http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38199
--- Comment #35 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- > http://gcc.gnu.org/ml/fortran/2014-03/msg00079.html The test character buffer*100000 integer i,j DO j=1,9999 write(buffer,'(i4)') j read(buffer,'(i100000)') i ENDDO end takes ~3.5s without the patch (and 4.7.4 or 4.8.3) and ~0.7s with it (~2s with 4.6). The test character buffer(1)*100000 integer i,j DO j=1,9999 write(buffer(1),'(i4)') j read(buffer,*) i ENDDO end takes ~1.8s with/without the patch (~11.3s with 4.6, ~10.2s with 4.7.4, and ~13.6 with 4.8.3, i7 2.8Ghz, turbo 3.8Ghz).