fp_fixint_impl.inc revision 287516
1287516Sdim//===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===// 2287516Sdim// 3287516Sdim// The LLVM Compiler Infrastructure 4287516Sdim// 5287516Sdim// This file is dual licensed under the MIT and the University of Illinois Open 6287516Sdim// Source Licenses. See LICENSE.TXT for details. 7287516Sdim// 8287516Sdim//===----------------------------------------------------------------------===// 9287516Sdim// 10287516Sdim// This file implements float to integer conversion for the 11287516Sdim// compiler-rt library. 12287516Sdim// 13287516Sdim//===----------------------------------------------------------------------===// 14287516Sdim 15287516Sdim#include "fp_lib.h" 16287516Sdim 17287516Sdimstatic inline fixint_t __fixint(fp_t a) { 18287516Sdim const fixint_t fixint_max = (fixint_t)((~(fixuint_t)0) / 2); 19287516Sdim const fixint_t fixint_min = -fixint_max - 1; 20287516Sdim // Break a into sign, exponent, significand 21287516Sdim const rep_t aRep = toRep(a); 22287516Sdim const rep_t aAbs = aRep & absMask; 23287516Sdim const fixint_t sign = aRep & signBit ? -1 : 1; 24287516Sdim const int exponent = (aAbs >> significandBits) - exponentBias; 25287516Sdim const rep_t significand = (aAbs & significandMask) | implicitBit; 26287516Sdim 27287516Sdim // If exponent is negative, the result is zero. 28287516Sdim if (exponent < 0) 29287516Sdim return 0; 30287516Sdim 31287516Sdim // If the value is too large for the integer type, saturate. 32287516Sdim if ((unsigned)exponent >= sizeof(fixint_t) * CHAR_BIT) 33287516Sdim return sign == 1 ? fixint_max : fixint_min; 34287516Sdim 35287516Sdim // If 0 <= exponent < significandBits, right shift to get the result. 36287516Sdim // Otherwise, shift left. 37287516Sdim if (exponent < significandBits) 38287516Sdim return sign * (significand >> (significandBits - exponent)); 39287516Sdim else 40287516Sdim return sign * ((fixint_t)significand << (exponent - significandBits)); 41287516Sdim} 42