readme

TGFF省城程序

----
Introduction

Please see ``TGFF: Task Graphs for Free'' by Robert Dick
and David Rhodes in the 1998 Proceedings of the International
Workshop Hardware/Software Codesign for more information.

There is a link to the TGFF web page at
http://www.ee.princeton.edu/~cad/projects.html.

----
Building and installing

TGFF builds with GNU make and a recent version of GCC's C++
compiler.  We use version 4.0.2.  Other makes and C++
compilers may also work.  If you want to install TGFF in a
shared directory, just copy the tgff file there and set the
file permissions appropriately.

----
Getting Started

Please see the enclosed example parameter files (.tgffopt suffix).
When the tgff command is run without any arguments, it prints
out information about the format of its parameters.  When
run with an argument, X, it reads X.tgffopt and produces
X.tgff and X.eps.

----
Release Notes

TGFF has evolved since its beta release.  When possible, we have kept
compatability with previous versions when adding new features.
However, this hasn't always been possible.  Bugfixes have sometimes
resulted in a change in TGFF output, given the same input as a
previous version.  In order to make it easy for other researchers to
produce your example sets, it is best to include the version of TGFF
which you used, in addition to the TGFF parameters, when publishing an
academic paper.  A brief description of changes to TGFF follows.

----
Release 2.0

--
New features: 

When TGFF combines multiple uniform random variables (URV) in order to
produce table entries, the result is filtered to ensure that it is a
URV, as well.  See flat_merge() in DBase.cc.

Now supports hard and soft task deadlines ***.

--
Changes to default behavior:

Defaults to filtering merged URVs in order to make the merged variable
a URV as well.  You can get the pre-1.3 behavior, a simple weighted
summation which results in a decreased variance, by putting
'urv_merge false' in the options file.

The default task graph period was awfully high.  It has been reduced.
You can get the pre-1.3 behavior by putting '***' in the options file.

--
Critical loss of backward comparability:

There was a bug which caused the periods of individual task graphs to
increase as the number of task graphs increased.  This bug has been
fixed.  Unfortunately, TGFF outputs will be different than they were
in pre-1.3 TGFF versions.