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