[Mesa-dev] [PATCH 1/5] nir: Add a couple of simplifications of csel operations.

Eric Anholt eric at anholt.net
Fri Feb 20 12:04:49 PST 2015


vc4 was already cleaning these up, but it does shave 4 NIR instructions in
shader-db.
---
 src/glsl/nir/nir_opt_algebraic.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index b0c206a..dd4557f 100644
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -146,6 +146,9 @@ optimizations = [
    # next round of opt_algebraic, get picked up by one of the above two.
    (('bcsel', '#a', b, c), ('bcsel', ('ine', 'a', 0), b, c)),
 
+   (('bcsel', a, b, b), b),
+   (('fcsel', a, b, b), b),
+
    # Subtracts
    (('fsub', 0.0, ('fsub', 0.0, a)), a),
    (('isub', 0, ('isub', 0, a)), a),
-- 
2.1.4



More information about the mesa-dev mailing list