forked from OSchip/llvm-project
61 lines
2.2 KiB
C
61 lines
2.2 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 dual licensed under the MIT and the University of Illinois Open
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* Source Licenses. 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 "int_math.h"
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/* Returns: the quotient of (a + ib) / (c + id) */
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COMPILER_RT_ABI Dcomplex
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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 = crt_logb(crt_fmax(crt_fabs(__c), crt_fabs(__d)));
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if (crt_isfinite(__logbw))
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{
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__ilogbw = (int)__logbw;
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__c = crt_scalbn(__c, -__ilogbw);
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__d = crt_scalbn(__d, -__ilogbw);
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}
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double __denom = __c * __c + __d * __d;
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Dcomplex z;
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COMPLEX_REAL(z) = crt_scalbn((__a * __c + __b * __d) / __denom, -__ilogbw);
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COMPLEX_IMAGINARY(z) = crt_scalbn((__b * __c - __a * __d) / __denom, -__ilogbw);
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if (crt_isnan(COMPLEX_REAL(z)) && crt_isnan(COMPLEX_IMAGINARY(z)))
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{
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if ((__denom == 0.0) && (!crt_isnan(__a) || !crt_isnan(__b)))
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{
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COMPLEX_REAL(z) = crt_copysign(CRT_INFINITY, __c) * __a;
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COMPLEX_IMAGINARY(z) = crt_copysign(CRT_INFINITY, __c) * __b;
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}
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else if ((crt_isinf(__a) || crt_isinf(__b)) &&
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crt_isfinite(__c) && crt_isfinite(__d))
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{
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__a = crt_copysign(crt_isinf(__a) ? 1.0 : 0.0, __a);
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__b = crt_copysign(crt_isinf(__b) ? 1.0 : 0.0, __b);
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COMPLEX_REAL(z) = CRT_INFINITY * (__a * __c + __b * __d);
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COMPLEX_IMAGINARY(z) = CRT_INFINITY * (__b * __c - __a * __d);
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}
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else if (crt_isinf(__logbw) && __logbw > 0.0 &&
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crt_isfinite(__a) && crt_isfinite(__b))
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{
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__c = crt_copysign(crt_isinf(__c) ? 1.0 : 0.0, __c);
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__d = crt_copysign(crt_isinf(__d) ? 1.0 : 0.0, __d);
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COMPLEX_REAL(z) = 0.0 * (__a * __c + __b * __d);
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COMPLEX_IMAGINARY(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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