GCC equivalent to VC's floating point model switch?

Question

Does GCC have an equivalent compiler switch to VC's floating point model switch (/fp)?

In particular, my application benefits from compiling with /fp:fast and precision is not a big deal, how should I compile it with GCC?

Answer 1

Try -ffast-math. On gcc 4.4.1, this turns on:

• -fno-math-errno - Don't set errno for single instruction math functions.
• -funsafe-math-optimizations - Assume arguments and result of math operations are valid, and potentially violate standards
• -ffinite-math-only - Assume arguments and results are finite.
• -fno-rounding-math - Enable optimizations that assume default rounding. This is the default, but it could be overridden by something else.
• -fno-signaling-nans - Enable optimizations that can change number of math exceptions.; also default
• -fcx-limited-range - Assume range reduction is not needed for complex number division:
• __FAST_MATH__ macro.

You could also enable these individually.