHORT);
756 }
757
758 inline bool is_signed_subword_type(BasicType t) {
759 return (t == T_BYTE || t == T_SHORT);
760 }
761
762 inline bool is_unsigned_subword_type(BasicType t) {
763 return (t == T_BOOLEAN || t == T_CHAR);
764 }
765
766 inline bool is_double_word_type(BasicType t) {
767 return (t == T_DOUBLE || t == T_LONG);
768 }
769
770 inline bool is_reference_type(BasicType t, bool include_narrow_oop = false) {
771 return (t == T_OBJECT || t == T_ARRAY || t == T_FLAT_ELEMENT || (include_narrow_oop && t == T_NARROWOOP));
772 }
773
774 inline bool is_integral_type(BasicType t) {
775 return is_subword_type(t) || t == T_INT || t == T_LONG;
776 }
777
778 inline bool is_non_subword_integral_type(BasicType t) {
779 return t == T_INT || t == T_LONG;
780 }
781
782 inline bool is_floating_point_type(BasicType t) {
783 return (t == T_FLOAT || t == T_DOUBLE);
784 }
785
786 extern char type2char_tab[T_CONFLICT+1]; // Map a BasicType to a jchar
787 inline char type2char(BasicType t) { return (uint)t < T_CONFLICT+1 ? type2char_tab[t] : 0; }
788 extern int type2size[T_CONFLICT+1]; // Map BasicType to result stack elements
789 extern const char* type2name_tab[T_CONFLICT+1]; // Map a BasicType to a char*
790 extern BasicType name2type(const char* name);
791
792 const char* type2name(BasicType t);
793
794 inline jlong max_signed_integer(BasicType bt) {
795 if (bt == T_INT) {
796 return max_jint;
797 }
798 assert(bt == T_LONG, "unsupported");
799 return max_jlong;
800 }
801
802 inline jlong min_signed_integer(BasicType bt) {
803 if (bt == T_INT) {
804 return min_jint;
805 }
806 assert(bt == T_LONG, "unsupported");
807 return min_jlong;
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 T_FLAT_ELEMENT_size = 1
839 };
840
841 // this works on valid parameter types but not T_VOID, T_CONFLICT, etc.
842 inline int parameter_type_word_count(BasicType t) {
843 if (is_double_word_type(t)) return 2;
844 assert(is_java_primitive(t) || is_reference_type(t), "no goofy types here please");
845 assert(type2size[t] == 1, "must be");
846 return 1;
847 }
848
849 // maps a BasicType to its instance field storage type:
850 // all sub-word integral types are widened to T_INT
851 extern BasicType type2field[T_CONFLICT+1];
852 extern BasicType type2wfield[T_CONFLICT+1];
853
854
855 // size in bytes
856 enum ArrayElementSize {
857 T_BOOLEAN_aelem_bytes = 1,
858 T_CHAR_aelem_bytes = 2,
859 T_FLOAT_aelem_bytes = 4,
860 T_DOUBLE_aelem_bytes = 8,
861 T_BYTE_aelem_bytes = 1,
862 T_SHORT_aelem_bytes = 2,
863 T_INT_aelem_bytes = 4,
864 T_LONG_aelem_bytes = 8,
865 #ifdef _LP64
866 T_OBJECT_aelem_bytes = 8,
867 T_ARRAY_aelem_bytes = 8,
868 T_FLAT_ELEMENT_aelem_bytes = 8,
869 #else
870 T_OBJECT_aelem_bytes = 4,
871 T_ARRAY_aelem_bytes = 4,
872 T_FLAT_ELEMENT_aelem_bytes = 4,
873 #endif
874 T_NARROWOOP_aelem_bytes = 4,
875 T_NARROWKLASS_aelem_bytes = 4,
876 T_VOID_aelem_bytes = 0
877 };
878
879 extern int _type2aelembytes[T_CONFLICT+1]; // maps a BasicType to nof bytes used by its array element
880 #ifdef ASSERT
881 extern int type2aelembytes(BasicType t, bool allow_address = false); // asserts
882 #else
883 inline int type2aelembytes(BasicType t, bool allow_address = false) { return _type2aelembytes[t]; }
884 #endif
885
886 inline bool same_type_or_subword_size(BasicType t1, BasicType t2) {
887 return (t1 == t2) || (is_subword_type(t1) && type2aelembytes(t1) == type2aelembytes(t2));
888 }
889
890 // JavaValue serves as a container for arbitrary Java values.
891
892 class JavaValue {
893
894 public:
895 typedef union JavaCallValue {
896 jfloat f;
897 jdouble d;
898 jint i;
899 jlong l;
900 jobject h;
901 oopDesc* o;
902 } JavaCallValue;
903
904 private:
905 BasicType _type;
906 JavaCallValue _value;
907
908 public:
909 JavaValue(BasicType t = T_ILLEGAL) { _type = t; }
910
911 JavaValue(jfloat value) {
912 _type = T_FLOAT;
913 _value.f = value;
914 }
915
916 JavaValue(jdouble value) {
917 _type = T_DOUBLE;
918 _value.d = value;
919 }
920
921 jfloat get_jfloat() const { return _value.f; }
922 jdouble get_jdouble() const { return _value.d; }
923 jint get_jint() const { return _value.i; }
924 jlong get_jlong() const { return _value.l; }
925 jobject get_jobject() const { return _value.h; }
926 oopDesc* get_oop() const { return _value.o; }
927 JavaCallValue* get_value_addr() { return &_value; }
928 BasicType get_type() const { return _type; }
929
930 void set_jfloat(jfloat f) { _value.f = f;}
931 void set_jdouble(jdouble d) { _value.d = d;}
932 void set_jint(jint i) { _value.i = i;}
933 void set_jshort(jshort i) { _value.i = i;}
934 void set_jlong(jlong l) { _value.l = l;}
935 void set_jobject(jobject h) { _value.h = h;}
936 void set_oop(oopDesc* o) { _value.o = o;}
937 void set_type(BasicType t) { _type = t; }
938
939 jboolean get_jboolean() const { return (jboolean) (_value.i);}
940 jbyte get_jbyte() const { return (jbyte) (_value.i);}
941 jchar get_jchar() const { return (jchar) (_value.i);}
942 jshort get_jshort() const { return (jshort) (_value.i);}
943
944 };
945
946
947 // TosState describes the top-of-stack state before and after the execution of
948 // a bytecode or method. The top-of-stack value may be cached in one or more CPU
949 // registers. The TosState corresponds to the 'machine representation' of this cached
950 // value. There's 4 states corresponding to the JAVA types int, long, float & double
951 // as well as a 5th state in case the top-of-stack value is actually on the top
952 // of stack (in memory) and thus not cached. The atos state corresponds to the itos
953 // state when it comes to machine representation but is used separately for (oop)
954 // type specific operations (e.g. verification code).
955
956 enum TosState { // describes the tos cache contents
957 btos = 0, // byte, bool tos cached
958 ztos = 1, // byte, bool tos cached
959 ctos = 2, // char tos cached
960 stos = 3, // short tos cached
961 itos = 4, // int tos cached
962 ltos = 5, // long tos cached
963 ftos = 6, // float tos cached
964 dtos = 7, // double tos cached
965 atos = 8, // object cached
966 vtos = 9, // tos not cached,
967 number_of_states,
968 ilgl // illegal state: should not occur
969 };
970
971
972 inline TosState as_TosState(BasicType type) {
973 switch (type) {
974 case T_BYTE : return btos;
975 case T_BOOLEAN: return ztos;
976 case T_CHAR : return ctos;
977 case T_SHORT : return stos;
978 case T_INT : return itos;
979 case T_LONG : return ltos;
980 case T_FLOAT : return ftos;
981 case T_DOUBLE : return dtos;
982 case T_VOID : return vtos;
983 case T_ARRAY : // fall through
984 case T_OBJECT : return atos;
985 default : return ilgl;
986 }
987 }
988
989 inline BasicType as_BasicType(TosState state) {
990 switch (state) {
991 case btos : return T_BYTE;
992 case ztos : return T_BOOLEAN;
993 case ctos : return T_CHAR;
994 case stos : return T_SHORT;
995 case itos : return T_INT;
996 case ltos : return T_LONG;
997 case ftos : return T_FLOAT;
998 case dtos : return T_DOUBLE;
999 case atos : return T_OBJECT;
1000 case vtos : return T_VOID;
1001 default : return T_ILLEGAL;
1002 }
1003 }
1004
1005
1006 // Helper function to convert BasicType info into TosState
1007 // Note: Cannot define here as it uses global constant at the time being.
1008 TosState as_TosState(BasicType type);
1009
1010
1011 // JavaThreadState keeps track of which part of the code a thread is executing in. This
1012 // information is needed by the safepoint code.
1013 //
1014 // There are 4 essential states:
1015 //
1016 // _thread_new : Just started, but not executed init. code yet (most likely still in OS init code)
1017 // _thread_in_native : In native code. This is a safepoint region, since all oops will be in jobject handles
1018 // _thread_in_vm : Executing in the vm
1019 // _thread_in_Java : Executing either interpreted or compiled Java code (or could be in a stub)
1020 //
1021 // Each state has an associated xxxx_trans state, which is an intermediate state used when a thread is in
1022 // a transition from one state to another. These extra states makes it possible for the safepoint code to
1023 // handle certain thread_states without having to suspend the thread - making the safepoint code faster.
1024 //
1025 // Given a state, the xxxx_trans state can always be found by adding 1.
1026 //
1027 enum JavaThreadState {
1028 _thread_uninitialized = 0, // should never happen (missing initialization)
1029 _thread_new = 2, // just starting up, i.e., in process of being initialized
1030 _thread_new_trans = 3, // corresponding transition state (not used, included for completeness)
1031 _thread_in_native = 4, // running in native code
1032 _thread_in_native_trans = 5, // corresponding transition state
1033 _thread_in_vm = 6, // running in VM
1034 _thread_in_vm_trans = 7, // corresponding transition state
1035 _thread_in_Java = 8, // running in Java or in stub code
1036 _thread_in_Java_trans = 9, // corresponding transition state (not used, included for completeness)
1037 _thread_blocked = 10, // blocked in vm
1038 _thread_blocked_trans = 11, // corresponding transition state
1039 _thread_max_state = 12 // maximum thread state+1 - used for statistics allocation
1040 };
1041
1042 enum LockingMode {
1043 // Use only heavy monitors for locking
1044 LM_MONITOR = 0,
1045 // Legacy stack-locking, with monitors as 2nd tier
1046 LM_LEGACY = 1,
1047 // New lightweight locking, with monitors as 2nd tier
1048 LM_LIGHTWEIGHT = 2
1049 };
1050
1051 //----------------------------------------------------------------------------------------------------
1052 // Special constants for debugging
1053
1054 const jint badInt = -3; // generic "bad int" value
1055 const intptr_t badAddressVal = -2; // generic "bad address" value
1056 const intptr_t badOopVal = -1; // generic "bad oop" value
1057 const intptr_t badHeapOopVal = (intptr_t) CONST64(0x2BAD4B0BBAADBABE); // value used to zap heap after GC
1058 const int badStackSegVal = 0xCA; // value used to zap stack segments
1059 const int badHandleValue = 0xBC; // value used to zap vm handle area
1060 const int badResourceValue = 0xAB; // value used to zap resource area
1061 const int freeBlockPad = 0xBA; // value used to pad freed blocks.
1062 const int uninitBlockPad = 0xF1; // value used to zap newly malloc'd blocks.
1063 const juint uninitMetaWordVal = 0xf7f7f7f7; // value used to zap newly allocated metachunk
1064 const jubyte heapPaddingByteVal = 0xBD; // value used to zap object padding in the heap
1065 const juint badHeapWordVal = 0xBAADBABE; // value used to zap heap after GC
1066 const int badCodeHeapNewVal = 0xCC; // value used to zap Code heap at allocation
1067 const int badCodeHeapFreeVal = 0xDD; // value used to zap Code heap at deallocation
1068 const intptr_t badDispHeaderDeopt = 0xDE0BD000; // value to fill unused displaced header during deoptimization
1069 const intptr_t badDispHeaderOSR = 0xDEAD05A0; // value to fill unused displaced header during OSR
1070
1071 // (These must be implemented as #defines because C++ compilers are
1072 // not obligated to inline non-integral constants!)
1073 #define badAddress ((address)::badAddressVal)
1074 #define badHeapWord (::badHeapWordVal)
1075
1076 // Default TaskQueue size is 16K (32-bit) or 128K (64-bit)
1077 const uint TASKQUEUE_SIZE = (NOT_LP64(1<<14) LP64_ONLY(1<<17));
1078
1079 //----------------------------------------------------------------------------------------------------
1080 // Utility functions for bitfield manipulations
1081
1082 const intptr_t AllBits = ~0; // all bits set in a word
1083 const intptr_t NoBits = 0; // no bits set in a word
1084 const jlong NoLongBits = 0; // no bits set in a long
1085 const intptr_t OneBit = 1; // only right_most bit set in a word
1086
1087 // get a word with the n.th or the right-most or left-most n bits set
1088 // (note: #define used only so that they can be used in enum constant definitions)
1089 #define nth_bit(n) (((n) >= BitsPerWord) ? 0 : (OneBit << (n)))
1090 #define right_n_bits(n) (nth_bit(n) - 1)
1091
1092 // bit-operations using a mask m
1093 inline void set_bits (intptr_t& x, intptr_t m) { x |= m; }
1094 inline void clear_bits (intptr_t& x, intptr_t m) { x &= ~m; }
1095 inline intptr_t mask_bits (intptr_t x, intptr_t m) { return x & m; }
1096 inline jlong mask_long_bits (jlong x, jlong m) { return x & m; }
1097 inline bool mask_bits_are_true (intptr_t flags, intptr_t mask) { return (flags & mask) == mask; }
1098
1099 // bit-operations using the n.th bit
1100 inline void set_nth_bit(intptr_t& x, int n) { set_bits (x, nth_bit(n)); }
1101 inline void clear_nth_bit(intptr_t& x, int n) { clear_bits(x, nth_bit(n)); }
1102 inline bool is_set_nth_bit(intptr_t x, int n) { return mask_bits (x, nth_bit(n)) != NoBits; }
1103
1104 // returns the bitfield of x starting at start_bit_no with length field_length (no sign-extension!)
1105 inline intptr_t bitfield(intptr_t x, int start_bit_no, int field_length) {
1106 return mask_bits(x >> start_bit_no, right_n_bits(field_length));
1107 }
1108
1109
1110 //----------------------------------------------------------------------------------------------------
1111 // Utility functions for integers
1112
1113 // Avoid use of global min/max macros which may cause unwanted double
1114 // evaluation of arguments.
1115 #ifdef max
1116 #undef max
1117 #endif
1118
1119 #ifdef min
1120 #undef min
1121 #endif
1122
1123 // It is necessary to use templates here. Having normal overloaded
1124 // functions does not work because it is necessary to provide both 32-
1125 // and 64-bit overloaded functions, which does not work, and having
1126 // explicitly-typed versions of these routines (i.e., MAX2I, MAX2L)
1127 // will be even more error-prone than macros.
1128 template<class T> constexpr T MAX2(T a, T b) { return (a > b) ? a : b; }
1129 template<class T> constexpr T MIN2(T a, T b) { return (a < b) ? a : b; }
1130 template<class T> constexpr T MAX3(T a, T b, T c) { return MAX2(MAX2(a, b), c); }
1131 template<class T> constexpr T MIN3(T a, T b, T c) { return MIN2(MIN2(a, b), c); }
1132 template<class T> constexpr T MAX4(T a, T b, T c, T d) { return MAX2(MAX3(a, b, c), d); }
1133 template<class T> constexpr T MIN4(T a, T b, T c, T d) { return MIN2(MIN3(a, b, c), d); }
1134
1135 #define ABS(x) asserted_abs(x, __FILE__, __LINE__)
1136
1137 template<class T> inline T asserted_abs(T x, const char* file, int line) {
1138 bool valid_arg = !(std::is_integral<T>::value && x == std::numeric_limits<T>::min());
1139 #ifdef ASSERT
1140 if (!valid_arg) {
1141 report_vm_error(file, line, "ABS: argument should not allow overflow");
1142 }
1143 #endif
1144 // Prevent exposure to UB by checking valid_arg here as well.
1145 return (x < 0 && valid_arg) ? -x : x;
1146 }
1147
1148 // Return the given value clamped to the range [min ... max]
1149 template<typename T>
1150 inline T clamp(T value, T min, T max) {
1151 assert(min <= max, "must be");
1152 return MIN2(MAX2(value, min), max);
1153 }
1154
1155 inline bool is_odd (intx x) { return x & 1; }
1156 inline bool is_even(intx x) { return !is_odd(x); }
1157
1158 // abs methods which cannot overflow and so are well-defined across
1159 // the entire domain of integer types.
1160 static inline unsigned int uabs(unsigned int n) {
1161 union {
1162 unsigned int result;
1163 int value;
1164 };
1165 result = n;
1166 if (value < 0) result = 0-result;
1167 return result;
1168 }
1169 static inline julong uabs(julong n) {
1170 union {
1171 julong result;
1172 jlong value;
1173 };
1174 result = n;
1175 if (value < 0) result = 0-result;
1176 return result;
1177 }
1178 static inline julong uabs(jlong n) { return uabs((julong)n); }
1179 static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1180
1181 // "to" should be greater than "from."
1182 inline size_t byte_size(void* from, void* to) {
1183 return pointer_delta(to, from, sizeof(char));
1184 }
1185
1186 // Pack and extract shorts to/from ints:
1187
1188 inline u2 extract_low_short_from_int(u4 x) {
1189 return u2(x & 0xffff);
1190 }
1191
1192 inline u2 extract_high_short_from_int(u4 x) {
1193 return u2((x >> 16) & 0xffff);
1194 }
1195
1196 inline int build_int_from_shorts( u2 low, u2 high ) {
1197 return ((int)((unsigned int)high << 16) | (unsigned int)low);
1198 }
1199
1200 // swap a & b
1201 template<class T> static void swap(T& a, T& b) {
1202 T tmp = a;
1203 a = b;
1204 b = tmp;
1205 }
1206
1207 // array_size_impl is a function that takes a reference to T[N] and
1208 // returns a reference to char[N]. It is not ODR-used, so not defined.
1209 template<typename T, size_t N> char (&array_size_impl(T (&)[N]))[N];
1210
1211 #define ARRAY_SIZE(array) sizeof(array_size_impl(array))
1212
1213 //----------------------------------------------------------------------------------------------------
1214 // Sum and product which can never overflow: they wrap, just like the
1215 // Java operations. Note that we don't intend these to be used for
1216 // general-purpose arithmetic: their purpose is to emulate Java
1217 // operations.
1218
1219 // The goal of this code to avoid undefined or implementation-defined
1220 // behavior. The use of an lvalue to reference cast is explicitly
1221 // permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1222 // 15 in C++03]
1223 #define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1224 inline TYPE NAME (TYPE in1, TYPE in2) { \
1225 UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1226 ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1227 return reinterpret_cast<TYPE&>(ures); \
1228 }
1229
1230 JAVA_INTEGER_OP(+, java_add, jint, juint)
1231 JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1232 JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1233 JAVA_INTEGER_OP(+, java_add, jlong, julong)
1234 JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1235 JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1236
1237 inline jint java_negate(jint v) { return java_subtract((jint) 0, v); }
1238 inline jlong java_negate(jlong v) { return java_subtract((jlong)0, v); }
1239
1240 #undef JAVA_INTEGER_OP
1241
1242 // Provide integer shift operations with Java semantics. No overflow
1243 // issues - left shifts simply discard shifted out bits. No undefined
1244 // behavior for large or negative shift quantities; instead the actual
1245 // shift distance is the argument modulo the lhs value's size in bits.
1246 // No undefined or implementation defined behavior for shifting negative
1247 // values; left shift discards bits, right shift sign extends. We use
1248 // the same safe conversion technique as above for java_add and friends.
1249 #define JAVA_INTEGER_SHIFT_OP(OP, NAME, TYPE, XTYPE) \
1250 inline TYPE NAME (TYPE lhs, jint rhs) { \
1251 const uint rhs_mask = (sizeof(TYPE) * 8) - 1; \
1252 STATIC_ASSERT(rhs_mask == 31 || rhs_mask == 63); \
1253 XTYPE xres = static_cast<XTYPE>(lhs); \
1254 xres OP ## = (rhs & rhs_mask); \
1255 return reinterpret_cast<TYPE&>(xres); \
1256 }
1257
1258 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jint, juint)
1259 JAVA_INTEGER_SHIFT_OP(<<, java_shift_left, jlong, julong)
1260
1261 // For signed shift right, assume C++ implementation >> sign extends.
1262 //
1263 // C++14 5.8/3: In the description of "E1 >> E2" it says "If E1 has a signed type
1264 // and a negative value, the resulting value is implementation-defined."
1265 //
1266 // However, C++20 7.6.7/3 further defines integral arithmetic, as part of
1267 // requiring two's-complement behavior.
1268 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0907r3.html
1269 // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html
1270 // The corresponding C++20 text is "Right-shift on signed integral types is an
1271 // arithmetic right shift, which performs sign-extension."
1272 //
1273 // As discussed in the two's complement proposal, all known modern C++ compilers
1274 // already behave that way. And it is unlikely any would go off and do something
1275 // different now, with C++20 tightening things up.
1276 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jint, jint)
1277 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right, jlong, jlong)
1278 // For >>> use C++ unsigned >>.
1279 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jint, juint)
1280 JAVA_INTEGER_SHIFT_OP(>>, java_shift_right_unsigned, jlong, julong)
1281
1282 #undef JAVA_INTEGER_SHIFT_OP
1283
1284 //----------------------------------------------------------------------------------------------------
1285 // The goal of this code is to provide saturating operations for int/uint.
1286 // Checks overflow conditions and saturates the result to min_jint/max_jint.
1287 #define SATURATED_INTEGER_OP(OP, NAME, TYPE1, TYPE2) \
1288 inline int NAME (TYPE1 in1, TYPE2 in2) { \
1289 jlong res = static_cast<jlong>(in1); \
1290 res OP ## = static_cast<jlong>(in2); \
1291 if (res > max_jint) { \
1292 res = max_jint; \
1293 } else if (res < min_jint) { \
1294 res = min_jint; \
1295 } \
1296 return static_cast<int>(res); \
1297 }
1298
1299 SATURATED_INTEGER_OP(+, saturated_add, int, int)
1300 SATURATED_INTEGER_OP(+, saturated_add, int, uint)
1301 SATURATED_INTEGER_OP(+, saturated_add, uint, int)
1302 SATURATED_INTEGER_OP(+, saturated_add, uint, uint)
1303
1304 #undef SATURATED_INTEGER_OP
1305
1306 // Taken from rom section 8-2 of Henry S. Warren, Jr., Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174.
1307 inline uint64_t multiply_high_unsigned(const uint64_t x, const uint64_t y) {
1308 const uint64_t x1 = x >> 32u;
1309 const uint64_t x2 = x & 0xFFFFFFFF;
1310 const uint64_t y1 = y >> 32u;
1311 const uint64_t y2 = y & 0xFFFFFFFF;
1312 const uint64_t z2 = x2 * y2;
1313 const uint64_t t = x1 * y2 + (z2 >> 32u);
1314 uint64_t z1 = t & 0xFFFFFFFF;
1315 const uint64_t z0 = t >> 32u;
1316 z1 += x2 * y1;
1317
1318 return x1 * y1 + z0 + (z1 >> 32u);
1319 }
1320
1321 // Taken from java.lang.Math::multiplyHigh which uses the technique from section 8-2 of Henry S. Warren, Jr.,
1322 // Hacker's Delight (2nd ed.) (Addison Wesley, 2013), 173-174 but adapted for signed longs.
1323 inline int64_t multiply_high_signed(const int64_t x, const int64_t y) {
1324 const jlong x1 = java_shift_right((jlong)x, 32);
1325 const jlong x2 = x & 0xFFFFFFFF;
1326 const jlong y1 = java_shift_right((jlong)y, 32);
1327 const jlong y2 = y & 0xFFFFFFFF;
1328
1329 const uint64_t z2 = (uint64_t)x2 * y2;
1330 const int64_t t = x1 * y2 + (z2 >> 32u); // Unsigned shift
1331 int64_t z1 = t & 0xFFFFFFFF;
1332 const int64_t z0 = java_shift_right((jlong)t, 32);
1333 z1 += x2 * y1;
1334
1335 return x1 * y1 + z0 + java_shift_right((jlong)z1, 32);
1336 }
1337
1338 // Dereference vptr
1339 // All C++ compilers that we know of have the vtbl pointer in the first
1340 // word. If there are exceptions, this function needs to be made compiler
1341 // specific.
1342 static inline void* dereference_vptr(const void* addr) {
1343 return *(void**)addr;
1344 }
1345
1346 //----------------------------------------------------------------------------------------------------
1347 // String type aliases used by command line flag declarations and
1348 // processing utilities.
1349
1350 typedef const char* ccstr;
1351 typedef const char* ccstrlist; // represents string arguments which accumulate
1352
1353 //----------------------------------------------------------------------------------------------------
1354 // Default hash/equals functions used by ResourceHashtable
1355
1356 template<typename K> unsigned primitive_hash(const K& k) {
1357 unsigned hash = (unsigned)((uintptr_t)k);
1358 return hash ^ (hash >> 3); // just in case we're dealing with aligned ptrs
1359 }
1360
1361 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
1362 return k0 == k1;
1363 }
1364
1365 template<typename K> int primitive_compare(const K& k0, const K& k1) {
1366 return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
1367 }
1368
1369 //----------------------------------------------------------------------------------------------------
1370
1371 // Allow use of C++ thread_local when approved - see JDK-8282469.
1372 #define APPROVED_CPP_THREAD_LOCAL thread_local
1373
1374 // Converts any type T to a reference type.
1375 template<typename T>
1376 std::add_rvalue_reference_t<T> declval() noexcept;
1377
1378 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
1379 // handled.
1380 bool IEEE_subnormal_handling_OK();
1381
1382 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_HPP