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llvm-6502/lib/Transforms/IPO/OldPoolAllocate.cpp
Chris Lattner 0b12b5f50e MEGAPATCH checkin. 
For details, See: docs/2002-06-25-MegaPatchInfo.txt


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2778 91177308-0d34-0410-b5e6-96231b3b80d8
2002-06-25 16:13:21 +00:00

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//===-- PoolAllocate.cpp - Pool Allocation Pass ---------------------------===//
//
// This transform changes programs so that disjoint data structures are
// allocated out of different pools of memory, increasing locality and shrinking
// pointer size.
//
// This pass requires a DCE & instcombine pass to be run after it for best
// results.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/IPO/PoolAllocate.h"
#include "llvm/Transforms/Utils/CloneFunction.h"
#include "llvm/Analysis/DataStructureGraph.h"
#include "llvm/Module.h"
#include "llvm/iMemory.h"
#include "llvm/iTerminators.h"
#include "llvm/iPHINode.h"
#include "llvm/iOther.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/InstVisitor.h"
#include "Support/DepthFirstIterator.h"
#include "Support/STLExtras.h"
#include <algorithm>
// DEBUG_CREATE_POOLS - Enable this to turn on debug output for the pool
// creation phase in the top level function of a transformed data structure.
//
//#define DEBUG_CREATE_POOLS 1
// DEBUG_TRANSFORM_PROGRESS - Enable this to get lots of debug output on what
// the transformation is doing.
//
//#define DEBUG_TRANSFORM_PROGRESS 1
// DEBUG_POOLBASE_LOAD_ELIMINATOR - Turn this on to get statistics about how
// many static loads were eliminated from a function...
//
#define DEBUG_POOLBASE_LOAD_ELIMINATOR 1
#include "Support/CommandLine.h"
enum PtrSize {
Ptr8bits, Ptr16bits, Ptr32bits
};
static cl::Enum<enum PtrSize> ReqPointerSize("ptrsize", 0,
"Set pointer size for -poolalloc pass",
clEnumValN(Ptr32bits, "32", "Use 32 bit indices for pointers"),
clEnumValN(Ptr16bits, "16", "Use 16 bit indices for pointers"),
clEnumValN(Ptr8bits , "8", "Use 8 bit indices for pointers"), 0);
static cl::Flag DisableRLE("no-pool-load-elim", "Disable pool load elimination after poolalloc pass", cl::Hidden);
const Type *POINTERTYPE;
// FIXME: This is dependant on the sparc backend layout conventions!!
static TargetData TargetData("test");
static const Type *getPointerTransformedType(const Type *Ty) {
if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
return POINTERTYPE;
} else if (const StructType *STy = dyn_cast<StructType>(Ty)) {
vector<const Type *> NewElTypes;
NewElTypes.reserve(STy->getElementTypes().size());
for (StructType::ElementTypes::const_iterator
I = STy->getElementTypes().begin(),
E = STy->getElementTypes().end(); I != E; ++I)
NewElTypes.push_back(getPointerTransformedType(*I));
return StructType::get(NewElTypes);
} else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
return ArrayType::get(getPointerTransformedType(ATy->getElementType()),
ATy->getNumElements());
} else {
assert(Ty->isPrimitiveType() && "Unknown derived type!");
return Ty;
}
}
namespace {
struct PoolInfo {
DSNode *Node; // The node this pool allocation represents
Value *Handle; // LLVM value of the pool in the current context
const Type *NewType; // The transformed type of the memory objects
const Type *PoolType; // The type of the pool
const Type *getOldType() const { return Node->getType(); }
PoolInfo() { // Define a default ctor for map::operator[]
cerr << "Map subscript used to get element that doesn't exist!\n";
abort(); // Invalid
}
PoolInfo(DSNode *N, Value *H, const Type *NT, const Type *PT)
: Node(N), Handle(H), NewType(NT), PoolType(PT) {
// Handle can be null...
assert(N && NT && PT && "Pool info null!");
}
PoolInfo(DSNode *N) : Node(N), Handle(0), NewType(0), PoolType(0) {
assert(N && "Invalid pool info!");
// The new type of the memory object is the same as the old type, except
// that all of the pointer values are replaced with POINTERTYPE values.
NewType = getPointerTransformedType(getOldType());
}
};
// ScalarInfo - Information about an LLVM value that we know points to some
// datastructure we are processing.
//
struct ScalarInfo {
Value *Val; // Scalar value in Current Function
PoolInfo Pool; // The pool the scalar points into
ScalarInfo(Value *V, const PoolInfo &PI) : Val(V), Pool(PI) {
assert(V && "Null value passed to ScalarInfo ctor!");
}
};
// CallArgInfo - Information on one operand for a call that got expanded.
struct CallArgInfo {
int ArgNo; // Call argument number this corresponds to
DSNode *Node; // The graph node for the pool
Value *PoolHandle; // The LLVM value that is the pool pointer
CallArgInfo(int Arg, DSNode *N, Value *PH)
: ArgNo(Arg), Node(N), PoolHandle(PH) {
assert(Arg >= -1 && N && PH && "Illegal values to CallArgInfo ctor!");
}
// operator< when sorting, sort by argument number.
bool operator<(const CallArgInfo &CAI) const {
return ArgNo < CAI.ArgNo;
}
};
// TransformFunctionInfo - Information about how a function eeds to be
// transformed.
//
struct TransformFunctionInfo {
// ArgInfo - Maintain information about the arguments that need to be
// processed. Each CallArgInfo corresponds to an argument that needs to
// have a pool pointer passed into the transformed function with it.
//
// As a special case, "argument" number -1 corresponds to the return value.
//
vector<CallArgInfo> ArgInfo;
// Func - The function to be transformed...
Function *Func;
// The call instruction that is used to map CallArgInfo PoolHandle values
// into the new function values.
CallInst *Call;
// default ctor...
TransformFunctionInfo() : Func(0), Call(0) {}
bool operator<(const TransformFunctionInfo &TFI) const {
if (Func < TFI.Func) return true;
if (Func > TFI.Func) return false;
if (ArgInfo.size() < TFI.ArgInfo.size()) return true;
if (ArgInfo.size() > TFI.ArgInfo.size()) return false;
return ArgInfo < TFI.ArgInfo;
}
void finalizeConstruction() {
// Sort the vector so that the return value is first, followed by the
// argument records, in order. Note that this must be a stable sort so
// that the entries with the same sorting criteria (ie they are multiple
// pool entries for the same argument) are kept in depth first order.
stable_sort(ArgInfo.begin(), ArgInfo.end());
}
// addCallInfo - For a specified function call CI, figure out which pool
// descriptors need to be passed in as arguments, and which arguments need
// to be transformed into indices. If Arg != -1, the specified call
// argument is passed in as a pointer to a data structure.
//
void addCallInfo(DataStructure *DS, CallInst *CI, int Arg,
DSNode *GraphNode, map<DSNode*, PoolInfo> &PoolDescs);
// Make sure that all dependant arguments are added to this transformation
// info. For example, if we call foo(null, P) and foo treats it's first and
// second arguments as belonging to the same data structure, the we MUST add
// entries to know that the null needs to be transformed into an index as
// well.
//
void ensureDependantArgumentsIncluded(DataStructure *DS,
map<DSNode*, PoolInfo> &PoolDescs);
};
// Define the pass class that we implement...
struct PoolAllocate : public Pass {
const char *getPassName() const { return "Pool Allocate"; }
PoolAllocate() {
switch (ReqPointerSize) {
case Ptr32bits: POINTERTYPE = Type::UIntTy; break;
case Ptr16bits: POINTERTYPE = Type::UShortTy; break;
case Ptr8bits: POINTERTYPE = Type::UByteTy; break;
}
CurModule = 0; DS = 0;
PoolInit = PoolDestroy = PoolAlloc = PoolFree = 0;
}
// getPoolType - Get the type used by the backend for a pool of a particular
// type. This pool record is used to allocate nodes of type NodeType.
//
// Here, PoolTy = { NodeType*, sbyte*, uint }*
//
const StructType *getPoolType(const Type *NodeType) {
vector<const Type*> PoolElements;
PoolElements.push_back(PointerType::get(NodeType));
PoolElements.push_back(PointerType::get(Type::SByteTy));
PoolElements.push_back(Type::UIntTy);
StructType *Result = StructType::get(PoolElements);
// Add a name to the symbol table to correspond to the backend
// representation of this pool...
assert(CurModule && "No current module!?");
string Name = CurModule->getTypeName(NodeType);
if (Name.empty()) Name = CurModule->getTypeName(PoolElements[0]);
CurModule->addTypeName(Name+"oolbe", Result);
return Result;
}
bool run(Module &M);
// getAnalysisUsage - This function requires data structure information
// to be able to see what is pool allocatable.
//
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired(DataStructure::ID);
}
public:
// CurModule - The module being processed.
Module *CurModule;
// DS - The data structure graph for the module being processed.
DataStructure *DS;
// Prototypes that we add to support pool allocation...
Function *PoolInit, *PoolDestroy, *PoolAlloc, *PoolAllocArray, *PoolFree;
// The map of already transformed functions... note that the keys of this
// map do not have meaningful values for 'Call' or the 'PoolHandle' elements
// of the ArgInfo elements.
//
map<TransformFunctionInfo, Function*> TransformedFunctions;
// getTransformedFunction - Get a transformed function, or return null if
// the function specified hasn't been transformed yet.
//
Function *getTransformedFunction(TransformFunctionInfo &TFI) const {
map<TransformFunctionInfo, Function*>::const_iterator I =
TransformedFunctions.find(TFI);
if (I != TransformedFunctions.end()) return I->second;
return 0;
}
// addPoolPrototypes - Add prototypes for the pool functions to the
// specified module and update the Pool* instance variables to point to
// them.
//
void addPoolPrototypes(Module &M);
// CreatePools - Insert instructions into the function we are processing to
// create all of the memory pool objects themselves. This also inserts
// destruction code. Add an alloca for each pool that is allocated to the
// PoolDescs map.
//
void CreatePools(Function *F, const vector<AllocDSNode*> &Allocs,
map<DSNode*, PoolInfo> &PoolDescs);
// processFunction - Convert a function to use pool allocation where
// available.
//
bool processFunction(Function *F);
// transformFunctionBody - This transforms the instruction in 'F' to use the
// pools specified in PoolDescs when modifying data structure nodes
// specified in the PoolDescs map. IPFGraph is the closed data structure
// graph for F, of which the PoolDescriptor nodes come from.
//
void transformFunctionBody(Function *F, FunctionDSGraph &IPFGraph,
map<DSNode*, PoolInfo> &PoolDescs);
// transformFunction - Transform the specified function the specified way.
// It we have already transformed that function that way, don't do anything.
// The nodes in the TransformFunctionInfo come out of callers data structure
// graph, and the PoolDescs passed in are the caller's.
//
void transformFunction(TransformFunctionInfo &TFI,
FunctionDSGraph &CallerIPGraph,
map<DSNode*, PoolInfo> &PoolDescs);
};
}
// isNotPoolableAlloc - This is a predicate that returns true if the specified
// allocation node in a data structure graph is eligable for pool allocation.
//
static bool isNotPoolableAlloc(const AllocDSNode *DS) {
if (DS->isAllocaNode()) return true; // Do not pool allocate alloca's.
return false;
}
// processFunction - Convert a function to use pool allocation where
// available.
//
bool PoolAllocate::processFunction(Function *F) {
// Get the closed datastructure graph for the current function... if there are
// any allocations in this graph that are not escaping, we need to pool
// allocate them here!
//
FunctionDSGraph &IPGraph = DS->getClosedDSGraph(F);
// Get all of the allocations that do not escape the current function. Since
// they are still live (they exist in the graph at all), this means we must
// have scalar references to these nodes, but the scalars are never returned.
//
vector<AllocDSNode*> Allocs;
IPGraph.getNonEscapingAllocations(Allocs);
// Filter out allocations that we cannot handle. Currently, this includes
// variable sized array allocations and alloca's (which we do not want to
// pool allocate)
//
Allocs.erase(remove_if(Allocs.begin(), Allocs.end(), isNotPoolableAlloc),
Allocs.end());
if (Allocs.empty()) return false; // Nothing to do.
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "Transforming Function: " << F->getName() << "\n";
#endif
// Insert instructions into the function we are processing to create all of
// the memory pool objects themselves. This also inserts destruction code.
// This fills in the PoolDescs map to associate the alloc node with the
// allocation of the memory pool corresponding to it.
//
map<DSNode*, PoolInfo> PoolDescs;
CreatePools(F, Allocs, PoolDescs);
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "Transformed Entry Function: \n" << F;
#endif
// Now we need to figure out what called functions we need to transform, and
// how. To do this, we look at all of the scalars, seeing which functions are
// either used as a scalar value (so they return a data structure), or are
// passed one of our scalar values.
//
transformFunctionBody(F, IPGraph, PoolDescs);
return true;
}
//===----------------------------------------------------------------------===//
//
// NewInstructionCreator - This class is used to traverse the function being
// modified, changing each instruction visit'ed to use and provide pointer
// indexes instead of real pointers. This is what changes the body of a
// function to use pool allocation.
//
class NewInstructionCreator : public InstVisitor<NewInstructionCreator> {
PoolAllocate &PoolAllocator;
vector<ScalarInfo> &Scalars;
map<CallInst*, TransformFunctionInfo> &CallMap;
map<Value*, Value*> &XFormMap; // Map old pointers to new indexes
struct RefToUpdate {
Instruction *I; // Instruction to update
unsigned OpNum; // Operand number to update
Value *OldVal; // The old value it had
RefToUpdate(Instruction *i, unsigned o, Value *ov)
: I(i), OpNum(o), OldVal(ov) {}
};
vector<RefToUpdate> ReferencesToUpdate;
const ScalarInfo &getScalarRef(const Value *V) {
for (unsigned i = 0, e = Scalars.size(); i != e; ++i)
if (Scalars[i].Val == V) return Scalars[i];
cerr << "Could not find scalar " << V << " in scalar map!\n";
assert(0 && "Scalar not found in getScalar!");
abort();
return Scalars[0];
}
const ScalarInfo *getScalar(const Value *V) {
for (unsigned i = 0, e = Scalars.size(); i != e; ++i)
if (Scalars[i].Val == V) return &Scalars[i];
return 0;
}
BasicBlock::iterator ReplaceInstWith(Instruction &I, Instruction *New) {
BasicBlock *BB = I.getParent();
BasicBlock::iterator RI = &I;
BB->getInstList().remove(RI);
BB->getInstList().insert(RI, New);
XFormMap[&I] = New;
return New;
}
Instruction *createPoolBaseInstruction(Value *PtrVal) {
const ScalarInfo &SC = getScalarRef(PtrVal);
vector<Value*> Args(3);
Args[0] = ConstantUInt::get(Type::UIntTy, 0); // No pointer offset
Args[1] = ConstantUInt::get(Type::UByteTy, 0); // Field #0 of pool descriptr
Args[2] = ConstantUInt::get(Type::UByteTy, 0); // Field #0 of poolalloc val
return new LoadInst(SC.Pool.Handle, Args, PtrVal->getName()+".poolbase");
}
public:
NewInstructionCreator(PoolAllocate &PA, vector<ScalarInfo> &S,
map<CallInst*, TransformFunctionInfo> &C,
map<Value*, Value*> &X)
: PoolAllocator(PA), Scalars(S), CallMap(C), XFormMap(X) {}
// updateReferences - The NewInstructionCreator is responsible for creating
// new instructions to replace the old ones in the function, and then link up
// references to values to their new values. For it to do this, however, it
// keeps track of information about the value mapping of old values to new
// values that need to be patched up. Given this value map and a set of
// instruction operands to patch, updateReferences performs the updates.
//
void updateReferences() {
for (unsigned i = 0, e = ReferencesToUpdate.size(); i != e; ++i) {
RefToUpdate &Ref = ReferencesToUpdate[i];
Value *NewVal = XFormMap[Ref.OldVal];
if (NewVal == 0) {
if (isa<Constant>(Ref.OldVal) && // Refering to a null ptr?
cast<Constant>(Ref.OldVal)->isNullValue()) {
// Transform the null pointer into a null index... caching in XFormMap
XFormMap[Ref.OldVal] = NewVal = Constant::getNullValue(POINTERTYPE);
//} else if (isa<Argument>(Ref.OldVal)) {
} else {
cerr << "Unknown reference to: " << Ref.OldVal << "\n";
assert(XFormMap[Ref.OldVal] &&
"Reference to value that was not updated found!");
}
}
Ref.I->setOperand(Ref.OpNum, NewVal);
}
ReferencesToUpdate.clear();
}
//===--------------------------------------------------------------------===//
// Transformation methods:
// These methods specify how each type of instruction is transformed by the
// NewInstructionCreator instance...
//===--------------------------------------------------------------------===//
void visitGetElementPtrInst(GetElementPtrInst &I) {
assert(0 && "Cannot transform get element ptr instructions yet!");
}
// Replace the load instruction with a new one.
void visitLoadInst(LoadInst &I) {
vector<Instruction *> BeforeInsts;
// Cast our index to be a UIntTy so we can use it to index into the pool...
CastInst *Index = new CastInst(Constant::getNullValue(POINTERTYPE),
Type::UIntTy, I.getOperand(0)->getName());
BeforeInsts.push_back(Index);
ReferencesToUpdate.push_back(RefToUpdate(Index, 0, I.getOperand(0)));
// Include the pool base instruction...
Instruction *PoolBase = createPoolBaseInstruction(I.getOperand(0));
BeforeInsts.push_back(PoolBase);
Instruction *IdxInst =
BinaryOperator::create(Instruction::Add, *I.idx_begin(), Index,
I.getName()+".idx");
BeforeInsts.push_back(IdxInst);
vector<Value*> Indices(I.idx_begin(), I.idx_end());
Indices[0] = IdxInst;
Instruction *Address = new GetElementPtrInst(PoolBase, Indices,
I.getName()+".addr");
BeforeInsts.push_back(Address);
Instruction *NewLoad = new LoadInst(Address, I.getName());
// Replace the load instruction with the new load instruction...
BasicBlock::iterator II = ReplaceInstWith(I, NewLoad);
// Add all of the instructions before the load...
NewLoad->getParent()->getInstList().insert(II, BeforeInsts.begin(),
BeforeInsts.end());
// If not yielding a pool allocated pointer, use the new load value as the
// value in the program instead of the old load value...
//
if (!getScalar(&I))
I.replaceAllUsesWith(NewLoad);
}
// Replace the store instruction with a new one. In the store instruction,
// the value stored could be a pointer type, meaning that the new store may
// have to change one or both of it's operands.
//
void visitStoreInst(StoreInst &I) {
assert(getScalar(I.getOperand(1)) &&
"Store inst found only storing pool allocated pointer. "
"Not imp yet!");
Value *Val = I.getOperand(0); // The value to store...
// Check to see if the value we are storing is a data structure pointer...
//if (const ScalarInfo *ValScalar = getScalar(I.getOperand(0)))
if (isa<PointerType>(I.getOperand(0)->getType()))
Val = Constant::getNullValue(POINTERTYPE); // Yes, store a dummy
Instruction *PoolBase = createPoolBaseInstruction(I.getOperand(1));
// Cast our index to be a UIntTy so we can use it to index into the pool...
CastInst *Index = new CastInst(Constant::getNullValue(POINTERTYPE),
Type::UIntTy, I.getOperand(1)->getName());
ReferencesToUpdate.push_back(RefToUpdate(Index, 0, I.getOperand(1)));
// Instructions to add after the Index...
vector<Instruction*> AfterInsts;
Instruction *IdxInst =
BinaryOperator::create(Instruction::Add, *I.idx_begin(), Index, "idx");
AfterInsts.push_back(IdxInst);
vector<Value*> Indices(I.idx_begin(), I.idx_end());
Indices[0] = IdxInst;
Instruction *Address = new GetElementPtrInst(PoolBase, Indices,
I.getName()+"storeaddr");
AfterInsts.push_back(Address);
Instruction *NewStore = new StoreInst(Val, Address);
AfterInsts.push_back(NewStore);
if (Val != I.getOperand(0)) // Value stored was a pointer?
ReferencesToUpdate.push_back(RefToUpdate(NewStore, 0, I.getOperand(0)));
// Replace the store instruction with the cast instruction...
BasicBlock::iterator II = ReplaceInstWith(I, Index);
// Add the pool base calculator instruction before the index...
II = ++Index->getParent()->getInstList().insert(II, PoolBase);
++II;
// Add the instructions that go after the index...
Index->getParent()->getInstList().insert(II, AfterInsts.begin(),
AfterInsts.end());
}
// Create call to poolalloc for every malloc instruction
void visitMallocInst(MallocInst &I) {
const ScalarInfo &SCI = getScalarRef(&I);
vector<Value*> Args;
CallInst *Call;
if (!I.isArrayAllocation()) {
Args.push_back(SCI.Pool.Handle);
Call = new CallInst(PoolAllocator.PoolAlloc, Args, I.getName());
} else {
Args.push_back(I.getArraySize());
Args.push_back(SCI.Pool.Handle);
Call = new CallInst(PoolAllocator.PoolAllocArray, Args, I.getName());
}
ReplaceInstWith(I, Call);
}
// Convert a call to poolfree for every free instruction...
void visitFreeInst(FreeInst &I) {
// Create a new call to poolfree before the free instruction
vector<Value*> Args;
Args.push_back(Constant::getNullValue(POINTERTYPE));
Args.push_back(getScalarRef(I.getOperand(0)).Pool.Handle);
Instruction *NewCall = new CallInst(PoolAllocator.PoolFree, Args);
ReplaceInstWith(I, NewCall);
ReferencesToUpdate.push_back(RefToUpdate(NewCall, 1, I.getOperand(0)));
}
// visitCallInst - Create a new call instruction with the extra arguments for
// all of the memory pools that the call needs.
//
void visitCallInst(CallInst &I) {
TransformFunctionInfo &TI = CallMap[&I];
// Start with all of the old arguments...
vector<Value*> Args(I.op_begin()+1, I.op_end());
for (unsigned i = 0, e = TI.ArgInfo.size(); i != e; ++i) {
// Replace all of the pointer arguments with our new pointer typed values.
if (TI.ArgInfo[i].ArgNo != -1)
Args[TI.ArgInfo[i].ArgNo] = Constant::getNullValue(POINTERTYPE);
// Add all of the pool arguments...
Args.push_back(TI.ArgInfo[i].PoolHandle);
}
Function *NF = PoolAllocator.getTransformedFunction(TI);
Instruction *NewCall = new CallInst(NF, Args, I.getName());
ReplaceInstWith(I, NewCall);
// Keep track of the mapping of operands so that we can resolve them to real
// values later.
Value *RetVal = NewCall;
for (unsigned i = 0, e = TI.ArgInfo.size(); i != e; ++i)
if (TI.ArgInfo[i].ArgNo != -1)
ReferencesToUpdate.push_back(RefToUpdate(NewCall, TI.ArgInfo[i].ArgNo+1,
I.getOperand(TI.ArgInfo[i].ArgNo+1)));
else
RetVal = 0; // If returning a pointer, don't change retval...
// If not returning a pointer, use the new call as the value in the program
// instead of the old call...
//
if (RetVal)
I.replaceAllUsesWith(RetVal);
}
// visitPHINode - Create a new PHI node of POINTERTYPE for all of the old Phi
// nodes...
//
void visitPHINode(PHINode &PN) {
Value *DummyVal = Constant::getNullValue(POINTERTYPE);
PHINode *NewPhi = new PHINode(POINTERTYPE, PN.getName());
for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
NewPhi->addIncoming(DummyVal, PN.getIncomingBlock(i));
ReferencesToUpdate.push_back(RefToUpdate(NewPhi, i*2,
PN.getIncomingValue(i)));
}
ReplaceInstWith(PN, NewPhi);
}
// visitReturnInst - Replace ret instruction with a new return...
void visitReturnInst(ReturnInst &I) {
Instruction *Ret = new ReturnInst(Constant::getNullValue(POINTERTYPE));
ReplaceInstWith(I, Ret);
ReferencesToUpdate.push_back(RefToUpdate(Ret, 0, I.getOperand(0)));
}
// visitSetCondInst - Replace a conditional test instruction with a new one
void visitSetCondInst(SetCondInst &SCI) {
BinaryOperator &I = (BinaryOperator&)SCI;
Value *DummyVal = Constant::getNullValue(POINTERTYPE);
BinaryOperator *New = BinaryOperator::create(I.getOpcode(), DummyVal,
DummyVal, I.getName());
ReplaceInstWith(I, New);
ReferencesToUpdate.push_back(RefToUpdate(New, 0, I.getOperand(0)));
ReferencesToUpdate.push_back(RefToUpdate(New, 1, I.getOperand(1)));
// Make sure branches refer to the new condition...
I.replaceAllUsesWith(New);
}
void visitInstruction(Instruction &I) {
cerr << "Unknown instruction to FunctionBodyTransformer:\n" << I;
}
};
// PoolBaseLoadEliminator - Every load and store through a pool allocated
// pointer causes a load of the real pool base out of the pool descriptor.
// Iterate through the function, doing a local elimination pass of duplicate
// loads. This attempts to turn the all too common:
//
// %reg109.poolbase22 = load %root.pool* %root.pool, uint 0, ubyte 0, ubyte 0
// %reg207 = load %root.p* %reg109.poolbase22, uint %reg109, ubyte 0, ubyte 0
// %reg109.poolbase23 = load %root.pool* %root.pool, uint 0, ubyte 0, ubyte 0
// store double %reg207, %root.p* %reg109.poolbase23, uint %reg109, ...
//
// into:
// %reg109.poolbase22 = load %root.pool* %root.pool, uint 0, ubyte 0, ubyte 0
// %reg207 = load %root.p* %reg109.poolbase22, uint %reg109, ubyte 0, ubyte 0
// store double %reg207, %root.p* %reg109.poolbase22, uint %reg109, ...
//
//
class PoolBaseLoadEliminator : public InstVisitor<PoolBaseLoadEliminator> {
// PoolDescValues - Keep track of the values in the current function that are
// pool descriptors (loads from which we want to eliminate).
//
vector<Value*> PoolDescValues;
// PoolDescMap - As we are analyzing a BB, keep track of which load to use
// when referencing a pool descriptor.
//
map<Value*, LoadInst*> PoolDescMap;
// These two fields keep track of statistics of how effective we are, if
// debugging is enabled.
//
unsigned Eliminated, Remaining;
public:
// Compact the pool descriptor map into a list of the pool descriptors in the
// current context that we should know about...
//
PoolBaseLoadEliminator(const map<DSNode*, PoolInfo> &PoolDescs) {
Eliminated = Remaining = 0;
for (map<DSNode*, PoolInfo>::const_iterator I = PoolDescs.begin(),
E = PoolDescs.end(); I != E; ++I)
PoolDescValues.push_back(I->second.Handle);
// Remove duplicates from the list of pool values
sort(PoolDescValues.begin(), PoolDescValues.end());
PoolDescValues.erase(unique(PoolDescValues.begin(), PoolDescValues.end()),
PoolDescValues.end());
}
#ifdef DEBUG_POOLBASE_LOAD_ELIMINATOR
void visitFunction(Function &F) {
cerr << "Pool Load Elim '" << F.getName() << "'\t";
}
~PoolBaseLoadEliminator() {
unsigned Total = Eliminated+Remaining;
if (Total)
cerr << "removed " << Eliminated << "["
<< Eliminated*100/Total << "%] loads, leaving "
<< Remaining << ".\n";
}
#endif
// Loop over the function, looking for loads to eliminate. Because we are a
// local transformation, we reset all of our state when we enter a new basic
// block.
//
void visitBasicBlock(BasicBlock &) {
PoolDescMap.clear(); // Forget state.
}
// Starting with an empty basic block, we scan it looking for loads of the
// pool descriptor. When we find a load, we add it to the PoolDescMap,
// indicating that we have a value available to recycle next time we see the
// poolbase of this instruction being loaded.
//
void visitLoadInst(LoadInst &LI) {
Value *LoadAddr = LI.getPointerOperand();
map<Value*, LoadInst*>::iterator VIt = PoolDescMap.find(LoadAddr);
if (VIt != PoolDescMap.end()) { // We already have a value for this load?
LI.replaceAllUsesWith(VIt->second); // Make the current load dead
++Eliminated;
} else {
// This load might not be a load of a pool pointer, check to see if it is
if (LI.getNumOperands() == 4 && // load pool, uint 0, ubyte 0, ubyte 0
find(PoolDescValues.begin(), PoolDescValues.end(), LoadAddr) !=
PoolDescValues.end()) {
assert("Make sure it's a load of the pool base, not a chaining field" &&
LI.getOperand(1) == Constant::getNullValue(Type::UIntTy) &&
LI.getOperand(2) == Constant::getNullValue(Type::UByteTy) &&
LI.getOperand(3) == Constant::getNullValue(Type::UByteTy));
// If it is a load of a pool base, keep track of it for future reference
PoolDescMap.insert(make_pair(LoadAddr, &LI));
++Remaining;
}
}
}
// If we run across a function call, forget all state... Calls to
// poolalloc/poolfree can invalidate the pool base pointer, so it should be
// reloaded the next time it is used. Furthermore, a call to a random
// function might call one of these functions, so be conservative. Through
// more analysis, this could be improved in the future.
//
void visitCallInst(CallInst &) {
PoolDescMap.clear();
}
};
static void addNodeMapping(DSNode *SrcNode, const PointerValSet &PVS,
map<DSNode*, PointerValSet> &NodeMapping) {
for (unsigned i = 0, e = PVS.size(); i != e; ++i)
if (NodeMapping[SrcNode].add(PVS[i])) { // Not in map yet?
assert(PVS[i].Index == 0 && "Node indexing not supported yet!");
DSNode *DestNode = PVS[i].Node;
// Loop over all of the outgoing links in the mapped graph
for (unsigned l = 0, le = DestNode->getNumOutgoingLinks(); l != le; ++l) {
PointerValSet &SrcSet = SrcNode->getOutgoingLink(l);
const PointerValSet &DestSet = DestNode->getOutgoingLink(l);
// Add all of the node mappings now!
for (unsigned si = 0, se = SrcSet.size(); si != se; ++si) {
assert(SrcSet[si].Index == 0 && "Can't handle node offset!");
addNodeMapping(SrcSet[si].Node, DestSet, NodeMapping);
}
}
}
}
// CalculateNodeMapping - There is a partial isomorphism between the graph
// passed in and the graph that is actually used by the function. We need to
// figure out what this mapping is so that we can transformFunctionBody the
// instructions in the function itself. Note that every node in the graph that
// we are interested in must be both in the local graph of the called function,
// and in the local graph of the calling function. Because of this, we only
// define the mapping for these nodes [conveniently these are the only nodes we
// CAN define a mapping for...]
//
// The roots of the graph that we are transforming is rooted in the arguments
// passed into the function from the caller. This is where we start our
// mapping calculation.
//
// The NodeMapping calculated maps from the callers graph to the called graph.
//
static void CalculateNodeMapping(Function *F, TransformFunctionInfo &TFI,
FunctionDSGraph &CallerGraph,
FunctionDSGraph &CalledGraph,
map<DSNode*, PointerValSet> &NodeMapping) {
int LastArgNo = -2;
for (unsigned i = 0, e = TFI.ArgInfo.size(); i != e; ++i) {
// Figure out what nodes in the called graph the TFI.ArgInfo[i].Node node
// corresponds to...
//
// Only consider first node of sequence. Extra nodes may may be added
// to the TFI if the data structure requires more nodes than just the
// one the argument points to. We are only interested in the one the
// argument points to though.
//
if (TFI.ArgInfo[i].ArgNo != LastArgNo) {
if (TFI.ArgInfo[i].ArgNo == -1) {
addNodeMapping(TFI.ArgInfo[i].Node, CalledGraph.getRetNodes(),
NodeMapping);
} else {
// Figure out which node argument # ArgNo points to in the called graph.
Function::aiterator AI = F->abegin();
std::advance(AI, TFI.ArgInfo[i].ArgNo);
addNodeMapping(TFI.ArgInfo[i].Node, CalledGraph.getValueMap()[AI],
NodeMapping);
}
LastArgNo = TFI.ArgInfo[i].ArgNo;
}
}
}
// addCallInfo - For a specified function call CI, figure out which pool
// descriptors need to be passed in as arguments, and which arguments need to be
// transformed into indices. If Arg != -1, the specified call argument is
// passed in as a pointer to a data structure.
//
void TransformFunctionInfo::addCallInfo(DataStructure *DS, CallInst *CI,
int Arg, DSNode *GraphNode,
map<DSNode*, PoolInfo> &PoolDescs) {
assert(CI->getCalledFunction() && "Cannot handle indirect calls yet!");
assert(Func == 0 || Func == CI->getCalledFunction() &&
"Function call record should always call the same function!");
assert(Call == 0 || Call == CI &&
"Call element already filled in with different value!");
Func = CI->getCalledFunction();
Call = CI;
//FunctionDSGraph &CalledGraph = DS->getClosedDSGraph(Func);
// For now, add the entire graph that is pointed to by the call argument.
// This graph can and should be pruned to only what the function itself will
// use, because often this will be a dramatically smaller subset of what we
// are providing.
//
// FIXME: This should use pool links instead of extra arguments!
//
for (df_iterator<DSNode*> I = df_begin(GraphNode), E = df_end(GraphNode);
I != E; ++I)
ArgInfo.push_back(CallArgInfo(Arg, *I, PoolDescs[*I].Handle));
}
static void markReachableNodes(const PointerValSet &Vals,
set<DSNode*> &ReachableNodes) {
for (unsigned n = 0, ne = Vals.size(); n != ne; ++n) {
DSNode *N = Vals[n].Node;
if (ReachableNodes.count(N) == 0) // Haven't already processed node?
ReachableNodes.insert(df_begin(N), df_end(N)); // Insert all
}
}
// Make sure that all dependant arguments are added to this transformation info.
// For example, if we call foo(null, P) and foo treats it's first and second
// arguments as belonging to the same data structure, the we MUST add entries to
// know that the null needs to be transformed into an index as well.
//
void TransformFunctionInfo::ensureDependantArgumentsIncluded(DataStructure *DS,
map<DSNode*, PoolInfo> &PoolDescs) {
// FIXME: This does not work for indirect function calls!!!
if (Func == 0) return; // FIXME!
// Make sure argument entries are sorted.
finalizeConstruction();
// Loop over the function signature, checking to see if there are any pointer
// arguments that we do not convert... if there is something we haven't
// converted, set done to false.
//
unsigned PtrNo = 0;
bool Done = true;
if (isa<PointerType>(Func->getReturnType())) // Make sure we convert retval
if (PtrNo < ArgInfo.size() && ArgInfo[PtrNo++].ArgNo == -1) {
// We DO transform the ret val... skip all possible entries for retval
while (PtrNo < ArgInfo.size() && ArgInfo[PtrNo].ArgNo == -1)
PtrNo++;
} else {
Done = false;
}
unsigned i = 0;
for (Function::aiterator I = Func->abegin(), E = Func->aend(); I!=E; ++I,++i){
if (isa<PointerType>(I->getType())) {
if (PtrNo < ArgInfo.size() && ArgInfo[PtrNo++].ArgNo == (int)i) {
// We DO transform this arg... skip all possible entries for argument
while (PtrNo < ArgInfo.size() && ArgInfo[PtrNo].ArgNo == (int)i)
PtrNo++;
} else {
Done = false;
break;
}
}
}
// If we already have entries for all pointer arguments and retvals, there
// certainly is no work to do. Bail out early to avoid building relatively
// expensive data structures.
//
if (Done) return;
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "Must ensure dependant arguments for: " << Func->getName() << "\n";
#endif
// Otherwise, we MIGHT have to add the arguments/retval if they are part of
// the same datastructure graph as some other argument or retval that we ARE
// processing.
//
// Get the data structure graph for the called function.
//
FunctionDSGraph &CalledDS = DS->getClosedDSGraph(Func);
// Build a mapping between the nodes in our current graph and the nodes in the
// called function's graph. We build it based on our _incomplete_
// transformation information, because it contains all of the info that we
// should need.
//
map<DSNode*, PointerValSet> NodeMapping;
CalculateNodeMapping(Func, *this,
DS->getClosedDSGraph(Call->getParent()->getParent()),
CalledDS, NodeMapping);
// Build the inverted version of the node mapping, that maps from a node in
// the called functions graph to a single node in the caller graph.
//
map<DSNode*, DSNode*> InverseNodeMap;
for (map<DSNode*, PointerValSet>::iterator I = NodeMapping.begin(),
E = NodeMapping.end(); I != E; ++I) {
PointerValSet &CalledNodes = I->second;
for (unsigned i = 0, e = CalledNodes.size(); i != e; ++i)
InverseNodeMap[CalledNodes[i].Node] = I->first;
}
NodeMapping.clear(); // Done with information, free memory
// Build a set of reachable nodes from the arguments/retval that we ARE
// passing in...
set<DSNode*> ReachableNodes;
// Loop through all of the arguments, marking all of the reachable data
// structure nodes reachable if they are from this pointer...
//
for (unsigned i = 0, e = ArgInfo.size(); i != e; ++i) {
if (ArgInfo[i].ArgNo == -1) {
if (i == 0) // Only process retvals once (performance opt)
markReachableNodes(CalledDS.getRetNodes(), ReachableNodes);
} else { // If it's an argument value...
Function::aiterator AI = Func->abegin();
std::advance(AI, ArgInfo[i].ArgNo);
if (isa<PointerType>(AI->getType()))
markReachableNodes(CalledDS.getValueMap()[AI], ReachableNodes);
}
}
// Now that we know which nodes are already reachable, see if any of the
// arguments that we are not passing values in for can reach one of the
// existing nodes...
//
// <FIXME> IN THEORY, we should allow arbitrary paths from the argument to
// nodes we know about. The problem is that if we do this, then I don't know
// how to get pool pointers for this head list. Since we are completely
// deadline driven, I'll just allow direct accesses to the graph. </FIXME>
//
PtrNo = 0;
if (isa<PointerType>(Func->getReturnType())) // Make sure we convert retval
if (PtrNo < ArgInfo.size() && ArgInfo[PtrNo++].ArgNo == -1) {
// We DO transform the ret val... skip all possible entries for retval
while (PtrNo < ArgInfo.size() && ArgInfo[PtrNo].ArgNo == -1)
PtrNo++;
} else {
// See what the return value points to...
// FIXME: This should generalize to any number of nodes, just see if any
// are reachable.
assert(CalledDS.getRetNodes().size() == 1 &&
"Assumes only one node is returned");
DSNode *N = CalledDS.getRetNodes()[0].Node;
// If the return value is not marked as being passed in, but it NEEDS to
// be transformed, then make it known now.
//
if (ReachableNodes.count(N)) {
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "ensure dependant arguments adds return value entry!\n";
#endif
addCallInfo(DS, Call, -1, InverseNodeMap[N], PoolDescs);
// Keep sorted!
finalizeConstruction();
}
}
i = 0;
for (Function::aiterator I = Func->abegin(), E = Func->aend(); I!=E; ++I, ++i)
if (isa<PointerType>(I->getType())) {
if (PtrNo < ArgInfo.size() && ArgInfo[PtrNo++].ArgNo == (int)i) {
// We DO transform this arg... skip all possible entries for argument
while (PtrNo < ArgInfo.size() && ArgInfo[PtrNo].ArgNo == (int)i)
PtrNo++;
} else {
// This should generalize to any number of nodes, just see if any are
// reachable.
assert(CalledDS.getValueMap()[I].size() == 1 &&
"Only handle case where pointing to one node so far!");
// If the arg is not marked as being passed in, but it NEEDS to
// be transformed, then make it known now.
//
DSNode *N = CalledDS.getValueMap()[I][0].Node;
if (ReachableNodes.count(N)) {
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "ensure dependant arguments adds for arg #" << i << "\n";
#endif
addCallInfo(DS, Call, i, InverseNodeMap[N], PoolDescs);
// Keep sorted!
finalizeConstruction();
}
}
}
}
// transformFunctionBody - This transforms the instruction in 'F' to use the
// pools specified in PoolDescs when modifying data structure nodes specified in
// the PoolDescs map. Specifically, scalar values specified in the Scalars
// vector must be remapped. IPFGraph is the closed data structure graph for F,
// of which the PoolDescriptor nodes come from.
//
void PoolAllocate::transformFunctionBody(Function *F, FunctionDSGraph &IPFGraph,
map<DSNode*, PoolInfo> &PoolDescs) {
// Loop through the value map looking for scalars that refer to nonescaping
// allocations. Add them to the Scalars vector. Note that we may have
// multiple entries in the Scalars vector for each value if it points to more
// than one object.
//
map<Value*, PointerValSet> &ValMap = IPFGraph.getValueMap();
vector<ScalarInfo> Scalars;
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "Building scalar map for fn '" << F->getName() << "' body:\n";
#endif
for (map<Value*, PointerValSet>::iterator I = ValMap.begin(),
E = ValMap.end(); I != E; ++I) {
const PointerValSet &PVS = I->second; // Set of things pointed to by scalar
// Check to see if the scalar points to a data structure node...
for (unsigned i = 0, e = PVS.size(); i != e; ++i) {
if (PVS[i].Index) { cerr << "Problem in " << F->getName() << " for " << I->first << "\n"; }
assert(PVS[i].Index == 0 && "Nonzero not handled yet!");
// If the allocation is in the nonescaping set...
map<DSNode*, PoolInfo>::iterator AI = PoolDescs.find(PVS[i].Node);
if (AI != PoolDescs.end()) { // Add it to the list of scalars
Scalars.push_back(ScalarInfo(I->first, AI->second));
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "\nScalar Mapping from:" << I->first
<< "Scalar Mapping to: "; PVS.print(cerr);
#endif
}
}
}
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "\nIn '" << F->getName()
<< "': Found the following values that point to poolable nodes:\n";
for (unsigned i = 0, e = Scalars.size(); i != e; ++i)
cerr << Scalars[i].Val;
cerr << "\n";
#endif
// CallMap - Contain an entry for every call instruction that needs to be
// transformed. Each entry in the map contains information about what we need
// to do to each call site to change it to work.
//
map<CallInst*, TransformFunctionInfo> CallMap;
// Now we need to figure out what called functions we need to transform, and
// how. To do this, we look at all of the scalars, seeing which functions are
// either used as a scalar value (so they return a data structure), or are
// passed one of our scalar values.
//
for (unsigned i = 0, e = Scalars.size(); i != e; ++i) {
Value *ScalarVal = Scalars[i].Val;
// Check to see if the scalar _IS_ a call...
if (CallInst *CI = dyn_cast<CallInst>(ScalarVal))
// If so, add information about the pool it will be returning...
CallMap[CI].addCallInfo(DS, CI, -1, Scalars[i].Pool.Node, PoolDescs);
// Check to see if the scalar is an operand to a call...
for (Value::use_iterator UI = ScalarVal->use_begin(),
UE = ScalarVal->use_end(); UI != UE; ++UI) {
if (CallInst *CI = dyn_cast<CallInst>(*UI)) {
// Find out which operand this is to the call instruction...
User::op_iterator OI = find(CI->op_begin(), CI->op_end(), ScalarVal);
assert(OI != CI->op_end() && "Call on use list but not an operand!?");
assert(OI != CI->op_begin() && "Pointer operand is call destination?");
// FIXME: This is broken if the same pointer is passed to a call more
// than once! It will get multiple entries for the first pointer.
// Add the operand number and pool handle to the call table...
CallMap[CI].addCallInfo(DS, CI, OI-CI->op_begin()-1,
Scalars[i].Pool.Node, PoolDescs);
}
}
}
// Make sure that all dependant arguments are added as well. For example, if
// we call foo(null, P) and foo treats it's first and second arguments as
// belonging to the same data structure, the we MUST set up the CallMap to
// know that the null needs to be transformed into an index as well.
//
for (map<CallInst*, TransformFunctionInfo>::iterator I = CallMap.begin();
I != CallMap.end(); ++I)
I->second.ensureDependantArgumentsIncluded(DS, PoolDescs);
#ifdef DEBUG_TRANSFORM_PROGRESS
// Print out call map...
for (map<CallInst*, TransformFunctionInfo>::iterator I = CallMap.begin();
I != CallMap.end(); ++I) {
cerr << "For call: " << I->first;
cerr << I->second.Func->getName() << " must pass pool pointer for args #";
for (unsigned i = 0; i < I->second.ArgInfo.size(); ++i)
cerr << I->second.ArgInfo[i].ArgNo << ", ";
cerr << "\n\n";
}
#endif
// Loop through all of the call nodes, recursively creating the new functions
// that we want to call... This uses a map to prevent infinite recursion and
// to avoid duplicating functions unneccesarily.
//
for (map<CallInst*, TransformFunctionInfo>::iterator I = CallMap.begin(),
E = CallMap.end(); I != E; ++I) {
// Transform all of the functions we need, or at least ensure there is a
// cached version available.
transformFunction(I->second, IPFGraph, PoolDescs);
}
// Now that all of the functions that we want to call are available, transform
// the local function so that it uses the pools locally and passes them to the
// functions that we just hacked up.
//
// First step, find the instructions to be modified.
vector<Instruction*> InstToFix;
for (unsigned i = 0, e = Scalars.size(); i != e; ++i) {
Value *ScalarVal = Scalars[i].Val;
// Check to see if the scalar _IS_ an instruction. If so, it is involved.
if (Instruction *Inst = dyn_cast<Instruction>(ScalarVal))
InstToFix.push_back(Inst);
// All all of the instructions that use the scalar as an operand...
for (Value::use_iterator UI = ScalarVal->use_begin(),
UE = ScalarVal->use_end(); UI != UE; ++UI)
InstToFix.push_back(cast<Instruction>(*UI));
}
// Make sure that we get return instructions that return a null value from the
// function...
//
if (!IPFGraph.getRetNodes().empty()) {
assert(IPFGraph.getRetNodes().size() == 1 && "Can only return one node?");
PointerVal RetNode = IPFGraph.getRetNodes()[0];
assert(RetNode.Index == 0 && "Subindexing not implemented yet!");
// Only process return instructions if the return value of this function is
// part of one of the data structures we are transforming...
//
if (PoolDescs.count(RetNode.Node)) {
// Loop over all of the basic blocks, adding return instructions...
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator()))
InstToFix.push_back(RI);
}
}
// Eliminate duplicates by sorting, then removing equal neighbors.
sort(InstToFix.begin(), InstToFix.end());
InstToFix.erase(unique(InstToFix.begin(), InstToFix.end()), InstToFix.end());
// Loop over all of the instructions to transform, creating the new
// replacement instructions for them. This also unlinks them from the
// function so they can be safely deleted later.
//
map<Value*, Value*> XFormMap;
NewInstructionCreator NIC(*this, Scalars, CallMap, XFormMap);
// Visit all instructions... creating the new instructions that we need and
// unlinking the old instructions from the function...
//
#ifdef DEBUG_TRANSFORM_PROGRESS
for (unsigned i = 0, e = InstToFix.size(); i != e; ++i) {
cerr << "Fixing: " << InstToFix[i];
NIC.visit(*InstToFix[i]);
}
#else
NIC.visit(InstToFix.begin(), InstToFix.end());
#endif
// Make all instructions we will delete "let go" of their operands... so that
// we can safely delete Arguments whose types have changed...
//
for_each(InstToFix.begin(), InstToFix.end(),
mem_fun(&Instruction::dropAllReferences));
// Loop through all of the pointer arguments coming into the function,
// replacing them with arguments of POINTERTYPE to match the function type of
// the function.
//
FunctionType::ParamTypes::const_iterator TI =
F->getFunctionType()->getParamTypes().begin();
for (Function::aiterator I = F->abegin(), E = F->aend(); I != E; ++I, ++TI) {
if (I->getType() != *TI) {
assert(isa<PointerType>(I->getType()) && *TI == POINTERTYPE);
Argument *NewArg = new Argument(*TI, I->getName());
XFormMap[I] = NewArg; // Map old arg into new arg...
// Replace the old argument and then delete it...
I = F->getArgumentList().erase(I);
I = F->getArgumentList().insert(I, NewArg);
}
}
// Now that all of the new instructions have been created, we can update all
// of the references to dummy values to be references to the actual values
// that are computed.
//
NIC.updateReferences();
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "TRANSFORMED FUNCTION:\n" << F;
#endif
// Delete all of the "instructions to fix"
for_each(InstToFix.begin(), InstToFix.end(), deleter<Instruction>);
// Eliminate pool base loads that we can easily prove are redundant
if (!DisableRLE)
PoolBaseLoadEliminator(PoolDescs).visit(F);
// Since we have liberally hacked the function to pieces, we want to inform
// the datastructure pass that its internal representation is out of date.
//
DS->invalidateFunction(F);
}
// transformFunction - Transform the specified function the specified way. It
// we have already transformed that function that way, don't do anything. The
// nodes in the TransformFunctionInfo come out of callers data structure graph.
//
void PoolAllocate::transformFunction(TransformFunctionInfo &TFI,
FunctionDSGraph &CallerIPGraph,
map<DSNode*, PoolInfo> &CallerPoolDesc) {
if (getTransformedFunction(TFI)) return; // Function xformation already done?
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "********** Entering transformFunction for "
<< TFI.Func->getName() << ":\n";
for (unsigned i = 0, e = TFI.ArgInfo.size(); i != e; ++i)
cerr << " ArgInfo[" << i << "] = " << TFI.ArgInfo[i].ArgNo << "\n";
cerr << "\n";
#endif
const FunctionType *OldFuncType = TFI.Func->getFunctionType();
assert(!OldFuncType->isVarArg() && "Vararg functions not handled yet!");
// Build the type for the new function that we are transforming
vector<const Type*> ArgTys;
ArgTys.reserve(OldFuncType->getNumParams()+TFI.ArgInfo.size());
for (unsigned i = 0, e = OldFuncType->getNumParams(); i != e; ++i)
ArgTys.push_back(OldFuncType->getParamType(i));
const Type *RetType = OldFuncType->getReturnType();
// Add one pool pointer for every argument that needs to be supplemented.
for (unsigned i = 0, e = TFI.ArgInfo.size(); i != e; ++i) {
if (TFI.ArgInfo[i].ArgNo == -1)
RetType = POINTERTYPE; // Return a pointer
else
ArgTys[TFI.ArgInfo[i].ArgNo] = POINTERTYPE; // Pass a pointer
ArgTys.push_back(PointerType::get(CallerPoolDesc.find(TFI.ArgInfo[i].Node)
->second.PoolType));
}
// Build the new function type...
const FunctionType *NewFuncType = FunctionType::get(RetType, ArgTys,
OldFuncType->isVarArg());
// The new function is internal, because we know that only we can call it.
// This also helps subsequent IP transformations to eliminate duplicated pool
// pointers (which look like the same value is always passed into a parameter,
// allowing it to be easily eliminated).
//
Function *NewFunc = new Function(NewFuncType, true,
TFI.Func->getName()+".poolxform");
CurModule->getFunctionList().push_back(NewFunc);
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "Created function prototype: " << NewFunc << "\n";
#endif
// Add the newly formed function to the TransformedFunctions table so that
// infinite recursion does not occur!
//
TransformedFunctions[TFI] = NewFunc;
// Add arguments to the function... starting with all of the old arguments
vector<Value*> ArgMap;
for (Function::const_aiterator I = TFI.Func->abegin(), E = TFI.Func->aend();
I != E; ++I) {
Argument *NFA = new Argument(I->getType(), I->getName());
NewFunc->getArgumentList().push_back(NFA);
ArgMap.push_back(NFA); // Keep track of the arguments
}
// Now add all of the arguments corresponding to pools passed in...
for (unsigned i = 0, e = TFI.ArgInfo.size(); i != e; ++i) {
CallArgInfo &AI = TFI.ArgInfo[i];
string Name;
if (AI.ArgNo == -1)
Name = "ret";
else
Name = ArgMap[AI.ArgNo]->getName(); // Get the arg name
const Type *Ty = PointerType::get(CallerPoolDesc[AI.Node].PoolType);
Argument *NFA = new Argument(Ty, Name+".pool");
NewFunc->getArgumentList().push_back(NFA);
}
// Now clone the body of the old function into the new function...
CloneFunctionInto(NewFunc, TFI.Func, ArgMap);
// Okay, now we have a function that is identical to the old one, except that
// it has extra arguments for the pools coming in. Now we have to get the
// data structure graph for the function we are replacing, and figure out how
// our graph nodes map to the graph nodes in the dest function.
//
FunctionDSGraph &DSGraph = DS->getClosedDSGraph(NewFunc);
// NodeMapping - Multimap from callers graph to called graph. We are
// guaranteed that the called function graph has more nodes than the caller,
// or exactly the same number of nodes. This is because the called function
// might not know that two nodes are merged when considering the callers
// context, but the caller obviously does. Because of this, a single node in
// the calling function's data structure graph can map to multiple nodes in
// the called functions graph.
//
map<DSNode*, PointerValSet> NodeMapping;
CalculateNodeMapping(NewFunc, TFI, CallerIPGraph, DSGraph,
NodeMapping);
// Print out the node mapping...
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "\nNode mapping for call of " << NewFunc->getName() << "\n";
for (map<DSNode*, PointerValSet>::iterator I = NodeMapping.begin();
I != NodeMapping.end(); ++I) {
cerr << "Map: "; I->first->print(cerr);
cerr << "To: "; I->second.print(cerr);
cerr << "\n";
}
#endif
// Fill in the PoolDescriptor information for the transformed function so that
// it can determine which value holds the pool descriptor for each data
// structure node that it accesses.
//
map<DSNode*, PoolInfo> PoolDescs;
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "\nCalculating the pool descriptor map:\n";
#endif
// Calculate as much of the pool descriptor map as possible. Since we have
// the node mapping between the caller and callee functions, and we have the
// pool descriptor information of the caller, we can calculate a partical pool
// descriptor map for the called function.
//
// The nodes that we do not have complete information for are the ones that
// are accessed by loading pointers derived from arguments passed in, but that
// are not passed in directly. In this case, we have all of the information
// except a pool value. If the called function refers to this pool, the pool
// value will be loaded from the pool graph and added to the map as neccesary.
//
for (map<DSNode*, PointerValSet>::iterator I = NodeMapping.begin();
I != NodeMapping.end(); ++I) {
DSNode *CallerNode = I->first;
PoolInfo &CallerPI = CallerPoolDesc[CallerNode];
// Check to see if we have a node pointer passed in for this value...
Value *CalleeValue = 0;
for (unsigned a = 0, ae = TFI.ArgInfo.size(); a != ae; ++a)
if (TFI.ArgInfo[a].Node == CallerNode) {
// Calculate the argument number that the pool is to the function
// call... The call instruction should not have the pool operands added
// yet.
unsigned ArgNo = TFI.Call->getNumOperands()-1+a;
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "Should be argument #: " << ArgNo << "[i = " << a << "]\n";
#endif
assert(ArgNo < NewFunc->asize() &&
"Call already has pool arguments added??");
// Map the pool argument into the called function...
Function::aiterator AI = NewFunc->abegin();
std::advance(AI, ArgNo);
CalleeValue = AI;
break; // Found value, quit loop
}
// Loop over all of the data structure nodes that this incoming node maps to
// Creating a PoolInfo structure for them.
for (unsigned i = 0, e = I->second.size(); i != e; ++i) {
assert(I->second[i].Index == 0 && "Doesn't handle subindexing yet!");
DSNode *CalleeNode = I->second[i].Node;
// Add the descriptor. We already know everything about it by now, much
// of it is the same as the caller info.
//
PoolDescs.insert(make_pair(CalleeNode,
PoolInfo(CalleeNode, CalleeValue,
CallerPI.NewType,
CallerPI.PoolType)));
}
}
// We must destroy the node mapping so that we don't have latent references
// into the data structure graph for the new function. Otherwise we get
// assertion failures when transformFunctionBody tries to invalidate the
// graph.
//
NodeMapping.clear();
// Now that we know everything we need about the function, transform the body
// now!
//
transformFunctionBody(NewFunc, DSGraph, PoolDescs);
#ifdef DEBUG_TRANSFORM_PROGRESS
cerr << "Function after transformation:\n" << NewFunc;
#endif
}
static unsigned countPointerTypes(const Type *Ty) {
if (isa<PointerType>(Ty)) {
return 1;
} else if (const StructType *STy = dyn_cast<StructType>(Ty)) {
unsigned Num = 0;
for (unsigned i = 0, e = STy->getElementTypes().size(); i != e; ++i)
Num += countPointerTypes(STy->getElementTypes()[i]);
return Num;
} else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
return countPointerTypes(ATy->getElementType());
} else {
assert(Ty->isPrimitiveType() && "Unknown derived type!");
return 0;
}
}
// CreatePools - Insert instructions into the function we are processing to
// create all of the memory pool objects themselves. This also inserts
// destruction code. Add an alloca for each pool that is allocated to the
// PoolDescs vector.
//
void PoolAllocate::CreatePools(Function *F, const vector<AllocDSNode*> &Allocs,
map<DSNode*, PoolInfo> &PoolDescs) {
// Find all of the return nodes in the function...
vector<BasicBlock*> ReturnNodes;
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
if (isa<ReturnInst>(I->getTerminator()))
ReturnNodes.push_back(I);
#ifdef DEBUG_CREATE_POOLS
cerr << "Allocs that we are pool allocating:\n";
for (unsigned i = 0, e = Allocs.size(); i != e; ++i)
Allocs[i]->dump();
#endif
map<DSNode*, PATypeHolder> AbsPoolTyMap;
// First pass over the allocations to process...
for (unsigned i = 0, e = Allocs.size(); i != e; ++i) {
// Create the pooldescriptor mapping... with null entries for everything
// except the node & NewType fields.
//
map<DSNode*, PoolInfo>::iterator PI =
PoolDescs.insert(make_pair(Allocs[i], PoolInfo(Allocs[i]))).first;
// Add a symbol table entry for the new type if there was one for the old
// type...
string OldName = CurModule->getTypeName(Allocs[i]->getType());
if (OldName.empty()) OldName = "node";
CurModule->addTypeName(OldName+".p", PI->second.NewType);
// Create the abstract pool types that will need to be resolved in a second
// pass once an abstract type is created for each pool.
//
// Can only handle limited shapes for now...
const Type *OldNodeTy = Allocs[i]->getType();
vector<const Type*> PoolTypes;
// Pool type is the first element of the pool descriptor type...
PoolTypes.push_back(getPoolType(PoolDescs[Allocs[i]].NewType));
unsigned NumPointers = countPointerTypes(OldNodeTy);
while (NumPointers--) // Add a different opaque type for each pointer
PoolTypes.push_back(OpaqueType::get());
assert(Allocs[i]->getNumLinks() == PoolTypes.size()-1 &&
"Node should have same number of pointers as pool!");
StructType *PoolType = StructType::get(PoolTypes);
// Add a symbol table entry for the pooltype if possible...
CurModule->addTypeName(OldName+".pool", PoolType);
// Create the pool type, with opaque values for pointers...
AbsPoolTyMap.insert(make_pair(Allocs[i], PoolType));
#ifdef DEBUG_CREATE_POOLS
cerr << "POOL TY: " << AbsPoolTyMap.find(Allocs[i])->second.get() << "\n";
#endif
}
// Now that we have types for all of the pool types, link them all together.
for (unsigned i = 0, e = Allocs.size(); i != e; ++i) {
PATypeHolder &PoolTyH = AbsPoolTyMap.find(Allocs[i])->second;
// Resolve all of the outgoing pointer types of this pool node...
for (unsigned p = 0, pe = Allocs[i]->getNumLinks(); p != pe; ++p) {
PointerValSet &PVS = Allocs[i]->getLink(p);
assert(!PVS.empty() && "Outgoing edge is empty, field unused, can"
" probably just leave the type opaque or something dumb.");
unsigned Out;
for (Out = 0; AbsPoolTyMap.count(PVS[Out].Node) == 0; ++Out)
assert(Out != PVS.size() && "No edge to an outgoing allocation node!?");
assert(PVS[Out].Index == 0 && "Subindexing not implemented yet!");
// The actual struct type could change each time through the loop, so it's
// NOT loop invariant.
const StructType *PoolTy = cast<StructType>(PoolTyH.get());
// Get the opaque type...
DerivedType *ElTy = (DerivedType*)(PoolTy->getElementTypes()[p+1].get());
#ifdef DEBUG_CREATE_POOLS
cerr << "Refining " << ElTy << " of " << PoolTy << " to "
<< AbsPoolTyMap.find(PVS[Out].Node)->second.get() << "\n";
#endif
const Type *RefPoolTy = AbsPoolTyMap.find(PVS[Out].Node)->second.get();
ElTy->refineAbstractTypeTo(PointerType::get(RefPoolTy));
#ifdef DEBUG_CREATE_POOLS
cerr << "Result pool type is: " << PoolTyH.get() << "\n";
#endif
}
}
// Create the code that goes in the entry and exit nodes for the function...
vector<Instruction*> EntryNodeInsts;
for (unsigned i = 0, e = Allocs.size(); i != e; ++i) {
PoolInfo &PI = PoolDescs[Allocs[i]];
// Fill in the pool type for this pool...
PI.PoolType = AbsPoolTyMap.find(Allocs[i])->second.get();
assert(!PI.PoolType->isAbstract() &&
"Pool type should not be abstract anymore!");
// Add an allocation and a free for each pool...
AllocaInst *PoolAlloc
= new AllocaInst(PointerType::get(PI.PoolType), 0,
CurModule->getTypeName(PI.PoolType));
PI.Handle = PoolAlloc;
EntryNodeInsts.push_back(PoolAlloc);
AllocationInst *AI = Allocs[i]->getAllocation();
// Initialize the pool. We need to know how big each allocation is. For
// our purposes here, we assume we are allocating a scalar, or array of
// constant size.
//
unsigned ElSize = TargetData.getTypeSize(PI.NewType);
vector<Value*> Args;
Args.push_back(ConstantUInt::get(Type::UIntTy, ElSize));
Args.push_back(PoolAlloc); // Pool to initialize
EntryNodeInsts.push_back(new CallInst(PoolInit, Args));
// Add code to destroy the pool in all of the exit nodes of the function...
Args.clear();
Args.push_back(PoolAlloc); // Pool to initialize
for (unsigned EN = 0, ENE = ReturnNodes.size(); EN != ENE; ++EN) {
Instruction *Destroy = new CallInst(PoolDestroy, Args);
// Insert it before the return instruction...
BasicBlock *RetNode = ReturnNodes[EN];
RetNode->getInstList().insert(RetNode->end()--, Destroy);
}
}
// Now that all of the pool descriptors have been created, link them together
// so that called functions can get links as neccesary...
//
for (unsigned i = 0, e = Allocs.size(); i != e; ++i) {
PoolInfo &PI = PoolDescs[Allocs[i]];
// For every pointer in the data structure, initialize a link that
// indicates which pool to access...
//
vector<Value*> Indices(2);
Indices[0] = ConstantUInt::get(Type::UIntTy, 0);
for (unsigned l = 0, le = PI.Node->getNumLinks(); l != le; ++l)
// Only store an entry for the field if the field is used!
if (!PI.Node->getLink(l).empty()) {
assert(PI.Node->getLink(l).size() == 1 && "Should have only one link!");
PointerVal PV = PI.Node->getLink(l)[0];
assert(PV.Index == 0 && "Subindexing not supported yet!");
PoolInfo &LinkedPool = PoolDescs[PV.Node];
Indices[1] = ConstantUInt::get(Type::UByteTy, 1+l);
EntryNodeInsts.push_back(new StoreInst(LinkedPool.Handle, PI.Handle,
Indices));
}
}
// Insert the entry node code into the entry block...
F->getEntryNode().getInstList().insert(++F->getEntryNode().begin(),
EntryNodeInsts.begin(),
EntryNodeInsts.end());
}
// addPoolPrototypes - Add prototypes for the pool functions to the specified
// module and update the Pool* instance variables to point to them.
//
void PoolAllocate::addPoolPrototypes(Module &M) {
// Get poolinit function...
vector<const Type*> Args;
Args.push_back(Type::UIntTy); // Num bytes per element
FunctionType *PoolInitTy = FunctionType::get(Type::VoidTy, Args, true);
PoolInit = M.getOrInsertFunction("poolinit", PoolInitTy);
// Get pooldestroy function...
Args.pop_back(); // Only takes a pool...
FunctionType *PoolDestroyTy = FunctionType::get(Type::VoidTy, Args, true);
PoolDestroy = M.getOrInsertFunction("pooldestroy", PoolDestroyTy);
// Get the poolalloc function...
FunctionType *PoolAllocTy = FunctionType::get(POINTERTYPE, Args, true);
PoolAlloc = M.getOrInsertFunction("poolalloc", PoolAllocTy);
// Get the poolfree function...
Args.push_back(POINTERTYPE); // Pointer to free
FunctionType *PoolFreeTy = FunctionType::get(Type::VoidTy, Args, true);
PoolFree = M.getOrInsertFunction("poolfree", PoolFreeTy);
Args[0] = Type::UIntTy; // Number of slots to allocate
FunctionType *PoolAllocArrayTy = FunctionType::get(POINTERTYPE, Args, true);
PoolAllocArray = M.getOrInsertFunction("poolallocarray", PoolAllocArrayTy);
}
bool PoolAllocate::run(Module &M) {
addPoolPrototypes(M);
CurModule = &M;
DS = &getAnalysis<DataStructure>();
bool Changed = false;
for (Module::iterator I = M.begin(); I != M.end(); ++I)
if (!I->isExternal()) {
Changed |= processFunction(I);
if (Changed) {
cerr << "Only processing one function\n";
break;
}
}
CurModule = 0;
DS = 0;
return false;
}
// createPoolAllocatePass - Global function to access the functionality of this
// pass...
//
Pass *createPoolAllocatePass() { return new PoolAllocate(); }
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