1 //===-- lib/fixsfsi.c - Single-precision -> integer conversion ----*- C -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements single-precision to integer conversion for the 11 // compiler-rt library. No range checking is performed; the behavior of this 12 // conversion is undefined for out of range values in the C standard. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #define SINGLE_PRECISION 17 #include "fp_lib.h" 18 19 ARM_EABI_FNALIAS(f2iz, fixsfsi); 20 21 COMPILER_RT_ABI int 22 __fixsfsi(fp_t a) { 23 // Break a into sign, exponent, significand 24 const rep_t aRep = toRep(a); 25 const rep_t aAbs = aRep & absMask; 26 const int sign = aRep & signBit ? -1 : 1; 27 const int exponent = (aAbs >> significandBits) - exponentBias; 28 const rep_t significand = (aAbs & significandMask) | implicitBit; 29 30 // If 0 < exponent < significandBits, right shift to get the result. 31 if ((unsigned int)exponent < significandBits) { 32 return sign * (significand >> (significandBits - exponent)); 33 } 34 35 // If exponent is negative, the result is zero. 36 else if (exponent < 0) { 37 return 0; 38 } 39 40 // If significandBits < exponent, left shift to get the result. This shift 41 // may end up being larger than the type width, which incurs undefined 42 // behavior, but the conversion itself is undefined in that case, so 43 // whatever the compiler decides to do is fine. 44 else { 45 return sign * (significand << (exponent - significandBits)); 46 } 47 } 48
