Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
14 pmbaty 1
//===- CodeLayout.h - Code layout/placement algorithms  ---------*- 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
/// \file
10
/// Declares methods and data structures for code layout algorithms.
11
//
12
//===----------------------------------------------------------------------===//
13
 
14
#ifndef LLVM_TRANSFORMS_UTILS_CODELAYOUT_H
15
#define LLVM_TRANSFORMS_UTILS_CODELAYOUT_H
16
 
17
#include "llvm/ADT/DenseMap.h"
18
 
19
#include <vector>
20
 
21
namespace llvm {
22
 
23
using EdgeT = std::pair<uint64_t, uint64_t>;
24
using EdgeCountT = std::pair<EdgeT, uint64_t>;
25
 
26
/// Find a layout of nodes (basic blocks) of a given CFG optimizing jump
27
/// locality and thus processor I-cache utilization. This is achieved via
28
/// increasing the number of fall-through jumps and co-locating frequently
29
/// executed nodes together.
30
/// The nodes are assumed to be indexed by integers from [0, |V|) so that the
31
/// current order is the identity permutation.
32
/// \p NodeSizes: The sizes of the nodes (in bytes).
33
/// \p NodeCounts: The execution counts of the nodes in the profile.
34
/// \p EdgeCounts: The execution counts of every edge (jump) in the profile. The
35
///    map also defines the edges in CFG and should include 0-count edges.
36
/// \returns The best block order found.
37
std::vector<uint64_t>
38
applyExtTspLayout(const std::vector<uint64_t> &NodeSizes,
39
                  const std::vector<uint64_t> &NodeCounts,
40
                  const std::vector<EdgeCountT> &EdgeCounts);
41
 
42
/// Estimate the "quality" of a given node order in CFG. The higher the score,
43
/// the better the order is. The score is designed to reflect the locality of
44
/// the given order, which is anti-correlated with the number of I-cache misses
45
/// in a typical execution of the function.
46
double calcExtTspScore(const std::vector<uint64_t> &Order,
47
                       const std::vector<uint64_t> &NodeSizes,
48
                       const std::vector<uint64_t> &NodeCounts,
49
                       const std::vector<EdgeCountT> &EdgeCounts);
50
 
51
/// Estimate the "quality" of the current node order in CFG.
52
double calcExtTspScore(const std::vector<uint64_t> &NodeSizes,
53
                       const std::vector<uint64_t> &NodeCounts,
54
                       const std::vector<EdgeCountT> &EdgeCounts);
55
 
56
} // end namespace llvm
57
 
58
#endif // LLVM_TRANSFORMS_UTILS_CODELAYOUT_H