Another F77 bug in 4.2BSD UNIX
Gary Mamon
gam at astrovax.UUCP
Fri Mar 16 08:04:18 AEST 1984
Subject: F77 exponentiation.
Index: /mnt/gam/BUGS/sumpow.f
Description:
4.2 F77 mishandles the following in single precision:
z = x1**alpha + x2**alpha + ... + xlast**alpha
where alpha is a floating point constant, and z and x sub i
are real variables.
F77 returns for z the value N*xlast**alpha, where N is the
number of terms in the sum.
Furthermore F77 mishandles the following in both single and
double precision.
z = (x1-y1)**alpha + (x2-y2)**alpha
where again alpha is a floating point constant, and z, the
x sub i and the y sub i are real (real*8 in double precision)
variables.
Fix:
Unknown.
Comment:
This is one of a few 4.2 BSD F77 bugs already discovered at our site.
The majority of Fortran users here are now using the 4.1BSD F77
compiler.
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