From e8505e982a3f911440cad8a963313d2d62d27fc6 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Fri, 12 Jul 2019 23:26:48 -0500 Subject: [PATCH] nir/algebraic: Optimize comparing unpacked values We could, in theory, add the same optimization for 64-bit unpack operations but that's likely to fight with 64-bit integer lowering on platforms which require it so it will require more infrastructure before that will be a good idea. Reviewed-by: Matt Turner --- src/compiler/nir/nir_opt_algebraic.py | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index 6ae937651e0..42462d5befa 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -722,6 +722,14 @@ optimizations = [ (('pack_64_2x32_split', ('unpack_64_2x32_split_x', a), ('unpack_64_2x32_split_y', a)), a), + # Comparing two halves of an unpack separately. While this optimization + # should be correct for non-constant values, it's less obvious that it's + # useful in that case. For constant values, the pack will fold and we're + # guaranteed to reduce the whole tree to one instruction. + (('iand', ('ieq', ('unpack_32_2x16_split_x', a), '#b'), + ('ieq', ('unpack_32_2x16_split_y', a), '#c')), + ('ieq', a, ('pack_32_2x16_split', b, c))), + # Byte extraction (('ushr', 'a@16', 8), ('extract_u8', a, 1), '!options->lower_extract_byte'), (('ushr', 'a@32', 24), ('extract_u8', a, 3), '!options->lower_extract_byte'), -- 2.30.2