CVS commit: src/lib/libm/src

["Eitan Adler" <eadler%netbsd.org@localhost>]

Module Name:    src
Committed By:   eadler
Date:           Sat Mar 10 09:44:47 UTC 2018

Modified Files:
        src/lib/libm/src: e_atan2.c

Log Message:
Fix signed overflow in atan2

As a component of atan2(y, x), the case of x == 1.0 is farmed out to
atan(y). The current implementation of this comparison is vulnerable
to signed integer underflow (that is, undefined behavior), and it's
performed in a somewhat more complicated way than it need be. Change
it to not be quite so cute, rather directly comparing the high/low
bits of x to the specific IEEE-754 bit pattern that encodes 1.0.

ok martin@ pgoyette@ maya@
obtained from FreeBSD


To generate a diff of this commit:
cvs rdiff -u -r1.12 -r1.13 src/lib/libm/src/e_atan2.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.