From 348e5a71d8bc1398c73b731d3e6d80fd3b122513 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Wed, 2 Mar 2016 15:36:14 -0800 Subject: [PATCH] nir: Simplify 0 < fabs(a) Sandy Bridge / Ivy Bridge / Haswell total instructions in shared programs: 8462180 -> 8462174 (-0.00%) instructions in affected programs: 564 -> 558 (-1.06%) helped: 6 HURT: 0 total cycles in shared programs: 117542462 -> 117542276 (-0.00%) cycles in affected programs: 9768 -> 9582 (-1.90%) helped: 12 HURT: 0 Broadwell / Skylake total instructions in shared programs: 8980833 -> 8980826 (-0.00%) instructions in affected programs: 626 -> 619 (-1.12%) helped: 7 HURT: 0 total cycles in shared programs: 70077900 -> 70077714 (-0.00%) cycles in affected programs: 9378 -> 9192 (-1.98%) helped: 12 HURT: 0 G45 and Ironlake showed no change. v2: Modify the comments to look more like a proof. Signed-off-by: Ian Romanick Reviewed-by: Matt Turner --- src/compiler/nir/nir_opt_algebraic.py | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index facc33b..c013fd7 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -108,6 +108,12 @@ optimizations = [ # inot(a) (('fge', 0.0, ('b2f', a)), ('inot', a)), + # 0.0 < fabs(a) + # fabs(a) > 0.0 + # fabs(a) != 0.0 because fabs(a) must be >= 0 + # a != 0.0 + (('flt', 0.0, ('fabs', a)), ('fne', a, 0.0)), + (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)), (('bcsel', ('flt', a, b), a, b), ('fmin', a, b)), (('bcsel', ('flt', a, b), b, a), ('fmax', a, b)), -- 2.7.4