1 /* ===-- divdc3.c - Implement __divdc3 -------------------------------------=== 2 * 3 * The LLVM Compiler Infrastructure 4 * 5 * This file is distributed under the University of Illinois Open Source 6 * License. See LICENSE.TXT for details. 7 * 8 * ===----------------------------------------------------------------------=== 9 * 10 * This file implements __divdc3 for the compiler_rt library. 11 * 12 * ===----------------------------------------------------------------------=== 13 */ 14 15 #include "int_lib.h" 16 #include <math.h> 17 #include <complex.h> 18 19 /* Returns: the quotient of (a + ib) / (c + id) */ 20 21 double _Complex 22 __divdc3(double __a, double __b, double __c, double __d) 23 { 24 int __ilogbw = 0; 25 double __logbw = logb(fmax(fabs(__c), fabs(__d))); 26 if (isfinite(__logbw)) 27 { 28 __ilogbw = (int)__logbw; 29 __c = scalbn(__c, -__ilogbw); 30 __d = scalbn(__d, -__ilogbw); 31 } 32 double __denom = __c * __c + __d * __d; 33 double _Complex z; 34 __real__ z = scalbn((__a * __c + __b * __d) / __denom, -__ilogbw); 35 __imag__ z = scalbn((__b * __c - __a * __d) / __denom, -__ilogbw); 36 if (isnan(__real__ z) && isnan(__imag__ z)) 37 { 38 if ((__denom == 0.0) && (!isnan(__a) || !isnan(__b))) 39 { 40 __real__ z = copysign(INFINITY, __c) * __a; 41 __imag__ z = copysign(INFINITY, __c) * __b; 42 } 43 else if ((isinf(__a) || isinf(__b)) && isfinite(__c) && isfinite(__d)) 44 { 45 __a = copysign(isinf(__a) ? 1.0 : 0.0, __a); 46 __b = copysign(isinf(__b) ? 1.0 : 0.0, __b); 47 __real__ z = INFINITY * (__a * __c + __b * __d); 48 __imag__ z = INFINITY * (__b * __c - __a * __d); 49 } 50 else if (isinf(__logbw) && __logbw > 0.0 && isfinite(__a) && isfinite(__b)) 51 { 52 __c = copysign(isinf(__c) ? 1.0 : 0.0, __c); 53 __d = copysign(isinf(__d) ? 1.0 : 0.0, __d); 54 __real__ z = 0.0 * (__a * __c + __b * __d); 55 __imag__ z = 0.0 * (__b * __c - __a * __d); 56 } 57 } 58 return z; 59 } 60
