cosmopolitan/third_party/compiler_rt/divxc3.c

67 lines
2.3 KiB
C

/* clang-format off */
/* ===-- divxc3.c - Implement __divxc3 -------------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __divxc3 for the compiler_rt library.
*
*/
STATIC_YOINK("huge_compiler_rt_license");
#if !_ARCH_PPC
#include "third_party/compiler_rt/int_lib.h"
#include "third_party/compiler_rt/int_math.h"
/* Returns: the quotient of (a + ib) / (c + id) */
COMPILER_RT_ABI Lcomplex
__divxc3(long double __a, long double __b, long double __c, long double __d)
{
int __ilogbw = 0;
long double __logbw = crt_logbl(crt_fmaxl(crt_fabsl(__c), crt_fabsl(__d)));
if (crt_isfinite(__logbw))
{
__ilogbw = (int)__logbw;
__c = crt_scalbnl(__c, -__ilogbw);
__d = crt_scalbnl(__d, -__ilogbw);
}
long double __denom = __c * __c + __d * __d;
Lcomplex z;
COMPLEX_REAL(z) = crt_scalbnl((__a * __c + __b * __d) / __denom, -__ilogbw);
COMPLEX_IMAGINARY(z) = crt_scalbnl((__b * __c - __a * __d) / __denom, -__ilogbw);
if (crt_isnan(COMPLEX_REAL(z)) && crt_isnan(COMPLEX_IMAGINARY(z)))
{
if ((__denom == 0) && (!crt_isnan(__a) || !crt_isnan(__b)))
{
COMPLEX_REAL(z) = crt_copysignl(CRT_INFINITY, __c) * __a;
COMPLEX_IMAGINARY(z) = crt_copysignl(CRT_INFINITY, __c) * __b;
}
else if ((crt_isinf(__a) || crt_isinf(__b)) &&
crt_isfinite(__c) && crt_isfinite(__d))
{
__a = crt_copysignl(crt_isinf(__a) ? 1 : 0, __a);
__b = crt_copysignl(crt_isinf(__b) ? 1 : 0, __b);
COMPLEX_REAL(z) = CRT_INFINITY * (__a * __c + __b * __d);
COMPLEX_IMAGINARY(z) = CRT_INFINITY * (__b * __c - __a * __d);
}
else if (crt_isinf(__logbw) && __logbw > 0 &&
crt_isfinite(__a) && crt_isfinite(__b))
{
__c = crt_copysignl(crt_isinf(__c) ? 1 : 0, __c);
__d = crt_copysignl(crt_isinf(__d) ? 1 : 0, __d);
COMPLEX_REAL(z) = 0 * (__a * __c + __b * __d);
COMPLEX_IMAGINARY(z) = 0 * (__b * __c - __a * __d);
}
}
return z;
}
#endif