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From: akcs.erk@tronsbox.xei.com (Erk)
Newsgroups: comp.lang.rexx
Subject: Re: Rexx compiler(s)
Message-ID: <26d00a0a-3d.4comp.lang.rexx-1@tronsbox.xei.com>
Date: 20 Aug 90 18:13:41 GMT
References: <90230.092947BOYDJ@QUCDN.BITNET> <90231.095318BOYDJ@QUCDN.BITNET>
Lines: 86

I attended a seminar where some of the details of a COMPLETED REXX
compiler for IBM VM/CMS were detailed.
 
The REXX compiler:
 
   programs run 2-10 times faster than the interpreted
   version. (Depending on program content)
 
   is plug compatible with interpreted REXX
 
   includes comprehensive REXX program documentation via source and
   cross reference listing
 
   provides support of SAA procedures language
 
   exploits eXtended Architecture. (can run above the 16 megabyte line)
 
 
Performance depends upon what your program does.
If your program contains a lot of you can expect performance
improvements on these orders:
 
   Arithmetic operations         6-10  times faster
   with default precision
                              
   Arithmetic operations         4-25  times faster
   with other precision
 
   Assignments                   6-20  times faster
 
   Changes to variables          4-6   times faster
   values, constants and
   simple variables
 
   Reuse of compound variables   2-4   times faster
 
   Host commands                 1-2   times faster
 
 
The compile-time module is written in C and compiled with SAA C/370
Compiler. The run-time module was written in BAL (assembler) and can
be loaded into the Discontiguous Shared Segment.
 
Now, for all of these great features, there must be a price.  :-(
 
   You have to compile in (gulp) a 4 megabyte virtual machine.
   1 megabyte of that is for C/370 library and the REXX compiler. 
 
   Run time storage is about the same amount as the interpreted 
   version plus you need an extra 180 kilobytes for run-time support.
 
   An SVC type argument/parameter interface is required mainly for the
   invocations from assembler programs.
 
   INTERPRET instruction not supported (big surprise, right?) BUT
   you can call the REXX interpreter to provide this support.
 
   TRACE instructions are ignored for the interest of performance
 
 
Now, where can I find a REXX compiler. A good question. It is
currently supported on 
   VM/SP Release 5         (5664-167) 
   VM/SP Release 5 HPO     (5664-173)
   VM/XA System Product 1  (5664-308)
 
   CMS REXX compiler       (5664-390)
   CMS REXX library        (5684-124)
 
 
All of this information is from a document by Bert Moser at IBM
Vienna Software Lab, Austria. There was no copywrite notice, but that
probably doesn't mean beans.
 
-----------------------------------------
 
 Eric Glenn - akcs.erk@tronsbox.xei.com 
 Be alert! The world needs more lerts.
 
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