1 /* ===-- fixunssfti.c - Implement __fixunssfti -----------------------------=== 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 __fixunssfti 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 unsigned long long, rounding toward zero. 20 * Negative values all become zero. 21 */ 22 23 /* Assumption: float is a IEEE 32 bit floating point type 24 * tu_int is a 64 bit integral type 25 * value in float is representable in tu_int or is negative 26 * (no range checking performed) 27 */ 28 29 /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */ 30 31 tu_int 32 __fixunssfti(float a) 33 { 34 float_bits fb; 35 fb.f = a; 36 int e = ((fb.u & 0x7F800000) >> 23) - 127; 37 if (e < 0 || (fb.u & 0x80000000)) 38 return 0; 39 tu_int r = (fb.u & 0x007FFFFF) | 0x00800000; 40 if (e > 23) 41 r <<= (e - 23); 42 else 43 r >>= (23 - e); 44 return r; 45 } 46 47 #endif 48
