[Mesa-dev] [PATCH 10/10] nir: Add algebraic optimizations for division and reciprocal.

[Kenneth Graunke]

These also exist in opt_algebraic.cpp.

total NIR instructions in shared programs: 2011430 -> 2011211 (-0.01%)
NIR instructions in affected programs:     42221 -> 42002 (-0.52%)
helped:                                    198

total i965 instructions in shared programs: 6020554 -> 6020118 (-0.01%)
i965 instructions in affected programs:     84497 -> 84061 (-0.52%)
helped:                                     394
HURT:                                       1 (by 1 instruction)
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/glsl/nir/nir_opt_algebraic.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index a5b5715..a1ed503 100644
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -109,6 +109,11 @@ optimizations = [
    (('fpow', a, 1.0), a),
    (('fpow', a, 2.0), ('fmul', a, a)),
    (('fpow', 2.0, a), ('fexp2', a)),
+   # Division and reciprocal
+   (('fdiv', 1.0, a), ('frcp', a)),
+   (('frcp', ('frcp', a)), a),
+   (('frcp', ('fsqrt', a)), ('frsq', a)),
+   (('frcp', ('frsq', a)), ('fsqrt', a)),
 
 # This one may not be exact
    (('feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
-- 
2.2.2