1 //===-- lib/floatunditf.c - uint -> quad-precision conversion -----*- C -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements du_int to quad-precision conversion for the 10 // compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even 11 // mode. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #define QUAD_PRECISION 16 #include "fp_lib.h" 17 18 #if defined(CRT_HAS_TF_MODE) 19 COMPILER_RT_ABI fp_t __floatunditf(du_int a) { 20 21 const int aWidth = sizeof a * CHAR_BIT; 22 23 // Handle zero as a special case to protect clz 24 if (a == 0) 25 return fromRep(0); 26 27 // Exponent of (fp_t)a is the width of abs(a). 28 const int exponent = (aWidth - 1) - __builtin_clzll(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