From c769641c8e92228334a284dd7f6ecb5f91c0c113 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Tue, 23 Oct 2018 14:30:41 -0700 Subject: [PATCH] nir/algebraic: Push unary operations into source operands of fsat source MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Pushing a unary operation, like fneg, into the operation that generates its operand allows the fsat to be applied to the inner instruction instead of on a separate instruction that performs the unary operation. This changes fmul ssa_100, ssa_99, ssa_98 fmov.sat ssa_101, -ssa_100 into fmul.sat ssa_100, -ssa_99, ssa_98 Ice Lake, Skylake, and Broadwell had similar results. (Ice Lake shown) total instructions in shared programs: 17228658 -> 17228584 (<.01%) instructions in affected programs: 3163 -> 3089 (-2.34%) helped: 49 HURT: 0 helped stats (abs) min: 1 max: 2 x̄: 1.51 x̃: 2 helped stats (rel) min: 0.58% max: 9.09% x̄: 3.69% x̃: 3.51% 95% mean confidence interval for instructions value: -1.66 -1.37 95% mean confidence interval for instructions %-change: -4.37% -3.00% Instructions are helped. total cycles in shared programs: 360937144 -> 360936431 (<.01%) cycles in affected programs: 24029 -> 23316 (-2.97%) helped: 47 HURT: 2 helped stats (abs) min: 4 max: 18 x̄: 15.34 x̃: 16 helped stats (rel) min: 0.69% max: 6.18% x̄: 3.78% x̃: 4.27% HURT stats (abs) min: 4 max: 4 x̄: 4.00 x̃: 4 HURT stats (rel) min: 0.34% max: 0.67% x̄: 0.50% x̃: 0.50% 95% mean confidence interval for cycles value: -16.05 -13.05 95% mean confidence interval for cycles %-change: -4.07% -3.15% Cycles are helped. All Gen7 and earlier platforms had similar results. (Haswell shown) total instructions in shared programs: 13536059 -> 13535884 (<.01%) instructions in affected programs: 8797 -> 8622 (-1.99%) helped: 150 HURT: 0 helped stats (abs) min: 1 max: 2 x̄: 1.17 x̃: 1 helped stats (rel) min: 0.40% max: 11.11% x̄: 3.51% x̃: 1.96% 95% mean confidence interval for instructions value: -1.23 -1.11 95% mean confidence interval for instructions %-change: -3.97% -3.05% Instructions are helped. total cycles in shared programs: 357696119 -> 357694193 (<.01%) cycles in affected programs: 50216 -> 48290 (-3.84%) helped: 109 HURT: 14 helped stats (abs) min: 2 max: 92 x̄: 18.97 x̃: 16 helped stats (rel) min: 0.26% max: 19.09% x̄: 7.37% x̃: 5.37% HURT stats (abs) min: 2 max: 26 x̄: 10.14 x̃: 5 HURT stats (rel) min: 0.18% max: 4.73% x̄: 1.84% x̃: 0.92% 95% mean confidence interval for cycles value: -19.27 -12.05 95% mean confidence interval for cycles %-change: -7.34% -5.31% Cycles are helped. Reviewed-by: Matt Turner --- src/compiler/nir/nir_opt_algebraic.py | 5 ++++- src/compiler/nir/nir_search_helpers.h | 19 +++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index bdf432b..c488b2c 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -375,6 +375,9 @@ optimizations = [ (('fsat', ('b2f', a)), ('b2f', a)), (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'), (('fsat', ('fsat', a)), ('fsat', a)), + (('fsat', ('fneg(is_used_once)', ('fadd(is_used_once)', a, b))), ('fsat', ('fadd', ('fneg', a), ('fneg', b))), '!options->lower_negate && !options->lower_fsat'), + (('fsat', ('fneg(is_used_once)', ('fmul(is_used_once)', a, b))), ('fsat', ('fmul', ('fneg', a), b)), '!options->lower_negate && !options->lower_fsat'), + (('fsat', ('fabs(is_used_once)', ('fmul(is_used_once)', a, b))), ('fsat', ('fmul', ('fabs', a), ('fabs', b))), '!options->lower_fsat'), (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)), (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)), (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)), @@ -698,7 +701,7 @@ optimizations.extend([ (('iabs', ('isub', 0, a)), ('iabs', a)), # Propagate negation up multiplication chains - (('fmul', ('fneg', a), b), ('fneg', ('fmul', a, b))), + (('fmul(is_used_by_non_fsat)', ('fneg', a), b), ('fneg', ('fmul', a, b))), (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))), # Propagate constants up multiplication chains diff --git a/src/compiler/nir/nir_search_helpers.h b/src/compiler/nir/nir_search_helpers.h index 1624508..91d638a 100644 --- a/src/compiler/nir/nir_search_helpers.h +++ b/src/compiler/nir/nir_search_helpers.h @@ -193,4 +193,23 @@ is_not_used_by_if(nir_alu_instr *instr) return list_empty(&instr->dest.dest.ssa.if_uses); } +static inline bool +is_used_by_non_fsat(nir_alu_instr *instr) +{ + nir_foreach_use(src, &instr->dest.dest.ssa) { + const nir_instr *const user_instr = src->parent_instr; + + if (user_instr->type != nir_instr_type_alu) + return true; + + const nir_alu_instr *const user_alu = nir_instr_as_alu(user_instr); + + assert(instr != user_alu); + if (user_alu->op != nir_op_fsat) + return true; + } + + return false; +} + #endif /* _NIR_SEARCH_ */ -- 2.7.4