freebsd-skq/contrib/compiler-rt/lib/divdc3.c
ed 0ece074de9 Upgrade libcompiler_rt to upstream revision 147390.
This version of libcompiler_rt adds support for __mulo[sdt]i4(), which
computes a multiply and its overflow flag. There are also a lot of
cleanup fixes to headers that don't really affect us.

Updating to this revision should make it a bit easier to contribute
changes back to the LLVM developers.
2011-12-31 19:01:48 +00:00

61 lines
2.2 KiB
C

/* ===-- divdc3.c - Implement __divdc3 -------------------------------------===
*
* 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 __divdc3 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
#include "int_math.h"
/* Returns: the quotient of (a + ib) / (c + id) */
double _Complex
__divdc3(double __a, double __b, double __c, double __d)
{
int __ilogbw = 0;
double __logbw = crt_logb(crt_fmax(crt_fabs(__c), crt_fabs(__d)));
if (crt_isfinite(__logbw))
{
__ilogbw = (int)__logbw;
__c = crt_scalbn(__c, -__ilogbw);
__d = crt_scalbn(__d, -__ilogbw);
}
double __denom = __c * __c + __d * __d;
double _Complex z;
__real__ z = crt_scalbn((__a * __c + __b * __d) / __denom, -__ilogbw);
__imag__ z = crt_scalbn((__b * __c - __a * __d) / __denom, -__ilogbw);
if (crt_isnan(__real__ z) && crt_isnan(__imag__ z))
{
if ((__denom == 0.0) && (!crt_isnan(__a) || !crt_isnan(__b)))
{
__real__ z = crt_copysign(CRT_INFINITY, __c) * __a;
__imag__ z = crt_copysign(CRT_INFINITY, __c) * __b;
}
else if ((crt_isinf(__a) || crt_isinf(__b)) &&
crt_isfinite(__c) && crt_isfinite(__d))
{
__a = crt_copysign(crt_isinf(__a) ? 1.0 : 0.0, __a);
__b = crt_copysign(crt_isinf(__b) ? 1.0 : 0.0, __b);
__real__ z = CRT_INFINITY * (__a * __c + __b * __d);
__imag__ z = CRT_INFINITY * (__b * __c - __a * __d);
}
else if (crt_isinf(__logbw) && __logbw > 0.0 &&
crt_isfinite(__a) && crt_isfinite(__b))
{
__c = crt_copysign(crt_isinf(__c) ? 1.0 : 0.0, __c);
__d = crt_copysign(crt_isinf(__d) ? 1.0 : 0.0, __d);
__real__ z = 0.0 * (__a * __c + __b * __d);
__imag__ z = 0.0 * (__b * __c - __a * __d);
}
}
return z;
}