.file	"zsvjmp.s"

# ZSVJMP, ZDOJMP -- Set up a jump (non-local goto) by saving the processor
# registers in the buffer jmpbuf.  A subsequent call to ZDOJMP restores
# the registers, effecting a call in the context of the procedure which
# originally called ZSVJMP, but with the new status code.  These are Fortran
# callable procedures.
#
#		zsvjmp (jmp_buf, status)	# (returns status)
#		zdojmp (jmp_buf, status)	# (passes status to zsvjmp)
#
# These routines are directly comparable to the UNIX setjmp/longjmp, except
# that they are Fortran callable kernel routines, i.e., trailing underscore,
# call by reference, and no function returns.  ZSVJMP requires an assembler
# jacket routine to avoid modifying the call stack, but relies upon setjmp
# to do the real work.  ZDOJMP is implemented as a portable C routine in OS,
# calling longjmp to do the restore.  In these routines, JMP_BUF consists
# of one longword containing the address of the STATUS variable, followed
# by the "jmp_buf" used by setjmp/longjmp.
#
# This file contains the SUN/UNIX 386i (80386) version of ZSVJMP.
 
        .globl	zsvjmp_
        .globl	setfpucw

	# The following has nothing to do with ZSVJMP, and is included here
	# only because this assembler module is loaded with every process.
	# This code sets the value of the symbol MEM (the VOS or Fortran Mem
	# common) to zero, setting the origin for IRAF pointers to zero
	# rather than some arbitrary value, and ensuring that the MEM common
	# is aligned for all datatypes as well as page aligned.  A further
	# advantage is that references to NULL pointers are likely to cause a
	# memory violation.

	.globl	mem_
	mem_	=	0

	.text
zsvjmp_:
	movl	4(%esp), %ecx		# &jmpbuf to ECX
	movl	8(%esp), %eax		# &status to EAX
	movl	%eax, (%ecx)		# store &status in jmpbuf[0]
	movl 	$0, (%eax)		# zero the value of status
	addl	$4, %ecx		# change stack to point to &jmpbuf[1]
	movl	%ecx, 4(%esp)		# 	...
	jmp	__setjmp		# let setjmp do the rest

setfpucw:
	pushl  %ebp
	movl   %esp,%ebp
	subl   $0x4,%esp
	movl   0x8(%ebp),%eax
	fnstcw 0xfffffffe(%ebp)
	movw   0xfffffffe(%ebp),%dx
	andl   $0xfffff0c0,%edx
	andl   $0xf3f,%eax
	orl    %eax,%edx
	movw   %dx,0xfffffffe(%ebp)
	fldcw  0xfffffffe(%ebp)
	leave  
	ret