Enabling --enable-check-lisp-object-type by default on x86 and AMD64 (was: Re: bug#26597: 25.1; Compilation error on master with --enable-check-lisp-object-type)

[Philipp Stephani]

Eli Zaretskii <address@hidden> schrieb am Sa., 22. Apr. 2017 um 15:35 Uhr:

> From: Philipp Stephani <address@hidden>
> Date: Sat, 22 Apr 2017 11:57:11 +0000
>
>  > (Tangentially, is there any reason not to define Lisp_Object as struct
>  > unconditionally, to avoid such coding errors?)
>
>  Yes, it produces slower code.
>
> Are you sure that's still the case? I've just diffed the assembly output for editfns.c with and without
> --enable-check-lisp-object-type, they seem identical (apart from minor diffs due to different register allocation
> and instruction ordering). Replacing a primitive value with a struct containing such a value should never
> degrade performance; that would be a compiler bug.

On what OS/architecture, and with what compiler options?

On macOS, with configure called e.g. as

./configure  '--without-xml2' '--with-modules' '--without-pop' '--with-mailutils' --enable-check-lisp-object-type 'CFLAGS=-O2 -save-temps' 'MAKEINFO=/usr/local/opt/texinfo/bin/makeinfo'

 

in any case, if you want to raise this issue, please post to
emacs-devel, not here.

Moved to emacs-devel.