Path: utzoo!mnetor!uunet!ncc!alberta!att-ih!ihnp4!ucbvax!tekgvs.GVS.TEK.COM!mikec
From: mikec@tekgvs.GVS.TEK.COM (Micheal Cranford)
Newsgroups: comp.lang.modula2
Subject: Re: "FOR loop" control var. and limit expression types
Message-ID: <8804140228.AA15714@tekgvs.GVS.TEK.COM>
Date: 14 Apr 88 02:28:23 GMT
References: <INFO-M2%88040714385483@UCF1VM>
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: Info-Modula2 Distribution List <INFO-M2%UCF1VM.bitnet@jade.berkeley.edu>
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 61


Harvard, you resently stated :

"I am interested in people's opinions on the restrictions of compatibility
between a FOR loop control variable and the types of limit expressions."
............................[deleted]..................................
"The issue arose during my work to port the 1-pass MC68K native code ETH
compiler."
............................[deleted]..................................
"I intend to change it to allow a free mix of CARDINAL and INTEGER control
variable and limit expressions, but I wanted to get others opinions and
interpretations first."
............................[deleted]..................................


  I have nothing useful to offer here except the painfully obvious `it seems
the parser is even more confused than Wirth's definition of compatibility.'.
Your proposed solution sounds just fine to me (follows Wirth's `INTEGER :=
CARDINAL assignment rules).

  So why am I bothering you?  I am interested in the "1-pass MC68K native code
ETH compiler".  I am currently using an optimizing MC68K native code Modula2
compiler that has a number of problems.

  1. A number of irritating `bugs'.
  2. No compiler support available due to (3).
  3. Original authors had a fight and went separate ways.
  4. Incredibly slow to optimize (over 1/2 hour on a 1K line program).
  5. No compiler source available (they are still fighting over `ownership').
  6. Some of the optimization is apparently for another microprocessor (i.e.
   instead of using BSET (BCLR) it uses `ROR, OR#1 (AND#FE), ROL' with sets!).
  7. Etc......

  Some Modula2 compilers that I currently have source to are :

  1. 4 pass for ETH Lilith (generates `M' code - currently unused)
  2. 4 pass for VMS VAX (derived from ETH multipass - currently unused)
  3. 5 pass for MC68000 (derived from ETH 5 pass PDP11 - currently unused)
  4. 1 (or 2?) pass for MC68000 (locally generated, little documentation,
   author departed over 2 years ago, has been used - currently unused).

  I just received #4 (above) and have started checking to see how involved it
will be to make it operational (I don't know about optimizations, etc).  My
best choice may be to look elsewhere for a compiler (with source available).

  Some standard questions for you :

    1. Is the "1-pass MC68K native code ETH compiler" `public domain'?
    2. IF `yes' then can you send me a copy, otherwise, how much $?
    3. What optimizations does it perform?  Reliability?  Bugs?

  Standard answers (check one or more) :

 [] 1. No.
 [] 2. Yes.
 [] 3. Maybe.
 [] 4. Go away.
 [] 5. Don't bother me.
 [] 6. Other ... please specify in reply

                                     Micheal Cranford