Re: Floating-point constant folding in Emacs byte compiler

[Noam Postavsky]

On 30 March 2018 at 12:26, Pip Cet <address@hidden> wrote:

> It's easy to fix this by merging the constvec based on eql rather than
> eq, but that makes the byte compiler inconsistent: with optimization,
> (lambda () (eq 1024.0 1024.0)) will still be false, but without
> optimization, it will turn into bytecode that always returns true.

The byte-compiler is already inconsistent in this way for string literals:

(funcall (byte-compile (lambda ()
                         (let ((s "one") (s2 "one"))
                           (eq s s2)))))
;=> t

(funcall (lambda ()
           (let ((s "one") (s2 "one"))
             (eq s s2))))

;=> nil

Although surprisingly:

(funcall (byte-compile (lambda ()
                         (eq "one" "one"))))
;=> nil