llvm-6502/lib/Target/SparcV9/ModuloScheduling/ModuloScheduling.cpp

705 lines
21 KiB
C++

//===-- ModuloScheduling.cpp - ModuloScheduling ----------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "ModuloSched"
#include "ModuloScheduling.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Support/CFG.h"
#include "llvm/Target/TargetSchedInfo.h"
#include "Support/Debug.h"
#include "Support/GraphWriter.h"
#include <vector>
#include <utility>
#include <iostream>
#include <fstream>
#include <sstream>
using namespace llvm;
/// Create ModuloSchedulingPass
///
FunctionPass *llvm::createModuloSchedulingPass(TargetMachine & targ) {
DEBUG(std::cerr << "Created ModuloSchedulingPass\n");
return new ModuloSchedulingPass(targ);
}
template<typename GraphType>
static void WriteGraphToFile(std::ostream &O, const std::string &GraphName,
const GraphType &GT) {
std::string Filename = GraphName + ".dot";
O << "Writing '" << Filename << "'...";
std::ofstream F(Filename.c_str());
if (F.good())
WriteGraph(F, GT);
else
O << " error opening file for writing!";
O << "\n";
};
namespace llvm {
template<>
struct DOTGraphTraits<MSchedGraph*> : public DefaultDOTGraphTraits {
static std::string getGraphName(MSchedGraph *F) {
return "Dependence Graph";
}
static std::string getNodeLabel(MSchedGraphNode *Node, MSchedGraph *Graph) {
if (Node->getInst()) {
std::stringstream ss;
ss << *(Node->getInst());
return ss.str(); //((MachineInstr*)Node->getInst());
}
else
return "No Inst";
}
static std::string getEdgeSourceLabel(MSchedGraphNode *Node,
MSchedGraphNode::succ_iterator I) {
//Label each edge with the type of dependence
std::string edgelabel = "";
switch (I.getEdge().getDepOrderType()) {
case MSchedGraphEdge::TrueDep:
edgelabel = "True";
break;
case MSchedGraphEdge::AntiDep:
edgelabel = "Anti";
break;
case MSchedGraphEdge::OutputDep:
edgelabel = "Output";
break;
default:
edgelabel = "Unknown";
break;
}
if(I.getEdge().getIteDiff() > 0)
edgelabel += I.getEdge().getIteDiff();
return edgelabel;
}
};
}
/// ModuloScheduling::runOnFunction - main transformation entry point
bool ModuloSchedulingPass::runOnFunction(Function &F) {
bool Changed = false;
DEBUG(std::cerr << "Creating ModuloSchedGraph for each BasicBlock in" + F.getName() + "\n");
//Get MachineFunction
MachineFunction &MF = MachineFunction::get(&F);
//Iterate over BasicBlocks and do ModuloScheduling if they are valid
for (MachineFunction::const_iterator BI = MF.begin(); BI != MF.end(); ++BI) {
if(MachineBBisValid(BI)) {
MSchedGraph *MSG = new MSchedGraph(BI, target);
//Write Graph out to file
DEBUG(WriteGraphToFile(std::cerr, "dependgraph", MSG));
//Print out BB for debugging
DEBUG(BI->print(std::cerr));
//Calculate Resource II
int ResMII = calculateResMII(BI);
calculateNodeAttributes(MSG, ResMII);
}
}
return Changed;
}
bool ModuloSchedulingPass::MachineBBisValid(const MachineBasicBlock *BI) {
//Valid basic blocks must be loops and can not have if/else statements or calls.
bool isLoop = false;
//Check first if its a valid loop
for(succ_const_iterator I = succ_begin(BI->getBasicBlock()),
E = succ_end(BI->getBasicBlock()); I != E; ++I) {
if (*I == BI->getBasicBlock()) // has single block loop
isLoop = true;
}
if(!isLoop) {
DEBUG(std::cerr << "Basic Block is not a loop\n");
return false;
}
else
DEBUG(std::cerr << "Basic Block is a loop\n");
//Get Target machine instruction info
/*const TargetInstrInfo& TMI = targ.getInstrInfo();
//Check each instruction and look for calls or if/else statements
unsigned count = 0;
for(MachineBasicBlock::const_iterator I = BI->begin(), E = BI->end(); I != E; ++I) {
//Get opcode to check instruction type
MachineOpCode OC = I->getOpcode();
if(TMI.isControlFlow(OC) && (count+1 < BI->size()))
return false;
count++;
}*/
return true;
}
//ResMII is calculated by determining the usage count for each resource
//and using the maximum.
//FIXME: In future there should be a way to get alternative resources
//for each instruction
int ModuloSchedulingPass::calculateResMII(const MachineBasicBlock *BI) {
const TargetInstrInfo & mii = target.getInstrInfo();
const TargetSchedInfo & msi = target.getSchedInfo();
int ResMII = 0;
//Map to keep track of usage count of each resource
std::map<unsigned, unsigned> resourceUsageCount;
for(MachineBasicBlock::const_iterator I = BI->begin(), E = BI->end(); I != E; ++I) {
//Get resource usage for this instruction
InstrRUsage rUsage = msi.getInstrRUsage(I->getOpcode());
std::vector<std::vector<resourceId_t> > resources = rUsage.resourcesByCycle;
//Loop over resources in each cycle and increments their usage count
for(unsigned i=0; i < resources.size(); ++i)
for(unsigned j=0; j < resources[i].size(); ++j) {
if( resourceUsageCount.find(resources[i][j]) == resourceUsageCount.end()) {
resourceUsageCount[resources[i][j]] = 1;
}
else {
resourceUsageCount[resources[i][j]] = resourceUsageCount[resources[i][j]] + 1;
}
}
}
//Find maximum usage count
//Get max number of instructions that can be issued at once.
int issueSlots = msi.maxNumIssueTotal;
for(std::map<unsigned,unsigned>::iterator RB = resourceUsageCount.begin(), RE = resourceUsageCount.end(); RB != RE; ++RB) {
//Get the total number of the resources in our cpu
//int resourceNum = msi.getCPUResourceNum(RB->first);
//Get total usage count for this resources
unsigned usageCount = RB->second;
//Divide the usage count by either the max number we can issue or the number of
//resources (whichever is its upper bound)
double finalUsageCount;
//if( resourceNum <= issueSlots)
//finalUsageCount = ceil(1.0 * usageCount / resourceNum);
//else
finalUsageCount = ceil(1.0 * usageCount / issueSlots);
DEBUG(std::cerr << "Resource ID: " << RB->first << " (usage=" << usageCount << ", resourceNum=X" << ", issueSlots=" << issueSlots << ", finalUsage=" << finalUsageCount << ")\n");
//Only keep track of the max
ResMII = std::max( (int) finalUsageCount, ResMII);
}
DEBUG(std::cerr << "Final Resource MII: " << ResMII << "\n");
return ResMII;
}
void ModuloSchedulingPass::calculateNodeAttributes(MSchedGraph *graph, int MII) {
//Loop over the nodes and add them to the map
for(MSchedGraph::iterator I = graph->begin(), E = graph->end(); I != E; ++I) {
//Assert if its already in the map
assert(nodeToAttributesMap.find(I->second) == nodeToAttributesMap.end() && "Node attributes are already in the map");
//Put into the map with default attribute values
nodeToAttributesMap[I->second] = MSNodeAttributes();
}
//Create set to deal with reccurrences
std::set<MSchedGraphNode*> visitedNodes;
std::vector<MSchedGraphNode*> vNodes;
//Now Loop over map and calculate the node attributes
for(std::map<MSchedGraphNode*, MSNodeAttributes>::iterator I = nodeToAttributesMap.begin(), E = nodeToAttributesMap.end(); I != E; ++I) {
// calculateASAP(I->first, (I->second), MII, visitedNodes);
findAllReccurrences(I->first, vNodes);
vNodes.clear();
visitedNodes.clear();
}
//Calculate ALAP which depends on ASAP being totally calculated
/*for(std::map<MSchedGraphNode*, MSNodeAttributes>::iterator I = nodeToAttributesMap.begin(), E = nodeToAttributesMap.end(); I != E; ++I) {
calculateALAP(I->first, (I->second), MII, MII, visitedNodes);
visitedNodes.clear();
}*/
//Calculate MOB which depends on ASAP being totally calculated, also do depth and height
/*for(std::map<MSchedGraphNode*, MSNodeAttributes>::iterator I = nodeToAttributesMap.begin(), E = nodeToAttributesMap.end(); I != E; ++I) {
(I->second).MOB = (I->second).ALAP - (I->second).ASAP;
DEBUG(std::cerr << "MOB: " << (I->second).MOB << " (" << *(I->first) << ")\n");
calculateDepth(I->first, (I->second), visitedNodes);
visitedNodes.clear();
calculateHeight(I->first, (I->second), visitedNodes);
visitedNodes.clear();
}*/
}
void ModuloSchedulingPass::calculateASAP(MSchedGraphNode *node, MSNodeAttributes &attributes,
int MII, std::set<MSchedGraphNode*> &visitedNodes) {
DEBUG(std::cerr << "Calculating ASAP for " << *node << "\n");
if(attributes.ASAP != -1 || (visitedNodes.find(node) != visitedNodes.end())) {
visitedNodes.erase(node);
return;
}
if(node->hasPredecessors()) {
int maxPredValue = 0;
//Iterate over all of the predecessors and fine max
for(MSchedGraphNode::pred_iterator P = node->pred_begin(), E = node->pred_end(); P != E; ++P) {
//Get that nodes ASAP
MSNodeAttributes predAttributes = nodeToAttributesMap.find(*P)->second;
if(predAttributes.ASAP == -1) {
//Put into set before you recurse
visitedNodes.insert(node);
calculateASAP(*P, predAttributes, MII, visitedNodes);
predAttributes = nodeToAttributesMap.find(*P)->second;
}
int iteDiff = node->getInEdge(*P).getIteDiff();
int currentPredValue = predAttributes.ASAP + node->getLatency() - iteDiff * MII;
DEBUG(std::cerr << "Current ASAP pred: " << currentPredValue << "\n");
maxPredValue = std::max(maxPredValue, currentPredValue);
}
visitedNodes.erase(node);
attributes.ASAP = maxPredValue;
}
else {
visitedNodes.erase(node);
attributes.ASAP = 0;
}
DEBUG(std::cerr << "ASAP: " << attributes.ASAP << " (" << *node << ")\n");
}
void ModuloSchedulingPass::calculateALAP(MSchedGraphNode *node, MSNodeAttributes &attributes,
int MII, int maxASAP,
std::set<MSchedGraphNode*> &visitedNodes) {
DEBUG(std::cerr << "Calculating AlAP for " << *node << "\n");
if(attributes.ALAP != -1|| (visitedNodes.find(node) != visitedNodes.end())) {
visitedNodes.erase(node);
return;
}
if(node->hasSuccessors()) {
int minSuccValue = 0;
//Iterate over all of the predecessors and fine max
for(MSchedGraphNode::succ_iterator P = node->succ_begin(),
E = node->succ_end(); P != E; ++P) {
MSNodeAttributes succAttributes = nodeToAttributesMap.find(*P)->second;
if(succAttributes.ASAP == -1) {
//Put into set before recursing
visitedNodes.insert(node);
calculateALAP(*P, succAttributes, MII, maxASAP, visitedNodes);
succAttributes = nodeToAttributesMap.find(*P)->second;
assert(succAttributes.ASAP == -1 && "Successors ALAP should have been caclulated");
}
int iteDiff = P.getEdge().getIteDiff();
int currentSuccValue = succAttributes.ALAP + node->getLatency() + iteDiff * MII;
minSuccValue = std::min(minSuccValue, currentSuccValue);
}
visitedNodes.erase(node);
attributes.ALAP = minSuccValue;
}
else {
visitedNodes.erase(node);
attributes.ALAP = maxASAP;
}
DEBUG(std::cerr << "ALAP: " << attributes.ALAP << " (" << *node << ")\n");
}
int ModuloSchedulingPass::findMaxASAP() {
int maxASAP = 0;
for(std::map<MSchedGraphNode*, MSNodeAttributes>::iterator I = nodeToAttributesMap.begin(),
E = nodeToAttributesMap.end(); I != E; ++I)
maxASAP = std::max(maxASAP, I->second.ASAP);
return maxASAP;
}
void ModuloSchedulingPass::calculateHeight(MSchedGraphNode *node,
MSNodeAttributes &attributes,
std::set<MSchedGraphNode*> &visitedNodes) {
if(attributes.depth != -1 || (visitedNodes.find(node) != visitedNodes.end())) {
//Remove from map before returning
visitedNodes.erase(node);
return;
}
if(node->hasSuccessors()) {
int maxHeight = 0;
//Iterate over all of the predecessors and fine max
for(MSchedGraphNode::succ_iterator P = node->succ_begin(),
E = node->succ_end(); P != E; ++P) {
MSNodeAttributes succAttributes = nodeToAttributesMap.find(*P)->second;
if(succAttributes.height == -1) {
//Put into map before recursing
visitedNodes.insert(node);
calculateHeight(*P, succAttributes, visitedNodes);
succAttributes = nodeToAttributesMap.find(*P)->second;
assert(succAttributes.height == -1 && "Successors Height should have been caclulated");
}
int currentHeight = succAttributes.height + node->getLatency();
maxHeight = std::max(maxHeight, currentHeight);
}
visitedNodes.erase(node);
attributes.height = maxHeight;
}
else {
visitedNodes.erase(node);
attributes.height = 0;
}
DEBUG(std::cerr << "Height: " << attributes.height << " (" << *node << ")\n");
}
void ModuloSchedulingPass::calculateDepth(MSchedGraphNode *node,
MSNodeAttributes &attributes,
std::set<MSchedGraphNode*> &visitedNodes) {
if(attributes.depth != -1 || (visitedNodes.find(node) != visitedNodes.end())) {
//Remove from map before returning
visitedNodes.erase(node);
return;
}
if(node->hasPredecessors()) {
int maxDepth = 0;
//Iterate over all of the predecessors and fine max
for(MSchedGraphNode::pred_iterator P = node->pred_begin(), E = node->pred_end(); P != E; ++P) {
//Get that nodes depth
MSNodeAttributes predAttributes = nodeToAttributesMap.find(*P)->second;
if(predAttributes.depth == -1) {
//Put into set before recursing
visitedNodes.insert(node);
calculateDepth(*P, predAttributes, visitedNodes);
predAttributes = nodeToAttributesMap.find(*P)->second;
assert(predAttributes.depth == -1 && "Predecessors ASAP should have been caclulated");
}
int currentDepth = predAttributes.depth + node->getLatency();
maxDepth = std::max(maxDepth, currentDepth);
}
//Remove from map before returning
visitedNodes.erase(node);
attributes.height = maxDepth;
}
else {
//Remove from map before returning
visitedNodes.erase(node);
attributes.depth = 0;
}
DEBUG(std::cerr << "Depth: " << attributes.depth << " (" << *node << "*)\n");
}
void ModuloSchedulingPass::findAllReccurrences(MSchedGraphNode *node,
std::vector<MSchedGraphNode*> &visitedNodes) {
if(find(visitedNodes.begin(), visitedNodes.end(), node) != visitedNodes.end()) {
//DUMP out recurrence
DEBUG(std::cerr << "Reccurrence:\n");
bool first = true;
for(std::vector<MSchedGraphNode*>::iterator I = visitedNodes.begin(), E = visitedNodes.end();
I !=E; ++I) {
if(*I == node)
first = false;
if(first)
continue;
DEBUG(std::cerr << **I << "\n");
}
DEBUG(std::cerr << "End Reccurrence:\n");
return;
}
for(MSchedGraphNode::succ_iterator I = node->succ_begin(), E = node->succ_end(); I != E; ++I) {
visitedNodes.push_back(node);
findAllReccurrences(*I, visitedNodes);
visitedNodes.pop_back();
}
}
void ModuloSchedulingPass::orderNodes() {
int BOTTOM_UP = 0;
int TOP_DOWN = 1;
//FIXME: Group nodes into sets and order all the sets based on RecMII
typedef std::vector<MSchedGraphNode*> NodeVector;
typedef std::pair<int, NodeVector> NodeSet;
std::vector<NodeSet> NodeSetsToOrder;
//Order the resulting sets
NodeVector FinalNodeOrder;
//Loop over all the sets and place them in the final node order
for(unsigned i=0; i < NodeSetsToOrder.size(); ++i) {
//Set default order
int order = BOTTOM_UP;
//Get Nodes in Current set
NodeVector CurrentSet = NodeSetsToOrder[i].second;
//Loop through the predecessors for each node in the final order
//and only keeps nodes both in the pred_set and currentset
NodeVector IntersectCurrent;
//Sort CurrentSet so we can use lowerbound
sort(CurrentSet.begin(), CurrentSet.end());
for(unsigned j=0; j < FinalNodeOrder.size(); ++j) {
for(MSchedGraphNode::pred_iterator P = FinalNodeOrder[j]->pred_begin(),
E = FinalNodeOrder[j]->pred_end(); P != E; ++P) {
if(lower_bound(CurrentSet.begin(),
CurrentSet.end(), *P) != CurrentSet.end())
IntersectCurrent.push_back(*P);
}
}
//If the intersection of predecessor and current set is not empty
//sort nodes bottom up
if(IntersectCurrent.size() != 0)
order = BOTTOM_UP;
//If empty, use successors
else {
for(unsigned j=0; j < FinalNodeOrder.size(); ++j) {
for(MSchedGraphNode::succ_iterator P = FinalNodeOrder[j]->succ_begin(),
E = FinalNodeOrder[j]->succ_end(); P != E; ++P) {
if(lower_bound(CurrentSet.begin(),
CurrentSet.end(), *P) != CurrentSet.end())
IntersectCurrent.push_back(*P);
}
}
//sort top-down
if(IntersectCurrent.size() != 0)
order = TOP_DOWN;
else {
//Find node with max ASAP in current Set
MSchedGraphNode *node;
int maxASAP = 0;
for(unsigned j=0; j < CurrentSet.size(); ++j) {
//Get node attributes
MSNodeAttributes nodeAttr= nodeToAttributesMap.find(CurrentSet[j])->second;
//assert(nodeAttr != nodeToAttributesMap.end() && "Node not in attributes map!");
if(maxASAP < nodeAttr.ASAP) {
maxASAP = nodeAttr.ASAP;
node = CurrentSet[j];
}
}
order = BOTTOM_UP;
}
}
//Repeat until all nodes are put into the final order from current set
/*while(IntersectCurrent.size() > 0) {
if(order == TOP_DOWN) {
while(IntersectCurrent.size() > 0) {
//FIXME
//Get node attributes
MSNodeAttributes nodeAttr= nodeToAttributesMap.find(IntersectCurrent[0])->second;
assert(nodeAttr != nodeToAttributesMap.end() && "Node not in attributes map!");
//Get node with highest height, if a tie, use one with lowest
//MOB
int MOB = nodeAttr.MBO;
int height = nodeAttr.height;
ModuloSchedGraphNode *V = IntersectCurrent[0];
for(unsigned j=0; j < IntersectCurrent.size(); ++j) {
int temp = IntersectCurrent[j]->getHeight();
if(height < temp) {
V = IntersectCurrent[j];
height = temp;
MOB = V->getMobility();
}
else if(height == temp) {
if(MOB > IntersectCurrent[j]->getMobility()) {
V = IntersectCurrent[j];
height = temp;
MOB = V->getMobility();
}
}
}
//Append V to the NodeOrder
NodeOrder.push_back(V);
//Remove V from IntersectOrder
IntersectCurrent.erase(find(IntersectCurrent.begin(),
IntersectCurrent.end(), V));
//Intersect V's successors with CurrentSet
for(mod_succ_iterator P = succ_begin(V),
E = succ_end(V); P != E; ++P) {
if(lower_bound(CurrentSet.begin(),
CurrentSet.end(), *P) != CurrentSet.end()) {
//If not already in Intersect, add
if(find(IntersectCurrent.begin(), IntersectCurrent.end(), *P) == IntersectCurrent.end())
IntersectCurrent.push_back(*P);
}
}
} //End while loop over Intersect Size
//Change direction
order = BOTTOM_UP;
//Reset Intersect to reflect changes in OrderNodes
IntersectCurrent.clear();
for(unsigned j=0; j < NodeOrder.size(); ++j) {
for(mod_pred_iterator P = pred_begin(NodeOrder[j]),
E = pred_end(NodeOrder[j]); P != E; ++P) {
if(lower_bound(CurrentSet.begin(),
CurrentSet.end(), *P) != CurrentSet.end())
IntersectCurrent.push_back(*P);
}
}
} //End If TOP_DOWN
//Begin if BOTTOM_UP
else {
while(IntersectCurrent.size() > 0) {
//Get node with highest depth, if a tie, use one with lowest
//MOB
int MOB = IntersectCurrent[0]->getMobility();
int depth = IntersectCurrent[0]->getDepth();
ModuloSchedGraphNode *V = IntersectCurrent[0];
for(unsigned j=0; j < IntersectCurrent.size(); ++j) {
int temp = IntersectCurrent[j]->getDepth();
if(depth < temp) {
V = IntersectCurrent[j];
depth = temp;
MOB = V->getMobility();
}
else if(depth == temp) {
if(MOB > IntersectCurrent[j]->getMobility()) {
V = IntersectCurrent[j];
depth = temp;
MOB = V->getMobility();
}
}
}
//Append V to the NodeOrder
NodeOrder.push_back(V);
//Remove V from IntersectOrder
IntersectCurrent.erase(find(IntersectCurrent.begin(),
IntersectCurrent.end(),V));
//Intersect V's pred with CurrentSet
for(mod_pred_iterator P = pred_begin(V),
E = pred_end(V); P != E; ++P) {
if(lower_bound(CurrentSet.begin(),
CurrentSet.end(), *P) != CurrentSet.end()) {
//If not already in Intersect, add
if(find(IntersectCurrent.begin(), IntersectCurrent.end(), *P) == IntersectCurrent.end())
IntersectCurrent.push_back(*P);
}
}
} //End while loop over Intersect Size
//Change order
order = TOP_DOWN;
//Reset IntersectCurrent to reflect changes in OrderNodes
IntersectCurrent.clear();
for(unsigned j=0; j < NodeOrder.size(); ++j) {
for(mod_succ_iterator P = succ_begin(NodeOrder[j]),
E = succ_end(NodeOrder[j]); P != E; ++P) {
if(lower_bound(CurrentSet.begin(),
CurrentSet.end(), *P) != CurrentSet.end())
IntersectCurrent.push_back(*P);
}
}
} //End if BOTTOM_DOWN
}*/
//End Wrapping while loop
}//End for over all sets of nodes
//Return final Order
//return FinalNodeOrder;
}