llvm-project/compiler-rt/lib/fixxfdi.c

42 lines
1.3 KiB
C

//===-- fixxfdi.c - Implement __fixxfdi -----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements __fixxfdi for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#if !_ARCH_PPC
#include "int_lib.h"
// Returns: convert a to a signed long long, rounding toward zero.
// Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
// su_int is a 32 bit integral type
// value in long double is representable in di_int (no range checking performed)
// gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
// 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
di_int
__fixxfdi(long double a)
{
long_double_bits fb;
fb.f = a;
int e = (fb.u.high.low & 0x00007FFF) - 16383;
if (e < 0)
return 0;
di_int s = -(si_int)((fb.u.high.low & 0x00008000) >> 15);
di_int r = fb.u.low.all;
r = (du_int)r >> (63 - e);
return (r ^ s) - s;
}
#endif