perm filename NEWLEP.TXT[DOC,AIL] blob sn#243886
filedate 1976-10-30 generic text, type C, neo UTF8
COMMENT ⊗ VALID 00002 PAGES
C REC PAGE DESCRIPTION
C00002 00002 October 30, 1976 New LEAP (?)
October 30, 1976 New LEAP (?)
Jim Low, Jerry Feldman, & Co. of the University of Rochester have rewritten
LEAP runtimes. Several advantages are claimed:
1. The hashing algorithm for associations has been improved so that
the overall running speed of several programs has increased by 10-30%.
2. More items: the 4K restriction on the number of items has been removed.
You can have as many as you have core for (minimum 2 words/item).
(It is probably the case that you have to state in advance how many you
wish to have.)
3. Less restrictive storage allocation. The storage for LEAP is no longer
restricted to lie in addresses less than 128K, as was formerly the case.
4. Items are allocated in decreasing order; some operations on sets are
more efficient becaue of this.
5. The user can request that all DATUM operations be checked to insure that
the item has not been DELETEd and that the type corresponds to the type
which the compiler expected.
6. The warning message TWO PROGRAMS WITH ITEMS can be disabled upon request.
The following considerations apply with respect to incorporating these
modifications into Sail at Stanford A.I. lab:
1. A new major version number and a new runtime segment (SAISG9, GLBSG9)
would be required. Old .REL files would need to be recompiled.
This would affect all users of Sail, not just users of LEAP.
(It is possible that the new version and segment may be coming shortly
anyway, due to the addition of other major features.)
2. It is possible that bugs in the new code would cause old programs to
3. JFR is planning to graduate shortly.
4. It is probable that the new code is somewhat larger than the old.
Please MAIL your comments and suggestions to AIL.