| //===- llvm/Analysis/WithCache.h - KnownBits cache for pointers -*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Store a pointer to any type along with the KnownBits information for it |
| // that is computed lazily (if required). |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_ANALYSIS_WITHCACHE_H |
| #define LLVM_ANALYSIS_WITHCACHE_H |
| |
| #include "llvm/ADT/PointerIntPair.h" |
| #include "llvm/IR/Value.h" |
| #include "llvm/Support/KnownBits.h" |
| #include <type_traits> |
| |
| namespace llvm { |
| struct SimplifyQuery; |
| KnownBits computeKnownBits(const Value *V, unsigned Depth, |
| const SimplifyQuery &Q); |
| |
| template <typename Arg> class WithCache { |
| static_assert(std::is_pointer_v<Arg>, "WithCache requires a pointer type!"); |
| |
| using UnderlyingType = std::remove_pointer_t<Arg>; |
| constexpr static bool IsConst = std::is_const_v<Arg>; |
| |
| template <typename T, bool Const> |
| using conditionally_const_t = std::conditional_t<Const, const T, T>; |
| |
| using PointerType = conditionally_const_t<UnderlyingType *, IsConst>; |
| using ReferenceType = conditionally_const_t<UnderlyingType &, IsConst>; |
| |
| // Store the presence of the KnownBits information in one of the bits of |
| // Pointer. |
| // true -> present |
| // false -> absent |
| mutable PointerIntPair<PointerType, 1, bool> Pointer; |
| mutable KnownBits Known; |
| |
| void calculateKnownBits(const SimplifyQuery &Q) const { |
| Known = computeKnownBits(Pointer.getPointer(), 0, Q); |
| Pointer.setInt(true); |
| } |
| |
| public: |
| WithCache(PointerType Pointer) : Pointer(Pointer, false) {} |
| WithCache(PointerType Pointer, const KnownBits &Known) |
| : Pointer(Pointer, true), Known(Known) {} |
| |
| [[nodiscard]] PointerType getValue() const { return Pointer.getPointer(); } |
| |
| [[nodiscard]] const KnownBits &getKnownBits(const SimplifyQuery &Q) const { |
| if (!hasKnownBits()) |
| calculateKnownBits(Q); |
| return Known; |
| } |
| |
| [[nodiscard]] bool hasKnownBits() const { return Pointer.getInt(); } |
| |
| operator PointerType() const { return Pointer.getPointer(); } |
| PointerType operator->() const { return Pointer.getPointer(); } |
| ReferenceType operator*() const { return *Pointer.getPointer(); } |
| }; |
| } // namespace llvm |
| |
| #endif |