1 /*
2 * Copyright (c) 1997, 2024, 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 #include "precompiled.hpp"
26 #include "runtime/globals.hpp"
27 #include "runtime/os.hpp"
28 #include "runtime/signature.hpp"
29 #include "utilities/globalDefinitions.hpp"
30 #include "utilities/powerOfTwo.hpp"
31
32 // Basic error support
33
34 // Info for oops within a java object. Defaults are zero so
35 // things will break badly if incorrectly initialized.
36 int heapOopSize = 0;
37 int LogBytesPerHeapOop = 0;
38 int LogBitsPerHeapOop = 0;
39 int BytesPerHeapOop = 0;
40 int BitsPerHeapOop = 0;
41
42 // Old CDS options
43 bool RequireSharedSpaces;
44 extern "C" {
45 JNIEXPORT jboolean UseSharedSpaces = true;
46 }
47
48 // Object alignment, in units of HeapWords.
49 // Defaults are -1 so things will break badly if incorrectly initialized.
50 int MinObjAlignment = -1;
51 int MinObjAlignmentInBytes = -1;
52 int MinObjAlignmentInBytesMask = 0;
53
54 int LogMinObjAlignment = -1;
55 int LogMinObjAlignmentInBytes = -1;
56
57 // Oop encoding heap max
58 uint64_t OopEncodingHeapMax = 0;
59
60 // Something to help porters sleep at night
61
62 #ifdef ASSERT
63 static BasicType char2type(int ch) {
64 switch (ch) {
65 #define EACH_SIG(ch, bt, ignore) \
66 case ch: return bt;
67 SIGNATURE_TYPES_DO(EACH_SIG, ignore)
68 #undef EACH_SIG
69 }
70 return T_ILLEGAL;
71 }
72
73 extern bool signature_constants_sane();
74 #endif //ASSERT
75
76 void basic_types_init() {
77 #ifdef ASSERT
78 #ifdef _LP64
79 static_assert(min_intx == (intx)CONST64(0x8000000000000000), "correct constant");
80 static_assert(max_intx == CONST64(0x7FFFFFFFFFFFFFFF), "correct constant");
81 static_assert(max_uintx == CONST64(0xFFFFFFFFFFFFFFFF), "correct constant");
82 static_assert( 8 == sizeof( intx), "wrong size for basic type");
83 static_assert( 8 == sizeof( jobject), "wrong size for basic type");
84 #else
85 static_assert(min_intx == (intx)0x80000000, "correct constant");
86 static_assert(max_intx == 0x7FFFFFFF, "correct constant");
87 static_assert(max_uintx == 0xFFFFFFFF, "correct constant");
88 static_assert( 4 == sizeof( intx), "wrong size for basic type");
89 static_assert( 4 == sizeof( jobject), "wrong size for basic type");
90 #endif
91 static_assert( (~max_juint) == 0, "max_juint has all its bits");
92 static_assert( (~max_uintx) == 0, "max_uintx has all its bits");
93 static_assert( (~max_julong) == 0, "max_julong has all its bits");
94 static_assert( 1 == sizeof( jbyte), "wrong size for basic type");
95 static_assert( 2 == sizeof( jchar), "wrong size for basic type");
96 static_assert( 2 == sizeof( jshort), "wrong size for basic type");
97 static_assert( 4 == sizeof( juint), "wrong size for basic type");
98 static_assert( 4 == sizeof( jint), "wrong size for basic type");
99 static_assert( 1 == sizeof( jboolean), "wrong size for basic type");
100 static_assert( 8 == sizeof( jlong), "wrong size for basic type");
101 static_assert( 4 == sizeof( jfloat), "wrong size for basic type");
102 static_assert( 8 == sizeof( jdouble), "wrong size for basic type");
103 static_assert( 1 == sizeof( u1), "wrong size for basic type");
104 static_assert( 2 == sizeof( u2), "wrong size for basic type");
105 static_assert( 4 == sizeof( u4), "wrong size for basic type");
106 static_assert(wordSize == BytesPerWord, "should be the same since they're used interchangeably");
107 static_assert(wordSize == HeapWordSize, "should be the same since they're also used interchangeably");
108
109 assert(signature_constants_sane(), "");
110
111 int num_type_chars = 0;
112 for (int i = 0; i < 99; i++) {
113 if (type2char((BasicType)i) != 0) {
114 assert(char2type(type2char((BasicType)i)) == i, "proper inverses");
115 assert(Signature::basic_type(type2char((BasicType)i)) == i, "proper inverses");
116 num_type_chars++;
117 }
118 }
119 assert(num_type_chars == 11, "must have tested the right number of mappings");
120 assert(char2type(0) == T_ILLEGAL, "correct illegality");
121
122 {
123 for (int i = T_BOOLEAN; i <= T_CONFLICT; i++) {
124 BasicType vt = (BasicType)i;
125 BasicType ft = type2field[vt];
126 switch (vt) {
127 // the following types might plausibly show up in memory layouts:
128 case T_BOOLEAN:
129 case T_BYTE:
130 case T_CHAR:
131 case T_SHORT:
132 case T_INT:
133 case T_FLOAT:
134 case T_DOUBLE:
135 case T_LONG:
136 case T_OBJECT:
137 case T_ADDRESS: // random raw pointer
138 case T_METADATA: // metadata pointer
139 case T_NARROWOOP: // compressed pointer
140 case T_NARROWKLASS: // compressed klass pointer
141 case T_CONFLICT: // might as well support a bottom type
142 case T_VOID: // padding or other unaddressed word
143 // layout type must map to itself
144 assert(vt == ft, "");
145 break;
146 default:
147 // non-layout type must map to a (different) layout type
148 assert(vt != ft, "");
149 assert(ft == type2field[ft], "");
150 }
151 // every type must map to same-sized layout type:
152 assert(type2size[vt] == type2size[ft], "");
153 }
154 }
155 // These are assumed, e.g., when filling HeapWords with juints.
156 static_assert(is_power_of_2(sizeof(juint)), "juint must be power of 2");
157 static_assert(is_power_of_2(HeapWordSize), "HeapWordSize must be power of 2");
158 static_assert((size_t)HeapWordSize >= sizeof(juint),
159 "HeapWord should be at least as large as juint");
160 #endif
161
162 if( JavaPriority1_To_OSPriority != -1 )
163 os::java_to_os_priority[1] = JavaPriority1_To_OSPriority;
164 if( JavaPriority2_To_OSPriority != -1 )
165 os::java_to_os_priority[2] = JavaPriority2_To_OSPriority;
166 if( JavaPriority3_To_OSPriority != -1 )
167 os::java_to_os_priority[3] = JavaPriority3_To_OSPriority;
168 if( JavaPriority4_To_OSPriority != -1 )
169 os::java_to_os_priority[4] = JavaPriority4_To_OSPriority;
170 if( JavaPriority5_To_OSPriority != -1 )
171 os::java_to_os_priority[5] = JavaPriority5_To_OSPriority;
172 if( JavaPriority6_To_OSPriority != -1 )
173 os::java_to_os_priority[6] = JavaPriority6_To_OSPriority;
174 if( JavaPriority7_To_OSPriority != -1 )
175 os::java_to_os_priority[7] = JavaPriority7_To_OSPriority;
176 if( JavaPriority8_To_OSPriority != -1 )
177 os::java_to_os_priority[8] = JavaPriority8_To_OSPriority;
178 if( JavaPriority9_To_OSPriority != -1 )
179 os::java_to_os_priority[9] = JavaPriority9_To_OSPriority;
180 if(JavaPriority10_To_OSPriority != -1 )
181 os::java_to_os_priority[10] = JavaPriority10_To_OSPriority;
182
183 // Set the size of basic types here (after argument parsing but before
184 // stub generation).
185 if (UseCompressedOops) {
186 // Size info for oops within java objects is fixed
187 heapOopSize = jintSize;
188 LogBytesPerHeapOop = LogBytesPerInt;
189 LogBitsPerHeapOop = LogBitsPerInt;
190 BytesPerHeapOop = BytesPerInt;
191 BitsPerHeapOop = BitsPerInt;
192 } else {
193 heapOopSize = oopSize;
194 LogBytesPerHeapOop = LogBytesPerWord;
195 LogBitsPerHeapOop = LogBitsPerWord;
196 BytesPerHeapOop = BytesPerWord;
197 BitsPerHeapOop = BitsPerWord;
198 }
199 _type2aelembytes[T_OBJECT] = heapOopSize;
200 _type2aelembytes[T_ARRAY] = heapOopSize;
201 }
202
203
204 // Map BasicType to signature character
205 char type2char_tab[T_CONFLICT+1] = {
206 0, 0, 0, 0,
207 JVM_SIGNATURE_BOOLEAN, JVM_SIGNATURE_CHAR,
208 JVM_SIGNATURE_FLOAT, JVM_SIGNATURE_DOUBLE,
209 JVM_SIGNATURE_BYTE, JVM_SIGNATURE_SHORT,
210 JVM_SIGNATURE_INT, JVM_SIGNATURE_LONG,
211 JVM_SIGNATURE_CLASS, JVM_SIGNATURE_ARRAY,
212 JVM_SIGNATURE_VOID, 0,
213 0, 0, 0, 0
214 };
215
216 // Map BasicType to Java type name
217 const char* type2name_tab[T_CONFLICT+1] = {
218 nullptr, nullptr, nullptr, nullptr,
219 "boolean",
220 "char",
221 "float",
222 "double",
223 "byte",
224 "short",
225 "int",
226 "long",
227 "object",
228 "array",
229 "void",
230 "*address*",
231 "*narrowoop*",
232 "*metadata*",
233 "*narrowklass*",
234 "*conflict*"
235 };
236 const char* type2name(BasicType t) {
237 if (t < ARRAY_SIZE(type2name_tab)) {
238 return type2name_tab[t];
239 } else if (t == T_ILLEGAL) {
240 return "*illegal*";
241 } else {
242 fatal("invalid type %d", t);
243 return "invalid type";
244 }
245 }
246
247
248
249 BasicType name2type(const char* name) {
250 for (int i = T_BOOLEAN; i <= T_VOID; i++) {
251 BasicType t = (BasicType)i;
252 if (type2name_tab[t] != nullptr && 0 == strcmp(type2name_tab[t], name))
253 return t;
254 }
255 return T_ILLEGAL;
256 }
257
258 // Map BasicType to size in words
259 int type2size[T_CONFLICT+1]={ -1, 0, 0, 0, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, -1};
260
261 BasicType type2field[T_CONFLICT+1] = {
262 (BasicType)0, // 0,
263 (BasicType)0, // 1,
264 (BasicType)0, // 2,
265 (BasicType)0, // 3,
266 T_BOOLEAN, // T_BOOLEAN = 4,
267 T_CHAR, // T_CHAR = 5,
268 T_FLOAT, // T_FLOAT = 6,
269 T_DOUBLE, // T_DOUBLE = 7,
270 T_BYTE, // T_BYTE = 8,
271 T_SHORT, // T_SHORT = 9,
272 T_INT, // T_INT = 10,
273 T_LONG, // T_LONG = 11,
274 T_OBJECT, // T_OBJECT = 12,
275 T_OBJECT, // T_ARRAY = 13,
276 T_VOID, // T_VOID = 14,
277 T_ADDRESS, // T_ADDRESS = 15,
278 T_NARROWOOP, // T_NARROWOOP= 16,
279 T_METADATA, // T_METADATA = 17,
280 T_NARROWKLASS, // T_NARROWKLASS = 18,
281 T_CONFLICT // T_CONFLICT = 19,
282 };
283
284
285 BasicType type2wfield[T_CONFLICT+1] = {
286 (BasicType)0, // 0,
287 (BasicType)0, // 1,
288 (BasicType)0, // 2,
289 (BasicType)0, // 3,
290 T_INT, // T_BOOLEAN = 4,
291 T_INT, // T_CHAR = 5,
292 T_FLOAT, // T_FLOAT = 6,
293 T_DOUBLE, // T_DOUBLE = 7,
294 T_INT, // T_BYTE = 8,
295 T_INT, // T_SHORT = 9,
296 T_INT, // T_INT = 10,
297 T_LONG, // T_LONG = 11,
298 T_OBJECT, // T_OBJECT = 12,
299 T_OBJECT, // T_ARRAY = 13,
300 T_VOID, // T_VOID = 14,
301 T_ADDRESS, // T_ADDRESS = 15,
302 T_NARROWOOP, // T_NARROWOOP = 16,
303 T_METADATA, // T_METADATA = 17,
304 T_NARROWKLASS, // T_NARROWKLASS = 18,
305 T_CONFLICT // T_CONFLICT = 19,
306 };
307
308
309 int _type2aelembytes[T_CONFLICT+1] = {
310 0, // 0
311 0, // 1
312 0, // 2
313 0, // 3
314 T_BOOLEAN_aelem_bytes, // T_BOOLEAN = 4,
315 T_CHAR_aelem_bytes, // T_CHAR = 5,
316 T_FLOAT_aelem_bytes, // T_FLOAT = 6,
317 T_DOUBLE_aelem_bytes, // T_DOUBLE = 7,
318 T_BYTE_aelem_bytes, // T_BYTE = 8,
319 T_SHORT_aelem_bytes, // T_SHORT = 9,
320 T_INT_aelem_bytes, // T_INT = 10,
321 T_LONG_aelem_bytes, // T_LONG = 11,
322 T_OBJECT_aelem_bytes, // T_OBJECT = 12,
323 T_ARRAY_aelem_bytes, // T_ARRAY = 13,
324 0, // T_VOID = 14,
325 T_OBJECT_aelem_bytes, // T_ADDRESS = 15,
326 T_NARROWOOP_aelem_bytes, // T_NARROWOOP= 16,
327 T_OBJECT_aelem_bytes, // T_METADATA = 17,
328 T_NARROWKLASS_aelem_bytes, // T_NARROWKLASS= 18,
329 0 // T_CONFLICT = 19,
330 };
331
332 #ifdef ASSERT
333 int type2aelembytes(BasicType t, bool allow_address) {
334 assert((allow_address || t != T_ADDRESS) && t <= T_CONFLICT, "unexpected basic type");
335 return _type2aelembytes[t];
336 }
337 #endif
338
339 // Support for 64-bit integer arithmetic
340
341 // The following code is mostly taken from JVM typedefs_md.h and system_md.c
342
343 static const jlong high_bit = (jlong)1 << (jlong)63;
344 static const jlong other_bits = ~high_bit;
345
346 jlong float2long(jfloat f) {
347 jlong tmp = (jlong) f;
348 if (tmp != high_bit) {
349 return tmp;
350 } else {
351 if (g_isnan((jdouble)f)) {
352 return 0;
353 }
354 if (f < 0) {
355 return high_bit;
356 } else {
357 return other_bits;
358 }
359 }
360 }
361
362
363 jlong double2long(jdouble f) {
364 jlong tmp = (jlong) f;
365 if (tmp != high_bit) {
366 return tmp;
367 } else {
368 if (g_isnan(f)) {
369 return 0;
370 }
371 if (f < 0) {
372 return high_bit;
373 } else {
374 return other_bits;
375 }
376 }
377 }
378
379 // least common multiple
380 size_t lcm(size_t a, size_t b) {
381 size_t cur, div, next;
382
383 cur = MAX2(a, b);
384 div = MIN2(a, b);
385
386 assert(div != 0, "lcm requires positive arguments");
387
388
389 while ((next = cur % div) != 0) {
390 cur = div; div = next;
391 }
392
393
394 julong result = julong(a) * b / div;
395 assert(result <= (size_t)max_uintx, "Integer overflow in lcm");
396
397 return size_t(result);
398 }
399
400
401 // Test that nth_bit macro and friends behave as
402 // expected, even with low-precedence operators.
403
404 STATIC_ASSERT(nth_bit(3) == 0x8);
405 STATIC_ASSERT(nth_bit(1|2) == 0x8);
406
407 STATIC_ASSERT(right_n_bits(3) == 0x7);
408 STATIC_ASSERT(right_n_bits(1|2) == 0x7);
409
410 // Check for Flush-To-Zero mode
411
412 // On some processors faster execution can be achieved by setting a
413 // mode to return zero for extremely small results, rather than an
414 // IEEE-754 subnormal number. This mode is not compatible with the
415 // Java Language Standard.
416
417 // We need the addition of _large_subnormal and _small_subnormal to be
418 // performed at runtime. _small_subnormal is volatile so that
419 // expressions involving it cannot be evaluated at compile time.
420 static const double large_subnormal_double
421 = jdouble_cast(0x0030000000000000); // 0x1.0p-1020;
422 static const volatile double small_subnormal_double
423 = jdouble_cast(0x0000000000000003); // 0x0.0000000000003p-1022;
424
425 // Quickly test to make sure IEEE-754 subnormal numbers are correctly
426 // handled.
427 bool IEEE_subnormal_handling_OK() {
428 // _small_subnormal is the smallest subnormal number that has two
429 // bits set. _large_subnormal is a number such that, when
430 // _small_subnormal is added to it, must be rounded according to the
431 // mode. These two tests detect the rounding mode in use. If
432 // subnormals are turned off (i.e. subnormals-are-zero) flush-to-
433 // zero mode is in use.
434
435 return (large_subnormal_double + small_subnormal_double > large_subnormal_double
436 && -large_subnormal_double - small_subnormal_double < -large_subnormal_double);
437 }