Testing a Fortran 90 Compiler Using the NSWC Fortran 77 Mathematics Library

摘要

This report describes tne analysis and associated Fortran program (TEST9O) that were developed to aid in establishing the validity of a new Fortran 90 mainframe compiler. The FORTRAN 77 Naval Surface Warfare Center (NSWC) Mathematics Library (MLIB) is used as a source of routines for checking the Fortran 90 compiler. At the same time, this study can be considered as an aid to determine whether MLIB can operate in a Fortran 90 environment The inputs for the routines were chosen so that many of the different possible paths of the routines were executed. Seventy-four directly cable routines, with 293 supporting routines, were chosen for testing. All but 17, and their supporting routines, were taken from MLIB. The ones not belonging to MLIB are double- precision versions of routines in MLIB. Thirteen hundred and twenty five numerical cases were submitted for testing. A true value for each test was obtained independently and given correctly to 35 digits by using MAPLE software. If the difference in the test output and the corresponding true value exceeds a prespecified error tolerance, an error message is printed identifying the routine and the input. Additional test cases were also prepared to check the bit and string instructions, since these do not appear in MUB. TEST90 has been used to test the latest Fortran 90 compilers of the CRAY EL98 and IBM PC machines. No errors were found; however, TEST90 did reveal a complex arithmetic error in an earlier version of the Cray EL98 compiler. MLIB routines ran under TEST90 without any problems on both machines. The transportability of MUB allows TEST90 to be used as an aid in testing Fortran 90 compilers on a variety of computers, with a single precision word length no larger than 64 bits.