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_SIZES_HPP
26 #define SHARE_VM_UTILITIES_SIZES_HPP
27
28 #include "memory/allocation.hpp"
29 #include "utilities/globalDefinitions.hpp"
30
31 // The following two classes are used to represent 'sizes' and 'offsets' in the VM;
32 // they serve as 'unit' types. ByteSize is used for sizes measured in bytes, while
33 // WordSize is used for sizes measured in machine words (i.e., 32bit or 64bit words
34 // depending on platform).
35 //
36 // The classes are defined with friend functions operating on them instead of member
37 // functions so that they (the classes) can be re-#define'd to int types in optimized
38 // mode. This allows full type checking and maximum safety in debug mode, and full
39 // optimizations (constant folding) and zero overhead (time and space wise) in the
40 // optimized build (some compilers do not optimize one-element value classes but
41 // instead create an object in memory - thus the overhead may be significant).
42 //
43 // Note: 1) DO NOT add new overloaded friend functions that do not have a unique function
44 // function name but require signature types for resolution. This will not work
45 // in optimized mode as both, ByteSize and WordSize are mapped to the same type
46 // and thus the distinction would not be possible anymore (=> compiler errors).
47 //
48 // 2) DO NOT add non-static member functions as they cannot be mapped so something
|
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_SIZES_HPP
26 #define SHARE_VM_UTILITIES_SIZES_HPP
27
28 #include "utilities/globalDefinitions.hpp"
29
30 // The following two classes are used to represent 'sizes' and 'offsets' in the VM;
31 // they serve as 'unit' types. ByteSize is used for sizes measured in bytes, while
32 // WordSize is used for sizes measured in machine words (i.e., 32bit or 64bit words
33 // depending on platform).
34 //
35 // The classes are defined with friend functions operating on them instead of member
36 // functions so that they (the classes) can be re-#define'd to int types in optimized
37 // mode. This allows full type checking and maximum safety in debug mode, and full
38 // optimizations (constant folding) and zero overhead (time and space wise) in the
39 // optimized build (some compilers do not optimize one-element value classes but
40 // instead create an object in memory - thus the overhead may be significant).
41 //
42 // Note: 1) DO NOT add new overloaded friend functions that do not have a unique function
43 // function name but require signature types for resolution. This will not work
44 // in optimized mode as both, ByteSize and WordSize are mapped to the same type
45 // and thus the distinction would not be possible anymore (=> compiler errors).
46 //
47 // 2) DO NOT add non-static member functions as they cannot be mapped so something
|