Am 12.05.2009 20:31, Xueming Shen schrieb:
Ulf Zibis wrote:
Sherman,
thanks for verifying my suggestions.
> (1) simplify the "plane number" byte check by adding a new static
array of cnspToIndex[16] for decoder
or simply:
static final byte[] cnspToIndex = new byte[0x100];
static {
Arrays.fill(cnspToIndex, -1);
cnspToIndex[0xa2] = 1; cnspToIndex[0xa3] = 2;
cnspToIndex[0xa4] = 3;
cnspToIndex[0xa5] = 4; cnspToIndex[0xa6] = 5;
cnspToIndex[0xa7] = 6; cnspToIndex[0xaf] = 7;
}
if ((cnsPlane = cnspToIndex[sa[sp + 1] && 0xff]) < 0)
return CoderResult.malformedForLength(2);
considered that, but ended up thinking it might not really worth the
0x100 bytes:-) at least based on my measurement.
Well, int[16] is even 64 bytes, and loop performance should be more
important here than wasting 196 bytes considering ~227,000 Bytes for the
mapping tables?
*** Question: Why you code:
} else if ((byte1 & MSB) == 0) { // ASCII G0
instead of:
} else if (byte1 >= 0) { // ASCII G0
I believe this line was written 10 years ago, so I have no idea (or
forgot) why we picked this one, my guess is the code might
be a little easier to read with "MSB"...you think the >=0 is better or
faster/
Yes, I think it's also faster, as loading of "MSB" + AND would be saved.
Not sure if HotSpot will detect the shortcut!
