Subject: Re: bug#42147: 28.0.50; pure vs side-effect-free, missing optimizations?

From: Eli Zaretskii <[email-masked]>
Date: Sun, 05 Jul 2020 05:38:55 +0300

> From: Pip Cet <[email-masked]>
> Date: Sat, 4 Jul 2020 22:25:55 +0000
> Cc: [email-masked], Paul Eggert <[email-masked]>, [email-masked],
>  [email-masked]
> 
> > I'm actually not completely sure why we care about those minor
> > rounding differences.
> 
> Neither am I. If the idea is to standardize Emacs on a single
> floating-point representation, let's at least use the 61-bit floats
> Paul suggested a while back? (Incidentally, I believe those can be
> implemented somewhat more efficiently on x87 hardware). Or we could go
> with bignum ratios or GMP floats.

Some other relevant questions:

  . why didn't GCC folks made SSE2 the default output?  shouldn't
    Emacs follow the defaults, and leave it to the experts to decide
    which instruction set should be the default?

  . which other projects use this non-standard instruction set?  GNU
    Guile, for example, doesn't, so why should we?