bugMIT/GNU Scheme - Bugs: bug #27385, compiler still generates bad i386...

 
 

bug #27385: compiler still generates bad i386 code in the general case of FIXNUM-LSH, for negative arguments

Submitted by:  Taylor R. Campbell <riastradh>
Submitted on:  Sat 05 Sep 2009 06:37:02 AM UTC  
 
Category:  compiler Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect behavior
Status:  Fixed Privacy:  Public
Assigned to:  Taylor R. Campbell <riastradh> Originator Name: 
Open/Closed:  Closed
Keywords: 

Add a New Comment(Rich Markup)
   

You are not logged in

Please log in, so followups can be emailed to you.

 

Fri 13 Nov 2009 10:10:24 PM UTC, comment #1:

Should be fixed in commit 1f62f5c1dc6575221159605ab72e44adcafdfe7b.

Taylor R. Campbell <riastradh>
Project MemberIn charge of this item.
Sat 05 Sep 2009 06:37:02 AM UTC, original submission:

All of the following should yield -1:

(fix:lsh -1 -1)
;Value: 33554431

(fix:lsh -1 -30)
;Value: 0

(fix:lsh -123 -30)
;Value: 0

This should yield -62:

(fix:lsh -123 -1)
;Value: 33554370

The general case is already so complex that it would probably be worthwhile just to bail and defer to the microcode primitive, but I don't think Liar can do that only for particular uses of primitives, and obviously we don't want to do that for every use of the FIXNUM-LSH primitive.

Taylor R. Campbell <riastradh>
Project MemberIn charge of this item.

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:
   
   
Comment:
   

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -email is unavailable- added by riastradh (Submitted the item)
  •  

    Do you think this task is very important?
    If so, you can add your encouragement to it.
    This task has 0 encouragements so far.

    Only logged-in users can vote.

     

    Please enter the title of George Orwell's famous dystopian book (it's a date):

     

     

    Follow 5 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    Fri 30 Aug 2013 06:17:22 PM UTC riastradh StatusReady For Test => Fixed
        Assigned toNone => riastradh
        Open/ClosedOpen => Closed
    Fri 13 Nov 2009 10:10:24 PM UTC riastradh StatusNone => Ready For Test
    Sat 05 Sep 2009 06:37:36 AM UTC riastradh Summarycompiler still generates bad code in the general case of FIXNUM-LSH, for negative arguments => compiler still generates bad i386 code in the general case of FIXNUM-LSH, for negative arguments

    Back to the top


    Powered by Savane 3.3