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

41 lines
1.2 KiB
C

//===-- fixunssfdi.c - Implement __fixunssfdi -----------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements __fixunssfdi for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#include "int_lib.h"
// Returns: convert a to a unsigned long long, rounding toward zero.
// Negative values all become zero.
// Assumption: float is a IEEE 32 bit floating point type
// du_int is a 64 bit integral type
// value in float is representable in du_int or is negative
// (no range checking performed)
// seee eeee emmm mmmm mmmm mmmm mmmm mmmm
du_int
__fixunssfdi(float a)
{
float_bits fb;
fb.f = a;
int e = ((fb.u & 0x7F800000) >> 23) - 127;
if (e < 0 || (fb.u & 0x80000000))
return 0;
du_int r = (fb.u & 0x007FFFFF) | 0x00800000;
if (e > 23)
r <<= (e - 23);
else
r >>= (23 - e);
return r;
}