1//===-- llvm/ADT/APSInt.cpp - Arbitrary Precision Signed Int ---*- C++ -*--===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the APSInt class, which is a simple class that 11// represents an arbitrary sized integer that knows its signedness. 12// 13//===----------------------------------------------------------------------===// 14 15#include "llvm/ADT/APSInt.h" 16#include "llvm/ADT/FoldingSet.h" 17#include "llvm/ADT/StringRef.h" 18 19using namespace llvm; 20 21APSInt::APSInt(StringRef Str) { 22 assert(!Str.empty() && "Invalid string length"); 23 24 // (Over-)estimate the required number of bits. 25 unsigned NumBits = ((Str.size() * 64) / 19) + 2; 26 APInt Tmp(NumBits, Str, /*Radix=*/10); 27 if (Str[0] == '-') { 28 unsigned MinBits = Tmp.getMinSignedBits(); 29 if (MinBits > 0 && MinBits < NumBits) 30 Tmp = Tmp.trunc(MinBits); 31 *this = APSInt(Tmp, /*IsUnsigned=*/false); 32 return; 33 } 34 unsigned ActiveBits = Tmp.getActiveBits(); 35 if (ActiveBits > 0 && ActiveBits < NumBits) 36 Tmp = Tmp.trunc(ActiveBits); 37 *this = APSInt(Tmp, /*IsUnsigned=*/true); 38} 39 40void APSInt::Profile(FoldingSetNodeID& ID) const { 41 ID.AddInteger((unsigned) (IsUnsigned ? 1 : 0)); 42 APInt::Profile(ID); 43} 44