llvm-6502/include/llvm/Analysis/CodeMetrics.h
2011-01-16 00:27:10 +00:00

96 lines
3.5 KiB
C++

//===- CodeMetrics.h - Measures the weight of a function---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements various weight measurements for code, helping
// the Inliner and other passes decide whether to duplicate its contents.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_CODEMETRICS_H
#define LLVM_ANALYSIS_CODEMETRICS_H
#include "llvm/ADT/DenseMap.h"
namespace llvm {
// CodeMetrics - Calculate size and a few similar metrics for a set of
// basic blocks.
struct CodeMetrics {
/// NeverInline - True if this callee should never be inlined into a
/// caller.
// bool NeverInline;
// True if this function contains a call to setjmp or _setjmp
bool callsSetJmp;
// True if this function calls itself
bool isRecursive;
// True if this function contains one or more indirect branches
bool containsIndirectBr;
/// usesDynamicAlloca - True if this function calls alloca (in the C sense).
bool usesDynamicAlloca;
/// NumInsts, NumBlocks - Keep track of how large each function is, which
/// is used to estimate the code size cost of inlining it.
unsigned NumInsts, NumBlocks;
/// NumBBInsts - Keeps track of basic block code size estimates.
DenseMap<const BasicBlock *, unsigned> NumBBInsts;
/// NumCalls - Keep track of the number of calls to 'big' functions.
unsigned NumCalls;
/// NumInlineCandidates - Keep track of the number of calls to internal
/// functions with only a single caller. These are likely targets for
/// future inlining, likely exposed by interleaved devirtualization.
unsigned NumInlineCandidates;
/// NumVectorInsts - Keep track of how many instructions produce vector
/// values. The inliner is being more aggressive with inlining vector
/// kernels.
unsigned NumVectorInsts;
/// NumRets - Keep track of how many Ret instructions the block contains.
unsigned NumRets;
CodeMetrics() : callsSetJmp(false), isRecursive(false),
containsIndirectBr(false), usesDynamicAlloca(false),
NumInsts(0), NumBlocks(0), NumCalls(0),
NumInlineCandidates(0), NumVectorInsts(0),
NumRets(0) {}
/// analyzeBasicBlock - Add information about the specified basic block
/// to the current structure.
void analyzeBasicBlock(const BasicBlock *BB);
/// analyzeFunction - Add information about the specified function
/// to the current structure.
void analyzeFunction(Function *F);
/// CountCodeReductionForConstant - Figure out an approximation for how
/// many instructions will be constant folded if the specified value is
/// constant.
unsigned CountCodeReductionForConstant(Value *V);
/// CountBonusForConstant - Figure out an approximation for how much
/// per-call performance boost we can expect if the specified value is
/// constant.
unsigned CountBonusForConstant(Value *V);
/// CountCodeReductionForAlloca - Figure out an approximation of how much
/// smaller the function will be if it is inlined into a context where an
/// argument becomes an alloca.
///
unsigned CountCodeReductionForAlloca(Value *V);
};
}
#endif