Thanks for reply.
Raymond Toy writes:
"Daniel" == Daniel Kochma <Daniel> writes:
Daniel> Hello, Daniel> I'm little in doubt. Problem is related to ieee-floating-point Daniel> extensions, which provide infinities and nan. Everything works fine Daniel> until we generate C code, which simply breaks, because it isn't taken Daniel> into account. Daniel> There are two possible solutions: Daniel> - for these cases use constant expressions, which trigger an error on Daniel> some compilers, that is (0.0 / 0.0) for nan, (1.0 / 0.0) for infinity Daniel> - use defined by C99 macros: INFINITY and NAN, which will work on any Daniel> compiler supporting C99.Option 3: Create them yourself in portable C. Something like
union { int i[2]; double d; } u;
/* +Infinity */ u.i[MSB] = 0x7ff00000; u.i[LSB] = 0; u.d is +Infinity
where MSB and LSB are 0 or 1 depending on the endianness of machine. If you have 64-bit integers, you can replace int i[2] with long i and just use i = 0x7ff0000000000000;
This works for NaN too, but there are many different values for NaN, so you'll have to choose something.
We have at least three float types – short-float, single-float and double-float, plus on some architectures long-float. Will this approach work on all of these types?
Also, we'll have to define such infinity for each architecture separately, depending on the endianess?
I'm don't know float numbers well enough, but soft floats and hard floats on arm architecture make any difference for us, or C compiler will handle it without any intervention?