1*0b57cec5SDimitry Andric//===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===// 2*0b57cec5SDimitry Andric// 3*0b57cec5SDimitry Andric// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*0b57cec5SDimitry Andric// See https://llvm.org/LICENSE.txt for license information. 5*0b57cec5SDimitry Andric// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*0b57cec5SDimitry Andric// 7*0b57cec5SDimitry Andric//===----------------------------------------------------------------------===// 8*0b57cec5SDimitry Andric// 9*0b57cec5SDimitry Andric// This file implements float to unsigned integer conversion for the 10*0b57cec5SDimitry Andric// compiler-rt library. 11*0b57cec5SDimitry Andric// 12*0b57cec5SDimitry Andric//===----------------------------------------------------------------------===// 13*0b57cec5SDimitry Andric 14*0b57cec5SDimitry Andric#include "fp_lib.h" 15*0b57cec5SDimitry Andric 16*0b57cec5SDimitry Andricstatic __inline fixuint_t __fixuint(fp_t a) { 17*0b57cec5SDimitry Andric // Break a into sign, exponent, significand parts. 18*0b57cec5SDimitry Andric const rep_t aRep = toRep(a); 19*0b57cec5SDimitry Andric const rep_t aAbs = aRep & absMask; 20*0b57cec5SDimitry Andric const int sign = aRep & signBit ? -1 : 1; 21*0b57cec5SDimitry Andric const int exponent = (aAbs >> significandBits) - exponentBias; 22*0b57cec5SDimitry Andric const rep_t significand = (aAbs & significandMask) | implicitBit; 23*0b57cec5SDimitry Andric 24*0b57cec5SDimitry Andric // If either the value or the exponent is negative, the result is zero. 25*0b57cec5SDimitry Andric if (sign == -1 || exponent < 0) 26*0b57cec5SDimitry Andric return 0; 27*0b57cec5SDimitry Andric 28*0b57cec5SDimitry Andric // If the value is too large for the integer type, saturate. 29*0b57cec5SDimitry Andric if ((unsigned)exponent >= sizeof(fixuint_t) * CHAR_BIT) 30*0b57cec5SDimitry Andric return ~(fixuint_t)0; 31*0b57cec5SDimitry Andric 32*0b57cec5SDimitry Andric // If 0 <= exponent < significandBits, right shift to get the result. 33*0b57cec5SDimitry Andric // Otherwise, shift left. 34*0b57cec5SDimitry Andric if (exponent < significandBits) 35*0b57cec5SDimitry Andric return significand >> (significandBits - exponent); 36*0b57cec5SDimitry Andric else 37*0b57cec5SDimitry Andric return (fixuint_t)significand << (exponent - significandBits); 38*0b57cec5SDimitry Andric} 39