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 a function, helping
11 // the Inliner and PartialSpecialization decide whether to duplicate its
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_ANALYSIS_CODEMETRICS_H
17 #define LLVM_ANALYSIS_CODEMETRICS_H
20 // CodeMetrics - Calculate size and a few similar metrics for a set of
23 /// NeverInline - True if this callee should never be inlined into a
27 // True if this function contains a call to setjmp or _setjmp
30 // True if this function calls itself
33 // True if this function contains one or more indirect branches
34 bool containsIndirectBr;
36 /// usesDynamicAlloca - True if this function calls alloca (in the C sense).
37 bool usesDynamicAlloca;
39 /// NumInsts, NumBlocks - Keep track of how large each function is, which
40 /// is used to estimate the code size cost of inlining it.
41 unsigned NumInsts, NumBlocks;
43 /// NumBBInsts - Keeps track of basic block code size estimates.
44 DenseMap<const BasicBlock *, unsigned> NumBBInsts;
46 /// NumCalls - Keep track of the number of calls to 'big' functions.
49 /// NumInlineCandidates - Keep track of the number of calls to internal
50 /// functions with only a single caller. These are likely targets for
51 /// future inlining, likely exposed by interleaved devirtualization.
52 unsigned NumInlineCandidates;
54 /// NumVectorInsts - Keep track of how many instructions produce vector
55 /// values. The inliner is being more aggressive with inlining vector
57 unsigned NumVectorInsts;
59 /// NumRets - Keep track of how many Ret instructions the block contains.
62 CodeMetrics() : callsSetJmp(false), isRecursive(false),
63 containsIndirectBr(false), usesDynamicAlloca(false),
64 NumInsts(0), NumBlocks(0), NumCalls(0),
65 NumInlineCandidates(0), NumVectorInsts(0),
68 /// analyzeBasicBlock - Add information about the specified basic block
69 /// to the current structure.
70 void analyzeBasicBlock(const BasicBlock *BB);
72 /// analyzeFunction - Add information about the specified function
73 /// to the current structure.
74 void analyzeFunction(Function *F);
76 /// CountCodeReductionForConstant - Figure out an approximation for how
77 /// many instructions will be constant folded if the specified value is
79 unsigned CountCodeReductionForConstant(Value *V);
81 /// CountCodeReductionForAlloca - Figure out an approximation of how much
82 /// smaller the function will be if it is inlined into a context where an
83 /// argument becomes an alloca.
85 unsigned CountCodeReductionForAlloca(Value *V);