This is due to a temporary change to not compile assignments, like your loop body, that appear within an argument. This is to work around a bug elsewhere in R that will take some time to fix. Once that fix is available these assignments will again be compiled.
Best, On Fri, 27 Oct 2017, Colin Gillespie wrote:
Dear All, In R 3.4.2 (Linux), the compiler seems to have regressed: $ R --vanilla g = function() { N = 1e7; ans = numeric(N) system.time({for (j in 1:N) ans[j] = 1}) } g() # user system elapsed # 4.272 0.000 4.272 g1 = compiler::cmpfun(g) g1() # user system elapsed # 4.232 0.004 4.235 Running the above code in Windows 3.3.1, g() takes the same time, but g1() takes around 0.5 seconds. Removing the function wrapper we have N = 1e7; ans = numeric(N) system.time({for (j in 1:N) ans[j] = 1}) # user system elapsed # 0.304 0.000 0.304 compiler::enableJIT(0) #[1] 3 N = 1e7; ans = numeric(N) system.time({for (j in 1:N) ans[j] = 1}) # user system elapsed # 5.448 0.000 5.446 Best wishes Colin ------------------sessionInfo()R version 3.4.2 (2017-09-28) Platform: x86_64-pc-linux-gnu (64-bit) Running under: Ubuntu 16.04.3 LTS Matrix products: default BLAS: /usr/lib/atlas-base/atlas/libblas.so.3.0 LAPACK: /usr/lib/atlas-base/atlas/liblapack.so.3.0 locale: [1] LC_CTYPE=en_GB.UTF-8 LC_NUMERIC=C [3] LC_TIME=en_GB.UTF-8 LC_COLLATE=en_GB.UTF-8 [5] LC_MONETARY=en_GB.UTF-8 LC_MESSAGES=en_GB.UTF-8 [7] LC_PAPER=en_GB.UTF-8 LC_NAME=C [9] LC_ADDRESS=C LC_TELEPHONE=C [11] LC_MEASUREMENT=en_GB.UTF-8 LC_IDENTIFICATION=C attached base packages: [1] stats graphics grDevices utils datasets methods base loaded via a namespace (and not attached): [1] compiler_3.4.2 [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
-- Luke Tierney Ralph E. Wareham Professor of Mathematical Sciences University of Iowa Phone: 319-335-3386 Department of Statistics and Fax: 319-335-3017 Actuarial Science 241 Schaeffer Hall email: luke-tier...@uiowa.edu Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
