From 5544b2cbbd23df82192aea09d909b5cc2c1f1af9 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Tue, 23 Jan 2018 17:35:51 +0800 Subject: [PATCH] nir/algebraic: Use value range analysis to eliminate useless unary ops MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Sandy Bridge is the big winner because it lies at something of a crossroads. It supports a fairly high OpenGL version, and it still has the old style math box. The high OpenGL version means a lot more shaders can run on it. The old style math box means extra moves are necessary to resolve source modifiers on operands to complex math instructions like COS, SQRT, and RCP. v2: Remove a couple patterns that are now redundant. All Gen7+ platforms had similar results. (Ice Lake shown) total instructions in shared programs: 16282006 -> 16278207 (-0.02%) instructions in affected programs: 174555 -> 170756 (-2.18%) helped: 661 HURT: 0 helped stats (abs) min: 1 max: 36 x̄: 5.75 x̃: 3 helped stats (rel) min: 0.06% max: 23.68% x̄: 2.81% x̃: 1.94% 95% mean confidence interval for instructions value: -6.16 -5.34 95% mean confidence interval for instructions %-change: -3.02% -2.60% Instructions are helped. total cycles in shared programs: 367168597 -> 367134284 (<.01%) cycles in affected programs: 1105276 -> 1070963 (-3.10%) helped: 460 HURT: 150 helped stats (abs) min: 1 max: 568 x̄: 96.60 x̃: 82 helped stats (rel) min: 0.02% max: 32.50% x̄: 7.99% x̃: 4.27% HURT stats (abs) min: 1 max: 901 x̄: 67.49 x̃: 39 HURT stats (rel) min: 0.07% max: 20.00% x̄: 4.90% x̃: 4.22% 95% mean confidence interval for cycles value: -65.68 -46.82 95% mean confidence interval for cycles %-change: -5.59% -4.05% Cycles are helped. Sandy Bridge total instructions in shared programs: 10824272 -> 10802557 (-0.20%) instructions in affected programs: 1237988 -> 1216273 (-1.75%) helped: 8199 HURT: 0 helped stats (abs) min: 1 max: 41 x̄: 2.65 x̃: 2 helped stats (rel) min: 0.12% max: 20.00% x̄: 2.04% x̃: 1.73% 95% mean confidence interval for instructions value: -2.70 -2.59 95% mean confidence interval for instructions %-change: -2.07% -2.00% Instructions are helped. total cycles in shared programs: 154009894 -> 153843598 (-0.11%) cycles in affected programs: 10650486 -> 10484190 (-1.56%) helped: 4973 HURT: 1533 helped stats (abs) min: 1 max: 3904 x̄: 40.20 x̃: 20 helped stats (rel) min: 0.02% max: 41.72% x̄: 2.63% x̃: 1.67% HURT stats (abs) min: 1 max: 453 x̄: 21.94 x̃: 8 HURT stats (rel) min: 0.02% max: 41.91% x̄: 1.54% x̃: 0.58% 95% mean confidence interval for cycles value: -28.02 -23.10 95% mean confidence interval for cycles %-change: -1.74% -1.56% Cycles are helped. LOST: 0 GAINED: 2 GM45 and Iron Lake had similar results. (Iron Lake shown) total instructions in shared programs: 8135196 -> 8134888 (<.01%) instructions in affected programs: 31920 -> 31612 (-0.96%) helped: 169 HURT: 0 helped stats (abs) min: 1 max: 12 x̄: 1.82 x̃: 2 helped stats (rel) min: 0.43% max: 3.23% x̄: 1.23% x̃: 1.16% 95% mean confidence interval for instructions value: -2.01 -1.64 95% mean confidence interval for instructions %-change: -1.32% -1.15% Instructions are helped. total cycles in shared programs: 188575724 -> 188574092 (<.01%) cycles in affected programs: 406840 -> 405208 (-0.40%) helped: 169 HURT: 0 helped stats (abs) min: 4 max: 72 x̄: 9.66 x̃: 10 helped stats (rel) min: 0.07% max: 2.16% x̄: 0.57% x̃: 0.47% 95% mean confidence interval for cycles value: -10.72 -8.59 95% mean confidence interval for cycles %-change: -0.63% -0.50% Cycles are helped. Reviewed-by: Caio Marcelo de Oliveira Filho --- src/compiler/nir/nir_opt_algebraic.py | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index d815db355bb..a3a244c41fb 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -764,8 +764,6 @@ optimizations = [ (('f2u', ('ftrunc', a)), ('f2u', a)), (('i2b', ('ineg', a)), ('i2b', a)), (('i2b', ('iabs', a)), ('i2b', a)), - (('fabs', ('b2f', a)), ('b2f', a)), - (('iabs', ('b2i', a)), ('b2i', a)), (('inot', ('f2b1', a)), ('feq', a, 0.0)), # Ironically, mark these as imprecise because removing the conversions may @@ -776,6 +774,14 @@ optimizations = [ (('~f2u32', ('i2f', 'a@32')), a), (('~f2u32', ('u2f', 'a@32')), a), + (('ffloor', 'a(is_integral)'), a), + (('fceil', 'a(is_integral)'), a), + (('ftrunc', 'a(is_integral)'), a), + (('ffract', 'a(is_integral)'), 0.0), + (('fabs', 'a(is_not_negative)'), a), + (('iabs', 'a(is_not_negative)'), a), + (('fsat', 'a(is_not_positive)'), 0.0), + # Section 5.4.1 (Conversion and Scalar Constructors) of the GLSL 4.60 spec # says: # -- 2.30.2