1287516Sdim//===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===//
2287516Sdim//
3287516Sdim//                     The LLVM Compiler Infrastructure
4287516Sdim//
5287516Sdim// This file is dual licensed under the MIT and the University of Illinois Open
6287516Sdim// Source Licenses. See LICENSE.TXT for details.
7287516Sdim//
8287516Sdim//===----------------------------------------------------------------------===//
9287516Sdim//
10287516Sdim// This file implements float to unsigned integer conversion for the
11287516Sdim// compiler-rt library.
12287516Sdim//
13287516Sdim//===----------------------------------------------------------------------===//
14287516Sdim
15287516Sdim#include "fp_lib.h"
16287516Sdim
17296417Sdimstatic __inline fixuint_t __fixuint(fp_t a) {
18287516Sdim    // Break a into sign, exponent, significand
19287516Sdim    const rep_t aRep = toRep(a);
20287516Sdim    const rep_t aAbs = aRep & absMask;
21287516Sdim    const int sign = aRep & signBit ? -1 : 1;
22287516Sdim    const int exponent = (aAbs >> significandBits) - exponentBias;
23287516Sdim    const rep_t significand = (aAbs & significandMask) | implicitBit;
24287516Sdim
25287516Sdim    // If either the value or the exponent is negative, the result is zero.
26287516Sdim    if (sign == -1 || exponent < 0)
27287516Sdim        return 0;
28287516Sdim
29287516Sdim    // If the value is too large for the integer type, saturate.
30296417Sdim    if ((unsigned)exponent >= sizeof(fixuint_t) * CHAR_BIT)
31287516Sdim        return ~(fixuint_t)0;
32287516Sdim
33287516Sdim    // If 0 <= exponent < significandBits, right shift to get the result.
34287516Sdim    // Otherwise, shift left.
35287516Sdim    if (exponent < significandBits)
36287516Sdim        return significand >> (significandBits - exponent);
37287516Sdim    else
38287516Sdim        return (fixuint_t)significand << (exponent - significandBits);
39287516Sdim}
40