Re: SuperH port

[Ulrich Mueller]

>>>>> On Thu, 16 Oct 2008, Dan Nicolaescu wrote:

> On all the machines that I am aware off that support both big and
> little endian the compiler predefines a symbol to distinguish
> between them.

It turns out that gcc defines __LITTLE_ENDIAN__ and __BIG_ENDIAN__,
respectively:

   $ echo | sh4-gentoo-linux-uclibc-gcc -nostdinc -dM -E - | grep ENDIAN
   __LITTLE_ENDIAN__

(To add some confusion, endian.h then also defines _all_ four of
__LITTLE_ENDIAN, LITTLE_ENDIAN, __BIG_ENDIAN, and BIG_ENDIAN,
regardless of the machine's byte sex. Go figure.)

> I'll install this when the endianess issue gets resolved.

I still think that my previous approach (include sys/param.h and
test for __BYTE_ORDER) was cleaner. But if you absolutely want a
compiler-defined symbol, an updated patch is included below.

Ulrich

emacs/ChangeLog entry:

2008-10-16  Ulrich Mueller  <address@hidden>

        * configure.in: Add support for GNU/Linux on SuperH.

emacs/etc/ChangeLog entry:

2008-10-16  Ulrich Mueller  <address@hidden>

        * MACHINES: Add section for SuperH.

emacs/src/ChangeLog entry:

2008-10-16  Ulrich Mueller  <address@hidden>

        * m/sh3.h: New file, machine description for SuperH.


--- emacs-orig/configure.in     2008-08-28 22:31:27.000000000 +0200
+++ emacs/configure.in  2008-10-16 17:27:37.000000000 +0200
@@ -540,6 +540,11 @@
     machine=xtensa opsys=gnu-linux
     ;;
 
+  ## SuperH Linux-based GNU system
+  sh[34]*-*-linux-gnu* )
+    machine=sh3 opsys=gnu-linux
+  ;;
+
   * )
     unported=yes
   ;;
--- emacs-orig/etc/MACHINES     2008-08-01 23:44:40.000000000 +0200
+++ emacs/etc/MACHINES  2008-10-16 17:27:37.000000000 +0200
@@ -426,6 +426,12 @@
   (now remapped as part of the text).  These are never
   swapped in.
 
+SuperH (sh[34]*-*-linux-gnu)
+
+  Emacs 23.0.60 was reported to work on GNU/Linux (October 2008).
+  Tested on a little-endian sh4 system (cpu type SH7751R) running
+  Gentoo Linux 2008.0.
+
 Tadpole 68K (m68k-tadpole-sysv)
 
   Changes merged in 19.1.
--- emacs-orig/src/m/sh3.h      1970-01-01 01:00:00.000000000 +0100
+++ emacs/src/m/sh3.h   2008-10-16 17:27:37.000000000 +0200
@@ -0,0 +1,20 @@
+/* Machine description file for SuperH. */
+
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
+   is the most significant byte.  */
+
+#if defined (__LITTLE_ENDIAN__) && !defined (__BIG_ENDIAN__)
+# undef WORDS_BIG_ENDIAN
+#elif defined (__BIG_ENDIAN__) && !defined (__LITTLE_ENDIAN__)
+# define WORDS_BIG_ENDIAN
+#else
+# error "cannot determine byte sex"
+#endif
+
+/* Define NO_ARG_ARRAY if you cannot take the address of the first of a
+   group of arguments and treat it as an array of the arguments.  */
+
+#define NO_ARG_ARRAY
+
+/* arch-tag: c997297c-9b92-11dd-b25e-0012f098dd76
+   (do not change this comment) */