llvm-6502/lib/Bitcode/Writer/ValueEnumerator.cpp
Chris Lattner a6245247e9 Add special case bitcode support for DebugLoc. This avoids
having the bitcode writer materialize mdnodes for all the
debug location tuples when writing out the bc file and 
stores the information in a more compact form.  For example,
the -O0 -g bc file for combine.c in 176.gcc shrinks from
739392 to 512096 bytes.

This concludes my planned short-term debug info work.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100261 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 02:17:50 +00:00

468 lines
16 KiB
C++

//===-- ValueEnumerator.cpp - Number values and types for bitcode writer --===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the ValueEnumerator class.
//
//===----------------------------------------------------------------------===//
#include "ValueEnumerator.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/TypeSymbolTable.h"
#include "llvm/ValueSymbolTable.h"
#include "llvm/Instructions.h"
#include <algorithm>
using namespace llvm;
static bool isSingleValueType(const std::pair<const llvm::Type*,
unsigned int> &P) {
return P.first->isSingleValueType();
}
static bool isIntegerValue(const std::pair<const Value*, unsigned> &V) {
return V.first->getType()->isIntegerTy();
}
static bool CompareByFrequency(const std::pair<const llvm::Type*,
unsigned int> &P1,
const std::pair<const llvm::Type*,
unsigned int> &P2) {
return P1.second > P2.second;
}
/// ValueEnumerator - Enumerate module-level information.
ValueEnumerator::ValueEnumerator(const Module *M) {
// Enumerate the global variables.
for (Module::const_global_iterator I = M->global_begin(),
E = M->global_end(); I != E; ++I)
EnumerateValue(I);
// Enumerate the functions.
for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
EnumerateValue(I);
EnumerateAttributes(cast<Function>(I)->getAttributes());
}
// Enumerate the aliases.
for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
I != E; ++I)
EnumerateValue(I);
// Remember what is the cutoff between globalvalue's and other constants.
unsigned FirstConstant = Values.size();
// Enumerate the global variable initializers.
for (Module::const_global_iterator I = M->global_begin(),
E = M->global_end(); I != E; ++I)
if (I->hasInitializer())
EnumerateValue(I->getInitializer());
// Enumerate the aliasees.
for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
I != E; ++I)
EnumerateValue(I->getAliasee());
// Enumerate types used by the type symbol table.
EnumerateTypeSymbolTable(M->getTypeSymbolTable());
// Insert constants and metadata that are named at module level into the slot
// pool so that the module symbol table can refer to them...
EnumerateValueSymbolTable(M->getValueSymbolTable());
EnumerateMDSymbolTable(M->getMDSymbolTable());
SmallVector<std::pair<unsigned, MDNode*>, 8> MDs;
// Enumerate types used by function bodies and argument lists.
for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
for (Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
I != E; ++I)
EnumerateType(I->getType());
for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E;++I){
for (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
OI != E; ++OI) {
if (MDNode *MD = dyn_cast<MDNode>(*OI))
if (MD->isFunctionLocal() && MD->getFunction())
// These will get enumerated during function-incorporation.
continue;
EnumerateOperandType(*OI);
}
EnumerateType(I->getType());
if (const CallInst *CI = dyn_cast<CallInst>(I))
EnumerateAttributes(CI->getAttributes());
else if (const InvokeInst *II = dyn_cast<InvokeInst>(I))
EnumerateAttributes(II->getAttributes());
// Enumerate metadata attached with this instruction.
MDs.clear();
I->getAllMetadataOtherThanDebugLoc(MDs);
for (unsigned i = 0, e = MDs.size(); i != e; ++i)
EnumerateMetadata(MDs[i].second);
if (!I->getDebugLoc().isUnknown()) {
MDNode *Scope, *IA;
I->getDebugLoc().getScopeAndInlinedAt(Scope, IA, I->getContext());
if (Scope) EnumerateMetadata(Scope);
if (IA) EnumerateMetadata(IA);
}
}
}
// Optimize constant ordering.
OptimizeConstants(FirstConstant, Values.size());
// Sort the type table by frequency so that most commonly used types are early
// in the table (have low bit-width).
std::stable_sort(Types.begin(), Types.end(), CompareByFrequency);
// Partition the Type ID's so that the single-value types occur before the
// aggregate types. This allows the aggregate types to be dropped from the
// type table after parsing the global variable initializers.
std::partition(Types.begin(), Types.end(), isSingleValueType);
// Now that we rearranged the type table, rebuild TypeMap.
for (unsigned i = 0, e = Types.size(); i != e; ++i)
TypeMap[Types[i].first] = i+1;
}
unsigned ValueEnumerator::getInstructionID(const Instruction *Inst) const {
InstructionMapType::const_iterator I = InstructionMap.find(Inst);
assert (I != InstructionMap.end() && "Instruction is not mapped!");
return I->second;
}
void ValueEnumerator::setInstructionID(const Instruction *I) {
InstructionMap[I] = InstructionCount++;
}
unsigned ValueEnumerator::getValueID(const Value *V) const {
if (isa<MDNode>(V) || isa<MDString>(V)) {
ValueMapType::const_iterator I = MDValueMap.find(V);
assert(I != MDValueMap.end() && "Value not in slotcalculator!");
return I->second-1;
}
ValueMapType::const_iterator I = ValueMap.find(V);
assert(I != ValueMap.end() && "Value not in slotcalculator!");
return I->second-1;
}
// Optimize constant ordering.
namespace {
struct CstSortPredicate {
ValueEnumerator &VE;
explicit CstSortPredicate(ValueEnumerator &ve) : VE(ve) {}
bool operator()(const std::pair<const Value*, unsigned> &LHS,
const std::pair<const Value*, unsigned> &RHS) {
// Sort by plane.
if (LHS.first->getType() != RHS.first->getType())
return VE.getTypeID(LHS.first->getType()) <
VE.getTypeID(RHS.first->getType());
// Then by frequency.
return LHS.second > RHS.second;
}
};
}
/// OptimizeConstants - Reorder constant pool for denser encoding.
void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
CstSortPredicate P(*this);
std::stable_sort(Values.begin()+CstStart, Values.begin()+CstEnd, P);
// Ensure that integer constants are at the start of the constant pool. This
// is important so that GEP structure indices come before gep constant exprs.
std::partition(Values.begin()+CstStart, Values.begin()+CstEnd,
isIntegerValue);
// Rebuild the modified portion of ValueMap.
for (; CstStart != CstEnd; ++CstStart)
ValueMap[Values[CstStart].first] = CstStart+1;
}
/// EnumerateTypeSymbolTable - Insert all of the types in the specified symbol
/// table.
void ValueEnumerator::EnumerateTypeSymbolTable(const TypeSymbolTable &TST) {
for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
TI != TE; ++TI)
EnumerateType(TI->second);
}
/// EnumerateValueSymbolTable - Insert all of the values in the specified symbol
/// table into the values table.
void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
for (ValueSymbolTable::const_iterator VI = VST.begin(), VE = VST.end();
VI != VE; ++VI)
EnumerateValue(VI->getValue());
}
/// EnumerateMDSymbolTable - Insert all of the values in the specified metadata
/// table.
void ValueEnumerator::EnumerateMDSymbolTable(const MDSymbolTable &MST) {
for (MDSymbolTable::const_iterator MI = MST.begin(), ME = MST.end();
MI != ME; ++MI)
EnumerateValue(MI->getValue());
}
void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) {
// Check to see if it's already in!
unsigned &MDValueID = MDValueMap[MD];
if (MDValueID) {
// Increment use count.
MDValues[MDValueID-1].second++;
return;
}
// Enumerate the type of this value.
EnumerateType(MD->getType());
for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i)
if (MDNode *E = MD->getOperand(i))
EnumerateValue(E);
MDValues.push_back(std::make_pair(MD, 1U));
MDValueMap[MD] = Values.size();
}
void ValueEnumerator::EnumerateMetadata(const Value *MD) {
assert((isa<MDNode>(MD) || isa<MDString>(MD)) && "Invalid metadata kind");
// Check to see if it's already in!
unsigned &MDValueID = MDValueMap[MD];
if (MDValueID) {
// Increment use count.
MDValues[MDValueID-1].second++;
return;
}
// Enumerate the type of this value.
EnumerateType(MD->getType());
if (const MDNode *N = dyn_cast<MDNode>(MD)) {
MDValues.push_back(std::make_pair(MD, 1U));
MDValueMap[MD] = MDValues.size();
MDValueID = MDValues.size();
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
if (Value *V = N->getOperand(i))
EnumerateValue(V);
else
EnumerateType(Type::getVoidTy(MD->getContext()));
}
return;
}
// Add the value.
assert(isa<MDString>(MD) && "Unknown metadata kind");
MDValues.push_back(std::make_pair(MD, 1U));
MDValueID = MDValues.size();
}
void ValueEnumerator::EnumerateValue(const Value *V) {
assert(!V->getType()->isVoidTy() && "Can't insert void values!");
if (isa<MDNode>(V) || isa<MDString>(V))
return EnumerateMetadata(V);
else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(V))
return EnumerateNamedMDNode(NMD);
// Check to see if it's already in!
unsigned &ValueID = ValueMap[V];
if (ValueID) {
// Increment use count.
Values[ValueID-1].second++;
return;
}
// Enumerate the type of this value.
EnumerateType(V->getType());
if (const Constant *C = dyn_cast<Constant>(V)) {
if (isa<GlobalValue>(C)) {
// Initializers for globals are handled explicitly elsewhere.
} else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
// Do not enumerate the initializers for an array of simple characters.
// The initializers just polute the value table, and we emit the strings
// specially.
} else if (C->getNumOperands()) {
// If a constant has operands, enumerate them. This makes sure that if a
// constant has uses (for example an array of const ints), that they are
// inserted also.
// We prefer to enumerate them with values before we enumerate the user
// itself. This makes it more likely that we can avoid forward references
// in the reader. We know that there can be no cycles in the constants
// graph that don't go through a global variable.
for (User::const_op_iterator I = C->op_begin(), E = C->op_end();
I != E; ++I)
if (!isa<BasicBlock>(*I)) // Don't enumerate BB operand to BlockAddress.
EnumerateValue(*I);
// Finally, add the value. Doing this could make the ValueID reference be
// dangling, don't reuse it.
Values.push_back(std::make_pair(V, 1U));
ValueMap[V] = Values.size();
return;
}
}
// Add the value.
Values.push_back(std::make_pair(V, 1U));
ValueID = Values.size();
}
void ValueEnumerator::EnumerateType(const Type *Ty) {
unsigned &TypeID = TypeMap[Ty];
if (TypeID) {
// If we've already seen this type, just increase its occurrence count.
Types[TypeID-1].second++;
return;
}
// First time we saw this type, add it.
Types.push_back(std::make_pair(Ty, 1U));
TypeID = Types.size();
// Enumerate subtypes.
for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
I != E; ++I)
EnumerateType(*I);
}
// Enumerate the types for the specified value. If the value is a constant,
// walk through it, enumerating the types of the constant.
void ValueEnumerator::EnumerateOperandType(const Value *V) {
EnumerateType(V->getType());
if (const Constant *C = dyn_cast<Constant>(V)) {
// If this constant is already enumerated, ignore it, we know its type must
// be enumerated.
if (ValueMap.count(V)) return;
// This constant may have operands, make sure to enumerate the types in
// them.
for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) {
const User *Op = C->getOperand(i);
// Don't enumerate basic blocks here, this happens as operands to
// blockaddress.
if (isa<BasicBlock>(Op)) continue;
EnumerateOperandType(cast<Constant>(Op));
}
if (const MDNode *N = dyn_cast<MDNode>(V)) {
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
if (Value *Elem = N->getOperand(i))
EnumerateOperandType(Elem);
}
} else if (isa<MDString>(V) || isa<MDNode>(V))
EnumerateValue(V);
}
void ValueEnumerator::EnumerateAttributes(const AttrListPtr &PAL) {
if (PAL.isEmpty()) return; // null is always 0.
// Do a lookup.
unsigned &Entry = AttributeMap[PAL.getRawPointer()];
if (Entry == 0) {
// Never saw this before, add it.
Attributes.push_back(PAL);
Entry = Attributes.size();
}
}
void ValueEnumerator::incorporateFunction(const Function &F) {
InstructionCount = 0;
NumModuleValues = Values.size();
// Adding function arguments to the value table.
for(Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end();
I != E; ++I)
EnumerateValue(I);
FirstFuncConstantID = Values.size();
// Add all function-level constants to the value table.
for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I)
for (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
OI != E; ++OI) {
if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
isa<InlineAsm>(*OI))
EnumerateValue(*OI);
}
BasicBlocks.push_back(BB);
ValueMap[BB] = BasicBlocks.size();
}
// Optimize the constant layout.
OptimizeConstants(FirstFuncConstantID, Values.size());
// Add the function's parameter attributes so they are available for use in
// the function's instruction.
EnumerateAttributes(F.getAttributes());
FirstInstID = Values.size();
SmallVector<MDNode *, 8> FunctionLocalMDs;
// Add all of the instructions.
for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) {
for (User::const_op_iterator OI = I->op_begin(), E = I->op_end();
OI != E; ++OI) {
if (MDNode *MD = dyn_cast<MDNode>(*OI))
if (MD->isFunctionLocal() && MD->getFunction())
// Enumerate metadata after the instructions they might refer to.
FunctionLocalMDs.push_back(MD);
}
if (!I->getType()->isVoidTy())
EnumerateValue(I);
}
}
// Add all of the function-local metadata.
for (unsigned i = 0, e = FunctionLocalMDs.size(); i != e; ++i)
EnumerateOperandType(FunctionLocalMDs[i]);
}
void ValueEnumerator::purgeFunction() {
/// Remove purged values from the ValueMap.
for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i)
ValueMap.erase(Values[i].first);
for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
ValueMap.erase(BasicBlocks[i]);
Values.resize(NumModuleValues);
BasicBlocks.clear();
}
static void IncorporateFunctionInfoGlobalBBIDs(const Function *F,
DenseMap<const BasicBlock*, unsigned> &IDMap) {
unsigned Counter = 0;
for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
IDMap[BB] = ++Counter;
}
/// getGlobalBasicBlockID - This returns the function-specific ID for the
/// specified basic block. This is relatively expensive information, so it
/// should only be used by rare constructs such as address-of-label.
unsigned ValueEnumerator::getGlobalBasicBlockID(const BasicBlock *BB) const {
unsigned &Idx = GlobalBasicBlockIDs[BB];
if (Idx != 0)
return Idx-1;
IncorporateFunctionInfoGlobalBBIDs(BB->getParent(), GlobalBasicBlockIDs);
return getGlobalBasicBlockID(BB);
}