Help needed: small piece of assembler code for IRAF

[Ole Streicher <olebole@debian.org>]

Dear m68k enthusiasts,

I am the maintainer of the "iraf" package [1]. Although most of the code 
is portable, it needs one piece of assembler code for each platform that 
provides a (sort of) setjmp for FORTRAN.

A "C" implementation for this looks like:

#include <setjmp.h>

int zsvjmp_( long *buf, long *status ) {
  *status = 0;
  ((long **)buf)[0] = status;
  return sigsetjmp ((void *)((long **)buf+1),0);
}

however this does not work, since the "sigsetjmp" call needs to be 
replaced by a jump to sigsetjmp instead.

As IRAF is a 40-year old package, there was already some assembler that 
was used ~35 years ago [2]:

-------------------------------8<-----------------------------------
	.proc
	.import setjmp
	.export zsvjmp
	.callinfo
zsvjmp
;
;	save address to status word in jmp_buf[0]
;
	stw 	arg1,0(0,arg0)
	ldi	0,1
	stws	1,0(0,arg1)
;
;	call setjmp with jmp_buf[1]..jmp_buf[51]
;
	addi	4,arg0,arg0
	b	setjmp
	nop
;
;	setjmp will return directly to the caller of zsvjmp at this
;	point, so the next statement will never be reached.
;
	nop
	.procend
-------------------------------8<-----------------------------------

However, just including this does not work because assembler syntax 
changed [3].

I created a small repository [4] that contains the assembler I collected
so far as well as two test programs.

As I am not familiar with HP assembler I have no idea how to adopt the 
assembler code. Maybe someone could help me here? Preferably under the 
IRAF license [5], so that it can be included upstream later.

One way that worked for other platforms was to compute the C snipped 
above (having the sigsetjmp function name by something else) with an 
optimizing compiler.

There is no request from the users to have this ported to hppa, and I
doubt that ever will. My main motivation to get it ported is to check
the package for hidden problems on "unusual" architectures.

Best regards

Ole


[1] https://tracker.debian.org/pkg/iraf
[2] 
https://github.com/iraf-community/iraf/blob/v2.16.1/unix/portkit/zsvjmp.s.HP800
[3] 
https://buildd.debian.org/status/fetch.php?pkg=iraf&arch=hppa&ver=2.18.1%7Erc1-3%7E2&stamp=1726682218&raw=0
[4] https://github.com/olebole/zsvjmp
[5] https://iraf-community.github.io/COPYRIGHT.html