Re: Floating-point constant folding in Emacs byte compiler

[Eli Zaretskii]

> From: Paul Eggert <address@hidden>
> Date: Thu, 22 Mar 2018 22:22:25 -0700
> 
> Nowadays Emacs hosts almost invariably use IEEE floating point, and I suppose 
> we 
> could hardwire that assumption into Emacs. Even so, IEEE floating-point is 
> not 
> bit-for-bit identical on all platforms, so if we're constant-folding 
> floating-point expressions surely we should at least document that we're 
> doing 
> so, so that programmers know that they can't rely on constant expressions 
> yielding a different value than what run-time evaluation would deliver.

I think we should strive to leave the byte code platform-independent.
If nothing else, it will make sure the *.elc files in a release
tarball can be used on all supported platforms with identical
results.  Otherwise, we will need to byte-compile files at build time,
something that will make the build much longer than it should be.