[307,20]	README.1ST

U.S. Geological Survey, Menlo Park, California, submissions to the
Spring 1986 DECUS Tape.

This material was discussed in the presentation "Fortran-77 Performance and
Optimization Issues" at the Dallas Symposium.

Contents of this UIC:

  F77VBUG.DOC	Description and correction to Fortran-77 V5.0 OTS
		which causes Virtual Array problems with I/D Tasks.

  VIRT.MAC	Experimental "Fast Virtual Array" package. This code is
  CRVIRT.MAC	meant to replace standard Virtual arrays when performance
  DSVIRT.MAC	or Virtual Array index limitations need to be stretched.
  DSWIND.MAC	Allows creation of one or more regions, and performs
  TEST.FTN	manual mapping to the region through any arbitrary common
  TESTBLD.CMD	block. Once mapped, array accesses to the "Virtual array" are
		as fast as normal array accesses. Look at the source 
		files and the test program for details.

  GETVIR.MAC	Map and return the virtual address of a Virtual Array element

  BLKIO.FTN	Virtual disk I/O routines from Fortran-77. Allows you to read
		and write disk blocks directly into arrays (regular OR
		Virtual!) using direct QIOs. Uses the GETVIR routine for
		accessing Virtual Arrays. A MUST for reducing disk I/O 
		overhead for an application. See the source files for details.

