[net.bugs.4bsd] Another F77 bug in 4.2BSD UNIX

gam@astrovax.UUCP (Gary Mamon) (03/16/84)

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.