| 1 | //===-- llvm/ADT/APSInt.cpp - Arbitrary Precision Signed Int ---*- C++ -*--===// |
|---|---|
| 2 | // |
| 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 |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // |
| 9 | // This file implements the APSInt class, which is a simple class that |
| 10 | // represents an arbitrary sized integer that knows its signedness. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "llvm/ADT/APSInt.h" |
| 15 | #include "llvm/ADT/FoldingSet.h" |
| 16 | #include "llvm/ADT/StringRef.h" |
| 17 | #include <cassert> |
| 18 | |
| 19 | using namespace llvm; |
| 20 | |
| 21 | APSInt::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.getSignificantBits(); |
| 29 | if (MinBits < NumBits) |
| 30 | Tmp = Tmp.trunc(width: std::max<unsigned>(a: 1, b: MinBits)); |
| 31 | *this = APSInt(Tmp, /*isUnsigned=*/false); |
| 32 | return; |
| 33 | } |
| 34 | unsigned ActiveBits = Tmp.getActiveBits(); |
| 35 | if (ActiveBits < NumBits) |
| 36 | Tmp = Tmp.trunc(width: std::max<unsigned>(a: 1, b: ActiveBits)); |
| 37 | *this = APSInt(Tmp, /*isUnsigned=*/true); |
| 38 | } |
| 39 | |
| 40 | void APSInt::Profile(FoldingSetNodeID& ID) const { |
| 41 | ID.AddInteger(I: (unsigned) (IsUnsigned ? 1 : 0)); |
| 42 | APInt::Profile(id&: ID); |
| 43 | } |
| 44 |