On Thu, 8 Jul 2021 00:38:45 GMT, Joe Darcy <[email protected]> wrote:
>> Please consider this change to make the `float` and `double` versions of
>> `java.lang.Math.abs()` branch-free.
>
> src/java.base/share/classes/java/lang/Math.java line 1530:
>
>> 1528: @IntrinsicCandidate
>> 1529: public static float abs(float a) {
>> 1530: return Float.intBitsToFloat(Float.floatToRawIntBits(a) &
>> 0x7fffffff);
>
> I'd like to see a brief comment on these methods along the lines of "zero out
> sign bit in the representation." Using underscores in the literal to better
> group the digits or using the constants in jdk.internal.math.DoubleConsts.
There is no specific constant in `{Float,Double}Consts` to mask all but the
sign bit, but I had thought it might be good to add one there.
-------------
PR: https://git.openjdk.java.net/jdk/pull/4711
