mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-22 18:54:02 +01:00
ae65e281f3
to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
77 lines
2.9 KiB
C++
77 lines
2.9 KiB
C++
//===- LoopTraversal.cpp - Optimal basic block traversal order --*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/CodeGen/LoopTraversal.h"
|
|
#include "llvm/ADT/PostOrderIterator.h"
|
|
#include "llvm/CodeGen/MachineFunction.h"
|
|
|
|
using namespace llvm;
|
|
|
|
bool LoopTraversal::isBlockDone(MachineBasicBlock *MBB) {
|
|
unsigned MBBNumber = MBB->getNumber();
|
|
assert(MBBNumber < MBBInfos.size() && "Unexpected basic block number.");
|
|
return MBBInfos[MBBNumber].PrimaryCompleted &&
|
|
MBBInfos[MBBNumber].IncomingCompleted ==
|
|
MBBInfos[MBBNumber].PrimaryIncoming &&
|
|
MBBInfos[MBBNumber].IncomingProcessed == MBB->pred_size();
|
|
}
|
|
|
|
LoopTraversal::TraversalOrder LoopTraversal::traverse(MachineFunction &MF) {
|
|
// Initialize the MMBInfos
|
|
MBBInfos.assign(MF.getNumBlockIDs(), MBBInfo());
|
|
|
|
MachineBasicBlock *Entry = &*MF.begin();
|
|
ReversePostOrderTraversal<MachineBasicBlock *> RPOT(Entry);
|
|
SmallVector<MachineBasicBlock *, 4> Workqueue;
|
|
SmallVector<TraversedMBBInfo, 4> MBBTraversalOrder;
|
|
for (MachineBasicBlock *MBB : RPOT) {
|
|
// N.B: IncomingProcessed and IncomingCompleted were already updated while
|
|
// processing this block's predecessors.
|
|
unsigned MBBNumber = MBB->getNumber();
|
|
assert(MBBNumber < MBBInfos.size() && "Unexpected basic block number.");
|
|
MBBInfos[MBBNumber].PrimaryCompleted = true;
|
|
MBBInfos[MBBNumber].PrimaryIncoming = MBBInfos[MBBNumber].IncomingProcessed;
|
|
bool Primary = true;
|
|
Workqueue.push_back(MBB);
|
|
while (!Workqueue.empty()) {
|
|
MachineBasicBlock *ActiveMBB = &*Workqueue.back();
|
|
Workqueue.pop_back();
|
|
bool Done = isBlockDone(ActiveMBB);
|
|
MBBTraversalOrder.push_back(TraversedMBBInfo(ActiveMBB, Primary, Done));
|
|
for (MachineBasicBlock *Succ : ActiveMBB->successors()) {
|
|
unsigned SuccNumber = Succ->getNumber();
|
|
assert(SuccNumber < MBBInfos.size() &&
|
|
"Unexpected basic block number.");
|
|
if (!isBlockDone(Succ)) {
|
|
if (Primary)
|
|
MBBInfos[SuccNumber].IncomingProcessed++;
|
|
if (Done)
|
|
MBBInfos[SuccNumber].IncomingCompleted++;
|
|
if (isBlockDone(Succ))
|
|
Workqueue.push_back(Succ);
|
|
}
|
|
}
|
|
Primary = false;
|
|
}
|
|
}
|
|
|
|
// We need to go through again and finalize any blocks that are not done yet.
|
|
// This is possible if blocks have dead predecessors, so we didn't visit them
|
|
// above.
|
|
for (MachineBasicBlock *MBB : RPOT) {
|
|
if (!isBlockDone(MBB))
|
|
MBBTraversalOrder.push_back(TraversedMBBInfo(MBB, false, true));
|
|
// Don't update successors here. We'll get to them anyway through this
|
|
// loop.
|
|
}
|
|
|
|
MBBInfos.clear();
|
|
|
|
return MBBTraversalOrder;
|
|
}
|