1214152Sed/* ===-- fixdfti.c - Implement __fixdfti -----------------------------------=== 2214152Sed * 3214152Sed * The LLVM Compiler Infrastructure 4214152Sed * 5222656Sed * This file is dual licensed under the MIT and the University of Illinois Open 6222656Sed * Source Licenses. See LICENSE.TXT for details. 7214152Sed * 8214152Sed * ===----------------------------------------------------------------------=== 9214152Sed * 10214152Sed * This file implements __fixdfti for the compiler_rt library. 11214152Sed * 12214152Sed * ===----------------------------------------------------------------------=== 13214152Sed */ 14214152Sed 15239138Sandrew#include "int_lib.h" 16239138Sandrew 17263763Sdim#ifdef CRT_HAS_128BIT 18214152Sed 19214152Sed/* Returns: convert a to a signed long long, rounding toward zero. */ 20214152Sed 21214152Sed/* Assumption: double is a IEEE 64 bit floating point type 22214152Sed * su_int is a 32 bit integral type 23214152Sed * value in double is representable in ti_int (no range checking performed) 24214152Sed */ 25214152Sed 26214152Sed/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */ 27214152Sed 28214152Sedti_int 29214152Sed__fixdfti(double a) 30214152Sed{ 31214152Sed double_bits fb; 32214152Sed fb.f = a; 33214152Sed int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023; 34214152Sed if (e < 0) 35214152Sed return 0; 36214152Sed ti_int s = (si_int)(fb.u.s.high & 0x80000000) >> 31; 37214152Sed ti_int r = 0x0010000000000000uLL | (0x000FFFFFFFFFFFFFuLL & fb.u.all); 38214152Sed if (e > 52) 39214152Sed r <<= (e - 52); 40214152Sed else 41214152Sed r >>= (52 - e); 42214152Sed return (r ^ s) - s; 43214152Sed} 44214152Sed 45263763Sdim#endif /* CRT_HAS_128BIT */ 46