freebsd-dev/contrib/llvm/lib/CodeGen/MachineBlockFrequencyInfo.cpp
Dimitry Andric 139f7f9bf5 Upgrade our copy of llvm/clang to trunk r178860, in preparation of the
upcoming 3.3 release (branching and freezing expected in a few weeks).

Preliminary release notes can be found at the usual location:
<http://llvm.org/docs/ReleaseNotes.html>

An MFC is planned once the actual 3.3 release is finished.
2013-04-12 17:57:40 +00:00

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2.3 KiB
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//====----- MachineBlockFrequencyInfo.cpp - Machine 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/CodeGen/MachineBlockFrequencyInfo.h"
#include "llvm/Analysis/BlockFrequencyImpl.h"
#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/InitializePasses.h"
using namespace llvm;
INITIALIZE_PASS_BEGIN(MachineBlockFrequencyInfo, "machine-block-freq",
"Machine Block Frequency Analysis", true, true)
INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
INITIALIZE_PASS_END(MachineBlockFrequencyInfo, "machine-block-freq",
"Machine Block Frequency Analysis", true, true)
char MachineBlockFrequencyInfo::ID = 0;
MachineBlockFrequencyInfo::MachineBlockFrequencyInfo() : MachineFunctionPass(ID) {
initializeMachineBlockFrequencyInfoPass(*PassRegistry::getPassRegistry());
MBFI = new BlockFrequencyImpl<MachineBasicBlock, MachineFunction,
MachineBranchProbabilityInfo>();
}
MachineBlockFrequencyInfo::~MachineBlockFrequencyInfo() {
delete MBFI;
}
void MachineBlockFrequencyInfo::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<MachineBranchProbabilityInfo>();
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool MachineBlockFrequencyInfo::runOnMachineFunction(MachineFunction &F) {
MachineBranchProbabilityInfo &MBPI = getAnalysis<MachineBranchProbabilityInfo>();
MBFI->doFunction(&F, &MBPI);
return false;
}
/// getblockFreq - Return block frequency. Return 0 if we don't have the
/// information. Please note that initial frequency is equal to 1024. It means
/// that we should not rely on the value itself, but only on the comparison to
/// the other block frequencies. We do this to avoid using of floating points.
///
BlockFrequency MachineBlockFrequencyInfo::
getBlockFreq(const MachineBasicBlock *MBB) const {
return MBFI->getBlockFreq(MBB);
}