[doc,patch] Fortran compiler on Ultrix and clobbered registers

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[doc,patch] Fortran compiler on Ultrix and clob...
\ FX Coudert (29 Apr 2007)
. \ John David Anglin (29 Apr 2007)

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Subject:	[doc,patch] Fortran compiler on Ultrix and clobbered registers
Group:	Gcc
From:	FX Coudert
Date:	29 Apr 2007

I noted in the GCC docs (see for example http://gcc.gnu.org/
onlinedocs/gcc/Interoperation.html) that we have the following text
in the section "Known Causes of Trouble with GCC":

> On Ultrix, the Fortran compiler expects registers 2 through 5 to be
> saved by function calls. However, the C compiler uses conventions
> compatible with BSD Unix: registers 2 through 5 may be clobbered by
> function calls.
>
> GCC uses the same convention as the Ultrix C compiler. You can use
> these options to produce code compatible with the Fortran compiler:
> -fcall-saved-r2 -fcall-saved-r3 -fcall-saved-r4 -fcall-
> saved-r5

That code was initially committed to gcc/gcc.texi in 1997 (it's now
in gcc/doc/gcc.texi). As there have been a few changes on the
compiler since that time, I wonder if it's still true, and still
useful to have that comment there. As there is no ultrix maintainer
(though it's still listed as a supported platform), I'm CCing the VAX
maintainers: can you comment on the usefulness of this part of the doc?

So, unless someone can raise a reason against it, I'd like to propose
the patch below to remove it. Built and tested on i686-linux (make
info && make html). OK for mainline?

FX

Index: gcc/doc/trouble.texi
===================================================================
--- gcc/doc/trouble.texi (revision 124144)
+++ gcc/doc/trouble.texi (working copy)
@@ -234,20 +234,6 @@ you cannot successfully use @samp{$} in
to a restriction in the IBM assembler. GAS supports these
identifiers.
-@cindex VAX calling convention
-@cindex Ultrix calling convention
-@item
-@opindex fcall-saved
-On Ultrix, the Fortran compiler expects registers 2 through 5 to be
saved
-by function calls. However, the C compiler uses conventions compatible
-with BSD Unix: registers 2 through 5 may be clobbered by function
calls.
-
-GCC uses the same convention as the Ultrix C compiler. You can use
-these options to produce code compatible with the Fortran compiler:
-
-@smallexample
--fcall-saved-r2 -fcall-saved-r3 -fcall-saved-r4 -fcall-saved-r5
-@end smallexample
@end itemize
@node Incompatibilities