From e3ea166a2c5d2bfcea54c08898c940c4abfb3537 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Mon, 12 Feb 2018 18:58:53 -0800 Subject: [PATCH] nir: Simplify some comparisons like a+b < a MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit All Gen7+ platforms had similar results. (Skylake shown) total instructions in shared programs: 14514555 -> 14514547 (<.01%) instructions in affected programs: 1972 -> 1964 (-0.41%) helped: 8 HURT: 0 helped stats (abs) min: 1 max: 1 x̄: 1.00 x̃: 1 helped stats (rel) min: 0.39% max: 0.42% x̄: 0.41% x̃: 0.41% 95% mean confidence interval for instructions value: -1.00 -1.00 95% mean confidence interval for instructions %-change: -0.41% -0.40% Instructions are helped. total cycles in shared programs: 533141444 -> 533136780 (<.01%) cycles in affected programs: 164728 -> 160064 (-2.83%) helped: 181 HURT: 3 helped stats (abs) min: 2 max: 94 x̄: 26.17 x̃: 30 helped stats (rel) min: 0.12% max: 5.33% x̄: 3.42% x̃: 3.80% HURT stats (abs) min: 4 max: 54 x̄: 24.00 x̃: 14 HURT stats (rel) min: 0.20% max: 2.39% x̄: 1.09% x̃: 0.68% 95% mean confidence interval for cycles value: -27.12 -23.58 95% mean confidence interval for cycles %-change: -3.54% -3.16% Cycles are helped. Sandy Bridge total instructions in shared programs: 10533667 -> 10533539 (<.01%) instructions in affected programs: 10148 -> 10020 (-1.26%) helped: 124 HURT: 0 helped stats (abs) min: 1 max: 2 x̄: 1.03 x̃: 1 helped stats (rel) min: 0.39% max: 4.35% x̄: 2.20% x̃: 2.04% 95% mean confidence interval for instructions value: -1.06 -1.00 95% mean confidence interval for instructions %-change: -2.46% -1.95% Instructions are helped. total cycles in shared programs: 146136887 -> 146132122 (<.01%) cycles in affected programs: 206382 -> 201617 (-2.31%) helped: 171 HURT: 0 helped stats (abs) min: 2 max: 40 x̄: 27.87 x̃: 30 helped stats (rel) min: 0.08% max: 5.73% x̄: 2.98% x̃: 2.67% 95% mean confidence interval for cycles value: -29.19 -26.54 95% mean confidence interval for cycles %-change: -3.20% -2.76% Cycles are helped. Iron Lake total instructions in shared programs: 7886515 -> 7886507 (<.01%) instructions in affected programs: 3016 -> 3008 (-0.27%) helped: 8 HURT: 0 helped stats (abs) min: 1 max: 1 x̄: 1.00 x̃: 1 helped stats (rel) min: 0.25% max: 0.28% x̄: 0.27% x̃: 0.27% 95% mean confidence interval for instructions value: -1.00 -1.00 95% mean confidence interval for instructions %-change: -0.27% -0.26% Instructions are helped. total cycles in shared programs: 178100396 -> 178100388 (<.01%) cycles in affected programs: 156128 -> 156120 (<.01%) helped: 4 HURT: 4 helped stats (abs) min: 4 max: 4 x̄: 4.00 x̃: 4 helped stats (rel) min: 0.02% max: 0.04% x̄: 0.03% x̃: 0.03% HURT stats (abs) min: 2 max: 2 x̄: 2.00 x̃: 2 HURT stats (rel) min: <.01% max: 0.01% x̄: <.01% x̃: <.01% 95% mean confidence interval for cycles value: -3.68 1.68 95% mean confidence interval for cycles %-change: -0.03% <.01% Inconclusive result (value mean confidence interval includes 0). GM45 total instructions in shared programs: 4857872 -> 4857868 (<.01%) instructions in affected programs: 1544 -> 1540 (-0.26%) helped: 4 HURT: 0 helped stats (abs) min: 1 max: 1 x̄: 1.00 x̃: 1 helped stats (rel) min: 0.25% max: 0.27% x̄: 0.26% x̃: 0.26% 95% mean confidence interval for instructions value: -1.00 -1.00 95% mean confidence interval for instructions %-change: -0.28% -0.24% Instructions are helped. total cycles in shared programs: 122167654 -> 122167662 (<.01%) cycles in affected programs: 96248 -> 96256 (<.01%) helped: 0 HURT: 4 HURT stats (abs) min: 2 max: 2 x̄: 2.00 x̃: 2 HURT stats (rel) min: <.01% max: 0.01% x̄: <.01% x̃: <.01% 95% mean confidence interval for cycles value: 2.00 2.00 95% mean confidence interval for cycles %-change: <.01% 0.02% Cycles are HURT. Signed-off-by: Ian Romanick Reviewed-by: Samuel Iglesias Gonsálvez --- src/compiler/nir/nir_opt_algebraic.py | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index f6800b419ba..e500a31d8e0 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -153,6 +153,15 @@ optimizations = [ (('fge', ('fneg', ('b2f', a)), 0.0), ('inot', a)), + (('~flt', ('fadd', a, b), a), ('flt', b, 0.0)), + (('~fge', ('fadd', a, b), a), ('fge', b, 0.0)), + (('~feq', ('fadd', a, b), a), ('feq', b, 0.0)), + (('~fne', ('fadd', a, b), a), ('fne', b, 0.0)), + + # Cannot remove the addition from ilt or ige due to overflow. + (('ieq', ('iadd', a, b), a), ('ieq', b, 0)), + (('ine', ('iadd', a, b), a), ('ine', b, 0)), + # fmin(-b2f(a), b) >= 0.0 # -b2f(a) >= 0.0 && b >= 0.0 # -b2f(a) == 0.0 && b >= 0.0 -b2f can only be 0 or -1, never >0 -- 2.30.2