svn commit: r268597 - head/lib/msun/src
Steve Kargl
kargl at FreeBSD.org
Sun Jul 13 23:10:40 UTC 2014
Author: kargl
Date: Sun Jul 13 23:10:39 2014
New Revision: 268597
URL: http://svnweb.freebsd.org/changeset/base/268597
Log:
* Update the comments to agree with commit r226595.
* While here, fix a nearby typo in a comment.
Modified:
head/lib/msun/src/e_pow.c
Modified: head/lib/msun/src/e_pow.c
==============================================================================
--- head/lib/msun/src/e_pow.c Sun Jul 13 17:52:07 2014 (r268596)
+++ head/lib/msun/src/e_pow.c Sun Jul 13 23:10:39 2014 (r268597)
@@ -19,20 +19,20 @@ __FBSDID("$FreeBSD$");
* 1. Compute and return log2(x) in two pieces:
* log2(x) = w1 + w2,
* where w1 has 53-24 = 29 bit trailing zeros.
- * 2. Perform y*log2(x) = n+y' by simulating muti-precision
+ * 2. Perform y*log2(x) = n+y' by simulating multi-precision
* arithmetic, where |y'|<=0.5.
* 3. Return x**y = 2**n*exp(y'*log2)
*
* Special cases:
* 1. (anything) ** 0 is 1
* 2. (anything) ** 1 is itself
- * 3. (anything) ** NAN is NAN
+ * 3. (anything) ** NAN is NAN except 1 ** NAN = 1
* 4. NAN ** (anything except 0) is NAN
* 5. +-(|x| > 1) ** +INF is +INF
* 6. +-(|x| > 1) ** -INF is +0
* 7. +-(|x| < 1) ** +INF is +0
* 8. +-(|x| < 1) ** -INF is +INF
- * 9. +-1 ** +-INF is NAN
+ * 9. +-1 ** +-INF is 1
* 10. +0 ** (+anything except 0, NAN) is +0
* 11. -0 ** (+anything except 0, NAN, odd integer) is +0
* 12. +0 ** (-anything except 0, NAN) is +INF
@@ -141,7 +141,7 @@ __ieee754_pow(double x, double y)
if(ly==0) {
if (iy==0x7ff00000) { /* y is +-inf */
if(((ix-0x3ff00000)|lx)==0)
- return one; /* (-1)**+-inf is NaN */
+ return one; /* (-1)**+-inf is 1 */
else if (ix >= 0x3ff00000)/* (|x|>1)**+-inf = inf,0 */
return (hy>=0)? y: zero;
else /* (|x|<1)**-,+inf = inf,0 */
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