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1//===-- divdc3.c - Implement __divdc3 -------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements __divdc3 for the compiler_rt library.10//11//===----------------------------------------------------------------------===//12 13#define DOUBLE_PRECISION14#include "fp_lib.h"15#include "int_lib.h"16#include "int_math.h"17 18// Returns: the quotient of (a + ib) / (c + id)19 20COMPILER_RT_ABI Dcomplex __divdc3(double __a, double __b, double __c,21 double __d) {22 int __ilogbw = 0;23 double __logbw = __compiler_rt_logb(__compiler_rt_fmax(crt_fabs(__c),24 crt_fabs(__d)));25 if (crt_isfinite(__logbw)) {26 __ilogbw = (int)__logbw;27 __c = __compiler_rt_scalbn(__c, -__ilogbw);28 __d = __compiler_rt_scalbn(__d, -__ilogbw);29 }30 double __denom = __c * __c + __d * __d;31 Dcomplex z;32 COMPLEX_REAL(z) =33 __compiler_rt_scalbn((__a * __c + __b * __d) / __denom, -__ilogbw);34 COMPLEX_IMAGINARY(z) =35 __compiler_rt_scalbn((__b * __c - __a * __d) / __denom, -__ilogbw);36 if (crt_isnan(COMPLEX_REAL(z)) && crt_isnan(COMPLEX_IMAGINARY(z))) {37 if ((__denom == 0.0) && (!crt_isnan(__a) || !crt_isnan(__b))) {38 COMPLEX_REAL(z) = crt_copysign(CRT_INFINITY, __c) * __a;39 COMPLEX_IMAGINARY(z) = crt_copysign(CRT_INFINITY, __c) * __b;40 } else if ((crt_isinf(__a) || crt_isinf(__b)) && crt_isfinite(__c) &&41 crt_isfinite(__d)) {42 __a = crt_copysign(crt_isinf(__a) ? 1.0 : 0.0, __a);43 __b = crt_copysign(crt_isinf(__b) ? 1.0 : 0.0, __b);44 COMPLEX_REAL(z) = CRT_INFINITY * (__a * __c + __b * __d);45 COMPLEX_IMAGINARY(z) = CRT_INFINITY * (__b * __c - __a * __d);46 } else if (crt_isinf(__logbw) && __logbw > 0.0 && crt_isfinite(__a) &&47 crt_isfinite(__b)) {48 __c = crt_copysign(crt_isinf(__c) ? 1.0 : 0.0, __c);49 __d = crt_copysign(crt_isinf(__d) ? 1.0 : 0.0, __d);50 COMPLEX_REAL(z) = 0.0 * (__a * __c + __b * __d);51 COMPLEX_IMAGINARY(z) = 0.0 * (__b * __c - __a * __d);52 }53 }54 return z;55}56