[Mesa-dev] [PATCH 2/2] nir: Optimize a + neg(a)

[Thomas Helland]

Shader-db i965 instructions:
total instructions in shared programs: 1711180 -> 1711159 (-0.00%)
instructions in affected programs:     825 -> 804 (-2.55%)
helped:                                9
HURT:                                  0
GAINED:                                3
LOST:                                  3

Shader-db NIR instructions:
total instructions in shared programs: 606187 -> 606179 (-0.00%)
instructions in affected programs:     298 -> 290 (-2.68%)
helped:                                4
HURT:                                  0
GAINED:                                0
LOST:                                  0

Signed-off-by: Thomas Helland <thomashelland90 at gmail.com>
---
 src/glsl/nir/nir_opt_algebraic.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index 688ceff..ef855aa 100644
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -58,6 +58,8 @@ optimizations = [
    (('iadd', a, 0), a),
    (('fadd', ('fmul', a, b), ('fmul', a, c)), ('fmul', a, ('fadd', b, c))),
    (('iadd', ('imul', a, b), ('imul', a, c)), ('imul', a, ('iadd', b, c))),
+   (('fadd', ('fneg', a), a), 0.0),
+   (('iadd', ('ineg', a), a), 0),
    (('fmul', a, 0.0), 0.0),
    (('imul', a, 0), 0),
    (('fmul', a, 1.0), a),
-- 
2.2.1