------- Additional Comments From jv244 at cam dot ac dot uk 2005-01-28 15:59 ------- Hi Steven, I now ( gcc version 4.0.0 20050128 (experimental) )get the following, where the first number is the timing.
multgen/basic_mult> gfortran -O3 -ffast-math mult.f90 multgen/basic_mult> ./a.out 59.0300000000000 10.2400000000000 which is good as compared to multgen/basic_mult> ifort -O3 mult.f90 multgen/basic_mult> ./a.out 64.8900000000000 10.2399999999998 but very bad (factor 20) as compared to multgen/basic_mult> ifort -O3 -xN mult.f90 mult.f90(4) : (col. 0) remark: LOOP WAS VECTORIZED. mult.f90(5) : (col. 0) remark: LOOP WAS VECTORIZED. mult.f90(6) : (col. 0) remark: LOOP WAS VECTORIZED. multgen/basic_mult> ./a.out 2.13000000000000 10.2399999999998 I'll try to attach the relevant asm for this. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14741
