1 /* ===-- fixsfti.c - Implement __fixsfti -----------------------------------=== 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 __fixsfti 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: float is a IEEE 32 bit floating point type 22 * su_int is a 32 bit integral type 23 * value in float is representable in ti_int (no range checking performed) 24 */ 25 26 /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */ 27 28 ti_int 29 __fixsfti(float a) 30 { 31 float_bits fb; 32 fb.f = a; 33 int e = ((fb.u & 0x7F800000) >> 23) - 127; 34 if (e < 0) 35 return 0; 36 ti_int s = (si_int)(fb.u & 0x80000000) >> 31; 37 ti_int r = (fb.u & 0x007FFFFF) | 0x00800000; 38 if (e > 23) 39 r <<= (e - 23); 40 else 41 r >>= (23 - e); 42 return (r ^ s) - s; 43 } 44 45 #endif 46
