llvm-6502/lib/Bytecode/Writer/SlotCalculator.cpp
2002-04-28 19:55:58 +00:00

347 lines
12 KiB
C++

//===-- SlotCalculator.cpp - Calculate what slots values land in ------------=//
//
// 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 is used primarily for when writing a file to disk, either in bytecode
// or source format.
//
//===----------------------------------------------------------------------===//
#include "llvm/SlotCalculator.h"
#include "llvm/Analysis/ConstantsScanner.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Module.h"
#include "llvm/BasicBlock.h"
#include "llvm/iOther.h"
#include "llvm/Constant.h"
#include "llvm/DerivedTypes.h"
#include "llvm/SymbolTable.h"
#include "llvm/Argument.h"
#include "Support/DepthFirstIterator.h"
#include "Support/STLExtras.h"
#include <algorithm>
#if 0
#define SC_DEBUG(X) cerr << X
#else
#define SC_DEBUG(X)
#endif
SlotCalculator::SlotCalculator(const Module *M, bool IgnoreNamed) {
IgnoreNamedNodes = IgnoreNamed;
TheModule = M;
// Preload table... Make sure that all of the primitive types are in the table
// and that their Primitive ID is equal to their slot #
//
for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
assert(Type::getPrimitiveType((Type::PrimitiveID)i));
insertVal(Type::getPrimitiveType((Type::PrimitiveID)i), true);
}
if (M == 0) return; // Empty table...
processModule();
}
SlotCalculator::SlotCalculator(const Function *M, bool IgnoreNamed) {
IgnoreNamedNodes = IgnoreNamed;
TheModule = M ? M->getParent() : 0;
// Preload table... Make sure that all of the primitive types are in the table
// and that their Primitive ID is equal to their slot #
//
for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
assert(Type::getPrimitiveType((Type::PrimitiveID)i));
insertVal(Type::getPrimitiveType((Type::PrimitiveID)i), true);
}
if (TheModule == 0) return; // Empty table...
processModule(); // Process module level stuff
incorporateFunction(M); // Start out in incorporated state
}
// processModule - Process all of the module level function declarations and
// types that are available.
//
void SlotCalculator::processModule() {
SC_DEBUG("begin processModule!\n");
// Add all of the constants that the global variables might refer to first.
//
for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
I != E; ++I) {
if ((*I)->hasInitializer())
insertValue((*I)->getInitializer());
}
// Add all of the global variables to the value table...
//
for_each(TheModule->gbegin(), TheModule->gend(),
bind_obj(this, &SlotCalculator::insertValue));
// Scavenge the types out of the functions, then add the functions themselves
// to the value table...
//
for_each(TheModule->begin(), TheModule->end(), // Insert functions...
bind_obj(this, &SlotCalculator::insertValue));
// Insert constants that are named at module level into the slot pool so that
// the module symbol table can refer to them...
//
if (TheModule->hasSymbolTable() && !IgnoreNamedNodes) {
SC_DEBUG("Inserting SymbolTable values:\n");
processSymbolTable(TheModule->getSymbolTable());
}
SC_DEBUG("end processModule!\n");
}
// processSymbolTable - Insert all of the values in the specified symbol table
// into the values table...
//
void SlotCalculator::processSymbolTable(const SymbolTable *ST) {
for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
for (SymbolTable::type_const_iterator TI = I->second.begin(),
TE = I->second.end(); TI != TE; ++TI)
insertValue(TI->second);
}
void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
for (SymbolTable::const_iterator I = ST->begin(), E = ST->end(); I != E; ++I)
for (SymbolTable::type_const_iterator TI = I->second.begin(),
TE = I->second.end(); TI != TE; ++TI)
if (isa<Constant>(TI->second))
insertValue(TI->second);
}
void SlotCalculator::incorporateFunction(const Function *M) {
assert(ModuleLevel.size() == 0 && "Module already incorporated!");
SC_DEBUG("begin processFunction!\n");
// Save the Table state before we process the function...
for (unsigned i = 0; i < Table.size(); ++i)
ModuleLevel.push_back(Table[i].size());
SC_DEBUG("Inserting function arguments\n");
// Iterate over function arguments, adding them to the value table...
for_each(M->getArgumentList().begin(), M->getArgumentList().end(),
bind_obj(this, &SlotCalculator::insertValue));
// Iterate over all of the instructions in the function, looking for constant
// values that are referenced. Add these to the value pools before any
// nonconstant values. This will be turned into the constant pool for the
// bytecode writer.
//
if (!IgnoreNamedNodes) { // Assembly writer does not need this!
SC_DEBUG("Inserting function constants:\n";
for (constant_iterator I = constant_begin(M), E = constant_end(M);
I != E; ++I) {
cerr << " " << *I->getType()
<< " " << *I << "\n";
});
// Emit all of the constants that are being used by the instructions in the
// function...
for_each(constant_begin(M), constant_end(M),
bind_obj(this, &SlotCalculator::insertValue));
// If there is a symbol table, it is possible that the user has names for
// constants that are not being used. In this case, we will have problems
// if we don't emit the constants now, because otherwise we will get
// symboltable references to constants not in the output. Scan for these
// constants now.
//
if (M->hasSymbolTable())
processSymbolTableConstants(M->getSymbolTable());
}
SC_DEBUG("Inserting Labels:\n");
// Iterate over basic blocks, adding them to the value table...
for_each(M->begin(), M->end(),
bind_obj(this, &SlotCalculator::insertValue));
SC_DEBUG("Inserting Instructions:\n");
// Add all of the instructions to the type planes...
for_each(inst_begin(M), inst_end(M),
bind_obj(this, &SlotCalculator::insertValue));
if (M->hasSymbolTable() && !IgnoreNamedNodes) {
SC_DEBUG("Inserting SymbolTable values:\n");
processSymbolTable(M->getSymbolTable());
}
SC_DEBUG("end processFunction!\n");
}
void SlotCalculator::purgeFunction() {
assert(ModuleLevel.size() != 0 && "Module not incorporated!");
unsigned NumModuleTypes = ModuleLevel.size();
SC_DEBUG("begin purgeFunction!\n");
// First, remove values from existing type planes
for (unsigned i = 0; i < NumModuleTypes; ++i) {
unsigned ModuleSize = ModuleLevel[i]; // Size of plane before function came
TypePlane &CurPlane = Table[i];
//SC_DEBUG("Processing Plane " <<i<< " of size " << CurPlane.size() <<endl);
while (CurPlane.size() != ModuleSize) {
//SC_DEBUG(" Removing [" << i << "] Value=" << CurPlane.back() << "\n");
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
}
}
// We don't need this state anymore, free it up.
ModuleLevel.clear();
// Next, remove any type planes defined by the function...
while (NumModuleTypes != Table.size()) {
TypePlane &Plane = Table.back();
SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
<< Plane.size() << endl);
while (Plane.size()) {
NodeMap.erase(NodeMap.find(Plane.back())); // Erase from nodemap
Plane.pop_back(); // Shrink plane
}
Table.pop_back(); // Nuke the plane, we don't like it.
}
SC_DEBUG("end purgeFunction!\n");
}
int SlotCalculator::getValSlot(const Value *D) const {
std::map<const Value*, unsigned>::const_iterator I = NodeMap.find(D);
if (I == NodeMap.end()) return -1;
return (int)I->second;
}
int SlotCalculator::insertValue(const Value *D) {
if (isa<Constant>(D) || isa<GlobalVariable>(D)) {
const User *U = cast<const User>(D);
// This makes sure that if a constant has uses (for example an array
// of const ints), that they are inserted also. Same for global variable
// initializers.
//
for(User::const_op_iterator I = U->op_begin(), E = U->op_end(); I != E; ++I)
if (!isa<GlobalValue>(*I)) // Don't chain insert global values
insertValue(*I);
}
int SlotNo = getValSlot(D); // Check to see if it's already in!
if (SlotNo != -1) return SlotNo;
return insertVal(D);
}
int SlotCalculator::insertVal(const Value *D, bool dontIgnore = false) {
assert(D && "Can't insert a null value!");
assert(getValSlot(D) == -1 && "Value is already in the table!");
// If this node does not contribute to a plane, or if the node has a
// name and we don't want names, then ignore the silly node... Note that types
// do need slot numbers so that we can keep track of where other values land.
//
if (!dontIgnore) // Don't ignore nonignorables!
if (D->getType() == Type::VoidTy || // Ignore void type nodes
(IgnoreNamedNodes && // Ignore named and constants
(D->hasName() || isa<Constant>(D)) && !isa<Type>(D))) {
SC_DEBUG("ignored value " << D << endl);
return -1; // We do need types unconditionally though
}
// If it's a type, make sure that all subtypes of the type are included...
if (const Type *TheTy = dyn_cast<const Type>(D)) {
// Insert the current type before any subtypes. This is important because
// recursive types elements are inserted in a bottom up order. Changing
// this here can break things. For example:
//
// global { \2 * } { { \2 }* null }
//
int ResultSlot;
if ((ResultSlot = getValSlot(TheTy)) == -1) {
ResultSlot = doInsertVal(TheTy);
SC_DEBUG(" Inserted type: " << TheTy->getDescription() << " slot=" <<
ResultSlot << endl);
}
// Loop over any contained types in the definition... in reverse depth first
// order. This assures that all of the leafs of a type are output before
// the type itself is. This also assures us that we will not hit infinite
// recursion on recursive types...
//
for (df_iterator<const Type*> I = df_begin(TheTy, true),
E = df_end(TheTy); I != E; ++I)
if (*I != TheTy) {
// If we haven't seen this sub type before, add it to our type table!
const Type *SubTy = *I;
if (getValSlot(SubTy) == -1) {
SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << endl);
int Slot = doInsertVal(SubTy);
SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() <<
" slot=" << Slot << endl);
}
}
return ResultSlot;
}
// Okay, everything is happy, actually insert the silly value now...
return doInsertVal(D);
}
// doInsertVal - This is a small helper function to be called only be insertVal.
//
int SlotCalculator::doInsertVal(const Value *D) {
const Type *Typ = D->getType();
unsigned Ty;
// Used for debugging DefSlot=-1 assertion...
//if (Typ == Type::TypeTy)
// cerr << "Inserting type '" << cast<Type>(D)->getDescription() << "'!\n";
if (Typ->isDerivedType()) {
int DefSlot = getValSlot(Typ);
if (DefSlot == -1) { // Have we already entered this type?
// Nope, this is the first we have seen the type, process it.
DefSlot = insertVal(Typ, true);
assert(DefSlot != -1 && "ProcessType returned -1 for a type?");
}
Ty = (unsigned)DefSlot;
} else {
Ty = Typ->getPrimitiveID();
}
if (Table.size() <= Ty) // Make sure we have the type plane allocated...
Table.resize(Ty+1, TypePlane());
// Insert node into table and NodeMap...
unsigned DestSlot = NodeMap[D] = Table[Ty].size();
Table[Ty].push_back(D);
SC_DEBUG(" Inserting value [" << Ty << "] = " << D << " slot=" <<
DestSlot << " [");
// G = Global, C = Constant, T = Type, F = Function, o = other
SC_DEBUG((isa<GlobalVariable>(D) ? "G" : (isa<Constant>(D) ? "C" :
(isa<Type>(D) ? "T" : (isa<Function>(D) ? "F" : "o")))));
SC_DEBUG("]\n");
return (int)DestSlot;
}