From bf2c3bc316cbfcc19d1bb65ab7410784ed7a3dac Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Wed, 25 Mar 2015 15:22:12 -0700 Subject: [PATCH] nir: Lower subtraction to add with negation when !lower_negate. prog->nir will generate fsub opcodes, but i965 doesn't implement them. We may as well lower them at the NIR level, since it's trivial to do. Suggested by Connor Abbott. Signed-off-by: Kenneth Graunke Reviewed-by: Connor Abbott Reviewed-by: Eric Anholt --- 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 20ec4d3a39a..66b456d1164 100644 --- a/src/glsl/nir/nir_opt_algebraic.py +++ b/src/glsl/nir/nir_opt_algebraic.py @@ -161,6 +161,8 @@ optimizations = [ # Subtracts (('fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)), (('isub', a, ('isub', 0, b)), ('iadd', a, b)), + (('fsub', a, b), ('fadd', a, ('fneg', b)), '!options->lower_negate'), + (('isub', a, b), ('iadd', a, ('ineg', b)), '!options->lower_negate'), (('fneg', a), ('fsub', 0.0, a), 'options->lower_negate'), (('ineg', a), ('isub', 0, a), 'options->lower_negate'), (('fadd', a, ('fsub', 0.0, b)), ('fsub', a, b)), -- 2.30.2