On Fri, 8 Jul 2022 06:11:22 GMT, Joe Darcy <da...@openjdk.org> wrote:
> Initial implementation.
src/java.base/share/classes/java/lang/Float.java line 1003:
> 1001: float abs_f = Math.abs(f);
> 1002: int doppel = Float.floatToRawIntBits(f);
> 1003: int f_sign = 0x8000_0000 & doppel;
The code would be a bit less branchy if sign were computed like this:
short sign_bit = (short)((doppel >> 16) & 0x8000);
and get rid of `f_sign`; instead of conditionals in various places use bitwise
or of `sign_bit`, such as:
if (abs_f > 65504.0f ) {
return (short)(sign_bit | 0x7c00); // Positive or negative infinity
}
I'm mainly looking forward to what the JIT produces, but I also think handling
the sign in this way makes the code at least as easy to understand as the
current branch-based exposition.
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PR: https://git.openjdk.org/jdk/pull/9422
