1 /* ===-- divdc3.c - Implement __divdc3 -------------------------------------=== 2 * 3 * The LLVM Compiler Infrastructure 4 * 5 * This file is dual licensed under the MIT and the University of Illinois Open 6 * Source Licenses. 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 "int_math.h" 17 18 /* Returns: the quotient of (a + ib) / (c + id) */ 19 20 COMPILER_RT_ABI Dcomplex 21 __divdc3(double __a, double __b, double __c, double __d) 22 { 23 int __ilogbw = 0; 24 double __logbw = crt_logb(crt_fmax(crt_fabs(__c), crt_fabs(__d))); 25 if (crt_isfinite(__logbw)) 26 { 27 __ilogbw = (int)__logbw; 28 __c = crt_scalbn(__c, -__ilogbw); 29 __d = crt_scalbn(__d, -__ilogbw); 30 } 31 double __denom = __c * __c + __d * __d; 32 Dcomplex z; 33 COMPLEX_REAL(z) = crt_scalbn((__a * __c + __b * __d) / __denom, -__ilogbw); 34 COMPLEX_IMAGINARY(z) = crt_scalbn((__b * __c - __a * __d) / __denom, -__ilogbw); 35 if (crt_isnan(COMPLEX_REAL(z)) && crt_isnan(COMPLEX_IMAGINARY(z))) 36 { 37 if ((__denom == 0.0) && (!crt_isnan(__a) || !crt_isnan(__b))) 38 { 39 COMPLEX_REAL(z) = crt_copysign(CRT_INFINITY, __c) * __a; 40 COMPLEX_IMAGINARY(z) = crt_copysign(CRT_INFINITY, __c) * __b; 41 } 42 else if ((crt_isinf(__a) || crt_isinf(__b)) && 43 crt_isfinite(__c) && crt_isfinite(__d)) 44 { 45 __a = crt_copysign(crt_isinf(__a) ? 1.0 : 0.0, __a); 46 __b = crt_copysign(crt_isinf(__b) ? 1.0 : 0.0, __b); 47 COMPLEX_REAL(z) = CRT_INFINITY * (__a * __c + __b * __d); 48 COMPLEX_IMAGINARY(z) = CRT_INFINITY * (__b * __c - __a * __d); 49 } 50 else if (crt_isinf(__logbw) && __logbw > 0.0 && 51 crt_isfinite(__a) && crt_isfinite(__b)) 52 { 53 __c = crt_copysign(crt_isinf(__c) ? 1.0 : 0.0, __c); 54 __d = crt_copysign(crt_isinf(__d) ? 1.0 : 0.0, __d); 55 COMPLEX_REAL(z) = 0.0 * (__a * __c + __b * __d); 56 COMPLEX_IMAGINARY(z) = 0.0 * (__b * __c - __a * __d); 57 } 58 } 59 return z; 60 } 61
