1 //===-- llvm/ADT/APSInt.cpp - Arbitrary Precision Signed Int ---*- C++ -*--===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file implements the APSInt class, which is a simple class that
10 // represents an arbitrary sized integer that knows its signedness.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/ADT/APSInt.h"
15 #include "llvm/ADT/FoldingSet.h"
16 #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 < NumBits)
30 Tmp = Tmp.trunc(std::max<unsigned>(1, MinBits));
31 *this = APSInt(Tmp, /*isUnsigned=*/false);
34 unsigned ActiveBits = Tmp.getActiveBits();
35 if (ActiveBits < NumBits)
36 Tmp = Tmp.trunc(std::max<unsigned>(1, ActiveBits));
37 *this = APSInt(Tmp, /*isUnsigned=*/true);
40 void APSInt::Profile(FoldingSetNodeID& ID) const {
41 ID.AddInteger((unsigned) (IsUnsigned ? 1 : 0));