lib/divxc3.c

   1 /* ===-- divxc3.c - Implement __divxc3 -------------------------------------===
   2  *
   3  *                     The LLVM Compiler Infrastructure
   4  *
   5  * This file is dual licensed under the MIT and the University of Illinois Open
   6  * Source Licenses. See LICENSE.TXT for details.
   7  *
   8  * ===----------------------------------------------------------------------===
   9  *
  10  * This file implements __divxc3 for the compiler_rt library.
  11  *
  12  */
  13
  14 #if !_ARCH_PPC
  15
  16 #include "int_lib.h"
  17 #include "int_math.h"
  18
  19 /* Returns: the quotient of (a + ib) / (c + id) */
  20
  21 long double _Complex
  22 __divxc3(long double __a, long double __b, long double __c, long double __d)
  23 {
  24     int __ilogbw = 0;
  25     long double __logbw = crt_logbl(crt_fmaxl(crt_fabsl(__c), crt_fabsl(__d)));
  26     if (crt_isfinite(__logbw))
  27     {
  28         __ilogbw = (int)__logbw;
  29         __c = crt_scalbnl(__c, -__ilogbw);
  30         __d = crt_scalbnl(__d, -__ilogbw);
  31     }
  32     long double __denom = __c * __c + __d * __d;
  33     long double _Complex z;
  34     __real__ z = crt_scalbnl((__a * __c + __b * __d) / __denom, -__ilogbw);
  35     __imag__ z = crt_scalbnl((__b * __c - __a * __d) / __denom, -__ilogbw);
  36     if (crt_isnan(__real__ z) && crt_isnan(__imag__ z))
  37     {
  38         if ((__denom == 0) && (!crt_isnan(__a) || !crt_isnan(__b)))
  39         {
  40             __real__ z = crt_copysignl(CRT_INFINITY, __c) * __a;
  41             __imag__ z = crt_copysignl(CRT_INFINITY, __c) * __b;
  42         }
  43         else if ((crt_isinf(__a) || crt_isinf(__b)) &&
  44                  crt_isfinite(__c) && crt_isfinite(__d))
  45         {
  46             __a = crt_copysignl(crt_isinf(__a) ? 1 : 0, __a);
  47             __b = crt_copysignl(crt_isinf(__b) ? 1 : 0, __b);
  48             __real__ z = CRT_INFINITY * (__a * __c + __b * __d);
  49             __imag__ z = CRT_INFINITY * (__b * __c - __a * __d);
  50         }
  51         else if (crt_isinf(__logbw) && __logbw > 0 &&
  52                  crt_isfinite(__a) && crt_isfinite(__b))
  53         {
  54             __c = crt_copysignl(crt_isinf(__c) ? 1 : 0, __c);
  55             __d = crt_copysignl(crt_isinf(__d) ? 1 : 0, __d);
  56             __real__ z = 0 * (__a * __c + __b * __d);
  57             __imag__ z = 0 * (__b * __c - __a * __d);
  58         }
  59     }
  60     return z;
  61 }
  62
  63 #endif