Dear Maude Abusers,

A new alpha release can be accessed at SRI-CSL in:

~eker/public_html/Maude/Alpha92c/

or downloaded from:

http://www.csl.sri.com/~eker/Maude/Alpha92c/

Alpha release site authentication:

User Name: maudeabuser
Password: bughunter

This version is intended as the Maude entry for REC III and thus I've
only made Linux64 and IntelDarwin versions.

Bug fix
--------
(1) A bug in the metaPrettyPrint() operation where opening parens were
generated rather than closing parens if the mixfix and with-parens
options were both used on an associative term. Provoked by this
example from Traian:

mod X is
  including META-LEVEL .
  sort S .
  op a : -> S .
  op __ : S S -> S [assoc] .
endm

red metaPrettyPrint(upModule('X,false),upTerm(a a a), mixfix with-parens) .

Other changes
--------------
I've done a number of optimizations, mostly for free theory
rewriting. The biggest win seems to be implementing tail recursion
elimination on the last argument for the comparison of free theory dag
nodes.

So comparing terms like s(s(s(... 0 ...))) or l(a, l(b, l(c, ... )))
to terms that are almost but not quite equal (or that are equal but
unshared) becomes much faster.

Other optimizations that proved worthwhile included:

(a) Reorganizing key data structures and functions to avoid extra sign
extension instructions in hot spots on the x86-64.

(b) Simplifying the "need to collect garbage test" to a single global
Boolean.

(c) A result encoding trick for binary-search in the ACU theory.

(d) Special casing the free theory descrimination net code for free
symbols that store their arguments internally

(e) Recoding the branch free following of branching data structures
trick so that gcc can do an even cuter right shift trick.

(f) Depointerizing the free theory descrimination net code
(pointerizing was a RISC era trick when address generation units
couldn't do two adds per cycle) and using the lack of pointers to
speed up saving state information during condition evaluation.

Steven