LLVM 17.0.0git
APSInt.cpp
Go to the documentation of this file.
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
19using namespace llvm;
20
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 < NumBits)
30 Tmp = Tmp.trunc(std::max<unsigned>(1, MinBits));
31 *this = APSInt(Tmp, /*isUnsigned=*/false);
32 return;
33 }
34 unsigned ActiveBits = Tmp.getActiveBits();
35 if (ActiveBits < NumBits)
36 Tmp = Tmp.trunc(std::max<unsigned>(1, ActiveBits));
37 *this = APSInt(Tmp, /*isUnsigned=*/true);
38}
39
41 ID.AddInteger((unsigned) (IsUnsigned ? 1 : 0));
43}
This file implements the APSInt class, which is a simple class that represents an arbitrary sized int...
This file defines a hash set that can be used to remove duplication of nodes in a graph.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Class for arbitrary precision integers.
Definition: APInt.h:75
unsigned getMinSignedBits() const
NOTE: This is soft-deprecated. Please use getSignificantBits() instead.
Definition: APInt.h:1487
unsigned getActiveBits() const
Compute the number of active bits in the value.
Definition: APInt.h:1463
APInt trunc(unsigned width) const
Truncate to new width.
Definition: APInt.cpp:898
void Profile(FoldingSetNodeID &id) const
Used to insert APInt objects, or objects that contain APInt objects, into FoldingSets.
Definition: APInt.cpp:154
void Profile(FoldingSetNodeID &ID) const
Used to insert APSInt objects, or objects that contain APSInt objects, into FoldingSets.
Definition: APSInt.cpp:40
APSInt()=default
Default constructor that creates an uninitialized APInt.
FoldingSetNodeID - This class is used to gather all the unique data bits of a node.
Definition: FoldingSet.h:318
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18