不使用IEEE754浮点的C ++编译器/平台

Question

I'm working on updating a serialization library to add support for serializing floating point in a portable manner. Ideally I'd like to be able to test the code in an environment where IEEE754 isn't supported. Would it be sufficient to test using a soft-float library? Or any other suggestions about how I can properly test the code?

Answer 1

Free toolchains that you can find for ARM (embedded Linux) development, mostly do not support hard-float operations but soft-float only. You could try with one of these (ie CodeSourcery ) but you would need some kind of a platform to run the compiled code (real HW or QEMU).

Or if you would want to do the same but on x86 machine, take a look at: Using software floating point on x86 linux

Answer 2

Should your library work on a system where both hardware floating point and soft-float are not available ? If so, if you test using a compiler with soft-float, your code may not compile/work on such a system.

Personally, I would test the library on a ARM9 system with a gcc compiler without soft-float.

Answer 3

Not an answer to your actual question, but describing what you must do to solve the problem.

If you want to support "different" floating point formats, your code would have to understand the internal format of floats [unless you only support "same architecture both ends"], pick the floating point number apart into your own format [which of course may be IEEE-754, but beware of denormals, 128-bit long doubles, NaN, INFINITY, and other "exception values", and of course out of range numbers], and then put it back together to the format required by the other end. If you are not doing this, there is no point in hunting down a non-IEEE-754 system, because it won't work.