nir: Transform expressions of b2f(a) and b2f(b) to !(a && b)

All Gen platforms had pretty similar results. (Skylake shown)
total cycles in shared programs: 532578400 -> 532578397 (<.01%)
cycles in affected programs: 2784 -> 2781 (-0.11%)
helped: 1
HURT: 1
helped stats (abs) min: 4 max: 4 x̄: 4.00 x̃: 4
helped stats (rel) min: 0.26% max: 0.26% x̄: 0.26% x̃: 0.26%
HURT stats (abs)   min: 1 max: 1 x̄: 1.00 x̃: 1
HURT stats (rel)   min: 0.08% max: 0.08% x̄: 0.08% x̃: 0.08%

v2: s/fmax/fmin/.  Noticed by Thomas Helland.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>

diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index 7431642..9ead2dd 100644 (file)
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -177,6 +177,9 @@ optimizations = [
    (('feq', ('fmax', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('ior', a, b))),
    (('feq', ('bcsel', a, 1.0, ('b2f', b))   , 0.0), ('inot', ('ior', a, b))),
    (('feq', ('b2f', a), ('fneg', ('b2f', b))),      ('inot', ('ior', a, b))),
+   (('feq', ('fmul', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('iand', a, b))),
+   (('feq', ('fmin', ('b2f', a), ('b2f', b)), 0.0), ('inot', ('iand', a, b))),
+   (('feq', ('bcsel', a, ('b2f', b), 0.0)   , 0.0), ('inot', ('iand', a, b))),
 
    # -(b2f(a) + b2f(b)) < 0
    # 0 < b2f(a) + b2f(b)