| Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 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 double _Complex |
| 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 | double _Complex z; |
| 33 | __real__ z = crt_scalbn((__a * __c + __b * __d) / __denom, -__ilogbw); |
| 34 | __imag__ z = crt_scalbn((__b * __c - __a * __d) / __denom, -__ilogbw); |
| 35 | if (crt_isnan(__real__ z) && crt_isnan(__imag__ z)) |
| 36 | { |
| 37 | if ((__denom == 0.0) && (!crt_isnan(__a) || !crt_isnan(__b))) |
| 38 | { |
| 39 | __real__ z = crt_copysign(CRT_INFINITY, __c) * __a; |
| 40 | __imag__ 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 | __real__ z = CRT_INFINITY * (__a * __c + __b * __d); |
| 48 | __imag__ 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 | __real__ z = 0.0 * (__a * __c + __b * __d); |
| 56 | __imag__ z = 0.0 * (__b * __c - __a * __d); |
| 57 | } |
| 58 | } |
| 59 | return z; |
| 60 | } |