Egor Pasko wrote:
> Ian Rogers wrote:
>> - is it worth specializing the code in Arrays.lessThan to something
>> like (I don't think Jikes RVM can inline compareTo and achieve an
>> equivalent transformation and it saves quite a number of compares):
>>
>> private static boolean lessThan(float float1, float float2) {
>> // Non-zero, non-NaN checking.
>> if (float2 > float1) {
>> return true;
>> }
>> if (float1 >= float2 && 0.0f != float1) {
>> return false;
>> }
For correctness, this got committed as
+ if (float1 >= float2 && (0.0f != float1 || 0.0f != float2)) {
+ return false;
+ }
The problem is that if you pass in float1 or float2 == +/-0.0 (which
Roger is apparently doing regularly) then it will fall through to the
slow rawintbits computation.
>> // NaNs are equal to other NaNs and larger than any other float
>> if (isNaN(float1)) {
>> return false;
>> } else if (isNaN(float2)) {
>> return true;
>> }
>> // Deal with +0.0 and -0.0
>> int f1 = floatToRawIntBits(float1);
>> int f2 = floatToRawIntBits(float2);
>> return f1 < f2;
>> }
I think it would be better to separate out the > and == tests, i.e.:
- if (float1 >= float2 && (0.0f != float1 || 0.0f != float2)) {
+ if (float1 > float2) {
return false;
}
+ if (float1 == float2 && 0.0f != float1) {
+ return false;
+ }
WDYT?
Regards,
Tim
