1 /*
   2  * Copyright (c) 2003, 2018, 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_VM_UTILITIES_COPY_HPP
  26 #define SHARE_VM_UTILITIES_COPY_HPP
  27 
  28 #include "runtime/stubRoutines.hpp"
  29 
  30 // Assembly code for platforms that need it.
  31 extern "C" {
  32   void _Copy_conjoint_words(HeapWord* from, HeapWord* to, size_t count);
  33   void _Copy_disjoint_words(HeapWord* from, HeapWord* to, size_t count);
  34 
  35   void _Copy_conjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);
  36   void _Copy_disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);
  37 
  38   void _Copy_aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count);
  39   void _Copy_aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count);
  40 
  41   void _Copy_conjoint_bytes(void* from, void* to, size_t count);
  42 
  43   void _Copy_conjoint_bytes_atomic  (void*   from, void*   to, size_t count);
  44   void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count);
  45   void _Copy_conjoint_jints_atomic  (jint*   from, jint*   to, size_t count);
  46   void _Copy_conjoint_jlongs_atomic (jlong*  from, jlong*  to, size_t count);
  47   void _Copy_conjoint_oops_atomic   (oop*    from, oop*    to, size_t count);
  48 
  49   void _Copy_arrayof_conjoint_bytes  (HeapWord* from, HeapWord* to, size_t count);
  50   void _Copy_arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count);
  51   void _Copy_arrayof_conjoint_jints  (HeapWord* from, HeapWord* to, size_t count);
  52   void _Copy_arrayof_conjoint_jlongs (HeapWord* from, HeapWord* to, size_t count);
  53   void _Copy_arrayof_conjoint_oops   (HeapWord* from, HeapWord* to, size_t count);
  54 }
  55 
  56 class Copy : AllStatic {
  57  public:
  58   // Block copy methods have four attributes.  We don't define all possibilities.
  59   //   alignment: aligned to BytesPerLong
  60   //   arrayof:   arraycopy operation with both operands aligned on the same
  61   //              boundary as the first element of an array of the copy unit.
  62   //              This is currently a HeapWord boundary on all platforms, except
  63   //              for long and double arrays, which are aligned on an 8-byte
  64   //              boundary on all platforms.
  65   //              arraycopy operations are implicitly atomic on each array element.
  66   //   overlap:   disjoint or conjoint.
  67   //   copy unit: bytes or words (i.e., HeapWords) or oops (i.e., pointers).
  68   //   atomicity: atomic or non-atomic on the copy unit.
  69   //
  70   // Names are constructed thusly:
  71   //
  72   //     [ 'aligned_' | 'arrayof_' ]
  73   //     ('conjoint_' | 'disjoint_')
  74   //     ('words' | 'bytes' | 'jshorts' | 'jints' | 'jlongs' | 'oops')
  75   //     [ '_atomic' ]
  76   //
  77   // Except in the arrayof case, whatever the alignment is, we assume we can copy
  78   // whole alignment units.  E.g., if BytesPerLong is 2x word alignment, an odd
  79   // count may copy an extra word.  In the arrayof case, we are allowed to copy
  80   // only the number of copy units specified.
  81   //
  82   // All callees check count for 0.
  83   //
  84 
  85   // HeapWords
  86 
  87   // Word-aligned words,    conjoint, not atomic on each word
  88   static void conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
  89     assert_params_ok(from, to, LogHeapWordSize);
  90     pd_conjoint_words(from, to, count);
  91   }
  92 
  93   // Word-aligned words,    disjoint, not atomic on each word
  94   static void disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
  95     assert_params_ok(from, to, LogHeapWordSize);
  96     assert_disjoint(from, to, count);
  97     pd_disjoint_words(from, to, count);
  98   }
  99 
 100   // Word-aligned words,    disjoint, atomic on each word
 101   static void disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count) {
 102     assert_params_ok(from, to, LogHeapWordSize);
 103     assert_disjoint(from, to, count);
 104     pd_disjoint_words_atomic(from, to, count);
 105   }
 106 
 107   // Object-aligned words,  conjoint, not atomic on each word
 108   static void aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
 109     assert_params_aligned(from, to);
 110     pd_aligned_conjoint_words(from, to, count);
 111   }
 112 
 113   // Object-aligned words,  disjoint, not atomic on each word
 114   static void aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
 115     assert_params_aligned(from, to);
 116     assert_disjoint(from, to, count);
 117     pd_aligned_disjoint_words(from, to, count);
 118   }
 119 
 120   // bytes, jshorts, jints, jlongs, oops
 121 
 122   // bytes,                 conjoint, not atomic on each byte (not that it matters)
 123   static void conjoint_jbytes(void* from, void* to, size_t count) {
 124     pd_conjoint_bytes(from, to, count);
 125   }
 126 
 127   // bytes,                 conjoint, atomic on each byte (not that it matters)
 128   static void conjoint_jbytes_atomic(void* from, void* to, size_t count) {
 129     pd_conjoint_bytes(from, to, count);
 130   }
 131 
 132   // jshorts,               conjoint, atomic on each jshort
 133   static void conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
 134     assert_params_ok(from, to, LogBytesPerShort);
 135     pd_conjoint_jshorts_atomic(from, to, count);
 136   }
 137 
 138   // jints,                 conjoint, atomic on each jint
 139   static void conjoint_jints_atomic(jint* from, jint* to, size_t count) {
 140     assert_params_ok(from, to, LogBytesPerInt);
 141     pd_conjoint_jints_atomic(from, to, count);
 142   }
 143 
 144   // jlongs,                conjoint, atomic on each jlong
 145   static void conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
 146     assert_params_ok(from, to, LogBytesPerLong);
 147     pd_conjoint_jlongs_atomic(from, to, count);
 148   }
 149 
 150   // oops,                  conjoint, atomic on each oop
 151   static void conjoint_oops_atomic(oop* from, oop* to, size_t count) {
 152     assert_params_ok(from, to, LogBytesPerHeapOop);
 153     pd_conjoint_oops_atomic(from, to, count);
 154   }
 155 
 156   // overloaded for UseCompressedOops
 157   static void conjoint_oops_atomic(narrowOop* from, narrowOop* to, size_t count) {
 158     assert(sizeof(narrowOop) == sizeof(jint), "this cast is wrong");
 159     assert_params_ok(from, to, LogBytesPerInt);
 160     pd_conjoint_jints_atomic((jint*)from, (jint*)to, count);
 161   }
 162 
 163   // Copy a span of memory.  If the span is an integral number of aligned
 164   // longs, words, or ints, copy those units atomically.
 165   // The largest atomic transfer unit is 8 bytes, or the largest power
 166   // of two which divides all of from, to, and size, whichever is smaller.
 167   static void conjoint_memory_atomic(void* from, void* to, size_t size);
 168 
 169   // bytes,                 conjoint array, atomic on each byte (not that it matters)
 170   static void arrayof_conjoint_jbytes(HeapWord* from, HeapWord* to, size_t count) {
 171     pd_arrayof_conjoint_bytes(from, to, count);
 172   }
 173 
 174   // jshorts,               conjoint array, atomic on each jshort
 175   static void arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count) {
 176     assert_params_ok(from, to, LogBytesPerShort);
 177     pd_arrayof_conjoint_jshorts(from, to, count);
 178   }
 179 
 180   // jints,                 conjoint array, atomic on each jint
 181   static void arrayof_conjoint_jints(HeapWord* from, HeapWord* to, size_t count) {
 182     assert_params_ok(from, to, LogBytesPerInt);
 183     pd_arrayof_conjoint_jints(from, to, count);
 184   }
 185 
 186   // jlongs,                conjoint array, atomic on each jlong
 187   static void arrayof_conjoint_jlongs(HeapWord* from, HeapWord* to, size_t count) {
 188     assert_params_ok(from, to, LogBytesPerLong);
 189     pd_arrayof_conjoint_jlongs(from, to, count);
 190   }
 191 
 192   // oops,                  conjoint array, atomic on each oop
 193   static void arrayof_conjoint_oops(HeapWord* from, HeapWord* to, size_t count) {
 194     assert_params_ok(from, to, LogBytesPerHeapOop);
 195     pd_arrayof_conjoint_oops(from, to, count);
 196   }
 197 
 198   // Known overlap methods
 199 
 200   // Copy word-aligned words from higher to lower addresses, not atomic on each word
 201   inline static void conjoint_words_to_lower(HeapWord* from, HeapWord* to, size_t byte_count) {
 202     // byte_count is in bytes to check its alignment
 203     assert_params_ok(from, to, LogHeapWordSize);
 204     assert_byte_count_ok(byte_count, HeapWordSize);
 205 
 206     size_t count = (size_t)round_to(byte_count, HeapWordSize) >> LogHeapWordSize;
 207     assert(to <= from || from + count <= to, "do not overwrite source data");
 208 
 209     while (count-- > 0) {
 210       *to++ = *from++;
 211     }
 212   }
 213 
 214   // Copy word-aligned words from lower to higher addresses, not atomic on each word
 215   inline static void conjoint_words_to_higher(HeapWord* from, HeapWord* to, size_t byte_count) {
 216     // byte_count is in bytes to check its alignment
 217     assert_params_ok(from, to, LogHeapWordSize);
 218     assert_byte_count_ok(byte_count, HeapWordSize);
 219 
 220     size_t count = (size_t)round_to(byte_count, HeapWordSize) >> LogHeapWordSize;
 221     assert(from <= to || to + count <= from, "do not overwrite source data");
 222 
 223     from += count - 1;
 224     to   += count - 1;
 225     while (count-- > 0) {
 226       *to-- = *from--;
 227     }
 228   }
 229 
 230   /**
 231    * Copy and *unconditionally* byte swap elements
 232    *
 233    * @param src address of source
 234    * @param dst address of destination
 235    * @param byte_count number of bytes to copy
 236    * @param elem_size size of the elements to copy-swap
 237    */
 238   static void conjoint_swap(address src, address dst, size_t byte_count, size_t elem_size);
 239 
 240   // Fill methods
 241 
 242   // Fill word-aligned words, not atomic on each word
 243   // set_words
 244   static void fill_to_words(HeapWord* to, size_t count, juint value = 0) {
 245     assert_params_ok(to, LogHeapWordSize);
 246     pd_fill_to_words(to, count, value);
 247   }
 248 
 249   static void fill_to_aligned_words(HeapWord* to, size_t count, juint value = 0) {
 250     assert_params_aligned(to);
 251     pd_fill_to_aligned_words(to, count, value);
 252   }
 253 
 254   // Fill bytes
 255   static void fill_to_bytes(void* to, size_t count, jubyte value = 0) {
 256     pd_fill_to_bytes(to, count, value);
 257   }
 258 
 259   // Fill a span of memory.  If the span is an integral number of aligned
 260   // longs, words, or ints, store to those units atomically.
 261   // The largest atomic transfer unit is 8 bytes, or the largest power
 262   // of two which divides both to and size, whichever is smaller.
 263   static void fill_to_memory_atomic(void* to, size_t size, jubyte value = 0);
 264 
 265   // Zero-fill methods
 266 
 267   // Zero word-aligned words, not atomic on each word
 268   static void zero_to_words(HeapWord* to, size_t count) {
 269     assert_params_ok(to, LogHeapWordSize);
 270     pd_zero_to_words(to, count);
 271   }
 272 
 273   // Zero bytes
 274   static void zero_to_bytes(void* to, size_t count) {
 275     pd_zero_to_bytes(to, count);
 276   }
 277 
 278  private:
 279   static bool params_disjoint(HeapWord* from, HeapWord* to, size_t count) {
 280     if (from < to) {
 281       return pointer_delta(to, from) >= count;
 282     }
 283     return pointer_delta(from, to) >= count;
 284   }
 285 
 286   // These methods raise a fatal if they detect a problem.
 287 
 288   static void assert_disjoint(HeapWord* from, HeapWord* to, size_t count) {
 289 #ifdef ASSERT
 290     if (!params_disjoint(from, to, count))
 291       basic_fatal("source and dest overlap");
 292 #endif
 293   }
 294 
 295   static void assert_params_ok(void* from, void* to, intptr_t log_align) {
 296 #ifdef ASSERT
 297     if (mask_bits((uintptr_t)from, right_n_bits(log_align)) != 0)
 298       basic_fatal("not aligned");
 299     if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)
 300       basic_fatal("not aligned");
 301 #endif
 302   }
 303 
 304   static void assert_params_ok(HeapWord* to, intptr_t log_align) {
 305 #ifdef ASSERT
 306     if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)
 307       basic_fatal("not word aligned");
 308 #endif
 309   }
 310   static void assert_params_aligned(HeapWord* from, HeapWord* to) {
 311 #ifdef ASSERT
 312     if (mask_bits((uintptr_t)from, BytesPerLong-1) != 0)
 313       basic_fatal("not long aligned");
 314     if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)
 315       basic_fatal("not long aligned");
 316 #endif
 317   }
 318 
 319   static void assert_params_aligned(HeapWord* to) {
 320 #ifdef ASSERT
 321     if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)
 322       basic_fatal("not long aligned");
 323 #endif
 324   }
 325 
 326   static void assert_byte_count_ok(size_t byte_count, size_t unit_size) {
 327 #ifdef ASSERT
 328     if ((size_t)round_to(byte_count, unit_size) != byte_count) {
 329       basic_fatal("byte count must be aligned");
 330     }
 331 #endif
 332   }
 333 
 334   // Platform dependent implementations of the above methods.
 335 #ifdef TARGET_ARCH_x86
 336 # include "copy_x86.hpp"
 337 #endif
 338 #ifdef TARGET_ARCH_aarch64
 339 # include "copy_aarch64.hpp"
 340 #endif
 341 #ifdef TARGET_ARCH_sparc
 342 # include "copy_sparc.hpp"
 343 #endif
 344 #ifdef TARGET_ARCH_zero
 345 # include "copy_zero.hpp"
 346 #endif
 347 #ifdef TARGET_ARCH_arm
 348 # include "copy_arm.hpp"
 349 #endif
 350 #ifdef TARGET_ARCH_ppc
 351 # include "copy_ppc.hpp"
 352 #endif
 353 
 354 };
 355 
 356 #endif // SHARE_VM_UTILITIES_COPY_HPP