http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58425
--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- Works for me: [macbook] f90/bug% gfcc ~/test/Rouson/ssdSource/chapter05/hermetic/hermetic.F90 -c -Ofast [macbook] f90/bug% gfcc ~/test/Rouson/ssdSource/chapter05/hermetic/vortex.F90 -c -Ofast [macbook] f90/bug% gfcc ~/test/Rouson/ssdSource/chapter05/hermetic/main.F90 hermetic.o vortex.o -Ofast [macbook] f90/bug% a.out 1.00000000 0.00000000 0.00000000 0.707106769 0.707106769 0.00000000 -4.37113883E-08 1.00000000 0.00000000 -0.707106769 0.707106769 0.00000000 -1.00000000 -8.74227766E-08 0.00000000 -0.707106650 -0.707106888 0.00000000 1.19248806E-08 -1.00000000 0.00000000 0.707107008 -0.707106531 0.00000000 [macbook] f90/bug% gfcc -v Using built-in specs. COLLECT_GCC=gfcc COLLECT_LTO_WRAPPER=/opt/gcc/gcc4.9c/libexec/gcc/x86_64-apple-darwin10.8.0/4.9.0/lto-wrapper Target: x86_64-apple-darwin10.8.0 Configured with: ../_clean/configure --prefix=/opt/gcc/gcc4.9c --enable-languages=c,c++,fortran,objc,obj-c++,java,ada,lto --with-gmp=/opt/mp --with-system-zlib --with-isl=/opt/mp --enable-lto --enable-plugin Thread model: posix gcc version 4.9.0 20130914 (experimental) [trunk revision 202590] (GCC) I also get the same output with -flto added or without -Ofast.