diff options
Diffstat (limited to 'libc/math/s_csin.c')
| -rw-r--r-- | libc/math/s_csin.c | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/libc/math/s_csin.c b/libc/math/s_csin.c index cd4c8f020..602c14e53 100644 --- a/libc/math/s_csin.c +++ b/libc/math/s_csin.c @@ -1,5 +1,5 @@ /* Complex sine function for double. - Copyright (C) 1997, 2011 Free Software Foundation, Inc. + Copyright (C) 1997-2012 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. @@ -20,9 +20,8 @@ #include <complex.h> #include <fenv.h> #include <math.h> - #include <math_private.h> - +#include <float.h> __complex__ double __csin (__complex__ double x) @@ -40,14 +39,44 @@ __csin (__complex__ double x) if (__builtin_expect (rcls >= FP_ZERO, 1)) { /* Real part is finite. */ - double sinh_val = __ieee754_sinh (__imag__ x); - double cosh_val = __ieee754_cosh (__imag__ x); + const int t = (int) ((DBL_MAX_EXP - 1) * M_LN2); double sinix, cosix; __sincos (__real__ x, &sinix, &cosix); - __real__ retval = cosh_val * sinix; - __imag__ retval = sinh_val * cosix; + if (fabs (__imag__ x) > t) + { + double exp_t = __ieee754_exp (t); + double ix = fabs (__imag__ x); + if (signbit (__imag__ x)) + cosix = -cosix; + ix -= t; + sinix *= exp_t / 2.0; + cosix *= exp_t / 2.0; + if (ix > t) + { + ix -= t; + sinix *= exp_t; + cosix *= exp_t; + } + if (ix > t) + { + /* Overflow (original imaginary part of x > 3t). */ + __real__ retval = DBL_MAX * sinix; + __imag__ retval = DBL_MAX * cosix; + } + else + { + double exp_val = __ieee754_exp (ix); + __real__ retval = exp_val * sinix; + __imag__ retval = exp_val * cosix; + } + } + else + { + __real__ retval = __ieee754_cosh (__imag__ x) * sinix; + __imag__ retval = __ieee754_sinh (__imag__ x) * cosix; + } if (negate) __real__ retval = -__real__ retval; |