Hello group, It appears there are some broken 64-bit single precision routines in the BLAS shipped with Apple's Accelerate Framework. Of course, it appears R doesn't use any single precision routines, but I haven't seen this described in R-devel or r-sig-mac so I figured I would report it in case it ever becomes an issue.
The problem is that complex single and double precision BLAS routines will throw a segfault if they are linked from the Accelerate framework in a way that is not compliant with the old g77 style. With gfortran, this is done with the -ff2c switch. However, if x86_64 binaries are being produced, the -ff2c switch causes some single precision real and complex routines to give erroneous results. For example, if the level 1 BLAS test routines sblat1 and cblat1 are downloaded from Netlib as sblat1.f and cblat1.f: http://www.netlib.org/blas/ The following command: gfortran -arch x86_64 -ff2c -o sblat1 sblat1.f -L/Library/Frameworks/R.framework/Resources/lib -lRblas Will produce a test program, sblat1, that shows failures for the following level 1 single precision real routines: SDOT SNRM2 SASUM And gfortran -arch x86_64 -ff2c -o cblat1 cblat1.f -L/Library/Frameworks/R.framework/Resources/lib -lRblas Will show failures for the following level 1 single precision complex routines: SCASUM SCNRM2 The failures only appear if 64 bit routines are used. -Charlie [[alternative HTML version deleted]] _______________________________________________ R-SIG-Mac mailing list R-SIG-Mac@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-mac
