I want to write cross-platform C/C++ which has reproducible behaviour across different environments.
I understand that gcc's ffast-math enables various floating-point approximations. This is fine, but I need two separately-compiled binaries to produce the same results.
Say I use gcc always, but variously for Windows, Linux, or whatever, and different compiler versions.
Is there any guarantee that these compilations will yield the same set of floating-point approximations for the same source code?