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"
27 /// \brief Check whether an instruction is likely to be "free" when lowered.
28 bool isInstructionFree(const Instruction *I, const TargetData *TD = 0);
30 /// \brief Check whether a call will lower to something small.
32 /// This tests checks whether calls to this function will lower to something
33 /// significantly cheaper than a traditional call, often a single
35 bool callIsSmall(const Function *F);
37 /// \brief Utility to calculate the size and a few similar metrics for a set
40 /// \brief True if this function contains a call to setjmp or other functions
41 /// with attribute "returns twice" without having the attribute itself.
42 bool exposesReturnsTwice;
44 /// \brief True if this function calls itself.
47 /// \brief True if this function contains one or more indirect branches.
48 bool containsIndirectBr;
50 /// \brief True if this function calls alloca (in the C sense).
51 bool usesDynamicAlloca;
53 /// \brief Number of instructions in the analyzed blocks.
56 /// \brief Number of analyzed blocks.
59 /// \brief Keeps track of basic block code size estimates.
60 DenseMap<const BasicBlock *, unsigned> NumBBInsts;
62 /// \brief Keep track of the number of calls to 'big' functions.
65 /// \brief The number of calls to internal functions with a single caller.
67 /// These are likely targets for future inlining, likely exposed by
68 /// interleaved devirtualization.
69 unsigned NumInlineCandidates;
71 /// \brief How many instructions produce vector values.
73 /// The inliner is more aggressive with inlining vector kernels.
74 unsigned NumVectorInsts;
76 /// \brief How many 'ret' instructions the blocks contain.
79 CodeMetrics() : exposesReturnsTwice(false), isRecursive(false),
80 containsIndirectBr(false), usesDynamicAlloca(false),
81 NumInsts(0), NumBlocks(0), NumCalls(0),
82 NumInlineCandidates(0), NumVectorInsts(0),
85 /// \brief Add information about a block to the current state.
86 void analyzeBasicBlock(const BasicBlock *BB, const TargetData *TD = 0);
88 /// \brief Add information about a function to the current state.
89 void analyzeFunction(Function *F, const TargetData *TD = 0);