diff options
| author |   kettenis <kettenis@openbsd.org> | 2013-08-02 20:23:28 +0000 |
|---|---|---|
| committer | kettenis <kettenis@openbsd.org> | 2013-08-02 20:23:28 +0000 |
| commit | d205ab02eabefec09df68de8ff35e0519ffc9a86 (patch) | |
| tree | bd1af2e134d4ae75481b006c069142022a9a87d2 /lib/libm/src/e_powf.c | |
| parent | No longer needed since miod taught elf to mkuboot. (diff) | |
| download | wireguard-openbsd-d205ab02eabefec09df68de8ff35e0519ffc9a86.tar.xz wireguard-openbsd-d205ab02eabefec09df68de8ff35e0519ffc9a86.zip | |
Fix a couple of corner cases in the implementation of pow(3) to make it
compatible with C99. Most notably:
- 1**y == 1, even if y is NaN
- (-1)**+-Inf == 1
and adjust the cephes testsuite to test for the right thing here.
ok martynas@
Diffstat (limited to 'lib/libm/src/e_powf.c')
| -rw-r--r-- | lib/libm/src/e_powf.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/libm/src/e_powf.c b/lib/libm/src/e_powf.c index d6e52d8b99b..3c4269d7146 100644 --- a/lib/libm/src/e_powf.c +++ b/lib/libm/src/e_powf.c @@ -64,6 +64,9 @@ powf(float x, float y) /* y==zero: x**0 = 1 */ if(iy==0) return one; + /* x==1: 1**y = 1, even if y is NaN */ + if (hx==0x3f800000) return one; + /* +-NaN return x+y */ if(ix > 0x7f800000 || iy > 0x7f800000) @@ -87,7 +90,7 @@ powf(float x, float y) /* special value of y */ if (iy==0x7f800000) { /* y is +-inf */ if (ix==0x3f800000) - return y - y; /* inf**+-1 is NaN */ + return one; /* (-1)**+-inf is NaN */ else if (ix > 0x3f800000)/* (|x|>1)**+-inf = inf,0 */ return (hy>=0)? y: zero; else /* (|x|<1)**-,+inf = inf,0 */ |