//
//===----------------------------------------------------------------------===//
//
-// This file implements a useful analysis step to figure out what numbered
-// slots values in a program will land in (keeping track of per plane
-// information as required.
+// This file implements a useful analysis step to figure out what numbered slots
+// values in a program will land in (keeping track of per plane information).
//
-// This is used primarily for when writing a file to disk, either in bytecode
-// or source format.
+// This is used when writing a file to disk, either in bytecode or assembly.
//
//===----------------------------------------------------------------------===//
if (TheModule == 0) return; // Empty table...
processModule(); // Process module level stuff
- incorporateFunction(M); // Start out in incorporated state
+ incorporateFunction(M); // Start out in incorporated state
}
unsigned SlotCalculator::getGlobalSlot(const Value *V) const {
if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(V))
V = CPR->getValue();
std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V);
- assert(I != NodeMap.end() && "Didn't find entry!");
+ assert(I != NodeMap.end() && "Didn't find global slot entry!");
return I->second;
}
+SlotCalculator::TypePlane &SlotCalculator::getPlane(unsigned Plane) {
+ unsigned PIdx = Plane;
+ if (CompactionTable.empty()) { // No compaction table active?
+ // fall out
+ } else if (!CompactionTable[Plane].empty()) { // Compaction table active.
+ assert(Plane < CompactionTable.size());
+ return CompactionTable[Plane];
+ } else {
+ // Final case: compaction table active, but this plane is not
+ // compactified. If the type plane is compactified, unmap back to the
+ // global type plane corresponding to "Plane".
+ if (!CompactionTable[Type::TypeTyID].empty()) {
+ const Type *Ty = cast<Type>(CompactionTable[Type::TypeTyID][Plane]);
+ std::map<const Value*, unsigned>::iterator It = NodeMap.find(Ty);
+ assert(It != NodeMap.end() && "Type not in global constant map?");
+ PIdx = It->second;
+ }
+ }
+
+ // Okay we are just returning an entry out of the main Table. Make sure the
+ // plane exists and return it.
+ if (PIdx >= Table.size())
+ Table.resize(PIdx+1);
+ return Table[PIdx];
+}
// processModule - Process all of the module level function declarations and
}
processSymbolTableConstants(&F->getSymbolTable());
}
-
-
}
// Insert constants that are named at module level into the slot pool so that
// If we emitted all of the function constants, build a compaction table.
if (BuildBytecodeInfo && ModuleContainsAllFunctionConstants)
buildCompactionTable(F);
- else {
- // Save the Table state before we process the function...
- for (unsigned i = 0, e = Table.size(); i != e; ++i)
- ModuleLevel.push_back(Table[i].size());
- }
+
+ // Update the ModuleLevel entries to be accurate.
+ ModuleLevel.resize(getNumPlanes());
+ for (unsigned i = 0, e = getNumPlanes(); i != e; ++i)
+ ModuleLevel[i] = getPlane(i).size();
// Iterate over function arguments, adding them to the value table...
for(Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
}
}
+ // If we are building a compaction table, prune out planes that do not benefit
+ // from being compactified.
+ if (!CompactionTable.empty())
+ pruneCompactionTable();
+
SC_DEBUG("end processFunction!\n");
}
CompactionNodeMap.clear();
// Next, remove values from existing type planes
- for (unsigned i = 0; i != NumModuleTypes; ++i)
- if (i >= CompactionTable.size() || CompactionTable[i].empty()) {
- unsigned ModuleSize = ModuleLevel[i];// Size of plane before function came
- TypePlane &CurPlane = Table[i];
-
- while (CurPlane.size() != ModuleSize) {
- std::map<const Value *, unsigned>::iterator NI =
- NodeMap.find(CurPlane.back());
- assert(NI != NodeMap.end() && "Node not in nodemap?");
- NodeMap.erase(NI); // Erase from nodemap
- CurPlane.pop_back(); // Shrink plane
- }
+ for (unsigned i = 0; i != NumModuleTypes; ++i) {
+ // Size of plane before function came
+ unsigned ModuleLev = getModuleLevel(i);
+ assert(int(ModuleLev) >= 0 && "BAD!");
+
+ TypePlane &Plane = getPlane(i);
+
+ assert(ModuleLev <= Plane.size() && "module levels higher than elements?");
+ while (Plane.size() != ModuleLev) {
+ assert(!isa<GlobalValue>(Plane.back()) &&
+ "Functions cannot define globals!");
+ NodeMap.erase(Plane.back()); // Erase from nodemap
+ Plane.pop_back(); // Shrink plane
}
+ }
// We don't need this state anymore, free it up.
ModuleLevel.clear();
+ // Finally, remove any type planes defined by the function...
if (!CompactionTable.empty()) {
CompactionTable.clear();
} else {
- // FIXME: this will require adjustment when we don't compact everything.
-
- // Finally, remove any type planes defined by the function...
- while (NumModuleTypes != Table.size()) {
+ while (Table.size() > NumModuleTypes) {
TypePlane &Plane = Table.back();
SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
<< Plane.size() << "\n");
while (Plane.size()) {
- NodeMap.erase(NodeMap.find(Plane.back())); // Erase from nodemap
- Plane.pop_back(); // Shrink plane
+ assert(!isa<GlobalValue>(Plane.back()) &&
+ "Functions cannot define globals!");
+ NodeMap.erase(Plane.back()); // Erase from nodemap
+ Plane.pop_back(); // Shrink plane
}
- Table.pop_back(); // Nuke the plane, we don't like it.
+ Table.pop_back(); // Nuke the plane, we don't like it.
}
}
+
SC_DEBUG("end purgeFunction!\n");
}
return I->second; // Already exists?
// Make sure the type is in the table.
- unsigned Ty = getOrCreateCompactionTableSlot(V->getType());
+ unsigned Ty;
+ if (!CompactionTable[Type::TypeTyID].empty())
+ Ty = getOrCreateCompactionTableSlot(V->getType());
+ else // If the type plane was decompactified, use the global plane ID
+ Ty = getSlot(V->getType());
if (CompactionTable.size() <= Ty)
CompactionTable.resize(Ty+1);
}
// Okay, now at this point, we have a legal compaction table. Since we want
- // to emit the smallest possible binaries, we delete planes that do not NEED
- // to be compacted, starting with the type plane.
+ // to emit the smallest possible binaries, do not compactify the type plane if
+ // it will not save us anything. Because we have not yet incorporated the
+ // function body itself yet, we don't know whether or not it's a good idea to
+ // compactify other planes. We will defer this decision until later.
+ TypePlane &GlobalTypes = Table[Type::TypeTyID];
+
+ // All of the values types will be scrunched to the start of the types plane
+ // of the global table. Figure out just how many there are.
+ assert(!GlobalTypes.empty() && "No global types???");
+ unsigned NumFCTypes = GlobalTypes.size()-1;
+ while (!cast<Type>(GlobalTypes[NumFCTypes])->isFirstClassType())
+ --NumFCTypes;
+
+ // If there are fewer that 64 types, no instructions will be exploded due to
+ // the size of the type operands. Thus there is no need to compactify types.
+ // Also, if the compaction table contains most of the entries in the global
+ // table, there really is no reason to compactify either.
+ if (NumFCTypes < 64) {
+ // Decompactifying types is tricky, because we have to move type planes all
+ // over the place. At least we don't need to worry about updating the
+ // CompactionNodeMap for non-types though.
+ std::vector<TypePlane> TmpCompactionTable;
+ std::swap(CompactionTable, TmpCompactionTable);
+ TypePlane Types;
+ std::swap(Types, TmpCompactionTable[Type::TypeTyID]);
+
+ // Move each plane back over to the uncompactified plane
+ while (!Types.empty()) {
+ const Type *Ty = cast<Type>(Types.back());
+ Types.pop_back();
+ CompactionNodeMap.erase(Ty); // Decompactify type!
+
+ if (Ty != Type::TypeTy) {
+ // Find the global slot number for this type.
+ int TySlot = getSlot(Ty);
+ assert(TySlot != -1 && "Type doesn't exist in global table?");
+
+ // Now we know where to put the compaction table plane.
+ if (CompactionTable.size() <= unsigned(TySlot))
+ CompactionTable.resize(TySlot+1);
+ // Move the plane back into the compaction table.
+ std::swap(CompactionTable[TySlot], TmpCompactionTable[Types.size()]);
+
+ // And remove the empty plane we just moved in.
+ TmpCompactionTable.pop_back();
+ }
+ }
+ }
+}
- // If decided not to compact anything, do not modify ModuleLevels.
- if (CompactionTable.empty())
- // FIXME: must update ModuleLevel.
- return;
+/// pruneCompactionTable - Once the entire function being processed has been
+/// incorporated into the current compaction table, look over the compaction
+/// table and check to see if there are any values whose compaction will not
+/// save us any space in the bytecode file. If compactifying these values
+/// serves no purpose, then we might as well not even emit the compactification
+/// information to the bytecode file, saving a bit more space.
+///
+/// Note that the type plane has already been compactified if possible.
+///
+void SlotCalculator::pruneCompactionTable() {
+ TypePlane &TyPlane = CompactionTable[Type::TypeTyID];
+ for (unsigned ctp = 0, e = CompactionTable.size(); ctp != e; ++ctp)
+ if (ctp != Type::TypeTyID && !CompactionTable[ctp].empty()) {
+ TypePlane &CPlane = CompactionTable[ctp];
+ unsigned GlobalSlot = ctp;
+ if (!TyPlane.empty())
+ GlobalSlot = getGlobalSlot(TyPlane[ctp]);
+
+ if (GlobalSlot >= Table.size())
+ Table.resize(GlobalSlot+1);
+ TypePlane &GPlane = Table[GlobalSlot];
+
+ unsigned ModLevel = getModuleLevel(ctp);
+ unsigned NumFunctionObjs = CPlane.size()-ModLevel;
+
+ // If the maximum index required if all entries in this plane were merged
+ // into the global plane is less than 64, go ahead and eliminate the
+ // plane.
+ bool PrunePlane = GPlane.size() + NumFunctionObjs < 64;
+
+ // If there are no function-local values defined, and the maximum
+ // referenced global entry is less than 64, we don't need to compactify.
+ if (!PrunePlane && NumFunctionObjs == 0) {
+ unsigned MaxIdx = 0;
+ for (unsigned i = 0; i != ModLevel; ++i) {
+ unsigned Idx = NodeMap[CPlane[i]];
+ if (Idx > MaxIdx) MaxIdx = Idx;
+ }
+ PrunePlane = MaxIdx < 64;
+ }
+
+ // Ok, finally, if we decided to prune this plane out of the compaction
+ // table, do so now.
+ if (PrunePlane) {
+ TypePlane OldPlane;
+ std::swap(OldPlane, CPlane);
+
+ // Loop over the function local objects, relocating them to the global
+ // table plane.
+ for (unsigned i = ModLevel, e = OldPlane.size(); i != e; ++i) {
+ const Value *V = OldPlane[i];
+ CompactionNodeMap.erase(V);
+ assert(NodeMap.count(V) == 0 && "Value already in table??");
+ getOrCreateSlot(V);
+ }
- // Finally, for any planes that we have decided to compact, update the
- // ModuleLevel entries to be accurate.
+ // For compactified global values, just remove them from the compaction
+ // node map.
+ for (unsigned i = 0; i != ModLevel; ++i)
+ CompactionNodeMap.erase(OldPlane[i]);
- // FIXME: This does not yet work for partially compacted tables.
- ModuleLevel.resize(CompactionTable.size());
- for (unsigned i = 0, e = CompactionTable.size(); i != e; ++i)
- ModuleLevel[i] = CompactionTable[i].size();
+ // Update the new modulelevel for this plane.
+ assert(ctp < ModuleLevel.size() && "Cannot set modulelevel!");
+ ModuleLevel[ctp] = GPlane.size()-NumFunctionObjs;
+ assert((int)ModuleLevel[ctp] >= 0 && "Bad computation!");
+ }
+ }
}
+
int SlotCalculator::getSlot(const Value *V) const {
// If there is a CompactionTable active...
if (!CompactionNodeMap.empty()) {
CompactionNodeMap.find(V);
if (I != CompactionNodeMap.end())
return (int)I->second;
- return -1;
+ // Otherwise, if it's not in the compaction table, it must be in a
+ // non-compactified plane.
}
std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(V);
int SlotCalculator::getOrCreateSlot(const Value *V) {
+ if (V->getType() == Type::VoidTy) return -1;
+
int SlotNo = getSlot(V); // Check to see if it's already in!
if (SlotNo != -1) return SlotNo;
assert(!isa<Type>(D) && !isa<Constant>(D) && !isa<GlobalValue>(D) &&
"Types, constants, and globals should be in global SymTab!");
- // FIXME: this does not yet handle partially compacted tables yet!
- return getOrCreateCompactionTableSlot(D);
+ int Plane = getSlot(D->getType());
+ assert(Plane != -1 && CompactionTable.size() > (unsigned)Plane &&
+ "Didn't find value type!");
+ if (!CompactionTable[Plane].empty())
+ return getOrCreateCompactionTableSlot(D);
}
// If this node does not contribute to a plane, or if the node has a
// cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
if (Typ->isDerivedType()) {
- int ValSlot = getSlot(Typ);
+ int ValSlot;
+ if (CompactionTable.empty())
+ ValSlot = getSlot(Typ);
+ else
+ ValSlot = getGlobalSlot(Typ);
if (ValSlot == -1) { // Have we already entered this type?
// Nope, this is the first we have seen the type, process it.
ValSlot = insertValue(Typ, true);
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