diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/e_acosh.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/e_acosh.c | 55 |
1 files changed, 33 insertions, 22 deletions
diff --git a/sysdeps/ieee754/dbl-64/e_acosh.c b/sysdeps/ieee754/dbl-64/e_acosh.c index b24a6f6459..c1f3590f75 100644 --- a/sysdeps/ieee754/dbl-64/e_acosh.c +++ b/sysdeps/ieee754/dbl-64/e_acosh.c @@ -28,31 +28,42 @@ #include <math_private.h> static const double -one = 1.0, -ln2 = 6.93147180559945286227e-01; /* 0x3FE62E42, 0xFEFA39EF */ + one = 1.0, + ln2 = 6.93147180559945286227e-01; /* 0x3FE62E42, 0xFEFA39EF */ double -__ieee754_acosh(double x) +__ieee754_acosh (double x) { - double t; - int32_t hx; - u_int32_t lx; - EXTRACT_WORDS(hx,lx,x); - if(hx<0x3ff00000) { /* x < 1 */ - return (x-x)/(x-x); - } else if(hx >=0x41b00000) { /* x > 2**28 */ - if(hx >=0x7ff00000) { /* x is inf of NaN */ - return x+x; - } else - return __ieee754_log(x)+ln2; /* acosh(huge)=log(2x) */ - } else if(((hx-0x3ff00000)|lx)==0) { - return 0.0; /* acosh(1) = 0 */ - } else if (hx > 0x40000000) { /* 2**28 > x > 2 */ - t=x*x; - return __ieee754_log(2.0*x-one/(x+__ieee754_sqrt(t-one))); - } else { /* 1<x<2 */ - t = x-one; - return __log1p(t+__ieee754_sqrt(2.0*t+t*t)); + double t; + int32_t hx; + u_int32_t lx; + EXTRACT_WORDS (hx, lx, x); + if (hx < 0x3ff00000) /* x < 1 */ + { + return (x - x) / (x - x); + } + else if (hx >= 0x41b00000) /* x > 2**28 */ + { + if (hx >= 0x7ff00000) /* x is inf of NaN */ + { + return x + x; } + else + return __ieee754_log (x) + ln2; /* acosh(huge)=log(2x) */ + } + else if (((hx - 0x3ff00000) | lx) == 0) + { + return 0.0; /* acosh(1) = 0 */ + } + else if (hx > 0x40000000) /* 2**28 > x > 2 */ + { + t = x * x; + return __ieee754_log (2.0 * x - one / (x + __ieee754_sqrt (t - one))); + } + else /* 1<x<2 */ + { + t = x - one; + return __log1p (t + __ieee754_sqrt (2.0 * t + t * t)); + } } strong_alias (__ieee754_acosh, __acosh_finite) |