1214152Sed//===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===// 2214152Sed// 3214152Sed// The LLVM Compiler Infrastructure 4214152Sed// 5222656Sed// This file is dual licensed under the MIT and the University of Illinois Open 6222656Sed// Source Licenses. See LICENSE.TXT for details. 7214152Sed// 8214152Sed//===----------------------------------------------------------------------===// 9214152Sed// 10214152Sed// This file implements double-precision to integer conversion for the 11214152Sed// compiler-rt library. No range checking is performed; the behavior of this 12214152Sed// conversion is undefined for out of range values in the C standard. 13214152Sed// 14214152Sed//===----------------------------------------------------------------------===// 15263560Sdim 16263560Sdim#define DOUBLE_PRECISION 17263764Sdim#include "fp_lib.h" 18214152Sed 19214152Sed#include "int_lib.h" 20214152Sed 21214152SedARM_EABI_FNALIAS(d2iz, fixdfsi) 22214152Sed 23214152Sedint __fixdfsi(fp_t a) { 24214152Sed 25214152Sed // Break a into sign, exponent, significand 26214152Sed const rep_t aRep = toRep(a); 27214152Sed const rep_t aAbs = aRep & absMask; 28214152Sed const int sign = aRep & signBit ? -1 : 1; 29214152Sed const int exponent = (aAbs >> significandBits) - exponentBias; 30214152Sed const rep_t significand = (aAbs & significandMask) | implicitBit; 31214152Sed 32214152Sed // If 0 < exponent < significandBits, right shift to get the result. 33214152Sed if ((unsigned int)exponent < significandBits) { 34214152Sed return sign * (significand >> (significandBits - exponent)); 35214152Sed } 36214152Sed 37263764Sdim // If exponent is negative, the result is zero. 38 else if (exponent < 0) { 39 return 0; 40 } 41 42 // If significandBits < exponent, left shift to get the result. This shift 43 // may end up being larger than the type width, which incurs undefined 44 // behavior, but the conversion itself is undefined in that case, so 45 // whatever the compiler decides to do is fine. 46 else { 47 return sign * (significand << (exponent - significandBits)); 48 } 49} 50