1 /* ===-- fixxfdi.c - Implement __fixxfdi -----------------------------------=== 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 __fixxfdi for the compiler_rt library. 11 * 12 * ===----------------------------------------------------------------------=== 13 */ 14 15 #if !_ARCH_PPC 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 * di_int is a 64 bit integral type 23 * value in long double is representable in di_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 COMPILER_RT_ABI di_int 31 __fixxfdi(long double a) 32 { 33 const di_int di_max = (di_int)((~(du_int)0) / 2); 34 const di_int di_min = -di_max - 1; 35 long_double_bits fb; 36 fb.f = a; 37 int e = (fb.u.high.s.low & 0x00007FFF) - 16383; 38 if (e < 0) 39 return 0; 40 if ((unsigned)e >= sizeof(di_int) * CHAR_BIT) 41 return a > 0 ? di_max : di_min; 42 di_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15); 43 di_int r = fb.u.low.all; 44 r = (du_int)r >> (63 - e); 45 return (r ^ s) - s; 46 } 47 48 #endif /* !_ARCH_PPC */ 49
