xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/divxc3.c (revision d4eeb02986980bf33dd56c41ceb9fc5f180c0d47)
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
56