About jChecs
Design
Miscellaneous
Miscellaneous
Optimization
Some J2SE 6 benchmarks done during jChecs development.
Measures taken with Sun JVM 6 (beta 104) under Linux, no option.
Results are given comparatively to the reference (bold) in each serie : the biggest number is the better.
Loops
| for (forward) | 100% |
| for (backward) | 100% |
| while (forward) | 75% |
| while (backward) | 100% |
Variables
| Static | 100% |
| Instance | 128% |
| Local | 131% |
Autoboxing
| int / new Integer(int).intValue() | 100% |
| int / Integer.valueOf(int).intValue() | 95% |
| int / Integer (Autoboxing) | 94% |
| int / int | 5,688% |
Allocation of arrays
| Array of objects | |
|---|---|
| Integer[64][64] | 100% |
| Integer[64*64] | 145% |
| Integer[32*64] | 289% |
| Integer[0] | 121,132% |
| Array of primitives | |
| int[64][64] | 104% |
| int[64*64] | 144% |
| int[32*64] | 291% |
| int[0] | 121,257% |
Copy of arrays
| Arrays of objects | |
|---|---|
| System.arraycopy(Integer) | 100% |
| Arrays.copyOf(Integer) | 99% |
| for (Integer, forward) | 49% |
| for (Integer, backward) | 37% |
| Arrays of primitives | |
| System.arraycopy(int) | 100% |
| Arrays.copyOf(int) | 100% |
| for (int, forward) | 95% |
| for (int, backward) | 91% |
Iterating over items
| ArrayList of objects | ||
|---|---|---|
| for on Enumeration (Java 1.0) | 100% | |
| while on Enumeration (Java 1.0) | 100% | |
| for on Iterator (Java 1.2) | 132% | |
| while on Iterator (Java 1.2) | 133% | |
| Extended for (J2SE 5.0) | 121% | |
| Direct access (get, forward) | 205% | |
| Direct access (get, backward) | 163% | |
| Vector of objects | ||
| for on Enumeration (Java 1.0) | 218% | |
| while on Enumeration (Java 1.0) | 218% | |
| for on Iterator (Java 1.2) | 161% | |
| while on Iterator (Java 1.2) | 161% | |
| Extended for (J2SE 5.0) | 160% | |
| Direct access (get, forward) | 208% | |
| Direct acces (get, backward) | 167% | |
| Array of objects | ||
| Extended for (J2SE 5.0) | 403% | |
| Direct access (get, forward) | 391% | |
| Direct acces (get, backward) | 313% | |
| Array of primitives | ||
| Extended for (J2SE 5.0) | 1,325% | |
| Direct access (get, forward) | 1,211% | |
| Direct access (get, backward) | 960% | |
Concatenation of strings
| Variables strings | |
|---|---|
| String | 100% |
| StringBuffer | 109% |
| StringBuilder | 111% |
| Constants strings | |
| String | 381% |
| StringBuffer | 220% |
| StringBuilder | 223% |
Generics
| Reading | |
|---|---|
| Integer = List<Integer> | 100% |
| Integer = List<Object> | 97% |
| Integer = List<? super Number> | 95% |
| Object = List<Integer> | 112% |
| Object = List<Object> | 119% |
| Object = List<? super Number> | 113% |
| Writing | |
| List<Integer> = Integer | 93% |
| List<Object> = Integer | 94% |
| List<? super Number> = Integer | 94% |
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