1 /*
  2  * Copyright (c) 1997, 2021, 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 DumpSharedSpaces;
 44 bool DynamicDumpSharedSpaces;
 45 bool RequireSharedSpaces;
 46 extern "C" {
 47 JNIEXPORT jboolean UseSharedSpaces = true;
 48 }
 49 
 50 // Object alignment, in units of HeapWords.
 51 // Defaults are -1 so things will break badly if incorrectly initialized.
 52 int MinObjAlignment            = -1;
 53 int MinObjAlignmentInBytes     = -1;
 54 int MinObjAlignmentInBytesMask = 0;
 55 
 56 int LogMinObjAlignment         = -1;
 57 int LogMinObjAlignmentInBytes  = -1;
 58 
 59 // Oop encoding heap max
 60 uint64_t OopEncodingHeapMax = 0;
 61 
 62 // Something to help porters sleep at night
 63 
 64 #ifdef ASSERT
 65 BasicType char2type(int ch) {
 66   switch (ch) {
 67 #define EACH_SIG(ch, bt, ignore) \
 68     case ch: return bt;
 69     SIGNATURE_TYPES_DO(EACH_SIG, ignore)
 70 #undef EACH_SIG
 71   }
 72   return T_ILLEGAL;
 73 }
 74 
 75 extern bool signature_constants_sane();
 76 #endif //ASSERT
 77 
 78 void basic_types_init() {
 79 #ifdef ASSERT
 80 #ifdef _LP64
 81   assert(min_intx ==  (intx)CONST64(0x8000000000000000), "correct constant");
 82   assert(max_intx ==  CONST64(0x7FFFFFFFFFFFFFFF), "correct constant");
 83   assert(max_uintx == CONST64(0xFFFFFFFFFFFFFFFF), "correct constant");
 84   assert( 8 == sizeof( intx),      "wrong size for basic type");
 85   assert( 8 == sizeof( jobject),   "wrong size for basic type");
 86 #else
 87   assert(min_intx ==  (intx)0x80000000,  "correct constant");
 88   assert(max_intx ==  0x7FFFFFFF,  "correct constant");
 89   assert(max_uintx == 0xFFFFFFFF,  "correct constant");
 90   assert( 4 == sizeof( intx),      "wrong size for basic type");
 91   assert( 4 == sizeof( jobject),   "wrong size for basic type");
 92 #endif
 93   assert( (~max_juint) == 0,  "max_juint has all its bits");
 94   assert( (~max_uintx) == 0,  "max_uintx has all its bits");
 95   assert( (~max_julong) == 0, "max_julong has all its bits");
 96   assert( 1 == sizeof( jbyte),     "wrong size for basic type");
 97   assert( 2 == sizeof( jchar),     "wrong size for basic type");
 98   assert( 2 == sizeof( jshort),    "wrong size for basic type");
 99   assert( 4 == sizeof( juint),     "wrong size for basic type");
100   assert( 4 == sizeof( jint),      "wrong size for basic type");
101   assert( 1 == sizeof( jboolean),  "wrong size for basic type");
102   assert( 8 == sizeof( jlong),     "wrong size for basic type");
103   assert( 4 == sizeof( jfloat),    "wrong size for basic type");
104   assert( 8 == sizeof( jdouble),   "wrong size for basic type");
105   assert( 1 == sizeof( u1),        "wrong size for basic type");
106   assert( 2 == sizeof( u2),        "wrong size for basic type");
107   assert( 4 == sizeof( u4),        "wrong size for basic type");
108   assert(wordSize == BytesPerWord, "should be the same since they're used interchangeably");
109   assert(wordSize == HeapWordSize, "should be the same since they're also used interchangeably");
110 
111   assert(signature_constants_sane(), "");
112 
113   int num_type_chars = 0;
114   for (int i = 0; i < 99; i++) {
115     if (type2char((BasicType)i) != 0) {
116       assert(char2type(type2char((BasicType)i)) == i, "proper inverses");
117       assert(Signature::basic_type(type2char((BasicType)i)) == i, "proper inverses");
118       num_type_chars++;
119     }
120   }
121   assert(num_type_chars == 12, "must have tested the right number of mappings");
122   assert(char2type(0) == T_ILLEGAL, "correct illegality");
123 
124   {
125     for (int i = T_BOOLEAN; i <= T_CONFLICT; i++) {
126       BasicType vt = (BasicType)i;
127       BasicType ft = type2field[vt];
128       switch (vt) {
129       // the following types might plausibly show up in memory layouts:
130       case T_BOOLEAN:
131       case T_BYTE:
132       case T_CHAR:
133       case T_SHORT:
134       case T_INT:
135       case T_FLOAT:
136       case T_DOUBLE:
137       case T_LONG:
138       case T_OBJECT:
139       case T_PRIMITIVE_OBJECT:
140       case T_ADDRESS:     // random raw pointer
141       case T_METADATA:    // metadata pointer
142       case T_NARROWOOP:   // compressed pointer
143       case T_NARROWKLASS: // compressed klass pointer
144       case T_CONFLICT:    // might as well support a bottom type
145       case T_VOID:        // padding or other unaddressed word
146         // layout type must map to itself
147         assert(vt == ft, "");
148         break;
149       default:
150         // non-layout type must map to a (different) layout type
151         assert(vt != ft, "");
152         assert(ft == type2field[ft], "");
153       }
154       // every type must map to same-sized layout type:
155       assert(type2size[vt] == type2size[ft], "");
156     }
157   }
158   // These are assumed, e.g., when filling HeapWords with juints.
159   assert(is_power_of_2(sizeof(juint)), "juint must be power of 2");
160   assert(is_power_of_2(HeapWordSize), "HeapWordSize must be power of 2");
161   assert((size_t)HeapWordSize >= sizeof(juint),
162          "HeapWord should be at least as large as juint");
163   assert(sizeof(NULL) == sizeof(char*), "NULL must be same size as pointer");
164 #endif
165 
166   if( JavaPriority1_To_OSPriority != -1 )
167     os::java_to_os_priority[1] = JavaPriority1_To_OSPriority;
168   if( JavaPriority2_To_OSPriority != -1 )
169     os::java_to_os_priority[2] = JavaPriority2_To_OSPriority;
170   if( JavaPriority3_To_OSPriority != -1 )
171     os::java_to_os_priority[3] = JavaPriority3_To_OSPriority;
172   if( JavaPriority4_To_OSPriority != -1 )
173     os::java_to_os_priority[4] = JavaPriority4_To_OSPriority;
174   if( JavaPriority5_To_OSPriority != -1 )
175     os::java_to_os_priority[5] = JavaPriority5_To_OSPriority;
176   if( JavaPriority6_To_OSPriority != -1 )
177     os::java_to_os_priority[6] = JavaPriority6_To_OSPriority;
178   if( JavaPriority7_To_OSPriority != -1 )
179     os::java_to_os_priority[7] = JavaPriority7_To_OSPriority;
180   if( JavaPriority8_To_OSPriority != -1 )
181     os::java_to_os_priority[8] = JavaPriority8_To_OSPriority;
182   if( JavaPriority9_To_OSPriority != -1 )
183     os::java_to_os_priority[9] = JavaPriority9_To_OSPriority;
184   if(JavaPriority10_To_OSPriority != -1 )
185     os::java_to_os_priority[10] = JavaPriority10_To_OSPriority;
186 
187   // Set the size of basic types here (after argument parsing but before
188   // stub generation).
189   if (UseCompressedOops) {
190     // Size info for oops within java objects is fixed
191     heapOopSize        = jintSize;
192     LogBytesPerHeapOop = LogBytesPerInt;
193     LogBitsPerHeapOop  = LogBitsPerInt;
194     BytesPerHeapOop    = BytesPerInt;
195     BitsPerHeapOop     = BitsPerInt;
196   } else {
197     heapOopSize        = oopSize;
198     LogBytesPerHeapOop = LogBytesPerWord;
199     LogBitsPerHeapOop  = LogBitsPerWord;
200     BytesPerHeapOop    = BytesPerWord;
201     BitsPerHeapOop     = BitsPerWord;
202   }
203   _type2aelembytes[T_OBJECT] = heapOopSize;
204   _type2aelembytes[T_ARRAY]  = heapOopSize;
205   _type2aelembytes[T_PRIMITIVE_OBJECT]  = heapOopSize;
206 }
207 
208 
209 // Map BasicType to signature character
210 char type2char_tab[T_CONFLICT+1] = {
211   0, 0, 0, 0,
212   JVM_SIGNATURE_BOOLEAN, JVM_SIGNATURE_CHAR,
213   JVM_SIGNATURE_FLOAT,   JVM_SIGNATURE_DOUBLE,
214   JVM_SIGNATURE_BYTE,    JVM_SIGNATURE_SHORT,
215   JVM_SIGNATURE_INT,     JVM_SIGNATURE_LONG,
216   JVM_SIGNATURE_CLASS,   JVM_SIGNATURE_ARRAY,
217   JVM_SIGNATURE_PRIMITIVE_OBJECT, JVM_SIGNATURE_VOID,
218   0, 0, 0, 0, 0
219 };
220 
221 // Map BasicType to Java type name
222 const char* type2name_tab[T_CONFLICT+1] = {
223   NULL, NULL, NULL, NULL,
224   "boolean",
225   "char",
226   "float",
227   "double",
228   "byte",
229   "short",
230   "int",
231   "long",
232   "object",
233   "array",
234   "inline_type",
235   "void",
236   "*address*",
237   "*narrowoop*",
238   "*metadata*",
239   "*narrowklass*",
240   "*conflict*"
241 };
242 
243 
244 BasicType name2type(const char* name) {
245   for (int i = T_BOOLEAN; i <= T_VOID; i++) {
246     BasicType t = (BasicType)i;
247     if (type2name_tab[t] != NULL && 0 == strcmp(type2name_tab[t], name))
248       return t;
249   }
250   return T_ILLEGAL;
251 }
252 
253 // Map BasicType to size in words
254 int type2size[T_CONFLICT+1]={ -1, 0, 0, 0, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 0, 1, 1, 1, 1, -1};
255 
256 BasicType type2field[T_CONFLICT+1] = {
257   (BasicType)0,            // 0,
258   (BasicType)0,            // 1,
259   (BasicType)0,            // 2,
260   (BasicType)0,            // 3,
261   T_BOOLEAN,               // T_BOOLEAN  =  4,
262   T_CHAR,                  // T_CHAR     =  5,
263   T_FLOAT,                 // T_FLOAT    =  6,
264   T_DOUBLE,                // T_DOUBLE   =  7,
265   T_BYTE,                  // T_BYTE     =  8,
266   T_SHORT,                 // T_SHORT    =  9,
267   T_INT,                   // T_INT      = 10,
268   T_LONG,                  // T_LONG     = 11,
269   T_OBJECT,                // T_OBJECT   = 12,
270   T_OBJECT,                // T_ARRAY    = 13,
271   T_PRIMITIVE_OBJECT,      // T_PRIMITIVE_OBJECT = 14,
272   T_VOID,                  // T_VOID     = 15,
273   T_ADDRESS,               // T_ADDRESS  = 16,
274   T_NARROWOOP,             // T_NARROWOOP= 17,
275   T_METADATA,              // T_METADATA = 18,
276   T_NARROWKLASS,           // T_NARROWKLASS = 19,
277   T_CONFLICT               // T_CONFLICT = 20
278 };
279 
280 
281 BasicType type2wfield[T_CONFLICT+1] = {
282   (BasicType)0,            // 0,
283   (BasicType)0,            // 1,
284   (BasicType)0,            // 2,
285   (BasicType)0,            // 3,
286   T_INT,     // T_BOOLEAN  =  4,
287   T_INT,     // T_CHAR     =  5,
288   T_FLOAT,   // T_FLOAT    =  6,
289   T_DOUBLE,  // T_DOUBLE   =  7,
290   T_INT,     // T_BYTE     =  8,
291   T_INT,     // T_SHORT    =  9,
292   T_INT,     // T_INT      = 10,
293   T_LONG,    // T_LONG     = 11,
294   T_OBJECT,  // T_OBJECT   = 12,
295   T_OBJECT,  // T_ARRAY    = 13,
296   T_OBJECT,  // T_PRIMITIVE_OBJECT = 14,
297   T_VOID,    // T_VOID     = 15,
298   T_ADDRESS, // T_ADDRESS  = 16,
299   T_NARROWOOP, // T_NARROWOOP  = 17,
300   T_METADATA,  // T_METADATA   = 18,
301   T_NARROWKLASS, // T_NARROWKLASS  = 19,
302   T_CONFLICT // T_CONFLICT = 20
303 };
304 
305 
306 int _type2aelembytes[T_CONFLICT+1] = {
307   0,                         // 0
308   0,                         // 1
309   0,                         // 2
310   0,                         // 3
311   T_BOOLEAN_aelem_bytes,     // T_BOOLEAN  =  4,
312   T_CHAR_aelem_bytes,        // T_CHAR     =  5,
313   T_FLOAT_aelem_bytes,       // T_FLOAT    =  6,
314   T_DOUBLE_aelem_bytes,      // T_DOUBLE   =  7,
315   T_BYTE_aelem_bytes,        // T_BYTE     =  8,
316   T_SHORT_aelem_bytes,       // T_SHORT    =  9,
317   T_INT_aelem_bytes,         // T_INT      = 10,
318   T_LONG_aelem_bytes,        // T_LONG     = 11,
319   T_OBJECT_aelem_bytes,      // T_OBJECT   = 12,
320   T_ARRAY_aelem_bytes,       // T_ARRAY    = 13,
321   T_PRIMITIVE_OBJECT_aelem_bytes, // T_PRIMITIVE_OBJECT = 14,
322   0,                         // T_VOID     = 15,
323   T_OBJECT_aelem_bytes,      // T_ADDRESS  = 16,
324   T_NARROWOOP_aelem_bytes,   // T_NARROWOOP= 17,
325   T_OBJECT_aelem_bytes,      // T_METADATA = 18,
326   T_NARROWKLASS_aelem_bytes, // T_NARROWKLASS= 19,
327   0                          // T_CONFLICT = 20
328 };
329 
330 #ifdef ASSERT
331 int type2aelembytes(BasicType t, bool allow_address) {
332   assert(allow_address || t != T_ADDRESS, " ");
333   return _type2aelembytes[t];
334 }
335 #endif
336 
337 // Support for 64-bit integer arithmetic
338 
339 // The following code is mostly taken from JVM typedefs_md.h and system_md.c
340 
341 static const jlong high_bit   = (jlong)1 << (jlong)63;
342 static const jlong other_bits = ~high_bit;
343 
344 jlong float2long(jfloat f) {
345   jlong tmp = (jlong) f;
346   if (tmp != high_bit) {
347     return tmp;
348   } else {
349     if (g_isnan((jdouble)f)) {
350       return 0;
351     }
352     if (f < 0) {
353       return high_bit;
354     } else {
355       return other_bits;
356     }
357   }
358 }
359 
360 
361 jlong double2long(jdouble f) {
362   jlong tmp = (jlong) f;
363   if (tmp != high_bit) {
364     return tmp;
365   } else {
366     if (g_isnan(f)) {
367       return 0;
368     }
369     if (f < 0) {
370       return high_bit;
371     } else {
372       return other_bits;
373     }
374   }
375 }
376 
377 // least common multiple
378 size_t lcm(size_t a, size_t b) {
379     size_t cur, div, next;
380 
381     cur = MAX2(a, b);
382     div = MIN2(a, b);
383 
384     assert(div != 0, "lcm requires positive arguments");
385 
386 
387     while ((next = cur % div) != 0) {
388         cur = div; div = next;
389     }
390 
391 
392     julong result = julong(a) * b / div;
393     assert(result <= (size_t)max_uintx, "Integer overflow in lcm");
394 
395     return size_t(result);
396 }
397 
398 
399 // Test that nth_bit macro and friends behave as
400 // expected, even with low-precedence operators.
401 
402 STATIC_ASSERT(nth_bit(3)   == 0x8);
403 STATIC_ASSERT(nth_bit(1|2) == 0x8);
404 
405 STATIC_ASSERT(right_n_bits(3)   == 0x7);
406 STATIC_ASSERT(right_n_bits(1|2) == 0x7);
--- EOF ---