1 /* ===-- fixxfti.c - Implement __fixxfti -----------------------------------=== 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 __fixxfti for the compiler_rt library. 11 * 12 * ===----------------------------------------------------------------------=== 13 */ 14 15 #if __x86_64 16 17 #include "int_lib.h" 18 19 /* Returns: convert a to a signed long long, rounding toward zero. */ 20 21 /* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes 22 * su_int is a 32 bit integral type 23 * value in long double is representable in ti_int (no range checking performed) 24 */ 25 26 /* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee | 27 * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm 28 */ 29 30 ti_int 31 __fixxfti(long double a) 32 { 33 long_double_bits fb; 34 fb.f = a; 35 int e = (fb.u.high.s.low & 0x00007FFF) - 16383; 36 if (e < 0) 37 return 0; 38 ti_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15); 39 ti_int r = fb.u.low.all; 40 if (e > 63) 41 r <<= (e - 63); 42 else 43 r >>= (63 - e); 44 return (r ^ s) - s; 45 } 46 47 #endif /* __x86_64 */ 48
