1 /* ===-- fixunsxfti.c - Implement __fixunsxfti -----------------------------=== 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 __fixunsxfti for the compiler_rt library. 11 * 12 * ===----------------------------------------------------------------------=== 13 */ 14 15 #include "int_lib.h" 16 17 #ifdef CRT_HAS_128BIT 18 19 /* Returns: convert a to a unsigned long long, rounding toward zero. 20 * Negative values all become zero. 21 */ 22 23 /* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes 24 * tu_int is a 128 bit integral type 25 * value in long double is representable in tu_int or is negative 26 */ 27 28 /* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee | 29 * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm 30 */ 31 32 COMPILER_RT_ABI tu_int 33 __fixunsxfti(long double a) 34 { 35 long_double_bits fb; 36 fb.f = a; 37 int e = (fb.u.high.s.low & 0x00007FFF) - 16383; 38 if (e < 0 || (fb.u.high.s.low & 0x00008000)) 39 return 0; 40 if ((unsigned)e > sizeof(tu_int) * CHAR_BIT) 41 return ~(tu_int)0; 42 tu_int r = fb.u.low.all; 43 if (e > 63) 44 r <<= (e - 63); 45 else 46 r >>= (63 - e); 47 return r; 48 } 49 50 #endif /* CRT_HAS_128BIT */ 51
