1//===-- lib/floatunsitf.c - uint -> quad-precision conversion -----*- C -*-===//
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 unsigned integer to quad-precision conversion for the
11// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
12// mode.
13//
14//===----------------------------------------------------------------------===//
15
16#define QUAD_PRECISION
17#include "fp_lib.h"
18
19#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT)
20COMPILER_RT_ABI fp_t __floatunsitf(unsigned int a) {
21
22    const int aWidth = sizeof a * CHAR_BIT;
23
24    // Handle zero as a special case to protect clz
25    if (a == 0) return fromRep(0);
26
27    // Exponent of (fp_t)a is the width of abs(a).
28    const int exponent = (aWidth - 1) - __builtin_clz(a);
29    rep_t result;
30
31    // Shift a into the significand field and clear the implicit bit.
32    const int shift = significandBits - exponent;
33    result = (rep_t)a << shift ^ implicitBit;
34
35    // Insert the exponent
36    result += (rep_t)(exponent + exponentBias) << significandBits;
37    return fromRep(result);
38}
39
40#endif
41