llvm-6502/lib/Bitcode/Writer/ValueEnumerator.cpp
Chandler Carruth 36b699f2b1 [C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
   detail
2) Change it to actually be a *Use* iterator rather than a *User*
   iterator.
3) Add an adaptor which is a User iterator that always looks through the
   Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
   they wanted a use_iterator (and to explicitly dig out the User when
   needed), or a user_iterator which makes the Use itself totally
   opaque.

Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.

The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.

However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203364 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-09 03:16:01 +00:00

535 lines
18 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/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ValueSymbolTable.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
using namespace llvm;
static bool isIntOrIntVectorValue(const std::pair<const Value*, unsigned> &V) {
return V.first->getType()->isIntOrIntVectorTy();
}
/// 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 the prefix data constants.
for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
if (I->hasPrefixData())
EnumerateValue(I->getPrefixData());
// 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());
EnumerateNamedMetadata(M);
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());
}
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;
}
void ValueEnumerator::dump() const {
print(dbgs(), ValueMap, "Default");
dbgs() << '\n';
print(dbgs(), MDValueMap, "MetaData");
dbgs() << '\n';
}
void ValueEnumerator::print(raw_ostream &OS, const ValueMapType &Map,
const char *Name) const {
OS << "Map Name: " << Name << "\n";
OS << "Size: " << Map.size() << "\n";
for (ValueMapType::const_iterator I = Map.begin(),
E = Map.end(); I != E; ++I) {
const Value *V = I->first;
if (V->hasName())
OS << "Value: " << V->getName();
else
OS << "Value: [null]\n";
V->dump();
OS << " Uses(" << std::distance(V->use_begin(),V->use_end()) << "):";
for (const Use &U : V->uses()) {
if (&U != &*V->use_begin())
OS << ",";
if(U->hasName())
OS << " " << U->getName();
else
OS << " [null]";
}
OS << "\n\n";
}
}
/// OptimizeConstants - Reorder constant pool for denser encoding.
void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
std::stable_sort(Values.begin() + CstStart, Values.begin() + CstEnd,
[this](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 getTypeID(LHS.first->getType()) < getTypeID(RHS.first->getType());
// Then by frequency.
return LHS.second > RHS.second;
});
// Ensure that integer and vector of 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,
isIntOrIntVectorValue);
// Rebuild the modified portion of ValueMap.
for (; CstStart != CstEnd; ++CstStart)
ValueMap[Values[CstStart].first] = CstStart+1;
}
/// 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());
}
/// EnumerateNamedMetadata - Insert all of the values referenced by
/// named metadata in the specified module.
void ValueEnumerator::EnumerateNamedMetadata(const Module *M) {
for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
E = M->named_metadata_end(); I != E; ++I)
EnumerateNamedMDNode(I);
}
void ValueEnumerator::EnumerateNamedMDNode(const NamedMDNode *MD) {
for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i)
EnumerateMetadata(MD->getOperand(i));
}
/// EnumerateMDNodeOperands - Enumerate all non-function-local values
/// and types referenced by the given MDNode.
void ValueEnumerator::EnumerateMDNodeOperands(const MDNode *N) {
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
if (Value *V = N->getOperand(i)) {
if (isa<MDNode>(V) || isa<MDString>(V))
EnumerateMetadata(V);
else if (!isa<Instruction>(V) && !isa<Argument>(V))
EnumerateValue(V);
} else
EnumerateType(Type::getVoidTy(N->getContext()));
}
}
void ValueEnumerator::EnumerateMetadata(const Value *MD) {
assert((isa<MDNode>(MD) || isa<MDString>(MD)) && "Invalid metadata kind");
// Enumerate the type of this value.
EnumerateType(MD->getType());
const MDNode *N = dyn_cast<MDNode>(MD);
// In the module-level pass, skip function-local nodes themselves, but
// do walk their operands.
if (N && N->isFunctionLocal() && N->getFunction()) {
EnumerateMDNodeOperands(N);
return;
}
// Check to see if it's already in!
unsigned &MDValueID = MDValueMap[MD];
if (MDValueID) {
// Increment use count.
MDValues[MDValueID-1].second++;
return;
}
MDValues.push_back(std::make_pair(MD, 1U));
MDValueID = MDValues.size();
// Enumerate all non-function-local operands.
if (N)
EnumerateMDNodeOperands(N);
}
/// EnumerateFunctionLocalMetadataa - Incorporate function-local metadata
/// information reachable from the given MDNode.
void ValueEnumerator::EnumerateFunctionLocalMetadata(const MDNode *N) {
assert(N->isFunctionLocal() && N->getFunction() &&
"EnumerateFunctionLocalMetadata called on non-function-local mdnode!");
// Enumerate the type of this value.
EnumerateType(N->getType());
// Check to see if it's already in!
unsigned &MDValueID = MDValueMap[N];
if (MDValueID) {
// Increment use count.
MDValues[MDValueID-1].second++;
return;
}
MDValues.push_back(std::make_pair(N, 1U));
MDValueID = MDValues.size();
// To incoroporate function-local information visit all function-local
// MDNodes and all function-local values they reference.
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
if (Value *V = N->getOperand(i)) {
if (MDNode *O = dyn_cast<MDNode>(V)) {
if (O->isFunctionLocal() && O->getFunction())
EnumerateFunctionLocalMetadata(O);
} else if (isa<Instruction>(V) || isa<Argument>(V))
EnumerateValue(V);
}
// Also, collect all function-local MDNodes for easy access.
FunctionLocalMDs.push_back(N);
}
void ValueEnumerator::EnumerateValue(const Value *V) {
assert(!V->getType()->isVoidTy() && "Can't insert void values!");
assert(!isa<MDNode>(V) && !isa<MDString>(V) &&
"EnumerateValue doesn't handle Metadata!");
// 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 (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(Type *Ty) {
unsigned *TypeID = &TypeMap[Ty];
// We've already seen this type.
if (*TypeID)
return;
// If it is a non-anonymous struct, mark the type as being visited so that we
// don't recursively visit it. This is safe because we allow forward
// references of these in the bitcode reader.
if (StructType *STy = dyn_cast<StructType>(Ty))
if (!STy->isLiteral())
*TypeID = ~0U;
// Enumerate all of the subtypes before we enumerate this type. This ensures
// that the type will be enumerated in an order that can be directly built.
for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
I != E; ++I)
EnumerateType(*I);
// Refresh the TypeID pointer in case the table rehashed.
TypeID = &TypeMap[Ty];
// Check to see if we got the pointer another way. This can happen when
// enumerating recursive types that hit the base case deeper than they start.
//
// If this is actually a struct that we are treating as forward ref'able,
// then emit the definition now that all of its contents are available.
if (*TypeID && *TypeID != ~0U)
return;
// Add this type now that its contents are all happily enumerated.
Types.push_back(Ty);
*TypeID = Types.size();
}
// 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 Value *Op = C->getOperand(i);
// Don't enumerate basic blocks here, this happens as operands to
// blockaddress.
if (isa<BasicBlock>(Op)) continue;
EnumerateOperandType(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))
EnumerateMetadata(V);
}
void ValueEnumerator::EnumerateAttributes(AttributeSet PAL) {
if (PAL.isEmpty()) return; // null is always 0.
// Do a lookup.
unsigned &Entry = AttributeMap[PAL];
if (Entry == 0) {
// Never saw this before, add it.
Attribute.push_back(PAL);
Entry = Attribute.size();
}
// Do lookups for all attribute groups.
for (unsigned i = 0, e = PAL.getNumSlots(); i != e; ++i) {
AttributeSet AS = PAL.getSlotAttributes(i);
unsigned &Entry = AttributeGroupMap[AS];
if (Entry == 0) {
AttributeGroups.push_back(AS);
Entry = AttributeGroups.size();
}
}
}
void ValueEnumerator::incorporateFunction(const Function &F) {
InstructionCount = 0;
NumModuleValues = Values.size();
NumModuleMDValues = MDValues.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> FnLocalMDVector;
// 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.
FnLocalMDVector.push_back(MD);
}
SmallVector<std::pair<unsigned, MDNode*>, 8> MDs;
I->getAllMetadataOtherThanDebugLoc(MDs);
for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
MDNode *N = MDs[i].second;
if (N->isFunctionLocal() && N->getFunction())
FnLocalMDVector.push_back(N);
}
if (!I->getType()->isVoidTy())
EnumerateValue(I);
}
}
// Add all of the function-local metadata.
for (unsigned i = 0, e = FnLocalMDVector.size(); i != e; ++i)
EnumerateFunctionLocalMetadata(FnLocalMDVector[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 = NumModuleMDValues, e = MDValues.size(); i != e; ++i)
MDValueMap.erase(MDValues[i].first);
for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
ValueMap.erase(BasicBlocks[i]);
Values.resize(NumModuleValues);
MDValues.resize(NumModuleMDValues);
BasicBlocks.clear();
FunctionLocalMDs.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);
}