1 //===- CodeMetrics.h - Measures the weight of a function---------*- 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 // CodeMetrics - Calculate size and a few similar metrics for a set of
30 /// NeverInline - True if this callee should never be inlined into a
34 // True if this function contains a call to setjmp or other functions
35 // with attribute "returns twice" without having the attribute itself.
36 bool exposesReturnsTwice;
38 // True if this function calls itself
41 // True if this function contains one or more indirect branches
42 bool containsIndirectBr;
44 /// usesDynamicAlloca - True if this function calls alloca (in the C sense).
45 bool usesDynamicAlloca;
47 /// NumInsts, NumBlocks - Keep track of how large each function is, which
48 /// is used to estimate the code size cost of inlining it.
49 unsigned NumInsts, NumBlocks;
51 /// NumBBInsts - Keeps track of basic block code size estimates.
52 DenseMap<const BasicBlock *, unsigned> NumBBInsts;
54 /// NumCalls - Keep track of the number of calls to 'big' functions.
57 /// NumInlineCandidates - Keep track of the number of calls to internal
58 /// functions with only a single caller. These are likely targets for
59 /// future inlining, likely exposed by interleaved devirtualization.
60 unsigned NumInlineCandidates;
62 /// NumVectorInsts - Keep track of how many instructions produce vector
63 /// values. The inliner is being more aggressive with inlining vector
65 unsigned NumVectorInsts;
67 /// NumRets - Keep track of how many Ret instructions the block contains.
70 CodeMetrics() : exposesReturnsTwice(false), isRecursive(false),
71 containsIndirectBr(false), usesDynamicAlloca(false),
72 NumInsts(0), NumBlocks(0), NumCalls(0),
73 NumInlineCandidates(0), NumVectorInsts(0),
76 /// analyzeBasicBlock - Add information about the specified basic block
77 /// to the current structure.
78 void analyzeBasicBlock(const BasicBlock *BB, const TargetData *TD = 0);
80 /// analyzeFunction - Add information about the specified function
81 /// to the current structure.
82 void analyzeFunction(Function *F, const TargetData *TD = 0);
84 /// CountBonusForConstant - Figure out an approximation for how much
85 /// per-call performance boost we can expect if the specified value is
87 unsigned CountBonusForConstant(Value *V);