Advanced Micro Devices Inc (AMD)

[Haddock]

it is simpler to make well optimized C compiler than Fortran one. And it is simpler to write a program, which will be properly optimized, using C

Quite the contrary.

Good Fortran compilers may be harder to do than good C compilers, but this is mostly because the bar is much higher. You have to do a lot more optimisations before people will say it's a "good" Fortran compiler. Fortran, being so simple gives the compiler a lot of possibilities to transform the program that simply aren't there in C.

In C it's easy to write a program where the compiler can't do any decent optimisations because it can't work out whether your pointers alias each other (point to the same data) or not.