We had a meeting of the Mercury group on Fri Mar 2, 2001, 
from 3.15 to 4.00pm. 
 
Attendees: 
 Fergus Henderson (fjh) 
 Zoltan Somogyi (zs) 
 David Jeffery (dgj) 
 Simon Taylor (stayl) 
 David Overton (dmo) 
 Thomas Conway (conway) 
 Kevin Glynn (keving)
 Adrian Pellas-Rice (apell) 
 
1. Background

 We have recently acquired two more machines, miles, a laptop, and earth, a
 workstation.  Simon Taylor (stayl) has returned to the fold. The summer
 students being supervised by Zoltan (zs) have left the office, although some
 are continuing their work remotely. 

2. Progress reports 
 
 We went around the table with each person in turn discussing what they had
 been working on recently and/or what they were planning to work on.  

 Fergus Henderson (fjh) 

	- some further work on the gcc back end.  At present, installing
	  libraries using mmake with the new back end does not work.
	- merging in Robert (rejj) Jeschofnik's changes to allow the expansion
	  of equivalence types to work with the .NET and Java backends.  Fergus
	  expressed some uncertainty about how best to go about these changes.
	  He then debated at length with Zoltan (zs) Somogyi about
	  whether/where equivalence types should occur in .int* files.
	- plans a similar change for the handling of abstract equivalence
	  types.  Zoltan suggests that abstract equivalence types should be
	  expanded no earlier than code generation, however Fergus was
	  concerned that this would be too hard.  Zoltan offered an additional
	  about idea using abstract maps for this task.  Zoltan and Fergus
	  agreed that this proposed change is likely to conflict with Zoltan's
	  current work.

 David Overton (dmo)

	- has continued work on mode checking.  Is experimenting with different
	  representations, particularly hash tables and bitsets.  Tom (conway)
	  Conway mentioned that in David Overton's case, specialisation of the
	  calls to the library's hash table module are highly desirable.  David
	  (dgj) Jeffery pointed out that the storage of the hash function in
	  the hash table data structure makes this a particularly tricky task.

 Zoltan Somogyi (zs)

	- has been fixing deep profiling bugs.  With these changes, deep
	  profiling now bootchecks.
	- posted the diff for liveness this week.  It bootchecks in two grades
	  and has been committed.
	- Has improved the accurate garbage collector so that it now succeeds
	  to the second stage of a bootcheck.  (It still bombs out in stage
	  three, of course.)

 David Jeffery (dgj)

	- has been working on his thesis.  A draft will be ready presently.

 Kevin Glynn (keving)

	- At this point Kevin revealed that he was attending the Mercury
	  meeting for stress relief.  It may not have killed him yet, but after
	  that remark, Kevin's thesis is clearly approaching the potency of
	  ebola.

 Simon Taylor (stayl)

	- has attended to software installation on earth.  (Recall that `earth'
	  is our new machine.)
	- part way to fixing a performance bug in deforestation.

 Thomas Conway (conway)

	- has been working on his thesis.
	- collaborated with Zoltan (zs) Somogyi on deep profiling.
	- plans to return to MDS within 3 weeks.

 Adrian Pellas-Rice (apell)

	- continued the well-behind-schedule implementation of sequence
	  quantification.
	- had some further assistance from Fergus (fjh) Henderson pertaining to
	  a serious bug.


3. Administrative Matters:

	- Zoltan (zs) Somogyi complained about the frequency of the emails
	  requesting bug fixes.  The present frequency is one email per bug per
	  day.  After some debate, Fergus (fjh) Henderson agreed to change the
	  frequency to the compromise position of one email per bug per three
	  days.
		- On this note, Fergus also suggested splitting the [mdev]
		  mailing list into two lists: one for diffs and one for all
		  other correspondence.  Zoltan advocated an even more radical
		  split into several topic based lists.  Discussion will resume
		  at a later date.
	- Zoltan requested that more file systems be exported to miles (the
	  laptop), and requested assistance with some of the more concisely
	  documented software on miles.  Simon (stayl) Taylor agreed to see to
	  the file systems, David (dmo) Overton agreed to see to the software.

4. General Matters:

	- Fergus and Zoltan discussed a problem with value numbering.  Though a
	  temporary fix is in place, Zoltan advocates the removal of value
	  numbering as the long term repair strategy.
	- There were some exchanges about the grades and modules that are
	  approaching redundancy.  Fergus wanted to dispose of the transient
	  register windows soon, but Zoltan would prefer to wait until the high
	  level back end supports debugging.  There was general agreement that
	  supporting high performance on the SPARC is no longer a priority, and
	  possible strategies for reducing the burden of the SPARC legacy were
	  mentioned.
	- Zoltan enquired about need to retain the old profiler once the new
	  (deep) profiler is completed.  Tom (conway) Conway declared that the
	  old profiler should be kept because a) in some cases it incurs less
	  overhead than the new profiler and b) it is easier to do time
	  profiling with the old profiler.  Zoltan observed that retaining both
	  profilers would be a great hassle, but said he would consider some of
	  the required changes.  

5. The 0.10 Release:

	- The 0.10 release has proceeded, with an announcement on
	  mercury-announce.
	- Fergus expressed his desire to freeze 0.10.1 next week, and reminded
	  everyone to commit bug fixes on the main branch too.
	- The release of 0.10.1 will be announced through the major channels as
	  well as mercury-announce.


Minutes taken by Adrian Pellas-Rice (apell@cs.mu.oz.au).