.help zlocva May84 "System Interface"
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NAME
zlocva -- get the memory address of a variable
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SYNOPSIS
.nf
zlocva (object, address)

arb	object			# reference to variable
int	address			# value of the reference
.fi
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DESCRIPTION
The memory address of \fIobject\fR in char storage units is returned as
the value of the integer variable \fIaddress\fR.  The referenced object
may be a variable or array element of actual datatype \fBcsilrdx\fR.
The referenced object may \fInot\fR be a procedure or a Fortran character
variable.
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RETURN VALUE
The memory address returned references the process logical address space
\fIin units of SPP chars\fR.  No zero point is assumed.
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NOTES
We assume that the maximum address in char units will fit into a signed
integer variable.  The high level code assumes that it can do signed integer
comparisons and arithmetic operations (additions and subtractions) upon the
addresses returned by \fBzlocva\fR to check arrays for equality and overlap
and to compute offsets when generating pointers into Mem.
Negative addresses are permitted provided the signed arithmetic and
comparison operations work properly, i.e., provided the negative addresses
are assigned to the first half of the process logical address space.
The following relationship must hold:

.nf
	call locva (Memc[1], addr1)
	call locva (Memc[2], addr2)
	if (addr2 - addr1 == 1 for all possible locations of Memc)
	    locva conforms to the standard
.fi

\fBMemc\fR is an SPP char array in the global common \fBMem\fR.
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SEE ALSO
zmaloc, zlocpr
.endhelp