Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #31533

Re: Return of the Applets?

Show key headers only | View raw

On 4/7/2015 7:00 PM, Martin Gregorie wrote:
> On Tue, 07 Apr 2015 17:11:48 -0400, Jerry Stuckle wrote:
> 
>> Internally, IBM had a language called PL/S which was a subset of PL/1
>> with an embedded assembler.  The compiler would convert the PL/S
>> statements to assembler statements, then assemble the program.  It sped
>> up development quite a bit, while still keeping the efficiency of
>> assembler where needed (even back then mainframe OS's had to be coded in
>> assembler for efficiency).
>>
> Interesting.
> 
> In the late 70s/early 80s the same thing showed up on 8/16 bit chips. I 
> did a fair amount of programming in both assembler and PL/9 (a clone of 
> the lowish-level PL/M for Intel chips but for the MC6809). A nice feature 
> of PL/9 was that it could generate out assembler source rather than 
> binary if you asked nicely and it was equally easy to drop chunks of 
> assembler back into a PL/9 . Consequently, it was dead easy to optimise 
> code that way. PL/9 was a good code generator (it was almost impossible 
> to improve in the code it generated for each statement) but a poor code 
> optimiser (it made no attempt to rationalise adjacent code where one 
> statement ended and the next began), so it was interesting that some 
> chunks of code could be improved a lot by recoding in assembler, but most 
> of the compiler's output could be improved only marginally. 
> 
> I've written a bit of PL/1 in the past - all on AS/400 or IBM System/88 
> (rebadged Stratus fault-tolerant boxes) though, never on a mainframe.
> 
> So, I'm curious: did PL/S show the same characteristic I discovered in 
> PL/9?  
> 
> 

Yup, it was basically just a generator; no optimization involved.  An
"if" statement always generated the same code (other than the condition
itself, anyway).  But like PL/9, it was expert assembler programmers who
coded the compiler, and they new every shortcut in the book, so it was
pretty much impossible to optimize any single statement.  And the
language itself was very slimmed down, with only the more common
statements such as if/then/else, loops and similar "easy" statements.

But even without optimization, the generated code was generally so good
it didn't require much, if any, rework.

-- 
==================
Remove the "x" from my email address
Jerry Stuckle
jstucklex@attglobal.net
==================

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-05 09:46 -0400
  Re: Return of the Applets? Jeff Higgins <jeff@invalid.invalid> - 2015-04-05 13:12 -0400
  Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-05 15:14 -0400
    Re: Return of the Applets? Arne Vajhøj <arne@vajhoej.dk> - 2015-04-05 16:41 -0400
      Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-05 16:54 -0400
        Re: Return of the Applets? Arne Vajhøj <arne@vajhoej.dk> - 2015-04-05 17:08 -0400
          Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-05 17:17 -0400
            Re: Return of the Applets? Arne Vajhøj <arne@vajhoej.dk> - 2015-04-05 17:30 -0400
              Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-05 17:42 -0400
                Re: Return of the Applets? Arne Vajhøj <arne@vajhoej.dk> - 2015-04-05 17:52 -0400
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-05 18:17 -0400
                Re: Return of the Applets? Luuk <luuk@invalid.lan> - 2015-04-06 11:26 +0200
    Re: Return of the Applets? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2015-04-06 13:23 -0500
      Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-06 15:09 -0400
        Re: Return of the Applets? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2015-04-06 17:33 -0500
          Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-06 17:44 -0400
            Re: Return of the Applets? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2015-04-06 19:10 -0500
              Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-06 20:03 -0400
                Re: Return of the Applets? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2015-04-06 21:36 -0500
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-07 09:11 -0400
            Re: Return of the Applets? Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-06 23:25 +0000
              Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-06 19:59 -0400
                Re: Return of the Applets? Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-07 13:29 +0000
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-07 10:45 -0400
                Re: Return of the Applets? Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-07 15:51 +0000
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-07 13:16 -0400
                Re: Return of the Applets? Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-07 20:22 +0000
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-07 17:03 -0400
                Re: Return of the Applets? Leif Roar Moldskred <leifm@huldreskog.localdomain> - 2015-04-07 11:34 -0500
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-07 13:18 -0400
                Re: Return of the Applets? Leif Roar Moldskred <leifm@huldreskog.localdomain> - 2015-04-07 12:40 -0500
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-07 17:06 -0400
                Re: Return of the Applets? Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-07 20:28 +0000
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-07 17:11 -0400
                Re: Return of the Applets? Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-07 23:00 +0000
                Re: Return of the Applets? Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-07 19:25 -0400
  Re: Return of the Applets? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2015-04-06 13:09 -0500

csiph-web