stat: optimize LinearRegression code, providing speedups of 40%

Created by: btracey

BenchmarkLinearRegression/n10wtot-8 23.2 23.6 +1.72% BenchmarkLinearRegression/n10wtot-8 23.7 23.9 +0.84% BenchmarkLinearRegression/n10wtot-8 23.8 26.6 +11.76% BenchmarkLinearRegression/n10wtot-8 23.4 25.4 +8.55% BenchmarkLinearRegression/n10wtot-8 23.5 25.0 +6.38% BenchmarkLinearRegression/n10wtof-8 120 99.8 -16.83% BenchmarkLinearRegression/n10wtof-8 125 97.1 -22.32% BenchmarkLinearRegression/n10wtof-8 122 92.1 -24.51% BenchmarkLinearRegression/n10wtof-8 120 92.6 -22.83% BenchmarkLinearRegression/n10wtof-8 122 91.0 -25.41% BenchmarkLinearRegression/n10wfot-8 20.2 20.0 -0.99% BenchmarkLinearRegression/n10wfot-8 19.7 19.9 +1.02% BenchmarkLinearRegression/n10wfot-8 19.9 20.0 +0.50% BenchmarkLinearRegression/n10wfot-8 19.9 20.0 +0.50% BenchmarkLinearRegression/n10wfot-8 19.7 20.2 +2.54% BenchmarkLinearRegression/n10wfof-8 116 78.6 -32.24% BenchmarkLinearRegression/n10wfof-8 115 82.8 -28.00% BenchmarkLinearRegression/n10wfof-8 116 79.6 -31.38% BenchmarkLinearRegression/n10wfof-8 117 78.9 -32.56% BenchmarkLinearRegression/n10wfof-8 117 80.5 -31.20% BenchmarkLinearRegression/n100wtot-8 161 166 +3.11% BenchmarkLinearRegression/n100wtot-8 164 165 +0.61% BenchmarkLinearRegression/n100wtot-8 162 166 +2.47% BenchmarkLinearRegression/n100wtot-8 161 164 +1.86% BenchmarkLinearRegression/n100wtot-8 161 166 +3.11% BenchmarkLinearRegression/n100wtof-8 749 509 -32.04% BenchmarkLinearRegression/n100wtof-8 750 512 -31.73% BenchmarkLinearRegression/n100wtof-8 751 507 -32.49% BenchmarkLinearRegression/n100wtof-8 777 512 -34.11% BenchmarkLinearRegression/n100wtof-8 773 552 -28.59% BenchmarkLinearRegression/n100wfot-8 124 133 +7.26% BenchmarkLinearRegression/n100wfot-8 126 129 +2.38% BenchmarkLinearRegression/n100wfot-8 126 128 +1.59% BenchmarkLinearRegression/n100wfot-8 125 130 +4.00% BenchmarkLinearRegression/n100wfot-8 126 131 +3.97% BenchmarkLinearRegression/n100wfof-8 686 451 -34.26% BenchmarkLinearRegression/n100wfof-8 699 435 -37.77% BenchmarkLinearRegression/n100wfof-8 688 456 -33.72% BenchmarkLinearRegression/n100wfof-8 699 445 -36.34% BenchmarkLinearRegression/n100wfof-8 691 451 -34.73% BenchmarkLinearRegression/n1000wtot-8 1456 1495 +2.68% BenchmarkLinearRegression/n1000wtot-8 1468 1461 -0.48% BenchmarkLinearRegression/n1000wtot-8 1493 1471 -1.47% BenchmarkLinearRegression/n1000wtot-8 1468 1482 +0.95% BenchmarkLinearRegression/n1000wtot-8 1477 1483 +0.41% BenchmarkLinearRegression/n1000wtof-8 7346 4698 -36.05% BenchmarkLinearRegression/n1000wtof-8 7204 4708 -34.65% BenchmarkLinearRegression/n1000wtof-8 7183 4673 -34.94% BenchmarkLinearRegression/n1000wtof-8 7176 4733 -34.04% BenchmarkLinearRegression/n1000wtof-8 7251 4727 -34.81% BenchmarkLinearRegression/n1000wfot-8 1171 1184 +1.11% BenchmarkLinearRegression/n1000wfot-8 1192 1158 -2.85% BenchmarkLinearRegression/n1000wfot-8 1163 1182 +1.63% BenchmarkLinearRegression/n1000wfot-8 1157 1150 -0.61% BenchmarkLinearRegression/n1000wfot-8 1170 1160 -0.85% BenchmarkLinearRegression/n1000wfof-8 6796 4197 -38.24% BenchmarkLinearRegression/n1000wfof-8 6811 4122 -39.48% BenchmarkLinearRegression/n1000wfof-8 6564 4132 -37.05% BenchmarkLinearRegression/n1000wfof-8 6542 4179 -36.12% BenchmarkLinearRegression/n1000wfof-8 6978 4109 -41.11% BenchmarkLinearRegression/n10000wtot-8 14613 14738 +0.86% BenchmarkLinearRegression/n10000wtot-8 14747 14746 -0.01% BenchmarkLinearRegression/n10000wtot-8 14489 14487 -0.01% BenchmarkLinearRegression/n10000wtot-8 14431 14549 +0.82% BenchmarkLinearRegression/n10000wtot-8 14557 14363 -1.33% BenchmarkLinearRegression/n10000wtof-8 70886 46425 -34.51% BenchmarkLinearRegression/n10000wtof-8 70992 46446 -34.58% BenchmarkLinearRegression/n10000wtof-8 71086 46828 -34.12% BenchmarkLinearRegression/n10000wtof-8 70830 46792 -33.94% BenchmarkLinearRegression/n10000wtof-8 71895 47131 -34.44% BenchmarkLinearRegression/n10000wfot-8 11325 11498 +1.53% BenchmarkLinearRegression/n10000wfot-8 11289 11635 +3.06% BenchmarkLinearRegression/n10000wfot-8 11592 11605 +0.11% BenchmarkLinearRegression/n10000wfot-8 11615 11929 +2.70% BenchmarkLinearRegression/n10000wfot-8 11595 12005 +3.54% BenchmarkLinearRegression/n10000wfof-8 70687 42916 -39.29% BenchmarkLinearRegression/n10000wfof-8 66305 40844 -38.40% BenchmarkLinearRegression/n10000wfof-8 66262 40922 -38.24% BenchmarkLinearRegression/n10000wfof-8 65864 42854 -34.94% BenchmarkLinearRegression/n10000wfof-8 65366 40753 -37.65%