68 lines
1.9 KiB
C++
68 lines
1.9 KiB
C++
//===- TailDuplication.cpp - Duplicate blocks into predecessors' tails ----===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This pass duplicates basic blocks ending in unconditional branches into
|
|
// the tails of their predecessors, using the TailDuplicator utility class.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
|
|
#include "llvm/CodeGen/MachineFunction.h"
|
|
#include "llvm/CodeGen/MachineFunctionPass.h"
|
|
#include "llvm/CodeGen/TailDuplicator.h"
|
|
#include "llvm/Pass.h"
|
|
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "tailduplication"
|
|
|
|
namespace {
|
|
|
|
/// Perform tail duplication. Delegates to TailDuplicator
|
|
class TailDuplicatePass : public MachineFunctionPass {
|
|
TailDuplicator Duplicator;
|
|
|
|
public:
|
|
static char ID;
|
|
|
|
explicit TailDuplicatePass() : MachineFunctionPass(ID) {}
|
|
|
|
bool runOnMachineFunction(MachineFunction &MF) override;
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override;
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
char TailDuplicatePass::ID = 0;
|
|
|
|
char &llvm::TailDuplicateID = TailDuplicatePass::ID;
|
|
|
|
INITIALIZE_PASS(TailDuplicatePass, DEBUG_TYPE, "Tail Duplication", false, false)
|
|
|
|
bool TailDuplicatePass::runOnMachineFunction(MachineFunction &MF) {
|
|
if (skipFunction(*MF.getFunction()))
|
|
return false;
|
|
|
|
auto MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
|
|
|
|
Duplicator.initMF(MF, MBPI, /* LayoutMode */ false);
|
|
|
|
bool MadeChange = false;
|
|
while (Duplicator.tailDuplicateBlocks())
|
|
MadeChange = true;
|
|
|
|
return MadeChange;
|
|
}
|
|
|
|
void TailDuplicatePass::getAnalysisUsage(AnalysisUsage &AU) const {
|
|
AU.addRequired<MachineBranchProbabilityInfo>();
|
|
MachineFunctionPass::getAnalysisUsage(AU);
|
|
}
|