1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
| //===-- lib/floatunsitf.c - uint -> quad-precision conversion -----*- C -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements unsigned integer to quad-precision conversion for the
// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
// mode.
//
//===----------------------------------------------------------------------===//
#define QUAD_PRECISION
#include "fp_lib.h"
#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT)
COMPILER_RT_ABI fp_t __floatunsitf(unsigned int a) {
const int aWidth = sizeof a * CHAR_BIT;
// Handle zero as a special case to protect clz
if (a == 0)
return fromRep(0);
// Exponent of (fp_t)a is the width of abs(a).
const int exponent = (aWidth - 1) - __builtin_clz(a);
rep_t result;
// Shift a into the significand field and clear the implicit bit.
const int shift = significandBits - exponent;
result = (rep_t)a << shift ^ implicitBit;
// Insert the exponent
result += (rep_t)(exponent + exponentBias) << significandBits;
return fromRep(result);
}
#endif
|