------- Comment #3 from pinskia at gcc dot gnu dot org 2006-01-26 14:47 ------- -ffast-math Sets -fno-math-errno, -funsafe-math-optimizations, -fno-trapping-math, -ffinite-math-only, -fno-rounding-math, -fno-signaling-nans and fcx-limited-range. This option causes the preprocessor macro __FAST_MATH__ to be defined.
This option should never be turned on by any -O option since it can result in incorrect output for programs which depend on an exact implementation of IEEE or ISO rules/specifications for math functions. -ffinite-math-only Allow optimizations for floating-point arithmetic that assume that arguments and results are not NaNs or +-Infs. This option should never be turned on by any -O option since it can result in incorrect output for programs which depend on an exact implementation of IEEE or ISO rules/specifications. The default is -fno-finite-math-only. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25975
