From: Ian Romanick <ian.d.roman...@intel.com> The replacement of the comparison operators must happen during this step. If it does not, the next pass of nir_opt_algebraic will reapply De Morgan's Law in the "opposite direction" before performing dead code elimination. The resulting infinite loop will eventually get OOM killed.

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Haswell, Broadwell, and Skylake had similar results. (Broadwell shown) total instructions in shared programs: 14808185 -> 14808036 (<.01%) instructions in affected programs: 13758 -> 13609 (-1.08%) helped: 39 HURT: 0 helped stats (abs) min: 1 max: 10 x̄: 3.82 x̃: 3 helped stats (rel) min: 0.44% max: 1.55% x̄: 0.98% x̃: 1.01% 95% mean confidence interval for instructions value: -4.67 -2.97 95% mean confidence interval for instructions %-change: -1.09% -0.88% Instructions are helped. total cycles in shared programs: 559438333 -> 559435832 (<.01%) cycles in affected programs: 199160 -> 196659 (-1.26%) helped: 42 HURT: 3 helped stats (abs) min: 2 max: 184 x̄: 61.50 x̃: 51 helped stats (rel) min: 0.02% max: 6.94% x̄: 1.41% x̃: 1.40% HURT stats (abs) min: 2 max: 40 x̄: 27.33 x̃: 40 HURT stats (rel) min: 0.05% max: 0.74% x̄: 0.51% x̃: 0.74% 95% mean confidence interval for cycles value: -71.47 -39.69 95% mean confidence interval for cycles %-change: -1.64% -0.93% Cycles are helped. Sandy Bridge and Ivy Bridge had similar results. (Ivy Bridge shown) total instructions in shared programs: 11811776 -> 11811553 (<.01%) instructions in affected programs: 15201 -> 14978 (-1.47%) helped: 39 HURT: 0 helped stats (abs) min: 1 max: 20 x̄: 5.72 x̃: 6 helped stats (rel) min: 0.44% max: 2.53% x̄: 1.30% x̃: 1.26% 95% mean confidence interval for instructions value: -7.21 -4.23 95% mean confidence interval for instructions %-change: -1.48% -1.12% Instructions are helped. total cycles in shared programs: 257617270 -> 257614589 (<.01%) cycles in affected programs: 212107 -> 209426 (-1.26%) helped: 45 HURT: 0 helped stats (abs) min: 2 max: 180 x̄: 59.58 x̃: 54 helped stats (rel) min: 0.02% max: 6.02% x̄: 1.30% x̃: 1.32% 95% mean confidence interval for cycles value: -74.02 -45.14 95% mean confidence interval for cycles %-change: -1.59% -1.01% Cycles are helped. Iron Lake total instructions in shared programs: 7886648 -> 7886515 (<.01%) instructions in affected programs: 14106 -> 13973 (-0.94%) helped: 29 HURT: 0 helped stats (abs) min: 1 max: 10 x̄: 4.59 x̃: 4 helped stats (rel) min: 0.35% max: 1.83% x̄: 0.90% x̃: 0.81% 95% mean confidence interval for instructions value: -5.65 -3.52 95% mean confidence interval for instructions %-change: -1.03% -0.76% Instructions are helped. total cycles in shared programs: 178100812 -> 178100396 (<.01%) cycles in affected programs: 67970 -> 67554 (-0.61%) helped: 29 HURT: 0 helped stats (abs) min: 2 max: 40 x̄: 14.34 x̃: 12 helped stats (rel) min: 0.15% max: 1.69% x̄: 0.58% x̃: 0.54% 95% mean confidence interval for cycles value: -18.30 -10.39 95% mean confidence interval for cycles %-change: -0.71% -0.45% Cycles are helped. GM45 total instructions in shared programs: 4857939 -> 4857872 (<.01%) instructions in affected programs: 7426 -> 7359 (-0.90%) helped: 15 HURT: 0 helped stats (abs) min: 1 max: 10 x̄: 4.47 x̃: 4 helped stats (rel) min: 0.33% max: 1.80% x̄: 0.87% x̃: 0.77% 95% mean confidence interval for instructions value: -6.06 -2.87 95% mean confidence interval for instructions %-change: -1.06% -0.67% Instructions are helped. total cycles in shared programs: 122167930 -> 122167654 (<.01%) cycles in affected programs: 43118 -> 42842 (-0.64%) helped: 15 HURT: 0 helped stats (abs) min: 4 max: 40 x̄: 18.40 x̃: 16 helped stats (rel) min: 0.15% max: 1.69% x̄: 0.62% x̃: 0.54% 95% mean confidence interval for cycles value: -25.03 -11.77 95% mean confidence interval for cycles %-change: -0.82% -0.41% Cycles are helped. Signed-off-by: Ian Romanick <ian.d.roman...@intel.com> --- 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 314b064..af3ad2c 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -24,6 +24,7 @@ # Jason Ekstrand (ja...@jlekstrand.net) import nir_algebraic +import itertools # Convenience variables a = 'a' @@ -545,6 +546,14 @@ optimizations = [ 'options->lower_unpack_snorm_4x8'), ] +invert = {'feq': 'fne', 'fne': 'feq', 'fge': 'flt', 'flt': 'fge' } + +for left, right in list(itertools.combinations(invert.keys(), 2)) + zip(invert.keys(), invert.keys()): + optimizations.append((('inot', ('ior(is_used_once)', (left, a, b), (right, c, d))), + ('iand', (invert[left], a, b), (invert[right], c, d)))) + optimizations.append((('inot', ('iand(is_used_once)', (left, a, b), (right, c, d))), + ('ior', (invert[left], a, b), (invert[right], c, d)))) + def fexp2i(exp, bits): # We assume that exp is already in the right range. if bits == 32: -- 2.9.5 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev