diff options
| author | Ian Romanick <[email protected]> | 2018-01-22 17:29:48 +0800 |
|---|---|---|
| committer | Ian Romanick <[email protected]> | 2018-03-06 11:17:14 -0800 |
| commit | 4addd34b0477cf87787afbcea989b3391a81d0a1 (patch) | |
| tree | 072017754a7910c961b4101348820133d3ba60eb /src/compiler | |
| parent | c62cf1f165919bc74296952452906b517d49b64a (diff) | |
nir: Recognize some more open-coded fmin / fmax
This transformation is inexact because section 4.7.1 (Range and
Precision) says:
Operations and built-in functions that operate on a NaN are not
required to return a NaN as the result.
The fmin or fmax might not return NaN in cases where the original
expression would be required to return NaN.
v2: Reorder operands and mark as inexact. The latter suggested by
Jason.
shader-db results:
Haswell, Broadwell, and Skylake had similar results. (Skylake shown)
total instructions in shared programs: 14514817 -> 14514808 (<.01%)
instructions in affected programs: 229 -> 220 (-3.93%)
helped: 3
HURT: 0
helped stats (abs) min: 1 max: 4 x̄: 3.00 x̃: 4
helped stats (rel) min: 2.86% max: 4.12% x̄: 3.70% x̃: 4.12%
total cycles in shared programs: 533145211 -> 533144939 (<.01%)
cycles in affected programs: 37268 -> 36996 (-0.73%)
helped: 8
HURT: 0
helped stats (abs) min: 2 max: 134 x̄: 34.00 x̃: 2
helped stats (rel) min: 0.02% max: 14.22% x̄: 3.53% x̃: 0.05%
Sandy Bridge and Ivy Bridge had similar results. (Ivy Bridge shown)
total cycles in shared programs: 257618409 -> 257618403 (<.01%)
cycles in affected programs: 12582 -> 12576 (-0.05%)
helped: 3
HURT: 0
helped stats (abs) min: 2 max: 2 x̄: 2.00 x̃: 2
helped stats (rel) min: 0.05% max: 0.05% x̄: 0.05% x̃: 0.05%
No changes on Iron Lake or GM45.
Signed-off-by: Ian Romanick <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>
Diffstat (limited to 'src/compiler')
| -rw-r--r-- | src/compiler/nir/nir_opt_algebraic.py | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index 296f0671386..ef240ae0e91 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -170,6 +170,8 @@ optimizations = [ (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)), (('bcsel', ('flt', b, a), b, a), ('fmin', a, b)), (('bcsel', ('flt', a, b), b, a), ('fmax', a, b)), + (('~bcsel', ('fge', a, b), b, a), ('fmin', a, b)), + (('~bcsel', ('fge', b, a), b, a), ('fmax', a, b)), (('bcsel', ('inot', a), b, c), ('bcsel', a, c, b)), (('bcsel', a, ('bcsel', a, b, c), d), ('bcsel', a, b, d)), (('bcsel', a, True, 'b@bool'), ('ior', a, b)), |