1 /* ===-- fixdfdi.c - Implement __fixdfdi -----------------------------------=== 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 __fixdfdi for the compiler_rt library. 11 * 12 * ===----------------------------------------------------------------------=== 13 */ 14 15 #include "int_lib.h" 16 17 /* Returns: convert a to a signed long long, rounding toward zero. */ 18 19 /* Assumption: double is a IEEE 64 bit floating point type 20 * su_int is a 32 bit integral type 21 * value in double is representable in di_int (no range checking performed) 22 */ 23 24 /* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */ 25 26 di_int 27 __fixdfdi(double a) 28 { 29 double_bits fb; 30 fb.f = a; 31 int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023; 32 if (e < 0) 33 return 0; 34 di_int s = (si_int)(fb.u.s.high & 0x80000000) >> 31; 35 dwords r; 36 r.s.high = (fb.u.s.high & 0x000FFFFF) | 0x00100000; 37 r.s.low = fb.u.s.low; 38 if (e > 52) 39 r.all <<= (e - 52); 40 else 41 r.all >>= (52 - e); 42 return (r.all ^ s) - s; 43 } 44
