-//===- LevelRaise.cpp - Code to change LLVM to higher level -----------------=//
+//===- LevelRaise.cpp - Code to change LLVM to higher level ---------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// This file implements the 'raising' part of the LevelChange API. This is
// useful because, in general, it makes the LLVM code terser and easier to
-// analyze. Note that it is good to run DCE after doing this transformation.
-//
-// Eliminate silly things in the source that do not effect the level, but do
-// clean up the code:
-// * Casts of casts
-// - getelementptr/load & getelementptr/store are folded into a direct
-// load or store
-// - Convert this code (for both alloca and malloc):
-// %reg110 = shl uint %n, ubyte 2 ;;<uint>
-// %reg108 = alloca ubyte, uint %reg110 ;;<ubyte*>
-// %cast76 = cast ubyte* %reg108 to uint* ;;<uint*>
-// To: %cast76 = alloca uint, uint %n
-// Convert explicit addressing to use getelementptr instruction where possible
-// - ...
-//
-// Convert explicit addressing on pointers to use getelementptr instruction.
-// - If a pointer is used by arithmetic operation, insert an array casted
-// version into the source program, only for the following pointer types:
-// * Method argument pointers
-// - Pointers returned by alloca or malloc
-// - Pointers returned by function calls
-// - If a pointer is indexed with a value scaled by a constant size equal
-// to the element size of the array, the expression is replaced with a
-// getelementptr instruction.
+// analyze.
//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/LevelChange.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "TransformInternals.h"
-#include "llvm/Method.h"
-#include "llvm/Support/STLExtras.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/Analysis/Expressions.h"
+#include "llvm/Instructions.h"
+#include "llvm/Pass.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/STLExtras.h"
#include <algorithm>
+using namespace llvm;
+
+// StartInst - This enables the -raise-start-inst=foo option to cause the level
+// raising pass to start at instruction "foo", which is immensely useful for
+// debugging!
+//
+static cl::opt<std::string>
+StartInst("raise-start-inst", cl::Hidden, cl::value_desc("inst name"),
+ cl::desc("Start raise pass at the instruction with the specified name"));
+
+static Statistic<>
+NumLoadStorePeepholes("raise", "Number of load/store peepholes");
-#include "llvm/Assembly/Writer.h"
+static Statistic<>
+NumGEPInstFormed("raise", "Number of other getelementptr's formed");
-//#define DEBUG_PEEPHOLE_INSTS 1
+static Statistic<>
+NumExprTreesConv("raise", "Number of expression trees converted");
+
+static Statistic<>
+NumCastOfCast("raise", "Number of cast-of-self removed");
+
+static Statistic<>
+NumDCEorCP("raise", "Number of insts DCEd or constprop'd");
+
+static Statistic<>
+NumVarargCallChanges("raise", "Number of vararg call peepholes");
-#ifdef DEBUG_PEEPHOLE_INSTS
#define PRINT_PEEPHOLE(ID, NUM, I) \
- cerr << "Inst P/H " << ID << "[" << NUM << "] " << I;
-#else
-#define PRINT_PEEPHOLE(ID, NUM, I)
-#endif
+ DEBUG(std::cerr << "Inst P/H " << ID << "[" << NUM << "] " << I)
#define PRINT_PEEPHOLE1(ID, I1) do { PRINT_PEEPHOLE(ID, 0, I1); } while (0)
#define PRINT_PEEPHOLE2(ID, I1, I2) \
do { PRINT_PEEPHOLE(ID, 0, I1); PRINT_PEEPHOLE(ID, 1, I2); \
PRINT_PEEPHOLE(ID, 2, I3); PRINT_PEEPHOLE(ID, 3, I4); } while (0)
+namespace {
+ struct RPR : public FunctionPass {
+ virtual bool runOnFunction(Function &F);
-// isReinterpretingCast - Return true if the cast instruction specified will
-// cause the operand to be "reinterpreted". A value is reinterpreted if the
-// cast instruction would cause the underlying bits to change.
-//
-static inline bool isReinterpretingCast(const CastInst *CI) {
- return !losslessCastableTypes(CI->getOperand(0)->getType(), CI->getType());
-}
-
-
-
-
-// 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(Method *CurMeth, Value *V, BasicBlock *BB,
- BasicBlock::iterator &InsertBefore,
- CastInst *&CastResult) {
- const PointerType *ThePtrType = dyn_cast<PointerType>(V->getType());
- if (!ThePtrType) return false;
- 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()) {
- default: break; // Not an interesting use...
- case Instruction::Add: // It's being used as an array index!
- //case Instruction::Sub:
- InsertCast = true;
- break;
- 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! Return the existing one!
- CastResult = cast<CastInst>(Inst);
- return false; // No changes made to program though...
- }
- break;
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
+ AU.addRequired<TargetData>();
}
- }
- if (!InsertCast) return false; // There is no reason to insert a cast!
+ private:
+ bool DoRaisePass(Function &F);
+ bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI);
+ };
- // Insert a cast!
- const Type *ElTy = ThePtrType->getValueType();
- const PointerType *DestTy = PointerType::get(ArrayType::get(ElTy));
-
- CastResult = new CastInst(V, DestTy);
- BB->getInstList().insert(InsertBefore, CastResult);
- //cerr << "Inserted cast: " << CastResult;
- return true; // Made a change!
+ RegisterOpt<RPR> X("raise", "Raise Pointer References");
}
-// 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, a value created by alloca or malloc, or a value
-// returned from a function call. All casts are kept attached to their original
-// values through the PtrCasts map.
-//
-static bool DoInsertArrayCasts(Method *M, map<Value*, CastInst*> &PtrCasts) {
- assert(!M->isExternal() && "Can't handle external methods!");
-
- // Insert casts for all arguments to the function...
- bool Changed = false;
- BasicBlock *CurBB = M->front();
- BasicBlock::iterator It = CurBB->begin();
- for (Method::ArgumentListType::iterator AI = M->getArgumentList().begin(),
- AE = M->getArgumentList().end(); AI != AE; ++AI) {
- CastInst *TheCast = 0;
- if (DoInsertArrayCast(M, *AI, CurBB, It, TheCast)) {
- It = CurBB->begin(); // We might have just invalidated the iterator!
- Changed = true; // Yes we made a change
- ++It; // Insert next cast AFTER this one...
- }
-
- if (TheCast) // Is there a cast associated with this value?
- PtrCasts[*AI] = TheCast; // Yes, add it to the map...
- }
-
- // 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;
+Pass *llvm::createRaisePointerReferencesPass() {
+ return new RPR();
}
+// isReinterpretingCast - Return true if the cast instruction specified will
+// cause the operand to be "reinterpreted". A value is reinterpreted if the
+// cast instruction would cause the underlying bits to change.
+//
+static inline bool isReinterpretingCast(const CastInst *CI) {
+ return!CI->getOperand(0)->getType()->isLosslesslyConvertibleTo(CI->getType());
+}
-// DoElminatePointerArithmetic - Loop over each incoming pointer variable,
-// replacing indexing arithmetic with getelementptr calls.
+// Peephole optimize the following instructions:
+// %t1 = cast ? to x *
+// %t2 = add x * %SP, %t1 ;; Constant must be 2nd operand
//
-static bool DoEliminatePointerArithmetic(const pair<Value*, CastInst*> &Val) {
- Value *V = Val.first; // The original pointer
- CastInst *CV = Val.second; // The array casted version of the pointer...
-
- for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
- Instruction *Inst = cast<Instruction>(*I);
- if (Inst->getOpcode() != Instruction::Add)
- continue; // We only care about add instructions
+// Into: %t3 = getelementptr {<...>} * %SP, <element indices>
+// %t2 = cast <eltype> * %t3 to {<...>}*
+//
+static bool HandleCastToPointer(BasicBlock::iterator BI,
+ const PointerType *DestPTy,
+ const TargetData &TD) {
+ CastInst &CI = cast<CastInst>(*BI);
+ if (CI.use_empty()) return false;
+
+ // Scan all of the uses, looking for any uses that are not add or sub
+ // instructions. If we have non-adds, do not make this transformation.
+ //
+ bool HasSubUse = false; // Keep track of any subtracts...
+ 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 &&
+ BO->getOpcode() != Instruction::Sub) ||
+ // Avoid add sbyte* %X, %X cases...
+ BO->getOperand(0) == BO->getOperand(1))
+ return false;
+ else
+ HasSubUse |= BO->getOpcode() == Instruction::Sub;
+ } else {
+ return false;
+ }
- BinaryOperator *Add = cast<BinaryOperator>(Inst);
+ std::vector<Value*> Indices;
+ Value *Src = CI.getOperand(0);
+ const Type *Result = ConvertibleToGEP(DestPTy, Src, Indices, TD, &BI);
+ if (Result == 0) return false; // Not convertible...
- // Make sure the array is the first operand of the add expression...
- if (Add->getOperand(0) != V)
- Add->swapOperands();
+ // Cannot handle subtracts if there is more than one index required...
+ if (HasSubUse && Indices.size() != 1) return false;
- // Get the amount added to the pointer value...
- Value *AddAmount = Add->getOperand(1);
+ 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->getOpcode() == Instruction::Sub) &&
+ "Use is not a valid add instruction!");
- }
- return false;
-}
-
+ // 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 the instruction is actually a subtract, we are guaranteed to only have
+ // one index (from code above), so we just need to negate the pointer index
+ // long value.
+ if (I->getOpcode() == Instruction::Sub) {
+ Instruction *Neg = BinaryOperator::createNeg(GEP->getOperand(1),
+ GEP->getOperand(1)->getName()+".neg", I);
+ GEP->setOperand(1, Neg);
+ }
-// Peephole Malloc instructions: we take a look at the use chain of the
-// malloc instruction, and try to find out if the following conditions hold:
-// 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
-// 2. The only users of the malloc are cast & add instructions
-// 3. Of the cast instructions, there is only one destination pointer type
-// [RTy] where the size of the pointed to object is equal to the number
-// of bytes allocated.
-//
-// If these conditions hold, we convert the malloc to allocate an [RTy]
-// element. This should be extended in the future to handle arrays. TODO
-//
-static bool PeepholeMallocInst(BasicBlock *BB, BasicBlock::iterator &BI) {
- MallocInst *MI = cast<MallocInst>(*BI);
- if (!MI->isArrayAllocation()) return false; // No array allocation?
+ 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.
+ //
- ConstPoolUInt *Amt = dyn_cast<ConstPoolUInt>(MI->getArraySize());
- if (Amt == 0 || MI->getAllocatedType() != ArrayType::get(Type::SByteTy))
- return false;
+ // Insert the GEP instruction before the old add instruction...
+ I->getParent()->getInstList().insert(I, GEP);
- // Get the number of bytes allocated...
- unsigned Size = Amt->getValue();
- const Type *ResultTy = 0;
+ PRINT_PEEPHOLE1("cast-add-to-gep:o", *GEP);
+ GEP = new CastInst(GEP, I->getType());
- // Loop over all of the uses of the malloc instruction, inspecting casts.
- for (Value::use_iterator I = MI->use_begin(), E = MI->use_end();
- I != E; ++I) {
- if (CastInst *CI = dyn_cast<CastInst>(*I)) {
- //cerr << "\t" << CI;
-
- // We only work on casts to pointer types for sure, be conservative
- if (!isa<PointerType>(CI->getType())) {
- cerr << "Found cast of malloc value to non pointer type:\n" << CI;
- return false;
- }
-
- const Type *DestTy = cast<PointerType>(CI->getType())->getValueType();
- if (isa<ArrayType>(DestTy)) {
- cerr << "Avoided malloc conversion because of type: " << DestTy
- << " TODO.\n";
- return false;
- }
- if (TD.getTypeSize(DestTy) == Size && DestTy != ResultTy) {
- // Does the size of the allocated type match the number of bytes
- // allocated?
- //
- if (ResultTy == 0) {
- ResultTy = DestTy; // Keep note of this for future uses...
- } else {
- // It's overdefined! We don't know which type to convert to!
- return false;
- }
- }
+ // Replace the old add instruction with the shiny new GEP inst
+ ReplaceInstWithInst(I, GEP);
}
- }
- // If we get this far, we have either found, or not, a type that is cast to
- // that is of the same size as the malloc instruction.
- if (!ResultTy) return false;
-
- // Now we check to see if we can convert the return value of malloc to the
- // specified pointer type. All this is moot if we can't.
- //
- ValueTypeCache ConvertedTypes;
- if (RetValConvertableToType(MI, PointerType::get(ResultTy), ConvertedTypes)) {
- // Yup, it's convertable, do the transformation now!
- PRINT_PEEPHOLE1("mall-refine:in ", MI);
-
- // Create a new malloc instruction, and insert it into the method...
- MallocInst *NewMI = new MallocInst(PointerType::get(ResultTy));
- NewMI->setName(MI->getName());
- MI->setName("");
- BI = BB->getInstList().insert(BI, NewMI)+1;
-
- // Create a new cast instruction to cast it to the old type...
- CastInst *NewCI = new CastInst(NewMI, MI->getType());
- BB->getInstList().insert(BI, NewCI);
-
- // Move all users of the old malloc instruction over to use the new cast...
- MI->replaceAllUsesWith(NewCI);
-
- ValueMapCache ValueMap;
- ConvertUsersType(NewCI, NewMI, ValueMap); // This will delete MI!
-
- BI = BB->begin(); // Rescan basic block. BI might be invalidated.
- PRINT_PEEPHOLE1("mall-refine:out", NewMI);
- return true;
+ PRINT_PEEPHOLE1("cast-add-to-gep:o", *GEP);
}
- return false;
+ return true;
}
-
-
// Peephole optimize the following instructions:
// %t1 = cast ulong <const int> to {<...>} *
// %t2 = add {<...>} * %SP, %t1 ;; Constant must be 2nd operand
// %t2 = cast <eltype> * %t3 to {<...>}*
//
static bool PeepholeOptimizeAddCast(BasicBlock *BB, BasicBlock::iterator &BI,
- Value *AddOp1, CastInst *AddOp2) {
- Value *OffsetVal = AddOp2->getOperand(0);
- Value *SrcPtr; // Of type pointer to struct...
- const StructType *StructTy;
+ Value *AddOp1, CastInst *AddOp2,
+ const TargetData &TD) {
+ const CompositeType *CompTy;
+ Value *OffsetVal = AddOp2->getOperand(0);
+ Value *SrcPtr = 0; // Of type pointer to struct...
- if ((StructTy = getPointedToStruct(AddOp1->getType()))) {
+ if ((CompTy = getPointedToComposite(AddOp1->getType()))) {
SrcPtr = AddOp1; // Handle the first case...
} else if (CastInst *AddOp1c = dyn_cast<CastInst>(AddOp1)) {
SrcPtr = AddOp1c->getOperand(0); // Handle the second case...
- StructTy = getPointedToStruct(SrcPtr->getType());
+ CompTy = getPointedToComposite(SrcPtr->getType());
}
// Only proceed if we have detected all of our conditions successfully...
- if (!StructTy || !SrcPtr || !OffsetVal->getType()->isIntegral())
+ if (!CompTy || !SrcPtr || !OffsetVal->getType()->isInteger())
return false;
- // See if the cast is of an integer expression that is either a constant,
- // or a value scaled by some amount with a possible offset.
- //
- analysis::ExprType Expr = analysis::ClassifyExpression(OffsetVal);
- unsigned Offset = 0, Scale = 1;
-
- // The expression must either be a constant, or a scaled index to be useful
- if (!Expr.Offset && !Expr.Scale)
- return false;
+ std::vector<Value*> Indices;
+ if (!ConvertibleToGEP(SrcPtr->getType(), OffsetVal, Indices, TD, &BI))
+ return false; // Not convertible... perhaps next time
- // Get the offset value if it exists...
- if (Expr.Offset) {
- if (ConstPoolSInt *CPSI = dyn_cast<ConstPoolSInt>(Expr.Offset))
- Offset = (unsigned)CPSI->getValue();
- else {
- ConstPoolUInt *CPUI = cast<ConstPoolUInt>(Expr.Offset);
- Offset = (unsigned)CPUI->getValue();
- }
- assert(Offset != 0 && "Expression analysis failure!");
- }
-
- // Get the scale value if it exists...
- if (Expr.Scale) {
- if (ConstPoolSInt *CPSI = dyn_cast<ConstPoolSInt>(Expr.Scale))
- Scale = (unsigned)CPSI->getValue();
- else {
- ConstPoolUInt *CPUI = cast<ConstPoolUInt>(Expr.Scale);
- Scale = (unsigned)CPUI->getValue();
- }
- assert(Scale != 1 && "Expression analysis failure!");
- }
-
- // Check to make sure the offset is not negative or really large, outside the
- // scope of this structure...
- //
- if (Offset >= TD.getTypeSize(StructTy))
- return false;
-
- const StructLayout *SL = TD.getStructLayout(StructTy);
- vector<ConstPoolVal*> Offsets;
- unsigned ActualOffset = Offset;
- const Type *ElTy = getStructOffsetType(StructTy, ActualOffset, Offsets);
-
- if (getPointedToStruct(AddOp1->getType())) { // case 1
- PRINT_PEEPHOLE2("add-to-gep1:in", AddOp2, *BI);
+ if (getPointedToComposite(AddOp1->getType())) { // case 1
+ PRINT_PEEPHOLE2("add-to-gep1:in", *AddOp2, *BI);
} else {
- PRINT_PEEPHOLE3("add-to-gep2:in", AddOp1, AddOp2, *BI);
+ PRINT_PEEPHOLE3("add-to-gep2:in", *AddOp1, *AddOp2, *BI);
}
- GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Offsets);
- //AddOp2->getName());
- BI = BB->getInstList().insert(BI, GEP)+1;
-
- Instruction *AddrSrc = GEP;
-
- if (const ArrayType *AT = dyn_cast<ArrayType>(ElTy)) {
- assert((Scale == 1 || Offset == ActualOffset) &&
- "Cannot handle scaled expression and unused offset in the same "
- "instruction until after GEP array works!");
-
- // Check to see if we have bottomed out INSIDE of an array reference..
- //
- if (Offset != ActualOffset) {
- // Insert a cast of the "rest" of the offset to the appropriate
- // pointer type.
- CastInst *OffInst =
- new CastInst(ConstPoolUInt::get(Type::ULongTy,
- Offset-ActualOffset),
- GEP->getType());
- BI = BB->getInstList().insert(BI, OffInst)+1;
-
- // Now insert an ADD to actually adjust the pointer...
- Instruction *AddInst =
- BinaryOperator::create(Instruction::Add, GEP, OffInst);
- BI = BB->getInstList().insert(BI, AddInst)+1;
-
- PRINT_PEEPHOLE2("add-to-gep:out1", OffInst, AddInst);
-
- AddrSrc = AddInst;
- } else if (Scale != 1) {
- // If the scale factor occurs, then this means that there is an index into
- // this element of the array. Check to make sure the scale factor is the
- // same as the size of the datatype that we are dealing with.
- //
- assert(Scale == TD.getTypeSize(AT->getElementType()) &&
- "Scaling by something other than the array element size!!");
-
- // TODO: In the future, we will not want to cast the index and scale to
- // pointer types first. We will want to create a GEP directly here.
+ GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Indices,
+ AddOp2->getName(), BI);
- // Now we must actually perform the scaling operation to get an
- // appropriate value to add in... but the scale has to be done in the
- // appropriate destination pointer type, so cast the index value now.
- //
- // Cast the base index pointer
- CastInst *IdxValue = new CastInst(Expr.Var, GEP->getType());
- BI = BB->getInstList().insert(BI, IdxValue)+1;
-
- // Case the scale amount as well...
- CastInst *ScaleAmt =
- new CastInst(ConstPoolUInt::get(Type::ULongTy, Scale), GEP->getType());
- BI = BB->getInstList().insert(BI, ScaleAmt)+1;
-
- // Insert the multiply now. Make sure to make the constant the second arg
- Instruction *ScaledVal =
- BinaryOperator::create(Instruction::Mul, IdxValue, ScaleAmt);
- BI = BB->getInstList().insert(BI, ScaledVal)+1;
-
- // Now insert an ADD to actually adjust the pointer...
- Instruction *AddInst =
- BinaryOperator::create(Instruction::Add, GEP, ScaledVal);
- BI = BB->getInstList().insert(BI, AddInst)+1;
-
- PRINT_PEEPHOLE4("add-to-gep:out1", IdxValue, ScaleAmt, ScaledVal,
- AddInst);
- AddrSrc = AddInst;
- }
-
- // Insert a cast of the pointer to array of X to be a pointer to the
- // element of the array.
- //
- // Insert a cast of the "rest" of the offset to the appropriate
- // pointer type.
- CastInst *ACI = new CastInst(AddrSrc, AT->getElementType());
- BI = BB->getInstList().insert(BI, ACI)+1;
- AddrSrc = ACI;
-
- } else {
- assert(Offset == ActualOffset && "GEP to middle of non array!");
- assert(Scale == 1 && "Scale factor for expr that is not an array idx!");
- }
-
- Instruction *NCI = new CastInst(AddrSrc, AddOp1->getType());
+ Instruction *NCI = new CastInst(GEP, AddOp1->getType());
ReplaceInstWithInst(BB->getInstList(), BI, NCI);
- PRINT_PEEPHOLE2("add-to-gep:out", GEP, NCI);
+ PRINT_PEEPHOLE2("add-to-gep:out", *GEP, *NCI);
return true;
}
-// Peephole optimize the following instructions:
-// %t1 = cast int (uint) * %reg111 to uint (...) *
-// %t2 = call uint (...) * %cast111( uint %key )
-//
-// Into: %t3 = call int (uint) * %reg111( uint %key )
-// %t2 = cast int %t3 to uint
-//
-static bool PeepholeCallInst(BasicBlock *BB, BasicBlock::iterator &BI) {
- CallInst *CI = cast<CallInst>(*BI);
- return false;
-}
-
-
-static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
- Instruction *I = *BI;
+bool RPR::PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
+ Instruction *I = BI;
+ const TargetData &TD = getAnalysis<TargetData>();
if (CastInst *CI = dyn_cast<CastInst>(I)) {
Value *Src = CI->getOperand(0);
// Into: <nothing>
//
if (DestTy == Src->getType()) { // Check for a cast to same type as src!!
- PRINT_PEEPHOLE1("cast-of-self-ty", CI);
+ 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());
+ Src->setName(Name, &BB->getParent()->getSymbolTable());
}
+
+ // DCE the instruction now, to avoid having the iterative version of DCE
+ // have to worry about it.
+ //
+ BI = BB->getInstList().erase(BI);
+
+ ++NumCastOfCast;
return true;
}
- // Peephole optimize the following instructions:
- // %tmp = cast <ty> %V to <ty2>
- // %V = cast <ty2> %tmp to <ty3> ; Where ty & ty2 are same size
- //
- // Into: cast <ty> %V to <ty3>
- //
- if (SrcI)
- if (CastInst *CSrc = dyn_cast<CastInst>(SrcI))
- if (isReinterpretingCast(CI) + isReinterpretingCast(CSrc) < 2) {
- // We can only do c-c elimination if, at most, one cast does a
- // reinterpretation of the input data.
- //
- // If legal, make this cast refer the the original casts argument!
- //
- PRINT_PEEPHOLE2("cast-cast:in ", CI, CSrc);
- CI->setOperand(0, CSrc->getOperand(0));
- PRINT_PEEPHOLE1("cast-cast:out", CI);
- return true;
- }
-
// Check to see if it's a cast of an instruction that does not depend on the
// specific type of the operands to do it's job.
if (!isReinterpretingCast(CI)) {
ValueTypeCache ConvertedTypes;
- if (RetValConvertableToType(CI, Src->getType(), ConvertedTypes)) {
- PRINT_PEEPHOLE2("CAST-DEST-EXPR-CONV:in ", CI, Src);
-
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\nCONVERTING EXPR TYPE:\n";
-#endif
- ValueMapCache ValueMap;
- ConvertUsersType(CI, Src, ValueMap); // This will delete CI!
- 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 EXPR TYPE: \n\n";// << BB->getParent();
-#endif
- return true;
- } else {
- ConvertedTypes.clear();
- if (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) {
- PRINT_PEEPHOLE2("CAST-SRC-EXPR-CONV:in ", CI, Src);
+ // Check to see if we can convert the source of the cast to match the
+ // destination type of the cast...
+ //
+ ConvertedTypes[CI] = CI->getType(); // Make sure the cast doesn't change
+ if (ExpressionConvertibleToType(Src, DestTy, ConvertedTypes, TD)) {
+ PRINT_PEEPHOLE3("CAST-SRC-EXPR-CONV:in ", *Src, *CI, *BB->getParent());
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\nCONVERTING SRC EXPR TYPE:\n";
-#endif
+ DEBUG(std::cerr << "\nCONVERTING SRC EXPR TYPE:\n");
+ { // ValueMap must be destroyed before function verified!
ValueMapCache ValueMap;
- Value *E = ConvertExpressionToType(Src, DestTy, ValueMap);
- if (ConstPoolVal *CPV = dyn_cast<ConstPoolVal>(E))
+ Value *E = ConvertExpressionToType(Src, DestTy, ValueMap, TD);
+
+ if (Constant *CPV = dyn_cast<Constant>(E))
CI->replaceAllUsesWith(CPV);
+
+ PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", *E);
+ DEBUG(std::cerr << "DONE CONVERTING SRC EXPR TYPE: \n"
+ << *BB->getParent());
+ }
+
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ ++NumExprTreesConv;
+ return true;
+ }
- BI = BB->begin(); // Rescan basic block. BI might be invalidated.
- PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E);
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "DONE CONVERTING SRC EXPR TYPE: \n\n";// << BB->getParent();
-#endif
- return true;
+ // Check to see if we can convert the users of the cast value to match the
+ // source type of the cast...
+ //
+ ConvertedTypes.clear();
+ // Make sure the source doesn't change type
+ ConvertedTypes[Src] = Src->getType();
+ if (ValueConvertibleToType(CI, Src->getType(), ConvertedTypes, TD)) {
+ //PRINT_PEEPHOLE3("CAST-DEST-EXPR-CONV:in ", *Src, *CI,
+ // *BB->getParent());
+
+ DEBUG(std::cerr << "\nCONVERTING EXPR TYPE:\n");
+ { // ValueMap must be destroyed before function verified!
+ ValueMapCache ValueMap;
+ ConvertValueToNewType(CI, Src, ValueMap, TD); // This will delete CI!
}
+
+ PRINT_PEEPHOLE1("CAST-DEST-EXPR-CONV:out", *Src);
+ DEBUG(std::cerr << "DONE CONVERTING EXPR TYPE: \n\n" <<
+ *BB->getParent());
+
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ ++NumExprTreesConv;
+ 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, TD)) {
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ ++NumGEPInstFormed;
+ return true;
}
-
}
// Check to see if we are casting from a structure pointer to a pointer to
// Into: %t2 = getelementptr {<...>} * %StructPtr, <0, 0, 0, ...>
// %t1 = cast <eltype> * %t1 to <ty> *
//
-#if 1
- if (const StructType *STy = getPointedToStruct(Src->getType()))
+ if (const CompositeType *CTy = getPointedToComposite(Src->getType()))
if (const PointerType *DestPTy = dyn_cast<PointerType>(DestTy)) {
// Loop over uses of the cast, checking for add instructions. If an add
}
// If it doesn't have an add use, check to see if the dest type is
- // losslessly convertable to one of the types in the start of the struct
+ // losslessly convertible to one of the types in the start of the struct
// type.
//
if (!HasAddUse) {
- const Type *DestPointedTy = DestPTy->getValueType();
+ const Type *DestPointedTy = DestPTy->getElementType();
unsigned Depth = 1;
- const StructType *CurSTy = STy;
+ const CompositeType *CurCTy = CTy;
const Type *ElTy = 0;
- while (CurSTy) {
-
- // Check for a zero element struct type... if we have one, bail.
- if (CurSTy->getElementTypes().size() == 0) break;
+
+ // Build the index vector, full of all zeros
+ std::vector<Value*> Indices;
+
+ Indices.push_back(Constant::getNullValue(Type::UIntTy));
+ 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->getNumElements() == 0) break;
- // Grab the first element of the struct type, which must lie at
- // offset zero in the struct.
- //
- ElTy = CurSTy->getElementTypes()[0];
+ // Grab the first element of the struct type, which must lie at
+ // offset zero in the struct.
+ //
+ ElTy = CurSTy->getElementType(0);
+ } else {
+ ElTy = cast<ArrayType>(CurCTy)->getElementType();
+ }
+
+ // Insert a zero to index through this type...
+ Indices.push_back(Constant::getNullValue(Type::UIntTy));
// Did we find what we're looking for?
- if (losslessCastableTypes(ElTy, DestPointedTy)) break;
+ if (ElTy->isLosslesslyConvertibleTo(DestPointedTy)) break;
// Nope, go a level deeper.
++Depth;
- CurSTy = dyn_cast<StructType>(ElTy);
+ CurCTy = dyn_cast<CompositeType>(ElTy);
ElTy = 0;
}
// Did we find what we were looking for? If so, do the transformation
if (ElTy) {
- PRINT_PEEPHOLE1("cast-for-first:in", CI);
+ PRINT_PEEPHOLE1("cast-for-first:in", *CI);
- // Build the index vector, full of all zeros
- vector<ConstPoolVal *> Indices(Depth,
- ConstPoolUInt::get(Type::UByteTy,0));
+ std::string Name = CI->getName(); CI->setName("");
// Insert the new T cast instruction... stealing old T's name
GetElementPtrInst *GEP = new GetElementPtrInst(Src, Indices,
- CI->getName());
- CI->setName("");
- BI = BB->getInstList().insert(BI, GEP)+1;
+ Name, BI);
// Make the old cast instruction reference the new GEP instead of
// the old src value.
//
CI->setOperand(0, GEP);
- PRINT_PEEPHOLE2("cast-for-first:out", GEP, CI);
+ PRINT_PEEPHOLE2("cast-for-first:out", *GEP, *CI);
+ ++NumGEPInstFormed;
return true;
}
}
}
-#endif
-
-#if 1
- } else if (MallocInst *MI = dyn_cast<MallocInst>(I)) {
- if (PeepholeMallocInst(BB, BI)) return true;
-
- } else if (CallInst *CI = dyn_cast<CallInst>(I)) {
- if (PeepholeCallInst(BB, BI)) return true;
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
Value *Val = SI->getOperand(0);
- Value *Pointer = SI->getPtrOperand();
-
- // 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<ConstPoolVal*> Indices(GEP->getIndices());
- Indices.insert(Indices.end(), SI->getIndices().begin(),
- SI->getIndices().end());
-
- PRINT_PEEPHOLE2("gep-store:in", GEP, SI);
- ReplaceInstWithInst(BB->getInstList(), BI,
- SI = new StoreInst(Val, GEP->getPtrOperand(),
- Indices));
- PRINT_PEEPHOLE1("gep-store:out", SI);
- return true;
- }
+ Value *Pointer = SI->getPointerOperand();
// Peephole optimize the following instructions:
- // %t = cast <T1>* %P to <T2> * ;; If T1 is losslessly convertable to T2
+ // %t = cast <T1>* %P to <T2> * ;; If T1 is losslessly convertible to T2
// store <T2> %V, <T2>* %t
//
// Into:
// %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()))
- if (losslessCastableTypes(Val->getType(), // convertable types!
- CSPT->getValueType()) &&
- !SI->hasIndices()) { // No subscripts yet!
- PRINT_PEEPHOLE3("st-src-cast:in ", Pointer, Val, SI);
+ if (const PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType()))
+ // convertible types?
+ if (Val->getType()->isLosslesslyConvertibleTo(CSPT->getElementType())) {
+ 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(),
- CI->getName());
- CI->setName("");
- BI = BB->getInstList().insert(BI, NCI)+1;
+ std::string Name(CI->getName()); CI->setName("");
+ CastInst *NCI = new CastInst(Val, CSPT->getElementType(),
+ Name, BI);
// Replace the old store with a new one!
ReplaceInstWithInst(BB->getInstList(), BI,
SI = new StoreInst(NCI, CastSrc));
- PRINT_PEEPHOLE3("st-src-cast:out", NCI, CastSrc, SI);
+ PRINT_PEEPHOLE3("st-src-cast:out", *NCI, *CastSrc, *SI);
+ ++NumLoadStorePeepholes;
return true;
}
-
} else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
- Value *Pointer = LI->getPtrOperand();
+ Value *Pointer = LI->getOperand(0);
+ const Type *PtrElType =
+ cast<PointerType>(Pointer->getType())->getElementType();
// 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<ConstPoolVal*> Indices(GEP->getIndices());
- Indices.insert(Indices.end(), LI->getIndices().begin(),
- LI->getIndices().end());
-
- PRINT_PEEPHOLE2("gep-load:in", GEP, LI);
- ReplaceInstWithInst(BB->getInstList(), BI,
- LI = new LoadInst(GEP->getPtrOperand(),
- Indices));
- PRINT_PEEPHOLE1("gep-load:out", LI);
- return true;
- }
-
-
- // Peephole optimize the following instructions:
- // %t1 = cast <ty> * %t0 to <ty2> *
- // %V = load <ty2> * %t1
+ // %Val = cast <T1>* to <T2>* ;; If T1 is losslessly convertible to T2
+ // %t = load <T2>* %P
//
- // Into: %t1 = load <ty> * %t0
- // %V = cast <ty> %t1 to <ty2>
+ // Into:
+ // %t = load <T1>* %P
+ // %Val = cast <T1> to <T2>
//
- // 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.
+ // 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)) {
- 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 (SrcTy && losslessCastableTypes(ElTy, 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
+ if (CastInst *CI = dyn_cast<CastInst>(Pointer))
+ if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType
+ if (const PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType()))
+ // convertible types?
+ if (PtrElType->isLosslesslyConvertibleTo(CSPT->getElementType())) {
+ PRINT_PEEPHOLE2("load-src-cast:in ", *Pointer, *LI);
- // Insert the load before the old load
- BI = BB->getInstList().insert(BI, NLI)+1;
+ // Create the new load instruction... loading the pre-casted value
+ LoadInst *NewLI = new LoadInst(CastSrc, LI->getName(), BI);
+
+ // Insert the new T cast instruction... stealing old T's name
+ CastInst *NCI = new CastInst(NewLI, LI->getType(), CI->getName());
- // 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);
+ // Replace the old store with a new one!
+ ReplaceInstWithInst(BB->getInstList(), BI, NCI);
+ PRINT_PEEPHOLE3("load-src-cast:out", *NCI, *CastSrc, *NewLI);
+ ++NumLoadStorePeepholes;
+ return true;
+ }
- return true;
- }
- }
} else if (I->getOpcode() == Instruction::Add &&
isa<CastInst>(I->getOperand(1))) {
if (PeepholeOptimizeAddCast(BB, BI, I->getOperand(0),
- cast<CastInst>(I->getOperand(1))))
+ cast<CastInst>(I->getOperand(1)), TD)) {
+ ++NumGEPInstFormed;
+ return true;
+ }
+ } else if (CallInst *CI = dyn_cast<CallInst>(I)) {
+ // If we have a call with all varargs arguments, convert the call to use the
+ // actual argument types present...
+ //
+ const PointerType *PTy = cast<PointerType>(CI->getCalledValue()->getType());
+ const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
+
+ // Is the call to a vararg variable with no real parameters?
+ if (FTy->isVarArg() && FTy->getNumParams() == 0 &&
+ !CI->getCalledFunction()) {
+ // If so, insert a new cast instruction, casting it to a function type
+ // that matches the current arguments...
+ //
+ std::vector<const Type *> Params; // Parameter types...
+ for (unsigned i = 1, e = CI->getNumOperands(); i != e; ++i)
+ Params.push_back(CI->getOperand(i)->getType());
+
+ FunctionType *NewFT = FunctionType::get(FTy->getReturnType(),
+ Params, false);
+ PointerType *NewPFunTy = PointerType::get(NewFT);
+
+ // Create a new cast, inserting it right before the function call...
+ Value *NewCast;
+ Constant *ConstantCallSrc = 0;
+ if (Constant *CS = dyn_cast<Constant>(CI->getCalledValue()))
+ ConstantCallSrc = CS;
+
+ if (ConstantCallSrc)
+ NewCast = ConstantExpr::getCast(ConstantCallSrc, NewPFunTy);
+ else
+ NewCast = new CastInst(CI->getCalledValue(), NewPFunTy,
+ CI->getCalledValue()->getName()+"_c",CI);
+
+ // Create a new call instruction...
+ CallInst *NewCall = new CallInst(NewCast,
+ std::vector<Value*>(CI->op_begin()+1, CI->op_end()));
+ ++BI;
+ ReplaceInstWithInst(CI, NewCall);
+
+ ++NumVarargCallChanges;
return true;
+ }
-#endif
}
return false;
-static bool DoRaisePass(Method *M) {
+bool RPR::DoRaisePass(Function &F) {
bool Changed = false;
- for (Method::iterator MI = M->begin(), ME = M->end(); MI != ME; ++MI) {
- BasicBlock *BB = *MI;
- BasicBlock::InstListType &BIL = BB->getInstList();
-
+ for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB)
for (BasicBlock::iterator BI = BB->begin(); BI != BB->end();) {
- if (opt::DeadCodeElimination::dceInstruction(BIL, BI)) {
+ DEBUG(std::cerr << "LevelRaising: " << *BI);
+ if (dceInstruction(BI) || doConstantPropagation(BI)) {
Changed = true;
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "DeadCode Elinated!\n";
-#endif
- } else if (PeepholeOptimize(BB, BI))
+ ++NumDCEorCP;
+ DEBUG(std::cerr << "***\t\t^^-- Dead code eliminated!\n");
+ } else if (PeepholeOptimize(BB, BI)) {
Changed = true;
- else
+ } else {
++BI;
+ }
}
- }
+
return Changed;
}
-// RaisePointerReferences::doit - Raise a method representation to a higher
-// level.
-//
-bool RaisePointerReferences::doit(Method *M) {
- if (M->isExternal()) return false;
- bool Changed = false;
+// runOnFunction - Raise a function representation to a higher level.
+bool RPR::runOnFunction(Function &F) {
+ DEBUG(std::cerr << "\n\n\nStarting to work on Function '" << F.getName()
+ << "'\n");
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\n\n\nStarting to work on Method '" << M->getName() << "'\n";
-#endif
+ // Insert casts for all incoming pointer pointer values that are treated as
+ // arrays...
+ //
+ bool Changed = false, LocalChange;
- while (DoRaisePass(M)) Changed = true;
+ // If the StartInst option was specified, then Peephole optimize that
+ // instruction first if it occurs in this function.
+ //
+ if (!StartInst.empty()) {
+ for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB)
+ for (BasicBlock::iterator BI = BB->begin(); BI != BB->end(); ++BI)
+ if (BI->getName() == StartInst) {
+ bool SavedDebug = DebugFlag; // Save the DEBUG() controlling flag.
+ DebugFlag = true; // Turn on DEBUG's
+ Changed |= PeepholeOptimize(BB, BI);
+ DebugFlag = SavedDebug; // Restore DebugFlag to previous state
+ }
+ }
-#if 0
- // PtrCasts - Keep a mapping between the pointer values (the key of the
- // map), and the cast to array pointer (the value) in this map. This is
- // used when converting pointer math into array addressing.
- //
- map<Value*, CastInst*> PtrCasts;
+ do {
+ DEBUG(std::cerr << "Looping: \n" << F);
- // Insert casts for all incoming pointer values. Keep track of those casts
- // and the identified incoming values in the PtrCasts map.
- //
- Changed |= DoInsertArrayCasts(M, PtrCasts);
+ // Iterate over the function, refining it, until it converges on a stable
+ // state
+ LocalChange = false;
+ while (DoRaisePass(F)) LocalChange = true;
+ Changed |= LocalChange;
- // Loop over each incoming pointer variable, replacing indexing arithmetic
- // with getelementptr calls.
- //
- Changed |= reduce_apply_bool(PtrCasts.begin(), PtrCasts.end(),
- ptr_fun(DoEliminatePointerArithmetic));
-#endif
+ } while (LocalChange);
return Changed;
}
+
projects / oota-llvm.git / blobdiff