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1//===-- lib/floatsitf.c - integer -> 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-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements integer to quad-precision conversion for the10// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even11// mode.12//13//===----------------------------------------------------------------------===//14 15#define QUAD_PRECISION16#include "fp_lib.h"17 18#if defined(CRT_HAS_TF_MODE)19COMPILER_RT_ABI fp_t __floatsitf(si_int a) {20 21 const int aWidth = sizeof a * CHAR_BIT;22 23 // Handle zero as a special case to protect clz24 if (a == 0)25 return fromRep(0);26 27 // All other cases begin by extracting the sign and absolute value of a28 rep_t sign = 0;29 su_int aAbs = (su_int)a;30 if (a < 0) {31 sign = signBit;32 aAbs = -aAbs;33 }34 35 // Exponent of (fp_t)a is the width of abs(a).36 const int exponent = (aWidth - 1) - clzsi(aAbs);37 rep_t result;38 39 // Shift a into the significand field and clear the implicit bit.40 const int shift = significandBits - exponent;41 result = (rep_t)aAbs << shift ^ implicitBit;42 43 // Insert the exponent44 result += (rep_t)(exponent + exponentBias) << significandBits;45 // Insert the sign bit and return46 return fromRep(result | sign);47}48 49#endif50