diff options
Diffstat (limited to 'lib/msun/src/e_pow.c')
| -rw-r--r-- | lib/msun/src/e_pow.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/lib/msun/src/e_pow.c b/lib/msun/src/e_pow.c index 7607a4a..d54af9d 100644 --- a/lib/msun/src/e_pow.c +++ b/lib/msun/src/e_pow.c @@ -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 */ |
