[Mesa-dev] [PATCH 3/9] nir: Add lowering of POW instructions if the lower flag is set.

Eric Anholt eric at anholt.net
Sun Feb 1 13:17:22 PST 2015


This could be done in a separate pass like we do in GLSL IR, but it seems
to me like having the definitions of the transformations in the two
directions next to each other makes a lot of sense.
---
 src/glsl/nir/nir_opt_algebraic.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index 2414f71..41bfe04 100644
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -107,6 +107,7 @@ optimizations = [
    (('fexp',  ('flog',  a)), a), # e^ln(a)  = a
    (('flog2', ('fexp2', a)), a), # lg2(2^a) = a
    (('flog',  ('fexp',  a)), a), # ln(e^a)  = a
+   (('fpow', a, b), ('fexp2', ('fmul', ('flog2', a), b)), 'options->lower_fpow'), # 2^(lg2(a)*b) = a^b
    (('fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b), '!options->lower_fpow'), # 2^(lg2(a)*b) = a^b
    (('fexp',  ('fmul', ('flog', a), b)),  ('fpow', a, b), '!options->lower_fpow'), # e^(ln(a)*b) = a^b
    (('fpow', a, 1.0), a),
-- 
2.1.4



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