llvm-6502/lib/VMCore/SlotCalculator.cpp
Reid Spencer 798ff64328 Part of bug 122:
This change removes the BuildBytecodeInfo flag from the SlotCalculator
class. This flag was needed to distinguish between the Bytecode/Writer
and the AsmWriter. Now that AsmWriter doesn't use SlotCalculator, we can
remove this flag and simplify some code. Also, some minor name changes
to CachedWriter.h needed to be committed (missed in previous commit).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13785 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-26 07:37:11 +00:00

787 lines
30 KiB
C++

//===-- SlotCalculator.cpp - Calculate what slots values land in ----------===//
//
// 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.
//
//===----------------------------------------------------------------------===//
//
// 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 when writing a file to disk, either in bytecode or assembly.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/SlotCalculator.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/iOther.h"
#include "llvm/Module.h"
#include "llvm/SymbolTable.h"
#include "llvm/Analysis/ConstantsScanner.h"
#include "Support/PostOrderIterator.h"
#include "Support/STLExtras.h"
#include <algorithm>
using namespace llvm;
#if 0
#define SC_DEBUG(X) std::cerr << X
#else
#define SC_DEBUG(X)
#endif
SlotCalculator::SlotCalculator(const Module *M ) {
ModuleContainsAllFunctionConstants = false;
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 #
//
SC_DEBUG("Inserting primitive types:\n");
for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
assert(Type::getPrimitiveType((Type::PrimitiveID)i));
insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
}
if (M == 0) return; // Empty table...
processModule();
}
SlotCalculator::SlotCalculator(const Function *M ) {
ModuleContainsAllFunctionConstants = false;
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 #
//
SC_DEBUG("Inserting primitive types:\n");
for (unsigned i = 0; i < Type::FirstDerivedTyID; ++i) {
assert(Type::getPrimitiveType((Type::PrimitiveID)i));
insertValue(Type::getPrimitiveType((Type::PrimitiveID)i), true);
}
if (TheModule == 0) return; // Empty table...
processModule(); // Process module level stuff
incorporateFunction(M); // Start out in incorporated state
}
unsigned SlotCalculator::getGlobalSlot(const Value *V) const {
assert(!CompactionTable.empty() &&
"This method can only be used when compaction is enabled!");
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 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
// types that are available.
//
void SlotCalculator::processModule() {
SC_DEBUG("begin processModule!\n");
// Add all of the global variables to the value table...
//
for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
I != E; ++I)
getOrCreateSlot(I);
// Scavenge the types out of the functions, then add the functions themselves
// to the value table...
//
for (Module::const_iterator I = TheModule->begin(), E = TheModule->end();
I != E; ++I)
getOrCreateSlot(I);
// Add all of the module level constants used as initializers
//
for (Module::const_giterator I = TheModule->gbegin(), E = TheModule->gend();
I != E; ++I)
if (I->hasInitializer())
getOrCreateSlot(I->getInitializer());
// Now that all global constants have been added, rearrange constant planes
// that contain constant strings so that the strings occur at the start of the
// plane, not somewhere in the middle.
//
TypePlane &Types = Table[Type::TypeTyID];
for (unsigned plane = 0, e = Table.size(); plane != e; ++plane) {
if (const ArrayType *AT = dyn_cast<ArrayType>(Types[plane]))
if (AT->getElementType() == Type::SByteTy ||
AT->getElementType() == Type::UByteTy) {
TypePlane &Plane = Table[plane];
unsigned FirstNonStringID = 0;
for (unsigned i = 0, e = Plane.size(); i != e; ++i)
if (isa<ConstantAggregateZero>(Plane[i]) ||
cast<ConstantArray>(Plane[i])->isString()) {
// Check to see if we have to shuffle this string around. If not,
// don't do anything.
if (i != FirstNonStringID) {
// Swap the plane entries....
std::swap(Plane[i], Plane[FirstNonStringID]);
// Keep the NodeMap up to date.
NodeMap[Plane[i]] = i;
NodeMap[Plane[FirstNonStringID]] = FirstNonStringID;
}
++FirstNonStringID;
}
}
}
// If we are emitting a bytecode file, scan all of the functions for their
// constants, which allows us to emit more compact modules. This is optional,
// and is just used to compactify the constants used by different functions
// together.
//
// This functionality is completely optional for the bytecode writer, but
// tends to produce smaller bytecode files. This should not be used in the
// future by clients that want to, for example, build and emit functions on
// the fly. For now, however, it is unconditionally enabled when building
// bytecode information.
//
ModuleContainsAllFunctionConstants = true;
SC_DEBUG("Inserting function constants:\n");
for (Module::const_iterator F = TheModule->begin(), E = TheModule->end();
F != E; ++F) {
for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I){
for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
if (isa<Constant>(I->getOperand(op)))
getOrCreateSlot(I->getOperand(op));
getOrCreateSlot(I->getType());
if (const VANextInst *VAN = dyn_cast<VANextInst>(&*I))
getOrCreateSlot(VAN->getArgType());
}
processSymbolTableConstants(&F->getSymbolTable());
}
// Insert constants that are named at module level into the slot pool so that
// the module symbol table can refer to them...
SC_DEBUG("Inserting SymbolTable values:\n");
processSymbolTable(&TheModule->getSymbolTable());
// Now that we have collected together all of the information relevant to the
// module, compactify the type table if it is particularly big and outputting
// a bytecode file. The basic problem we run into is that some programs have
// a large number of types, which causes the type field to overflow its size,
// which causes instructions to explode in size (particularly call
// instructions). To avoid this behavior, we "sort" the type table so that
// all non-value types are pushed to the end of the type table, giving nice
// low numbers to the types that can be used by instructions, thus reducing
// the amount of explodage we suffer.
if (Table[Type::TypeTyID].size() >= 64) {
// Scan through the type table moving value types to the start of the table.
TypePlane *Types = &Table[Type::TypeTyID];
unsigned FirstNonValueTypeID = 0;
for (unsigned i = 0, e = Types->size(); i != e; ++i)
if (cast<Type>((*Types)[i])->isFirstClassType() ||
cast<Type>((*Types)[i])->isPrimitiveType()) {
// Check to see if we have to shuffle this type around. If not, don't
// do anything.
if (i != FirstNonValueTypeID) {
assert(i != Type::TypeTyID && FirstNonValueTypeID != Type::TypeTyID &&
"Cannot move around the type plane!");
// Swap the type ID's.
std::swap((*Types)[i], (*Types)[FirstNonValueTypeID]);
// Keep the NodeMap up to date.
NodeMap[(*Types)[i]] = i;
NodeMap[(*Types)[FirstNonValueTypeID]] = FirstNonValueTypeID;
// When we move a type, make sure to move its value plane as needed.
if (Table.size() > FirstNonValueTypeID) {
if (Table.size() <= i) Table.resize(i+1);
std::swap(Table[i], Table[FirstNonValueTypeID]);
Types = &Table[Type::TypeTyID];
}
}
++FirstNonValueTypeID;
}
}
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) {
// Do the types first.
for (SymbolTable::type_const_iterator TI = ST->type_begin(),
TE = ST->type_end(); TI != TE; ++TI )
getOrCreateSlot(TI->second);
// Now do the values.
for (SymbolTable::plane_const_iterator PI = ST->plane_begin(),
PE = ST->plane_end(); PI != PE; ++PI)
for (SymbolTable::value_const_iterator VI = PI->second.begin(),
VE = PI->second.end(); VI != VE; ++VI)
getOrCreateSlot(VI->second);
}
void SlotCalculator::processSymbolTableConstants(const SymbolTable *ST) {
// Do the types first
for (SymbolTable::type_const_iterator TI = ST->type_begin(),
TE = ST->type_end(); TI != TE; ++TI )
getOrCreateSlot(TI->second);
// Now do the constant values in all planes
for (SymbolTable::plane_const_iterator PI = ST->plane_begin(),
PE = ST->plane_end(); PI != PE; ++PI)
for (SymbolTable::value_const_iterator VI = PI->second.begin(),
VE = PI->second.end(); VI != VE; ++VI)
if (isa<Constant>(VI->second))
getOrCreateSlot(VI->second);
}
void SlotCalculator::incorporateFunction(const Function *F) {
assert(ModuleLevel.size() == 0 && "Module already incorporated!");
SC_DEBUG("begin processFunction!\n");
// If we emitted all of the function constants, build a compaction table.
if ( ModuleContainsAllFunctionConstants)
buildCompactionTable(F);
// 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)
getOrCreateSlot(I);
if ( !ModuleContainsAllFunctionConstants ) {
// 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.
//
// Emit all of the constants that are being used by the instructions in
// the function...
for_each(constant_begin(F), constant_end(F),
bind_obj(this, &SlotCalculator::getOrCreateSlot));
// 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
// symbol table references to constants not in the output. Scan for these
// constants now.
//
processSymbolTableConstants(&F->getSymbolTable());
}
SC_DEBUG("Inserting Instructions:\n");
// Add all of the instructions to the type planes...
for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
getOrCreateSlot(BB);
for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
getOrCreateSlot(I);
if (const VANextInst *VAN = dyn_cast<VANextInst>(I))
getOrCreateSlot(VAN->getArgType());
}
}
// 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");
}
void SlotCalculator::purgeFunction() {
assert(ModuleLevel.size() != 0 && "Module not incorporated!");
unsigned NumModuleTypes = ModuleLevel.size();
SC_DEBUG("begin purgeFunction!\n");
// First, free the compaction map if used.
CompactionNodeMap.clear();
// Next, remove values from existing type planes
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 {
while (Table.size() > NumModuleTypes) {
TypePlane &Plane = Table.back();
SC_DEBUG("Removing Plane " << (Table.size()-1) << " of size "
<< Plane.size() << "\n");
while (Plane.size()) {
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.
}
}
SC_DEBUG("end purgeFunction!\n");
}
static inline bool hasNullValue(unsigned TyID) {
return TyID != Type::LabelTyID && TyID != Type::TypeTyID &&
TyID != Type::VoidTyID;
}
/// getOrCreateCompactionTableSlot - This method is used to build up the initial
/// approximation of the compaction table.
unsigned SlotCalculator::getOrCreateCompactionTableSlot(const Value *V) {
if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(V))
V = CPR->getValue();
std::map<const Value*, unsigned>::iterator I =
CompactionNodeMap.lower_bound(V);
if (I != CompactionNodeMap.end() && I->first == V)
return I->second; // Already exists?
// Make sure the type is in the table.
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);
assert(!isa<Type>(V) || ModuleLevel.empty());
TypePlane &TyPlane = CompactionTable[Ty];
// Make sure to insert the null entry if the thing we are inserting is not a
// null constant.
if (TyPlane.empty() && hasNullValue(V->getType()->getPrimitiveID())) {
Value *ZeroInitializer = Constant::getNullValue(V->getType());
if (V != ZeroInitializer) {
TyPlane.push_back(ZeroInitializer);
CompactionNodeMap[ZeroInitializer] = 0;
}
}
unsigned SlotNo = TyPlane.size();
TyPlane.push_back(V);
CompactionNodeMap.insert(std::make_pair(V, SlotNo));
return SlotNo;
}
/// buildCompactionTable - Since all of the function constants and types are
/// stored in the module-level constant table, we don't need to emit a function
/// constant table. Also due to this, the indices for various constants and
/// types might be very large in large programs. In order to avoid blowing up
/// the size of instructions in the bytecode encoding, we build a compaction
/// table, which defines a mapping from function-local identifiers to global
/// identifiers.
void SlotCalculator::buildCompactionTable(const Function *F) {
assert(CompactionNodeMap.empty() && "Compaction table already built!");
// First step, insert the primitive types.
CompactionTable.resize(Type::TypeTyID+1);
for (unsigned i = 0; i != Type::FirstDerivedTyID; ++i) {
const Type *PrimTy = Type::getPrimitiveType((Type::PrimitiveID)i);
CompactionTable[Type::TypeTyID].push_back(PrimTy);
CompactionNodeMap[PrimTy] = i;
}
// Next, include any types used by function arguments.
for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
getOrCreateCompactionTableSlot(I->getType());
// Next, find all of the types and values that are referred to by the
// instructions in the program.
for (const_inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
getOrCreateCompactionTableSlot(I->getType());
for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
if (isa<Constant>(I->getOperand(op)) ||
isa<GlobalValue>(I->getOperand(op)))
getOrCreateCompactionTableSlot(I->getOperand(op));
if (const VANextInst *VAN = dyn_cast<VANextInst>(&*I))
getOrCreateCompactionTableSlot(VAN->getArgType());
}
// Do the types in the symbol table
const SymbolTable &ST = F->getSymbolTable();
for (SymbolTable::type_const_iterator TI = ST.type_begin(),
TE = ST.type_end(); TI != TE; ++TI)
getOrCreateCompactionTableSlot(TI->second);
// Now do the constants and global values
for (SymbolTable::plane_const_iterator PI = ST.plane_begin(),
PE = ST.plane_end(); PI != PE; ++PI)
for (SymbolTable::value_const_iterator VI = PI->second.begin(),
VE = PI->second.end(); VI != VE; ++VI)
if (isa<Constant>(VI->second) || isa<GlobalValue>(VI->second))
getOrCreateCompactionTableSlot(VI->second);
// Now that we have all of the values in the table, and know what types are
// referenced, make sure that there is at least the zero initializer in any
// used type plane. Since the type was used, we will be emitting instructions
// to the plane even if there are no constants in it.
CompactionTable.resize(CompactionTable[Type::TypeTyID].size());
for (unsigned i = 0, e = CompactionTable.size(); i != e; ++i)
if (CompactionTable[i].empty() && i != Type::VoidTyID &&
i != Type::LabelTyID) {
const Type *Ty = cast<Type>(CompactionTable[Type::TypeTyID][i]);
getOrCreateCompactionTableSlot(Constant::getNullValue(Ty));
}
// Okay, now at this point, we have a legal compaction table. Since we want
// 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();
}
}
}
}
/// 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);
}
// For compactified global values, just remove them from the compaction
// node map.
for (unsigned i = 0; i != ModLevel; ++i)
CompactionNodeMap.erase(OldPlane[i]);
// 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()) {
std::map<const Value*, unsigned>::const_iterator I =
CompactionNodeMap.find(V);
if (I != CompactionNodeMap.end())
return (int)I->second;
// 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);
if (I != NodeMap.end())
return (int)I->second;
// Do not number ConstantPointerRef's at all. They are an abomination.
if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(V))
return getSlot(CPR->getValue());
return -1;
}
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;
// Do not number ConstantPointerRef's at all. They are an abomination.
if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(V))
return getOrCreateSlot(CPR->getValue());
if (!isa<GlobalValue>(V)) // Initializers for globals are handled explicitly
if (const Constant *C = dyn_cast<Constant>(V)) {
assert(CompactionNodeMap.empty() &&
"All needed constants should be in the compaction map already!");
// Do not index the characters that make up constant strings. We emit
// constant strings as special entities that don't require their
// individual characters to be emitted.
if (!isa<ConstantArray>(C) || !cast<ConstantArray>(C)->isString()) {
// This makes sure that if a constant has uses (for example an array of
// const ints), that they are inserted also.
//
for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
I != E; ++I)
getOrCreateSlot(*I);
} else {
assert(ModuleLevel.empty() &&
"How can a constant string be directly accessed in a function?");
// Otherwise, if we are emitting a bytecode file and this IS a string,
// remember it.
if (!C->isNullValue())
ConstantStrings.push_back(cast<ConstantArray>(C));
}
}
return insertValue(V);
}
int SlotCalculator::insertValue(const Value *D, bool dontIgnore) {
assert(D && "Can't insert a null value!");
assert(getSlot(D) == -1 && "Value is already in the table!");
// If we are building a compaction map, and if this plane is being compacted,
// insert the value into the compaction map, not into the global map.
if (!CompactionNodeMap.empty()) {
if (D->getType() == Type::VoidTy) return -1; // Do not insert void values
assert(!isa<Type>(D) && !isa<Constant>(D) && !isa<GlobalValue>(D) &&
"Types, constants, and globals should be in global SymTab!");
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
// 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
SC_DEBUG("ignored value " << *D << "\n");
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<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 = doInsertValue(TheTy);
SC_DEBUG(" Inserted type: " << TheTy->getDescription() << " slot=" <<
ResultSlot << "\n");
// Loop over any contained types in the definition... in post
// order.
//
for (po_iterator<const Type*> I = po_begin(TheTy), E = po_end(TheTy);
I != E; ++I) {
if (*I != TheTy) {
const Type *SubTy = *I;
// If we haven't seen this sub type before, add it to our type table!
if (getSlot(SubTy) == -1) {
SC_DEBUG(" Inserting subtype: " << SubTy->getDescription() << "\n");
int Slot = doInsertValue(SubTy);
SC_DEBUG(" Inserted subtype: " << SubTy->getDescription() <<
" slot=" << Slot << "\n");
}
}
}
return ResultSlot;
}
// Okay, everything is happy, actually insert the silly value now...
return doInsertValue(D);
}
// doInsertValue - This is a small helper function to be called only
// be insertValue.
//
int SlotCalculator::doInsertValue(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 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);
assert(ValSlot != -1 && "ProcessType returned -1 for a type?");
}
Ty = (unsigned)ValSlot;
} else {
Ty = Typ->getPrimitiveID();
}
if (Table.size() <= Ty) // Make sure we have the type plane allocated...
Table.resize(Ty+1, TypePlane());
// If this is the first value to get inserted into the type plane, make sure
// to insert the implicit null value...
if (Table[Ty].empty() && hasNullValue(Ty)) {
Value *ZeroInitializer = Constant::getNullValue(Typ);
// If we are pushing zeroinit, it will be handled below.
if (D != ZeroInitializer) {
Table[Ty].push_back(ZeroInitializer);
NodeMap[ZeroInitializer] = 0;
}
}
// 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;
}