Re: i370 port

["Paul Edwards" <mutazilah at gmail dot com>]

There are a couple of places where I need to do something different
if I'm running on an EBCDIC host (e.g. MVS, CMS, MUSIC, VSE).

So in mvspdp.h I have put:

/* If running on MVS, need some EBCDIC-related differences */
#if defined(__MVS__) || defined(__CMS__)
#define HOST_EBCDIC 1
#endif

and c-parse.c:

#ifdef HOST_EBCDIC
#define YYTRANSLATE(YYX)                      \
 ((unsigned int) (YYX) <= YYMAXUTOK ? \
 ((unsigned int) (YYX) < 256 ? yytranslate[_sch_ebcasc[YYX]] \
 : yytranslate[YYX]) : YYUNDEFTOK)
#else
#define YYTRANSLATE(YYX) ^I^I^I^I^I^I\
 ((unsigned int) (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)
#endif

and opts.c:

#ifdef HOST_EBCDIC
static size_t
find_opt (const char *input, int lang_mask)
{
/* sequential search */


Is that a reasonable way to do it?

I think I should probably make the opts.c into a PUREISO so that
the sequential search is always used (ie work on an arbitrary C90
platform, not necessarily ASCII or EBCDIC).

But the c-parse one is definitely a translation that will only work
on EBCDIC.  That is useful so that I don't need to have a working
bison.  Similarly, the opts.c change doesn't require a working
shell!

> I think I would stop right there.  Why can't the i370 port support
> 64-bit integers?  Plenty of 32-bit hosts support them.

It got an internal error.  I don't have the skills to get that to work,
but I do have the skills to bypass it one way or another (and I
demonstrated what I am doing now, but I know that that
intrusive code will break everything else, so want to back it out,
without losing the functionality that I want).

> That said, these days gcc always defines __SIZEOF_LONG_LONG__.  It
> would be perfectly reasonable for hwint.h to test that.  Maybe
> something along the lines of
>
> #if !defined HAVE_LONG_LONG
> # if GCC_VERSION >= 3000
> #  ifdef __SIZEOF_LONG_LONG__
> #    define HAVE_LONG_LONG 1
> #    define SIZEOF_LONGLONG __SIZEOF_LONG_LONG__
> #  else
> #   define HAVE_LONG_LONG 1
> #   define SIZEOF_LONG_LONG 8

These both switch long_long on.  I want to switch it off (which it was
already).

> extern char sizeof_long_long_must_be_8[sizeof(long long) == 8 ? 1 : -1];
> #  endif
> # endif
> #endif

So would defining a new option be a reasonable solution for any
target that wants to limit code generation for whatever reason?

Thanks.  Paul.