compiler-rt/lib/builtins/divxc3.c

   1 //===-- divxc3.c - Implement __divxc3 -------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements __divxc3 for the compiler_rt library.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #if !_ARCH_PPC
  14
  15 #include "int_lib.h"
  16 #include "int_math.h"
  17
  18 // Returns: the quotient of (a + ib) / (c + id)
  19
  20 COMPILER_RT_ABI Lcomplex __divxc3(long double __a, long double __b,
  21                                   long double __c, long double __d) {
  22   int __ilogbw = 0;
  23   long double __logbw = crt_logbl(crt_fmaxl(crt_fabsl(__c), crt_fabsl(__d)));
  24   if (crt_isfinite(__logbw)) {
  25     __ilogbw = (int)__logbw;
  26     __c = crt_scalbnl(__c, -__ilogbw);
  27     __d = crt_scalbnl(__d, -__ilogbw);
  28   }
  29   long double __denom = __c * __c + __d * __d;
  30   Lcomplex z;
  31   COMPLEX_REAL(z) = crt_scalbnl((__a * __c + __b * __d) / __denom, -__ilogbw);
  32   COMPLEX_IMAGINARY(z) =
  33       crt_scalbnl((__b * __c - __a * __d) / __denom, -__ilogbw);
  34   if (crt_isnan(COMPLEX_REAL(z)) && crt_isnan(COMPLEX_IMAGINARY(z))) {
  35     if ((__denom == 0) && (!crt_isnan(__a) || !crt_isnan(__b))) {
  36       COMPLEX_REAL(z) = crt_copysignl(CRT_INFINITY, __c) * __a;
  37       COMPLEX_IMAGINARY(z) = crt_copysignl(CRT_INFINITY, __c) * __b;
  38     } else if ((crt_isinf(__a) || crt_isinf(__b)) && crt_isfinite(__c) &&
  39                crt_isfinite(__d)) {
  40       __a = crt_copysignl(crt_isinf(__a) ? 1 : 0, __a);
  41       __b = crt_copysignl(crt_isinf(__b) ? 1 : 0, __b);
  42       COMPLEX_REAL(z) = CRT_INFINITY * (__a * __c + __b * __d);
  43       COMPLEX_IMAGINARY(z) = CRT_INFINITY * (__b * __c - __a * __d);
  44     } else if (crt_isinf(__logbw) && __logbw > 0 && crt_isfinite(__a) &&
  45                crt_isfinite(__b)) {
  46       __c = crt_copysignl(crt_isinf(__c) ? 1 : 0, __c);
  47       __d = crt_copysignl(crt_isinf(__d) ? 1 : 0, __d);
  48       COMPLEX_REAL(z) = 0 * (__a * __c + __b * __d);
  49       COMPLEX_IMAGINARY(z) = 0 * (__b * __c - __a * __d);
  50     }
  51   }
  52   return z;
  53 }
  54
  55 #endif