1//===-- lib/fixdfsi.c - Double-precision -> integer 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 float to integer conversion for the 10// compiler-rt library. 11// 12//===----------------------------------------------------------------------===// 13 14#include "fp_lib.h" 15 16static __inline fixint_t __fixint(fp_t a) { 17 const fixint_t fixint_max = (fixint_t)((~(fixuint_t)0) / 2); 18 const fixint_t fixint_min = -fixint_max - 1; 19 // Break a into sign, exponent, significand parts. 20 const rep_t aRep = toRep(a); 21 const rep_t aAbs = aRep & absMask; 22 const fixint_t sign = aRep & signBit ? -1 : 1; 23 const int exponent = (aAbs >> significandBits) - exponentBias; 24 const rep_t significand = (aAbs & significandMask) | implicitBit; 25 26 // If exponent is negative, the result is zero. 27 if (exponent < 0) 28 return 0; 29 30 // If the value is too large for the integer type, saturate. 31 if ((unsigned)exponent >= sizeof(fixint_t) * CHAR_BIT) 32 return sign == 1 ? fixint_max : fixint_min; 33 34 // If 0 <= exponent < significandBits, right shift to get the result. 35 // Otherwise, shift left. 36 if (exponent < significandBits) 37 return sign * (significand >> (significandBits - exponent)); 38 else 39 return sign * ((fixint_t)significand << (exponent - significandBits)); 40} 41