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

41 lines
1.2 KiB
C

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