Minutes of ISAC meeting held via telecom on 07 February 2008

Present: Peter Ashenden, Larry Soule, Chuck Swart, Ajay Verikat

Absent: Jim Lewis, Lance Thompson

Next Meeting Thursday, February 28, 8 pm Pacific Standard time
             (Friday, February 29, 4 am GMT)

The primary activity of the next meeting will be to deal with open
Bugzilla issues for VHDL-200X (under the assumption that Accellera
approves D4.0 and passes it on to the IEEE). There are currently about
12 open or reopened issues.

TOPIC: IR 2128 Shared Variable declarations in generate?

Peter's analysis is accepted: 4.3.1.3 should be updated to include
generate statements, but there is insufficient benefit to adding
special terminology for concurrent and sequential declarative regions.

Since this analysis was not placed on the website there will be a vote
on this issue.

ACTION: Chuck to update website. All to vote on IR 2128

TOPIC: IR 2129 Bad requirements to check exprs with access type sub exprs

The LRM currently requires that a tool recognize the dereference of a null
access value and report this as an error. Most other languages leave this
behavior undefined and allow operating system action, usually termination,
for performance reasons.  The submitter suggests that VHDL also treat this
as erroneous to improve performance.

Ajay points out that a) recovery from tool crashing is very difficult
for a designer b) the error detection here is useful, c) the negative
performance effect of such tests is small compared to other actions of
the simulator and d) if a tool implementer is still concerned about
performance he could implement a non-compliant option to suppress this
check. Therefore the LRM should not be changed.

ACTION: Ajay to analyze.

TOPIC: Open Bugzilla issues for version D4.0.

Peter pointed out that there are several open issues for the
D4.0 version of the LRM. Since the Accellera board will vote on
this version on Feb 20, it is no longer appropriate for the
Accellera LRM committee to deal with these issues. The obvious
solution to this situation is to pass on this role to the ISAC.
We may need VASG approval for this.

ACTION: Chuck to work with Jim (VASG chair) to work out details and
to set a time frame for IEEE LRM activities.

TOPIC: IR 2123 Process resumption and callbacks 
       IR 2124 Ordering of process execution and callbacks

Francoise reports that the VHPI has met on these issues and hopes to
resolve them within a week.

ACTION: Awaiting response from VHPI.

TOPIC: IR 2127 Possible LRM interpretation pitfall related to the
predefined STANDARD package.

Peter's analysis is accepted. This IR is ISAC-Approved.

ACTION: Chuck to forward to VASG.

TOPIC: IR 2126 Concatenation ambiguity.

Chuck's analysis is a first step in resolving this issue. The general
problem is that phrases like "independently of the context" do not
have a clear meaning. The analysis suggests the intended
interpretation of these phrases and proposes alternative wording in
each instance in which similar phrases occur. However, the analysis is
complicated and the potential consequences of LRM changes in this area
are considerable, so everyone should review this analysis offline.

ACTION: All to review within 2 weeks.