1281223Semaste//===-- lib/floatunditf.c - uint -> quad-precision conversion -----*- C -*-===//
2281223Semaste//
3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4353358Sdim// See https://llvm.org/LICENSE.txt for license information.
5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6281223Semaste//
7281223Semaste//===----------------------------------------------------------------------===//
8281223Semaste//
9281223Semaste// This file implements du_int to quad-precision conversion for the
10281223Semaste// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
11281223Semaste// mode.
12281223Semaste//
13281223Semaste//===----------------------------------------------------------------------===//
14281223Semaste
15281223Semaste#define QUAD_PRECISION
16281223Semaste#include "fp_lib.h"
17281223Semaste
18281223Semaste#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT)
19281223SemasteCOMPILER_RT_ABI fp_t __floatunditf(du_int a) {
20281223Semaste
21353358Sdim  const int aWidth = sizeof a * CHAR_BIT;
22281223Semaste
23353358Sdim  // Handle zero as a special case to protect clz
24353358Sdim  if (a == 0)
25353358Sdim    return fromRep(0);
26281223Semaste
27353358Sdim  // Exponent of (fp_t)a is the width of abs(a).
28353358Sdim  const int exponent = (aWidth - 1) - __builtin_clzll(a);
29353358Sdim  rep_t result;
30281223Semaste
31353358Sdim  // Shift a into the significand field and clear the implicit bit.
32353358Sdim  const int shift = significandBits - exponent;
33353358Sdim  result = (rep_t)a << shift ^ implicitBit;
34281223Semaste
35353358Sdim  // Insert the exponent
36353358Sdim  result += (rep_t)(exponent + exponentBias) << significandBits;
37353358Sdim  return fromRep(result);
38281223Semaste}
39281223Semaste
40281223Semaste#endif
41