OpenMP on gcc

[Dima Sorkin]

Hi.
 I have some c++ code that should compile both
under GCCs (starting from gcc 3.1 to 4.0) and other
compiler. I want to insert OpenMP pragmas
into code, to optimize it.

1) Starting from which version does GCC support OpenMP ?
2) Will old versions of GCC just ignore OpenMP pragmas, or these
    will cause errors ?

Thank you.
 Dima.