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| author | Kenneth Graunke <kenneth@whitecape.org> | 2014-01-05 22:57:01 -0800 |
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| committer | Kenneth Graunke <kenneth@whitecape.org> | 2014-01-07 12:54:57 -0800 |
| commit | 847bc36a38d42967ad6bf0492fe90a4892d9d799 (patch) | |
| tree | da704ff271f8302bd2d25333d9b1118ffd8cf37b /bin | |
| parent | 5e3fd6a9dbd62ca5cd9965282fac01a34d23733e (diff) | |
| download | external_mesa3d-847bc36a38d42967ad6bf0492fe90a4892d9d799.zip external_mesa3d-847bc36a38d42967ad6bf0492fe90a4892d9d799.tar.gz external_mesa3d-847bc36a38d42967ad6bf0492fe90a4892d9d799.tar.bz2 | |
glsl: Optimize pow(2, x) --> exp2(x).
On Haswell, POW takes 24 cycles, while EXP2 only takes 14. Plus, using
POW requires putting 2.0 in a register, while EXP2 doesn't.
I believe that EXP2 will be faster than POW on basically all GPUs, so
it makes sense to optimize it.
Looking at the savage2 subset of shader-db:
total instructions in shared programs: 113225 -> 113179 (-0.04%)
instructions in affected programs: 2139 -> 2093 (-2.15%)
instances of 'math pow': 795 -> 749 (-6.14%)
instances of 'math exp': 389 -> 435 (11.8%)
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Diffstat (limited to 'bin')
0 files changed, 0 insertions, 0 deletions