diff options
| author | Ian Romanick <[email protected]> | 2020-02-10 18:23:54 -0800 |
|---|---|---|
| committer | Marge Bot <[email protected]> | 2020-04-01 00:28:38 +0000 |
| commit | af1bc7e0c7dd1f3c4f2226f93e819e410fd7a731 (patch) | |
| tree | ec3bb3f1b46d6ac5316e5581edb62f4f5a411597 /src | |
| parent | 62795475e8f45f92bb8f467d9e2318fdfdba6297 (diff) | |
nir/algebraic: Use value range analysis to convert fmax to fsat
This is conceptually similar to the 1-fsat(a) <=> fsat(1-a) rearragement
done in:
3b747909419 ("nir/algebraic: Recognize open-coded flrp(a, b, fsat(c))")
2d259713b7 ("nir/algebraic: Commute 1-fsat(a) to fsat(1-a) for all
non-fmul instructions").
Note: this helps the Aztex Ruins shader that was hurt for spills and
fills on Braodwell in the previous commit, but it does not fix the
spills or fills. :(
All Intel platforms had similar results. (Ice Lake shown)
total instructions in shared programs: 14528985 -> 14526116 (-0.02%)
instructions in affected programs: 477300 -> 474431 (-0.60%)
helped: 2332
HURT: 0
helped stats (abs) min: 1 max: 18 x̄: 1.23 x̃: 1
helped stats (rel) min: 0.07% max: 8.89% x̄: 0.88% x̃: 0.64%
95% mean confidence interval for instructions value: -1.27 -1.19
95% mean confidence interval for instructions %-change: -0.92% -0.85%
Instructions are helped.
total cycles in shared programs: 203723684 -> 203692984 (-0.02%)
cycles in affected programs: 4878847 -> 4848147 (-0.63%)
helped: 1764
HURT: 324
helped stats (abs) min: 1 max: 706 x̄: 22.94 x̃: 17
helped stats (rel) min: <.01% max: 17.75% x̄: 1.94% x̃: 1.66%
HURT stats (abs) min: 1 max: 400 x̄: 30.15 x̃: 10
HURT stats (rel) min: <.01% max: 17.76% x̄: 1.91% x̃: 0.69%
95% mean confidence interval for cycles value: -16.55 -12.86
95% mean confidence interval for cycles %-change: -1.44% -1.24%
Cycles are helped.
Reviewed-by: Matt Turner <[email protected]>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/1359>
Diffstat (limited to 'src')
| -rw-r--r-- | src/compiler/nir/nir_opt_algebraic.py | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index 76ec1acc056..bb490d2a19c 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -560,6 +560,16 @@ optimizations.extend([ (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)), (('fmax', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmax', a, b))), (('fmin', ('fsat', a), '#b@32(is_zero_to_one)'), ('fsat', ('fmin', a, b))), + + # If a in [0,b] then b-a is also in [0,b]. Since b in [0,1], max(b-a, 0) = + # fsat(b-a). + # + # If a > b, then b-a < 0 and max(b-a, 0) = fsat(b-a) = 0 + # + # This should be NaN safe since max(NaN, 0) = fsat(NaN) = 0. + (('fmax', ('fadd(is_used_once)', ('fneg', 'a(is_not_negative)'), '#b@32(is_zero_to_one)'), 0.0), + ('fsat', ('fadd', ('fneg', a), b)), '!options->lower_fsat'), + (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)), (('~ior', ('flt(is_used_once)', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))), (('~ior', ('flt(is_used_once)', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)), |