1235368Sgnn//===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===// 2235368Sgnn// 3235368Sgnn// The LLVM Compiler Infrastructure 4235368Sgnn// 5235368Sgnn// This file is dual licensed under the MIT and the University of Illinois Open 6235368Sgnn// Source Licenses. See LICENSE.TXT for details. 7235368Sgnn// 8235368Sgnn//===----------------------------------------------------------------------===// 9235368Sgnn// 10235368Sgnn// This file implements float to integer conversion for the 11235368Sgnn// compiler-rt library. 12235368Sgnn// 13235368Sgnn//===----------------------------------------------------------------------===// 14235368Sgnn 15235368Sgnn#include "fp_lib.h" 16235368Sgnn 17235368Sgnnstatic __inline fixint_t __fixint(fp_t a) { 18235368Sgnn const fixint_t fixint_max = (fixint_t)((~(fixuint_t)0) / 2); 19235368Sgnn const fixint_t fixint_min = -fixint_max - 1; 20235368Sgnn // Break a into sign, exponent, significand 21235368Sgnn const rep_t aRep = toRep(a); 22235368Sgnn const rep_t aAbs = aRep & absMask; 23235368Sgnn const fixint_t sign = aRep & signBit ? -1 : 1; 24235368Sgnn const int exponent = (aAbs >> significandBits) - exponentBias; 25235368Sgnn const rep_t significand = (aAbs & significandMask) | implicitBit; 26235368Sgnn 27235368Sgnn // If exponent is negative, the result is zero. 28235368Sgnn if (exponent < 0) 29235368Sgnn return 0; 30235368Sgnn 31235368Sgnn // If the value is too large for the integer type, saturate. 32235368Sgnn if ((unsigned)exponent >= sizeof(fixint_t) * CHAR_BIT) 33235368Sgnn return sign == 1 ? fixint_max : fixint_min; 34235368Sgnn 35235368Sgnn // If 0 <= exponent < significandBits, right shift to get the result. 36235368Sgnn // Otherwise, shift left. 37235368Sgnn if (exponent < significandBits) 38235368Sgnn return sign * (significand >> (significandBits - exponent)); 39235368Sgnn else 40235368Sgnn return sign * ((fixint_t)significand << (exponent - significandBits)); 41235368Sgnn} 42235368Sgnn