Subject: Re: bug#8794: (b) make the 64bit-on-32bit the default (if supported)

From: Paul Eggert <[email-masked]>
Date: Mon, 06 Jun 2011 21:21:07 -0700

On 06/06/11 07:52, Stefan Monnier wrote:
> We should make a --with-wide-int option for ./configure, tho.

I did that in the trunk as bzr 104521, with this patch:

[ChangeLog]
* configure.in: Add --with-wide-int.
* INSTALL: Mention this.
[etc/ChangeLog]
* NEWS: Mention new configure option --with-wide-int.
=== modified file 'INSTALL'
--- INSTALL	2011-05-18 03:39:45 +0000
+++ INSTALL	2011-06-07 04:13:43 +0000
@@ -309,6 +309,10 @@

 Use --without-sound to disable sound support.

+Use --with-wide-int to implement Emacs values with the type 'long long',
+even on hosts where a narrower type would do.  With this option, on a
+typical 32-bit host, Emacs integers have 62 bits instead of 30.
+
 The `--prefix=PREFIXDIR' option specifies where the installation process
 should put emacs and its data files.  This defaults to `/usr/local'.
 - Emacs (and the other utilities users run) go in PREFIXDIR/bin

=== modified file 'configure.in'
--- configure.in	2011-05-28 22:39:39 +0000
+++ configure.in	2011-06-07 04:13:43 +0000
@@ -144,6 +144,11 @@
 	  with_x_toolkit=$val
 ])

+OPTION_DEFAULT_OFF([wide-int], [prefer wide Emacs integers (typically 62-bit)])
+if test "$with_wide_int" = yes; then
+  AC_DEFINE([WIDE_EMACS_INT], 1, [Use long long for EMACS_INT if available.])
+fi
+
 dnl _ON results in a '--without' option in the --help output, so
 dnl the help text should refer to "don't compile", etc.
 OPTION_DEFAULT_ON([xpm],[don't compile with XPM image support])

=== modified file 'etc/NEWS'
--- etc/NEWS	2011-06-06 19:43:39 +0000
+++ etc/NEWS	2011-06-07 04:13:43 +0000
@@ -47,6 +47,9 @@
 This is only useful for Emacs developers to debug certain types of bugs.
 This is not a new feature; only the configure flag is new.

+** There is a new configure option --with-wide-int.
+With it, Emacs integers typically have 62 bits, even on 32-bit machines.
+
 ---
 ** New translation of the Emacs Tutorial in Hebrew is available.
 Type `C-u C-h t' to choose it in case your language setup doesn't