On Mon, 2019-01-28 at 09:31 -0800, Matt Turner wrote: > Use the trick of adding and then subtracting 2**52 (52 is the number > of > explicit mantissa bits a double-precision floating-point value has) > to > implement round-to-even. > > Cuts the number of instructions on SKL of the piglit test > fs-roundEven-double.shader_test from 109 to 21.
Won't this approach only work for "small" values, that is values equal to or smaller than DBL_MAX - 2**52? Once you add 2**52, you'll get infinity, and you can't subtract 2**52 away again without being stuck with infinity, no... _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
