Files
clang-r547379/include/llvm/IR/PredIteratorCache.h
Ryan Prichard 6024e5c395 Update prebuilt Clang to r547379 (20.0.0).
clang 20.0.0 (based on r547379) from build 12806354.

Bug: http://b/379133546
Test: N/A
Change-Id: I2eb8938af55d809de674be63cb30cf27e801862b

Upstream-Commit: ad834e67b1105d15ef907f6255d4c96e8e733f57
2025-11-26 14:59:46 -05:00

58 lines
1.8 KiB
C++

//===- PredIteratorCache.h - pred_iterator Cache ----------------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file defines the PredIteratorCache class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_PREDITERATORCACHE_H
#define LLVM_IR_PREDITERATORCACHE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/IR/CFG.h"
#include "llvm/Support/Allocator.h"
namespace llvm {
/// PredIteratorCache - This class is an extremely trivial cache for
/// predecessor iterator queries. This is useful for code that repeatedly
/// wants the predecessor list for the same blocks.
class PredIteratorCache {
/// Cached list of predecessors, allocated in Memory.
DenseMap<BasicBlock *, ArrayRef<BasicBlock *>> BlockToPredsMap;
/// Memory - This is the space that holds cached preds.
BumpPtrAllocator Memory;
public:
size_t size(BasicBlock *BB) { return get(BB).size(); }
ArrayRef<BasicBlock *> get(BasicBlock *BB) {
ArrayRef<BasicBlock *> &Entry = BlockToPredsMap[BB];
if (Entry.data())
return Entry;
SmallVector<BasicBlock *, 32> PredCache(predecessors(BB));
BasicBlock **Data = Memory.Allocate<BasicBlock *>(PredCache.size());
std::copy(PredCache.begin(), PredCache.end(), Data);
Entry = ArrayRef(Data, PredCache.size());
return Entry;
}
/// clear - Remove all information.
void clear() {
BlockToPredsMap.clear();
Memory.Reset();
}
};
} // end namespace llvm
#endif