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