From: Eric Anholt Date: Mon, 30 Mar 2015 06:04:21 +0000 (-0700) Subject: nir: Recognize a pattern of bool frobbing from TGSI KILL_IF. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=15b03b7964fc2c3c52e9f384815b76957f557878;p=mesa.git nir: Recognize a pattern of bool frobbing from TGSI KILL_IF. TGSI's conditional discards take float arg and negate it, so GLSL to TGSI generates a b2f and negates that value. Only, in NIR we want a proper bool once again, so we compare with 0. This is a lot of pointless extra instructions. total instructions in shared programs: 39735 -> 39702 (-0.08%) instructions in affected programs: 1342 -> 1309 (-2.46%) Reviewed-by: Connor Abbott --- diff --git a/src/glsl/nir/nir_opt_algebraic.py b/src/glsl/nir/nir_opt_algebraic.py index 301d7a8ebcf..190bd916efe 100644 --- a/src/glsl/nir/nir_opt_algebraic.py +++ b/src/glsl/nir/nir_opt_algebraic.py @@ -100,6 +100,8 @@ optimizations = [ (('fmul', ('b2f', a), ('b2f', b)), ('b2f', ('iand', a, b))), (('fsat', ('fadd', ('b2f', a), ('b2f', b))), ('b2f', ('ior', a, b))), (('iand', 'a@bool', 1.0), ('b2f', a)), + (('flt', ('fneg', ('b2f', a)), 0), a), # Generated by TGSI KILL_IF. + (('flt', ('fsub', 0.0, ('b2f', a)), 0), a), # Generated by TGSI KILL_IF. # Comparison with the same args. Note that these are not done for # the float versions because NaN always returns false on float # inequalities.