nir: Recognize another open coded lrp.

total instructions in shared programs: 6195924 -> 6195768 (-0.00%)
instructions in affected programs:     4876 -> 4720 (-3.20%)
helped:                                58
HURT:                                  10

Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py
index 368ec7f..5b84a4e 100644 (file)
--- a/src/glsl/nir/nir_opt_algebraic.py
+++ b/src/glsl/nir/nir_opt_algebraic.py
@@ -77,6 +77,7 @@ optimizations = [
    (('flrp', 0.0, a, b), ('fmul', a, b)),
    (('flrp', a, b, c), ('fadd', ('fmul', c, ('fsub', b, a)), a), 'options->lower_flrp'),
    (('fadd', ('fmul', a, ('fadd', 1.0, ('fneg', c))), ('fmul', b, c)), ('flrp', a, b, c), '!options->lower_flrp'),
+   (('fadd', a, ('fmul', c, ('fadd', b, ('fneg', a)))), ('flrp', a, b, c), '!options->lower_flrp'),
    (('ffma', a, b, c), ('fadd', ('fmul', a, b), c), 'options->lower_ffma'),
    (('fadd', ('fmul', a, b), c), ('ffma', a, b, c), '!options->lower_ffma'),
    # Comparison simplifications