60 lines
2.0 KiB
C
60 lines
2.0 KiB
C
/* ===-- divdc3.c - Implement __divdc3 -------------------------------------===
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*
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* The LLVM Compiler Infrastructure
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*
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* This file is distributed under the University of Illinois Open Source
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* License. See LICENSE.TXT for details.
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*
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* ===----------------------------------------------------------------------===
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*
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* This file implements __divdc3 for the compiler_rt library.
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*
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* ===----------------------------------------------------------------------===
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*/
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#include "int_lib.h"
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#include <math.h>
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#include <complex.h>
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/* Returns: the quotient of (a + ib) / (c + id) */
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double _Complex
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__divdc3(double __a, double __b, double __c, double __d)
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{
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int __ilogbw = 0;
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double __logbw = logb(fmax(fabs(__c), fabs(__d)));
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if (isfinite(__logbw))
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{
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__ilogbw = (int)__logbw;
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__c = scalbn(__c, -__ilogbw);
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__d = scalbn(__d, -__ilogbw);
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}
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double __denom = __c * __c + __d * __d;
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double _Complex z;
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__real__ z = scalbn((__a * __c + __b * __d) / __denom, -__ilogbw);
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__imag__ z = scalbn((__b * __c - __a * __d) / __denom, -__ilogbw);
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if (isnan(__real__ z) && isnan(__imag__ z))
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{
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if ((__denom == 0.0) && (!isnan(__a) || !isnan(__b)))
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{
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__real__ z = copysign(INFINITY, __c) * __a;
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__imag__ z = copysign(INFINITY, __c) * __b;
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}
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else if ((isinf(__a) || isinf(__b)) && isfinite(__c) && isfinite(__d))
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{
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__a = copysign(isinf(__a) ? 1.0 : 0.0, __a);
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__b = copysign(isinf(__b) ? 1.0 : 0.0, __b);
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__real__ z = INFINITY * (__a * __c + __b * __d);
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__imag__ z = INFINITY * (__b * __c - __a * __d);
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}
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else if (isinf(__logbw) && __logbw > 0.0 && isfinite(__a) && isfinite(__b))
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{
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__c = copysign(isinf(__c) ? 1.0 : 0.0, __c);
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__d = copysign(isinf(__d) ? 1.0 : 0.0, __d);
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__real__ z = 0.0 * (__a * __c + __b * __d);
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__imag__ z = 0.0 * (__b * __c - __a * __d);
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}
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}
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return z;
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}
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