llvm-6502/lib/Analysis/BlockFrequencyInfo.cpp
Cong Hou 1dd3d83c5e Add new constructors for LoopInfo/DominatorTree/BFI/BPI
Those new constructors make it more natural to construct an object for a function. For example, previously to build a LoopInfo for a function, we need four statements:

DominatorTree DT;
LoopInfo LI;
DT.recalculate(F);
LI.analyze(DT);

Now we only need one statement:

LoopInfo LI(DominatorTree(F));

http://reviews.llvm.org/D11274



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242486 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 23:23:35 +00:00

208 lines
6.4 KiB
C++

//===- BlockFrequencyInfo.cpp - Block Frequency Analysis ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Loops should be simplified before this analysis.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/BlockFrequencyInfo.h"
#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/IR/CFG.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/GraphWriter.h"
using namespace llvm;
#define DEBUG_TYPE "block-freq"
#ifndef NDEBUG
enum GVDAGType {
GVDT_None,
GVDT_Fraction,
GVDT_Integer
};
static cl::opt<GVDAGType>
ViewBlockFreqPropagationDAG("view-block-freq-propagation-dags", cl::Hidden,
cl::desc("Pop up a window to show a dag displaying how block "
"frequencies propagation through the CFG."),
cl::values(
clEnumValN(GVDT_None, "none",
"do not display graphs."),
clEnumValN(GVDT_Fraction, "fraction", "display a graph using the "
"fractional block frequency representation."),
clEnumValN(GVDT_Integer, "integer", "display a graph using the raw "
"integer fractional block frequency representation."),
clEnumValEnd));
namespace llvm {
template <>
struct GraphTraits<BlockFrequencyInfo *> {
typedef const BasicBlock NodeType;
typedef succ_const_iterator ChildIteratorType;
typedef Function::const_iterator nodes_iterator;
static inline const NodeType *getEntryNode(const BlockFrequencyInfo *G) {
return G->getFunction()->begin();
}
static ChildIteratorType child_begin(const NodeType *N) {
return succ_begin(N);
}
static ChildIteratorType child_end(const NodeType *N) {
return succ_end(N);
}
static nodes_iterator nodes_begin(const BlockFrequencyInfo *G) {
return G->getFunction()->begin();
}
static nodes_iterator nodes_end(const BlockFrequencyInfo *G) {
return G->getFunction()->end();
}
};
template<>
struct DOTGraphTraits<BlockFrequencyInfo*> : public DefaultDOTGraphTraits {
explicit DOTGraphTraits(bool isSimple=false) :
DefaultDOTGraphTraits(isSimple) {}
static std::string getGraphName(const BlockFrequencyInfo *G) {
return G->getFunction()->getName();
}
std::string getNodeLabel(const BasicBlock *Node,
const BlockFrequencyInfo *Graph) {
std::string Result;
raw_string_ostream OS(Result);
OS << Node->getName() << ":";
switch (ViewBlockFreqPropagationDAG) {
case GVDT_Fraction:
Graph->printBlockFreq(OS, Node);
break;
case GVDT_Integer:
OS << Graph->getBlockFreq(Node).getFrequency();
break;
case GVDT_None:
llvm_unreachable("If we are not supposed to render a graph we should "
"never reach this point.");
}
return Result;
}
};
} // end namespace llvm
#endif
BlockFrequencyInfo::BlockFrequencyInfo() {}
BlockFrequencyInfo::BlockFrequencyInfo(const Function &F,
const BranchProbabilityInfo &BPI,
const LoopInfo &LI) {
calculate(F, BPI, LI);
}
void BlockFrequencyInfo::calculate(const Function &F,
const BranchProbabilityInfo &BPI,
const LoopInfo &LI) {
if (!BFI)
BFI.reset(new ImplType);
BFI->calculate(F, BPI, LI);
#ifndef NDEBUG
if (ViewBlockFreqPropagationDAG != GVDT_None)
view();
#endif
}
BlockFrequency BlockFrequencyInfo::getBlockFreq(const BasicBlock *BB) const {
return BFI ? BFI->getBlockFreq(BB) : 0;
}
/// Pop up a ghostview window with the current block frequency propagation
/// rendered using dot.
void BlockFrequencyInfo::view() const {
// This code is only for debugging.
#ifndef NDEBUG
ViewGraph(const_cast<BlockFrequencyInfo *>(this), "BlockFrequencyDAGs");
#else
errs() << "BlockFrequencyInfo::view is only available in debug builds on "
"systems with Graphviz or gv!\n";
#endif // NDEBUG
}
const Function *BlockFrequencyInfo::getFunction() const {
return BFI ? BFI->getFunction() : nullptr;
}
raw_ostream &BlockFrequencyInfo::
printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const {
return BFI ? BFI->printBlockFreq(OS, Freq) : OS;
}
raw_ostream &
BlockFrequencyInfo::printBlockFreq(raw_ostream &OS,
const BasicBlock *BB) const {
return BFI ? BFI->printBlockFreq(OS, BB) : OS;
}
uint64_t BlockFrequencyInfo::getEntryFreq() const {
return BFI ? BFI->getEntryFreq() : 0;
}
void BlockFrequencyInfo::releaseMemory() { BFI.reset(); }
void BlockFrequencyInfo::print(raw_ostream &OS) const {
if (BFI)
BFI->print(OS);
}
INITIALIZE_PASS_BEGIN(BlockFrequencyInfoWrapperPass, "block-freq",
"Block Frequency Analysis", true, true)
INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_END(BlockFrequencyInfoWrapperPass, "block-freq",
"Block Frequency Analysis", true, true)
char BlockFrequencyInfoWrapperPass::ID = 0;
BlockFrequencyInfoWrapperPass::BlockFrequencyInfoWrapperPass()
: FunctionPass(ID) {
initializeBlockFrequencyInfoWrapperPassPass(*PassRegistry::getPassRegistry());
}
BlockFrequencyInfoWrapperPass::~BlockFrequencyInfoWrapperPass() {}
void BlockFrequencyInfoWrapperPass::print(raw_ostream &OS,
const Module *) const {
BFI.print(OS);
}
void BlockFrequencyInfoWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<BranchProbabilityInfoWrapperPass>();
AU.addRequired<LoopInfoWrapperPass>();
AU.setPreservesAll();
}
void BlockFrequencyInfoWrapperPass::releaseMemory() { BFI.releaseMemory(); }
bool BlockFrequencyInfoWrapperPass::runOnFunction(Function &F) {
BranchProbabilityInfo &BPI =
getAnalysis<BranchProbabilityInfoWrapperPass>().getBPI();
LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
BFI.calculate(F, BPI, LI);
return false;
}