Miro Kropáček wrote:
How GCC knows what instructions to inline? I guess there's support for m68k target for this option? And has -m68881 / -m68060 / -msoft-float any effect on --fast-math?
From my tests, -ffast-math affects only targets with a 68881 or compatible (like our -m68020-60). GCC has support for that, it knows which math functions are directly implemented in the FPU. When a program uses sqrt(), GCC simply generates the equivalent FPU instruction instead of calling the function from libm.
-- Vincent Rivière