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de79a71b98
`WidthPreservingAPIntDenseMapInfo` uses the same `getHashValue` and `isEqual` as the normal `DenseMapInfo` but with different empty and tombstone keys. `hash_value` is no longer a complete type, so just delegate to `DenseMapInfo<APInt>` rather than add another `#include`.
55 lines
1.8 KiB
C++
55 lines
1.8 KiB
C++
//===--- APIntMap.h - A map with APInts as the keys -------------*- C++ -*-===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// LLVM does not allow arbitrary APInts to be the keys of a DenseMap because
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// APInts are only comparable if they have the same bit-width. This map
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// implementation assumes that its keys will always be constrained to their
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// minimum width, so it's not a general-purpose structure, but it does work.
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_BASIC_APINTMAP_H
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#define SWIFT_BASIC_APINTMAP_H
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#include "llvm/ADT/APInt.h"
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#include "llvm/ADT/DenseMap.h"
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#include "swift/Basic/LLVM.h"
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namespace swift {
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struct WidthPreservingAPIntDenseMapInfo {
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// For the special values, we use -1 with a bit-width that isn't minimal
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// for the value, then use a parser that always produces values with
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// minimal bit-widths so that we don't get a conflict.
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static inline APInt getEmptyKey() {
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return APInt::getAllOnesValue(/*bitwidth*/2);
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}
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static inline APInt getTombstoneKey() {
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return APInt::getAllOnesValue(/*bitwidth*/3);
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}
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static unsigned getHashValue(const APInt &Key) {
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return llvm::DenseMapInfo<APInt>::getHashValue(Key);
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}
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static bool isEqual(const APInt &LHS, const APInt &RHS) {
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return llvm::DenseMapInfo<APInt>::isEqual(LHS, RHS);
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}
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};
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template <class Value>
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using APIntMap = llvm::DenseMap<APInt, Value, WidthPreservingAPIntDenseMapInfo>;
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}
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#endif
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