aco: remove pack_half_2x16(a, 0) optimization
This makes the compiler less predictable and should only have a very small effect on performance. fossil-db (Vega): Totals from 2410 (1.79% of 134756) affected shaders: CodeSize: 6911568 -> 6942840 (+0.45%) Fixes Horizon Zero Dawn artifacts. If a shader has: a = pack_half_2x16(a, 0) //rtne store(pack_half_2x16(0, b) | a) //rtne a = unpack_2x16(a).x It will become: store(pack_half_2x16(a, b)) //rtz a = unpack_2x16(pack_half_2x16(a, 0)).x //rtne So a later shader with "unpack_2x16(load()).x" will use "a" rounded to zero, while the previous shader will use "a" rounded to the nearest even. Signed-off-by:Rhys Perry <pendingchaos02@gmail.com> Reviewed-by:
Daniel Schürmann <daniel@schuermann.dev> Fixes: 2f125908 ("radv,aco: lower_pack_half_2x16") Part-of: <mesa/mesa!14475> (cherry picked from commit 60c71183)