https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71544
--- Comment #5 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- > I do not observe correct behavior with the options that the previous comment > list s as being turned on by -O1 (this is on OS X 10.10, macports gfortran > 4.9.3): gfortran-fsf-5: error: unrecognized command line option '-fssa-backprop' gfortran-fsf-4.9: error: unrecognized command line option '-fssa-phiopt' So these options are not available for 4.9 and older. For 4.8.5 and 4.9.3 on x86_64-apple-darwin15 (fink builds or mine ones), I get [Book15] f90/bug% gfortran-fsf-4.8 pr71544.f90 -fauto-inc-dec -fbranch-count-reg -fcombine-stack-adjustments -fcompare-elim -fcprop-registers -fdce -fdefer-pop -fdse -fforward-propagate -fguess-branch-probability -fif-conversion2 -fif-conversion -finline-functions-called-once -fipa-pure-const -fipa-profile -fipa-reference -fmerge-constants -fmove-loop-invariants -freorder-blocks -fshrink-wrap -fsplit-wide-types -ftree-bit-ccp -ftree-ccp -ftree-ch -ftree-coalesce-vars -ftree-copy-prop -ftree-dce -ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre -ftree-phiprop -ftree-sink -ftree-slsr -ftree-sra -ftree-pta -ftree-ter -funit-at-a-time -fomit-frame-pointer [Book15] f90/bug% ./a.out The following line should print 100 100