1 //===- CodeMetrics.h - Code cost measurements -------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements various weight measurements for code, helping
11 // the Inliner and other passes decide whether to duplicate its contents.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_ANALYSIS_CODEMETRICS_H
16 #define LLVM_ANALYSIS_CODEMETRICS_H
18 #include "llvm/ADT/DenseMap.h"
26 /// \brief Check whether a call will lower to something small.
28 /// This tests checks whether calls to this function will lower to something
29 /// significantly cheaper than a traditional call, often a single
31 bool callIsSmall(const Function *F);
33 /// \brief Utility to calculate the size and a few similar metrics for a set
36 /// \brief True if this function contains a call to setjmp or other functions
37 /// with attribute "returns twice" without having the attribute itself.
38 bool exposesReturnsTwice;
40 /// \brief True if this function calls itself.
43 /// \brief True if this function contains one or more indirect branches.
44 bool containsIndirectBr;
46 /// \brief True if this function calls alloca (in the C sense).
47 bool usesDynamicAlloca;
49 /// \brief Number of instructions in the analyzed blocks.
52 /// \brief Number of analyzed blocks.
55 /// \brief Keeps track of basic block code size estimates.
56 DenseMap<const BasicBlock *, unsigned> NumBBInsts;
58 /// \brief Keep track of the number of calls to 'big' functions.
61 /// \brief The number of calls to internal functions with a single caller.
63 /// These are likely targets for future inlining, likely exposed by
64 /// interleaved devirtualization.
65 unsigned NumInlineCandidates;
67 /// \brief How many instructions produce vector values.
69 /// The inliner is more aggressive with inlining vector kernels.
70 unsigned NumVectorInsts;
72 /// \brief How many 'ret' instructions the blocks contain.
75 CodeMetrics() : exposesReturnsTwice(false), isRecursive(false),
76 containsIndirectBr(false), usesDynamicAlloca(false),
77 NumInsts(0), NumBlocks(0), NumCalls(0),
78 NumInlineCandidates(0), NumVectorInsts(0),
81 /// \brief Add information about a block to the current state.
82 void analyzeBasicBlock(const BasicBlock *BB, const TargetData *TD = 0);
84 /// \brief Add information about a function to the current state.
85 void analyzeFunction(Function *F, const TargetData *TD = 0);