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From: phil@UX1.CSO.UIUC.EDU (Phil Howard KA9WGN)
Newsgroups: comp.lang.asm370
Subject: Re: MVCL (was Re: why code in 370 Assembler)
Message-ID: <9104290459.AA06764@ucbvax.Berkeley.EDU>
Date: 29 Apr 91 04:23:40 GMT
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Reply-To: IBM 370 Assembly Programming Discussion List
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rickert@CS.NIU.EDU ("Neil Rickert, N Illinois U, CS") writes:

>  What if you have a reentrant subroutine, R15 is your base reg, R1 has
>parameters, R2-12 are tied up for your computationally intense algorithm, and
>the routine will be used heavily enough that you cannot afford the cost of
>a GETMAIN?

If you were designing the calling interface, I'd go back and rethink it.
One possible savings might be in passing in a temporary data area to
play with, that would hopefully not need to be allocated over and over
in the calling program.

But then, I find it a but hard to imagine a program that is computationally
intense AND having shove some bytes, too.  But anything is possible.

> Don't assume that just because the instruction is MVC or MVCL you are dealing
>with characters.  It might just be an array of numbers.

Hopefully you at least know in advance.  I did write a FORTRAN callable
function called MVCL (and one called CLCL; guess what it did).  There
were 5 arguments:  array1, length1, array2, length2, pad.
Of course this program had no idea what the data type was, but the
calling program was the one to decide if there were any overlaps.
--
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