compiler-rt/lib/builtins/divsc3.c

   1 //===-- divsc3.c - Implement __divsc3 -------------------------------------===//
   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 __divsc3 for the compiler_rt library.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #define SINGLE_PRECISION
  14 #include "fp_lib.h"
  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 Fcomplex __divsc3(float __a, float __b, float __c, float __d) {
  21   int __ilogbw = 0;
  22   float __logbw =
  23       __compiler_rt_logbf(__compiler_rt_fmaxf(crt_fabsf(__c), crt_fabsf(__d)));
  24   if (crt_isfinite(__logbw)) {
  25     __ilogbw = (int)__logbw;
  26     __c = __compiler_rt_scalbnf(__c, -__ilogbw);
  27     __d = __compiler_rt_scalbnf(__d, -__ilogbw);
  28   }
  29   float __denom = __c * __c + __d * __d;
  30   Fcomplex z;
  31   COMPLEX_REAL(z) =
  32       __compiler_rt_scalbnf((__a * __c + __b * __d) / __denom, -__ilogbw);
  33   COMPLEX_IMAGINARY(z) =
  34       __compiler_rt_scalbnf((__b * __c - __a * __d) / __denom, -__ilogbw);
  35   if (crt_isnan(COMPLEX_REAL(z)) && crt_isnan(COMPLEX_IMAGINARY(z))) {
  36     if ((__denom == 0) && (!crt_isnan(__a) || !crt_isnan(__b))) {
  37       COMPLEX_REAL(z) = crt_copysignf(CRT_INFINITY, __c) * __a;
  38       COMPLEX_IMAGINARY(z) = crt_copysignf(CRT_INFINITY, __c) * __b;
  39     } else if ((crt_isinf(__a) || crt_isinf(__b)) && crt_isfinite(__c) &&
  40                crt_isfinite(__d)) {
  41       __a = crt_copysignf(crt_isinf(__a) ? 1 : 0, __a);
  42       __b = crt_copysignf(crt_isinf(__b) ? 1 : 0, __b);
  43       COMPLEX_REAL(z) = CRT_INFINITY * (__a * __c + __b * __d);
  44       COMPLEX_IMAGINARY(z) = CRT_INFINITY * (__b * __c - __a * __d);
  45     } else if (crt_isinf(__logbw) && __logbw > 0 && crt_isfinite(__a) &&
  46                crt_isfinite(__b)) {
  47       __c = crt_copysignf(crt_isinf(__c) ? 1 : 0, __c);
  48       __d = crt_copysignf(crt_isinf(__d) ? 1 : 0, __d);
  49       COMPLEX_REAL(z) = 0 * (__a * __c + __b * __d);
  50       COMPLEX_IMAGINARY(z) = 0 * (__b * __c - __a * __d);
  51     }
  52   }
  53   return z;
  54 }