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 }
55