#include "llvm/Transforms/LevelChange.h"
#include "TransformInternals.h"
-#include "llvm/Method.h"
-#include "llvm/Support/STLExtras.h"
+#include "llvm/Function.h"
#include "llvm/iOther.h"
#include "llvm/iMemory.h"
-#include "llvm/ConstPoolVals.h"
-#include "llvm/Optimizations/ConstantHandling.h"
-#include "llvm/Optimizations/DCE.h"
-#include "llvm/Optimizations/ConstantProp.h"
+#include "llvm/Constants.h"
+#include "llvm/Pass.h"
+#include "llvm/ConstantHandling.h"
+#include "llvm/Transforms/Scalar/DCE.h"
+#include "llvm/Transforms/Scalar/ConstantProp.h"
#include "llvm/Analysis/Expressions.h"
+#include "Support/STLExtras.h"
#include <algorithm>
-#include "llvm/Assembly/Writer.h"
-
-#define DEBUG_PEEPHOLE_INSTS 1
+//#define DEBUG_PEEPHOLE_INSTS 1
#ifdef DEBUG_PEEPHOLE_INSTS
#define PRINT_PEEPHOLE(ID, NUM, I) \
- cerr << "Inst P/H " << ID << "[" << NUM << "] " << I;
+ std::cerr << "Inst P/H " << ID << "[" << NUM << "] " << I;
#else
#define PRINT_PEEPHOLE(ID, NUM, I)
#endif
+// Peephole optimize the following instructions:
+// %t1 = cast ? to x *
+// %t2 = add x * %SP, %t1 ;; Constant must be 2nd operand
+//
+// Into: %t3 = getelementptr {<...>} * %SP, <element indices>
+// %t2 = cast <eltype> * %t3 to {<...>}*
+//
+static bool HandleCastToPointer(BasicBlock::iterator BI,
+ const PointerType *DestPTy) {
+ CastInst *CI = cast<CastInst>(*BI);
+ if (CI->use_empty()) return false;
+ // Scan all of the uses, looking for any uses that are not add
+ // instructions. If we have non-adds, do not make this transformation.
+ //
+ for (Value::use_iterator I = CI->use_begin(), E = CI->use_end();
+ I != E; ++I) {
+ if (BinaryOperator *BO = dyn_cast<BinaryOperator>(*I)) {
+ if (BO->getOpcode() != Instruction::Add)
+ return false;
+ } else {
+ return false;
+ }
+ }
+
+ std::vector<Value*> Indices;
+ Value *Src = CI->getOperand(0);
+ const Type *Result = ConvertableToGEP(DestPTy, Src, Indices, &BI);
+ if (Result == 0) return false; // Not convertable...
+
+ PRINT_PEEPHOLE2("cast-add-to-gep:in", Src, CI);
+
+ // If we have a getelementptr capability... transform all of the
+ // add instruction uses into getelementptr's.
+ while (!CI->use_empty()) {
+ BinaryOperator *I = cast<BinaryOperator>(*CI->use_begin());
+ assert(I->getOpcode() == Instruction::Add && I->getNumOperands() == 2 &&
+ "Use is not a valid add instruction!");
+
+ // Get the value added to the cast result pointer...
+ Value *OtherPtr = I->getOperand((I->getOperand(0) == CI) ? 1 : 0);
+
+ Instruction *GEP = new GetElementPtrInst(OtherPtr, Indices, I->getName());
+ PRINT_PEEPHOLE1("cast-add-to-gep:i", I);
+
+ if (GEP->getType() == I->getType()) {
+ // Replace the old add instruction with the shiny new GEP inst
+ ReplaceInstWithInst(I, GEP);
+ } else {
+ // If the type produced by the gep instruction differs from the original
+ // add instruction type, insert a cast now.
+ //
+
+ // Insert the GEP instruction before the old add instruction... and get an
+ // iterator to point at the add instruction...
+ BasicBlock::iterator GEPI = InsertInstBeforeInst(GEP, I)+1;
+
+ PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP);
+ CastInst *CI = new CastInst(GEP, I->getType());
+ GEP = CI;
+
+ // Replace the old add instruction with the shiny new GEP inst
+ ReplaceInstWithInst(I->getParent()->getInstList(), GEPI, GEP);
+ }
+
+ PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP);
+ }
+ return true;
+}
// Peephole optimize the following instructions:
// %t1 = cast ulong <const int> to {<...>} *
if (!CompTy || !SrcPtr || !OffsetVal->getType()->isIntegral())
return false;
- vector<Value*> Indices;
+ std::vector<Value*> Indices;
if (!ConvertableToGEP(SrcPtr->getType(), OffsetVal, Indices, &BI))
return false; // Not convertable... perhaps next time
PRINT_PEEPHOLE1("cast-of-self-ty", CI);
CI->replaceAllUsesWith(Src);
if (!Src->hasName() && CI->hasName()) {
- string Name = CI->getName();
+ std::string Name = CI->getName();
CI->setName("");
Src->setName(Name, BB->getParent()->getSymbolTable());
}
// Peephole optimize the following instructions:
// %tmp = cast <ty> %V to <ty2>
- // %V = cast <ty2> %tmp to <ty3> ; Where ty & ty2 are same size
+ // %V = cast <ty2> %tmp to <ty3> ; Where ty & ty2 are same size
//
// Into: cast <ty> %V to <ty3>
//
// specific type of the operands to do it's job.
if (!isReinterpretingCast(CI)) {
ValueTypeCache ConvertedTypes;
- if (ValueConvertableToType(CI, Src->getType(), ConvertedTypes)) {
- PRINT_PEEPHOLE2("CAST-DEST-EXPR-CONV:in ", Src, CI);
+ // Check to see if we can convert the users of the cast value to match the
+ // source type of the cast...
+ //
+ ConvertedTypes[CI] = CI->getType(); // Make sure the cast doesn't change
+ if (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) {
+ PRINT_PEEPHOLE3("CAST-SRC-EXPR-CONV:in ", Src, CI, BB->getParent());
+
#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\nCONVERTING EXPR TYPE:\n";
+ cerr << "\nCONVERTING SRC EXPR TYPE:\n";
#endif
ValueMapCache ValueMap;
- ConvertValueToNewType(CI, Src, ValueMap); // This will delete CI!
+ Value *E = ConvertExpressionToType(Src, DestTy, ValueMap);
+ if (Constant *CPV = dyn_cast<Constant>(E))
+ CI->replaceAllUsesWith(CPV);
BI = BB->begin(); // Rescan basic block. BI might be invalidated.
- PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", Src);
+ PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E);
#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "DONE CONVERTING EXPR TYPE: \n\n";// << BB->getParent();
+ cerr << "DONE CONVERTING SRC EXPR TYPE: \n" << BB->getParent();
#endif
return true;
- } else {
- ConvertedTypes.clear();
- if (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) {
- PRINT_PEEPHOLE2("CAST-SRC-EXPR-CONV:in ", Src, CI);
-
+ }
+
+ // Check to see if we can convert the source of the cast to match the
+ // destination type of the cast...
+ //
+ ConvertedTypes.clear();
+ if (ValueConvertableToType(CI, Src->getType(), ConvertedTypes)) {
+ PRINT_PEEPHOLE3("CAST-DEST-EXPR-CONV:in ", Src, CI, BB->getParent());
+
#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\nCONVERTING SRC EXPR TYPE:\n";
+ cerr << "\nCONVERTING EXPR TYPE:\n";
#endif
- ValueMapCache ValueMap;
- Value *E = ConvertExpressionToType(Src, DestTy, ValueMap);
- if (ConstPoolVal *CPV = dyn_cast<ConstPoolVal>(E))
- CI->replaceAllUsesWith(CPV);
+ ValueMapCache ValueMap;
+ ConvertValueToNewType(CI, Src, ValueMap); // This will delete CI!
- BI = BB->begin(); // Rescan basic block. BI might be invalidated.
- PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E);
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", Src);
#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "DONE CONVERTING SRC EXPR TYPE: \n\n";// << BB->getParent();
+ cerr << "DONE CONVERTING EXPR TYPE: \n\n" << BB->getParent();
#endif
- return true;
- }
+ return true;
+ }
+ }
+
+ // Otherwise find out it this cast is a cast to a pointer type, which is
+ // then added to some other pointer, then loaded or stored through. If
+ // so, convert the add into a getelementptr instruction...
+ //
+ if (const PointerType *DestPTy = dyn_cast<PointerType>(DestTy)) {
+ if (HandleCastToPointer(BI, DestPTy)) {
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ return true;
}
-
}
// Check to see if we are casting from a structure pointer to a pointer to
// type.
//
if (!HasAddUse) {
- const Type *DestPointedTy = DestPTy->getValueType();
+ const Type *DestPointedTy = DestPTy->getElementType();
unsigned Depth = 1;
const CompositeType *CurCTy = CTy;
const Type *ElTy = 0;
// Build the index vector, full of all zeros
- vector<Value*> Indices;
-
- while (CurCTy) {
+ std::vector<Value*> Indices;
+ Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
+ while (CurCTy && !isa<PointerType>(CurCTy)) {
if (const StructType *CurSTy = dyn_cast<StructType>(CurCTy)) {
// Check for a zero element struct type... if we have one, bail.
if (CurSTy->getElementTypes().size() == 0) break;
}
// Insert a zero to index through this type...
- Indices.push_back(ConstPoolUInt::get(CurCTy->getIndexType(), 0));
+ Indices.push_back(ConstantUInt::get(CurCTy->getIndexType(), 0));
// Did we find what we're looking for?
if (ElTy->isLosslesslyConvertableTo(DestPointedTy)) break;
Value *Val = SI->getOperand(0);
Value *Pointer = SI->getPointerOperand();
- // Peephole optimize the following instructions:
- // %t1 = getelementptr {<...>} * %StructPtr, <element indices>
- // store <elementty> %v, <elementty> * %t1
- //
- // Into: store <elementty> %v, {<...>} * %StructPtr, <element indices>
- //
- if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Pointer)) {
- // Append any indices that the store instruction has onto the end of the
- // ones that the GEP is carrying...
- //
- vector<Value*> Indices(GEP->copyIndices());
- Indices.insert(Indices.end(), SI->idx_begin(), SI->idx_end());
-
- PRINT_PEEPHOLE2("gep-store:in", GEP, SI);
- ReplaceInstWithInst(BB->getInstList(), BI,
- SI = new StoreInst(Val, GEP->getPointerOperand(),
- Indices));
- PRINT_PEEPHOLE1("gep-store:out", SI);
- return true;
- }
-
// Peephole optimize the following instructions:
// %t = cast <T1>* %P to <T2> * ;; If T1 is losslessly convertable to T2
// store <T2> %V, <T2>* %t
// %t = cast <T2> %V to <T1>
// store <T1> %t2, <T1>* %P
//
+ // Note: This is not taken care of by expr conversion because there might
+ // not be a cast available for the store to convert the incoming value of.
+ // This code is basically here to make sure that pointers don't have casts
+ // if possible.
+ //
if (CastInst *CI = dyn_cast<CastInst>(Pointer))
if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType
if (PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType()))
// convertable types?
- if (Val->getType()->isLosslesslyConvertableTo(CSPT->getValueType()) &&
+ if (Val->getType()->isLosslesslyConvertableTo(CSPT->getElementType()) &&
!SI->hasIndices()) { // No subscripts yet!
PRINT_PEEPHOLE3("st-src-cast:in ", Pointer, Val, SI);
// Insert the new T cast instruction... stealing old T's name
- CastInst *NCI = new CastInst(Val, CSPT->getValueType(),
+ CastInst *NCI = new CastInst(Val, CSPT->getElementType(),
CI->getName());
CI->setName("");
BI = BB->getInstList().insert(BI, NCI)+1;
return true;
}
-
- } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
- Value *Pointer = LI->getPointerOperand();
-
- // Peephole optimize the following instructions:
- // %t1 = getelementptr {<...>} * %StructPtr, <element indices>
- // %V = load <elementty> * %t1
- //
- // Into: load {<...>} * %StructPtr, <element indices>
- //
- if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Pointer)) {
- // Append any indices that the load instruction has onto the end of the
- // ones that the GEP is carrying...
- //
- vector<Value*> Indices(GEP->copyIndices());
- Indices.insert(Indices.end(), LI->idx_begin(), LI->idx_end());
-
- PRINT_PEEPHOLE2("gep-load:in", GEP, LI);
- ReplaceInstWithInst(BB->getInstList(), BI,
- LI = new LoadInst(GEP->getPointerOperand(),
- Indices));
- PRINT_PEEPHOLE1("gep-load:out", LI);
- return true;
- }
-
-
- // Peephole optimize the following instructions:
- // %t1 = cast <ty> * %t0 to <ty2> *
- // %V = load <ty2> * %t1
- //
- // Into: %t1 = load <ty> * %t0
- // %V = cast <ty> %t1 to <ty2>
- //
- // The idea behind this transformation is that if the expression type
- // conversion engine could not convert the cast into some other nice form,
- // that there is something fundementally wrong with the current shape of
- // the program. Move the cast through the load and try again. This will
- // leave the original cast instruction, to presumably become dead.
- //
- if (CastInst *CI = dyn_cast<CastInst>(Pointer)) {
- Value *SrcVal = CI->getOperand(0);
- const PointerType *SrcTy = dyn_cast<PointerType>(SrcVal->getType());
- const Type *ElTy = SrcTy ? SrcTy->getValueType() : 0;
-
- // Make sure that nothing will be lost in the new cast...
- if (!LI->hasIndices() && SrcTy &&
- ElTy->isLosslesslyConvertableTo(LI->getType())) {
- PRINT_PEEPHOLE2("CL-LoadCast:in ", CI, LI);
-
- string CName = CI->getName(); CI->setName("");
- LoadInst *NLI = new LoadInst(SrcVal, LI->getName());
- LI->setName(""); // Take over the old load's name
-
- // Insert the load before the old load
- BI = BB->getInstList().insert(BI, NLI)+1;
-
- // Replace the old load with a new cast...
- ReplaceInstWithInst(BB->getInstList(), BI,
- CI = new CastInst(NLI, LI->getType(), CName));
- PRINT_PEEPHOLE2("CL-LoadCast:out", NLI, CI);
-
- return true;
- }
- }
} else if (I->getOpcode() == Instruction::Add &&
isa<CastInst>(I->getOperand(1))) {
-static bool DoRaisePass(Method *M) {
+static bool DoRaisePass(Function *F) {
bool Changed = false;
- for (Method::iterator MI = M->begin(), ME = M->end(); MI != ME; ++MI) {
+ for (Function::iterator MI = F->begin(), ME = F->end(); MI != ME; ++MI) {
BasicBlock *BB = *MI;
BasicBlock::InstListType &BIL = BB->getInstList();
for (BasicBlock::iterator BI = BB->begin(); BI != BB->end();) {
- if (opt::DeadCodeElimination::dceInstruction(BIL, BI) ||
- opt::ConstantPropogation::doConstantPropogation(BB, BI)) {
+#if DEBUG_PEEPHOLE_INSTS
+ cerr << "Processing: " << *BI;
+#endif
+ if (dceInstruction(BIL, BI) || doConstantPropogation(BB, BI)) {
Changed = true;
#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "DeadCode Elinated!\n";
+ cerr << "***\t\t^^-- DeadCode Elinated!\n";
#endif
} else if (PeepholeOptimize(BB, BI))
Changed = true;
}
-
-
-// DoInsertArrayCast - If the argument value has a pointer type, and if the
-// argument value is used as an array, insert a cast before the specified
-// basic block iterator that casts the value to an array pointer. Return the
-// new cast instruction (in the CastResult var), or null if no cast is inserted.
-//
-static bool DoInsertArrayCast(Value *V, BasicBlock *BB,
- BasicBlock::iterator InsertBefore) {
- const PointerType *ThePtrType = dyn_cast<PointerType>(V->getType());
- if (!ThePtrType) return false;
-
- const Type *ElTy = ThePtrType->getValueType();
- if (isa<MethodType>(ElTy) || isa<ArrayType>(ElTy)) return false;
-
- unsigned ElementSize = TD.getTypeSize(ElTy);
- bool InsertCast = false;
-
- for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
- Instruction *Inst = cast<Instruction>(*I);
- switch (Inst->getOpcode()) {
- case Instruction::Cast: // There is already a cast instruction!
- if (const PointerType *PT = dyn_cast<const PointerType>(Inst->getType()))
- if (const ArrayType *AT = dyn_cast<const ArrayType>(PT->getValueType()))
- if (AT->getElementType() == ThePtrType->getValueType()) {
- // Cast already exists! Don't mess around with it.
- return false; // No changes made to program though...
- }
- break;
- case Instruction::Add: { // Analyze pointer arithmetic...
- Value *OtherOp = Inst->getOperand(Inst->getOperand(0) == V);
- analysis::ExprType Expr = analysis::ClassifyExpression(OtherOp);
-
- // This looks like array addressing iff:
- // A. The constant of the index is larger than the size of the element
- // type.
- // B. The scale factor is >= the size of the type.
- //
- if (Expr.Offset && getConstantValue(Expr.Offset) >= (int)ElementSize) // A
- InsertCast = true;
-
- if (Expr.Scale && getConstantValue(Expr.Scale) >= (int)ElementSize) // B
- InsertCast = true;
-
- break;
- }
- default: break; // Not an interesting use...
- }
- }
-
- if (!InsertCast) return false; // There is no reason to insert a cast!
-
- // Calculate the destination pointer type
- const PointerType *DestTy = PointerType::get(ArrayType::get(ElTy));
-
- // Check to make sure that all uses of the value can be converted over to use
- // the newly typed value.
- //
- ValueTypeCache ConvertedTypes;
- if (!ValueConvertableToType(V, DestTy, ConvertedTypes)) {
- cerr << "FAILED to convert types of values for " << V << "\n";
- ConvertedTypes.clear();
- ValueConvertableToType(V, DestTy, ConvertedTypes);
- return false;
- }
- ConvertedTypes.clear();
-
- // Insert a cast!
- CastInst *TheCast =
- new CastInst(ConstPoolVal::getNullConstant(V->getType()), DestTy,
- V->getName());
- BB->getInstList().insert(InsertBefore, TheCast);
-
- cerr << "Inserting cast for " << V << endl;
-
- // Convert users of the old value over to use the cast result...
- ValueMapCache VMC;
- ConvertValueToNewType(V, TheCast, VMC);
-
- // The cast is the only thing that is allowed to reference the value...
- TheCast->setOperand(0, V);
-
- cerr << "Inserted ptr-array cast: " << TheCast;
- return true; // Made a change!
-}
-
-
-// DoInsertArrayCasts - Loop over all "incoming" values in the specified method,
-// inserting a cast for pointer values that are used as arrays. For our
-// purposes, an incoming value is considered to be either a value that is
-// either a method parameter, or a pointer returned from a function call.
-//
-static bool DoInsertArrayCasts(Method *M) {
- assert(!M->isExternal() && "Can't handle external methods!");
-
- // Insert casts for all arguments to the function...
- bool Changed = false;
- BasicBlock *CurBB = M->front();
-
- for (Method::ArgumentListType::iterator AI = M->getArgumentList().begin(),
- AE = M->getArgumentList().end(); AI != AE; ++AI) {
-
- Changed |= DoInsertArrayCast(*AI, CurBB, CurBB->begin());
- }
-
- // TODO: insert casts for alloca, malloc, and function call results. Also,
- // look for pointers that already have casts, to add to the map.
-
- return Changed;
-}
-
-
-
-
-// RaisePointerReferences::doit - Raise a method representation to a higher
+// RaisePointerReferences::doit - Raise a function representation to a higher
// level.
//
-bool RaisePointerReferences::doit(Method *M) {
- if (M->isExternal()) return false;
-
+static bool doRPR(Function *F) {
#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\n\n\nStarting to work on Method '" << M->getName() << "'\n";
+ cerr << "\n\n\nStarting to work on Function '" << F->getName() << "'\n";
#endif
// Insert casts for all incoming pointer pointer values that are treated as
// arrays...
//
bool Changed = false, LocalChange;
+
do {
- LocalChange = DoInsertArrayCasts(M);
+#ifdef DEBUG_PEEPHOLE_INSTS
+ cerr << "Looping: \n" << F;
+#endif
- // Iterate over the method, refining it, until it converges on a stable
+ // Iterate over the function, refining it, until it converges on a stable
// state
- while (DoRaisePass(M)) LocalChange = true;
+ LocalChange = false;
+ while (DoRaisePass(F)) LocalChange = true;
Changed |= LocalChange;
} while (LocalChange);
return Changed;
}
+
+namespace {
+ struct RaisePointerReferences : public FunctionPass {
+ const char *getPassName() const { return "Raise Pointer References"; }
+
+ virtual bool runOnFunction(Function *F) { return doRPR(F); }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.preservesCFG();
+ }
+ };
+}
+
+Pass *createRaisePointerReferencesPass() {
+ return new RaisePointerReferences();
+}
+
+
projects / oota-llvm.git / blobdiff