From 83f7fdf83a0546e477aba7fb3685cf78588ea2be Mon Sep 17 00:00:00 2001 From: Timothy Arceri Date: Thu, 12 Jan 2017 17:01:03 +1100 Subject: [PATCH] nir: add flt comparision simplification Didn't turn out as useful as I'd hoped, but it will help alot more on i965 by reducing regressions when we drop brw_do_channel_expressions() and brw_do_vector_splitting(). I'm not sure how much sense 'is_not_used_by_conditional' makes on platforms other than i965 but since this is a new opt it at least won't do any harm. shader-db BDW: total instructions in shared programs: 13029581 -> 13029415 (-0.00%) instructions in affected programs: 15268 -> 15102 (-1.09%) helped: 86 HURT: 0 total cycles in shared programs: 247038346 -> 247036198 (-0.00%) cycles in affected programs: 692634 -> 690486 (-0.31%) helped: 183 HURT: 27 Reviewed-by: Elie Tournier Reviewed-by: Kenneth Graunke --- src/compiler/nir/nir_opt_algebraic.py | 4 ++++ src/compiler/nir/nir_search_helpers.h | 15 +++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index 49c1460e25a..bd65eff8b59 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -158,6 +158,10 @@ optimizations = [ # a != 0.0 (('flt', 0.0, ('fabs', a)), ('fne', a, 0.0)), + # ignore this opt when the result is used by a bcsel or if so we can make + # use of conditional modifiers on supported hardware. + (('flt(is_not_used_by_conditional)', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)), + (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)), (('bcsel', ('flt', b, a), b, a), ('fmin', a, b)), (('bcsel', ('flt', a, b), b, a), ('fmax', a, b)), diff --git a/src/compiler/nir/nir_search_helpers.h b/src/compiler/nir/nir_search_helpers.h index faa3bdfd12b..7decf6582a7 100644 --- a/src/compiler/nir/nir_search_helpers.h +++ b/src/compiler/nir/nir_search_helpers.h @@ -158,4 +158,19 @@ is_not_used_by_if(nir_alu_instr *instr) return list_empty(&instr->dest.dest.ssa.if_uses); } +static inline bool +is_not_used_by_conditional(nir_alu_instr *instr) +{ + if (!is_not_used_by_if(instr)) + return false; + + nir_foreach_use(use, &instr->dest.dest.ssa) { + if (use->parent_instr->type == nir_instr_type_alu && + nir_instr_as_alu(use->parent_instr)->op == nir_op_bcsel) + return false; + } + + return true; +} + #endif /* _NIR_SEARCH_ */ -- 2.30.2