//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/LevelChange.h"
+#include "llvm/Transforms/RaisePointerReferences.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "TransformInternals.h"
-#include "llvm/Method.h"
#include "llvm/iOther.h"
#include "llvm/iMemory.h"
-#include "llvm/ConstantVals.h"
-#include "llvm/Optimizations/ConstantHandling.h"
-#include "llvm/Optimizations/DCE.h"
-#include "llvm/Optimizations/ConstantProp.h"
+#include "llvm/Pass.h"
+#include "llvm/ConstantHandling.h"
#include "llvm/Analysis/Expressions.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "Support/STLExtras.h"
+#include "Support/StatisticReporter.h"
+#include "Support/CommandLine.h"
#include <algorithm>
+using std::cerr;
-#include "llvm/Assembly/Writer.h"
+// 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\t\t- Number of load/store peepholes");
+
+static Statistic<>
+NumGEPInstFormed("raise\t\t- Number of other getelementptr's formed");
+
+static Statistic<>
+NumExprTreesConv("raise\t\t- Number of expression trees converted");
+
+static Statistic<>
+NumCastOfCast("raise\t\t- Number of cast-of-self removed");
+
+static Statistic<>
+NumDCEorCP("raise\t\t- Number of insts DCEd or constprop'd");
-//#define DEBUG_PEEPHOLE_INSTS 1
-#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) \
}
-
// Peephole optimize the following instructions:
// %t1 = cast ? to x *
// %t2 = add x * %SP, %t1 ;; Constant must be 2nd operand
//
static bool HandleCastToPointer(BasicBlock::iterator BI,
const PointerType *DestPTy) {
- CastInst *CI = cast<CastInst>(*BI);
+ 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();
+ 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)
+ if (BO->getOpcode() != Instruction::Add ||
+ // Avoid add sbyte* %X, %X cases...
+ BO->getOperand(0) == BO->getOperand(1))
return false;
} else {
return false;
}
std::vector<Value*> Indices;
- Value *Src = CI->getOperand(0);
+ Value *Src = CI.getOperand(0);
const Type *Result = ConvertableToGEP(DestPTy, Src, Indices, &BI);
if (Result == 0) return false; // Not convertable...
// If we have a getelementptr capability... transform all of the
// add instruction uses into getelementptr's.
- for (Value::use_iterator UI = CI->use_begin(), E = CI->use_end();
- UI != E; ++UI) {
- Instruction *I = cast<Instruction>(*UI);
+ 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);
+ Value *OtherPtr = I->getOperand((I->getOperand(0) == &CI) ? 1 : 0);
- BasicBlock *BB = I->getParent();
- BasicBlock::iterator AddIt = find(BB->getInstList().begin(),
- BB->getInstList().end(), I);
+ Instruction *GEP = new GetElementPtrInst(OtherPtr, Indices, I->getName());
+ PRINT_PEEPHOLE1("cast-add-to-gep:i", I);
- GetElementPtrInst *GEP = new GetElementPtrInst(OtherPtr, Indices);
+ 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...
+ I->getParent()->getInstList().insert(I, GEP);
+
+ PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP);
+ GEP = new CastInst(GEP, I->getType());
+
+ // Replace the old add instruction with the shiny new GEP inst
+ ReplaceInstWithInst(I, GEP);
+ }
- PRINT_PEEPHOLE1("cast-add-to-gep:i", I);
-
- // Replace the old add instruction with the shiny new GEP inst
- ReplaceInstWithInst(BB->getInstList(), AddIt, GEP);
PRINT_PEEPHOLE1("cast-add-to-gep:o", GEP);
}
return true;
}
// Only proceed if we have detected all of our conditions successfully...
- if (!CompTy || !SrcPtr || !OffsetVal->getType()->isIntegral())
+ if (!CompTy || !SrcPtr || !OffsetVal->getType()->isInteger())
return false;
std::vector<Value*> Indices;
}
GetElementPtrInst *GEP = new GetElementPtrInst(SrcPtr, Indices,
- AddOp2->getName());
- BI = BB->getInstList().insert(BI, GEP)+1;
+ AddOp2->getName(), BI);
Instruction *NCI = new CastInst(GEP, AddOp1->getType());
ReplaceInstWithInst(BB->getInstList(), BI, NCI);
}
static bool PeepholeOptimize(BasicBlock *BB, BasicBlock::iterator &BI) {
- Instruction *I = *BI;
+ Instruction *I = BI;
if (CastInst *CI = dyn_cast<CastInst>(I)) {
Value *Src = CI->getOperand(0);
CI->setName("");
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;
- // Check to see if we can convert the users of the cast value to match the
- // source type of the cast...
+ // 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 (ExpressionConvertableToType(Src, DestTy, ConvertedTypes)) {
PRINT_PEEPHOLE3("CAST-SRC-EXPR-CONV:in ", Src, CI, BB->getParent());
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\nCONVERTING SRC EXPR TYPE:\n";
-#endif
- ValueMapCache ValueMap;
- Value *E = ConvertExpressionToType(Src, DestTy, ValueMap);
- if (Constant *CPV = dyn_cast<Constant>(E))
- CI->replaceAllUsesWith(CPV);
+ DEBUG(cerr << "\nCONVERTING SRC EXPR TYPE:\n");
+ { // ValueMap must be destroyed before function verified!
+ ValueMapCache ValueMap;
+ Value *E = ConvertExpressionToType(Src, DestTy, ValueMap);
+ if (Constant *CPV = dyn_cast<Constant>(E))
+ CI->replaceAllUsesWith(CPV);
+
+ PRINT_PEEPHOLE1("CAST-SRC-EXPR-CONV:out", E);
+ DEBUG(cerr << "DONE CONVERTING SRC EXPR TYPE: \n" << BB->getParent());
+ }
+
+ DEBUG(assert(verifyFunction(*BB->getParent()) == false &&
+ "Function broken!"));
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" << BB->getParent();
-#endif
+ ++NumExprTreesConv;
return true;
}
- // Check to see if we can convert the source of the cast to match the
- // destination type of the cast...
+ // Check to see if we can convert the users of the cast value to match the
+ // source type of the cast...
//
ConvertedTypes.clear();
+ ConvertedTypes[Src] = Src->getType(); // Make sure the source doesn't change type
if (ValueConvertableToType(CI, Src->getType(), ConvertedTypes)) {
PRINT_PEEPHOLE3("CAST-DEST-EXPR-CONV:in ", Src, CI, BB->getParent());
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\nCONVERTING EXPR TYPE:\n";
-#endif
- ValueMapCache ValueMap;
- ConvertValueToNewType(CI, Src, ValueMap); // This will delete CI!
+ DEBUG(cerr << "\nCONVERTING EXPR TYPE:\n");
+ { // ValueMap must be destroyed before function verified!
+ ValueMapCache ValueMap;
+ ConvertValueToNewType(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
+ DEBUG(cerr << "DONE CONVERTING EXPR TYPE: \n\n" << BB->getParent());
+
+ DEBUG(assert(verifyFunction(*BB->getParent()) == false &&
+ "Function broken!"));
+ BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ ++NumExprTreesConv;
return true;
}
}
if (const PointerType *DestPTy = dyn_cast<PointerType>(DestTy)) {
if (HandleCastToPointer(BI, DestPTy)) {
BI = BB->begin(); // Rescan basic block. BI might be invalidated.
+ ++NumGEPInstFormed;
return true;
}
}
// Into: %t2 = getelementptr {<...>} * %StructPtr, <0, 0, 0, ...>
// %t1 = cast <eltype> * %t1 to <ty> *
//
-#if 1
if (const CompositeType *CTy = getPointedToComposite(Src->getType()))
if (const PointerType *DestPTy = dyn_cast<PointerType>(DestTy)) {
// Build the index vector, full of all zeros
std::vector<Value*> Indices;
- Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
+ Indices.push_back(ConstantSInt::get(Type::LongTy, 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.
}
// Insert a zero to index through this type...
- Indices.push_back(ConstantUInt::get(CurCTy->getIndexType(), 0));
+ Indices.push_back(Constant::getNullValue(CurCTy->getIndexType()));
// Did we find what we're looking for?
if (ElTy->isLosslesslyConvertableTo(DestPointedTy)) break;
if (ElTy) {
PRINT_PEEPHOLE1("cast-for-first:in", CI);
+ 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);
+ ++NumGEPInstFormed;
return true;
}
}
}
-#endif
-#if 1
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
Value *Val = SI->getOperand(0);
Value *Pointer = SI->getPointerOperand();
//
if (CastInst *CI = dyn_cast<CastInst>(Pointer))
if (Value *CastSrc = CI->getOperand(0)) // CSPT = CastSrcPointerType
- if (PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType()))
+ if (const PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType()))
// convertable types?
- if (Val->getType()->isLosslesslyConvertableTo(CSPT->getElementType()) &&
- !SI->hasIndices()) { // No subscripts yet!
+ if (Val->getType()->isLosslesslyConvertableTo(CSPT->getElementType())) {
PRINT_PEEPHOLE3("st-src-cast:in ", Pointer, Val, SI);
// Insert the new T cast instruction... stealing old T's name
+ std::string Name(CI->getName()); CI->setName("");
CastInst *NCI = new CastInst(Val, CSPT->getElementType(),
- CI->getName());
- CI->setName("");
- BI = BB->getInstList().insert(BI, NCI)+1;
+ 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);
+ ++NumLoadStorePeepholes;
+ return true;
+ }
+
+ } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
+ Value *Pointer = LI->getOperand(0);
+ const Type *PtrElType =
+ cast<PointerType>(Pointer->getType())->getElementType();
+
+ // Peephole optimize the following instructions:
+ // %Val = cast <T1>* to <T2>* ;; If T1 is losslessly convertable to T2
+ // %t = load <T2>* %P
+ //
+ // Into:
+ // %t = load <T1>* %P
+ // %Val = cast <T1> to <T2>
+ //
+ // 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 (const PointerType *CSPT = dyn_cast<PointerType>(CastSrc->getType()))
+ // convertable types?
+ if (PtrElType->isLosslesslyConvertableTo(CSPT->getElementType())) {
+ PRINT_PEEPHOLE2("load-src-cast:in ", Pointer, LI);
+
+ // 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 store with a new one!
+ ReplaceInstWithInst(BB->getInstList(), BI, NCI);
+ PRINT_PEEPHOLE3("load-src-cast:out", NCI, CastSrc, NewLI);
+ ++NumLoadStorePeepholes;
return true;
}
isa<CastInst>(I->getOperand(1))) {
if (PeepholeOptimizeAddCast(BB, BI, I->getOperand(0),
- cast<CastInst>(I->getOperand(1))))
+ cast<CastInst>(I->getOperand(1)))) {
+ ++NumGEPInstFormed;
return true;
-
-#endif
+ }
}
return false;
-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) {
- 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 DEBUG_PEEPHOLE_INSTS
- cerr << "Processing: " << *BI;
-#endif
- if (opt::DeadCodeElimination::dceInstruction(BIL, BI) ||
- opt::ConstantPropogation::doConstantPropogation(BB, BI)) {
+ DEBUG(cerr << "Processing: " << *BI);
+ if (dceInstruction(BI) || doConstantPropogation(BI)) {
Changed = true;
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "DeadCode Elinated!\n";
-#endif
- } else if (PeepholeOptimize(BB, BI))
+ ++NumDCEorCP;
+ DEBUG(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
+// RaisePointerReferences::doit - Raise a function representation to a higher
// level.
//
-bool RaisePointerReferences::doit(Method *M) {
- if (M->isExternal()) return false;
-
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "\n\n\nStarting to work on Method '" << M->getName() << "'\n";
-#endif
+static bool doRPR(Function &F) {
+ DEBUG(cerr << "\n\n\nStarting to work on Function '" << F.getName() << "'\n");
// Insert casts for all incoming pointer pointer values that are treated as
// arrays...
//
bool Changed = false, LocalChange;
+
+ // 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
+ }
+ }
+
do {
-#ifdef DEBUG_PEEPHOLE_INSTS
- cerr << "Looping: \n" << M;
-#endif
+ DEBUG(cerr << "Looping: \n" << F);
- // 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
LocalChange = false;
- while (DoRaisePass(M)) LocalChange = true;
+ while (DoRaisePass(F)) LocalChange = true;
Changed |= LocalChange;
} while (LocalChange);
return Changed;
}
+
+namespace {
+ struct RaisePointerReferences : public FunctionPass {
+
+ // FIXME: constructor should save and use target data here!!
+ RaisePointerReferences(const TargetData &TD) {}
+
+ virtual bool runOnFunction(Function &F) { return doRPR(F); }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.preservesCFG();
+ }
+ };
+}
+
+Pass *createRaisePointerReferencesPass(const TargetData &TD) {
+ return new RaisePointerReferences(TD);
+}
+
+static RegisterOpt<RaisePointerReferences>
+X("raise", "Raise Pointer References", createRaisePointerReferencesPass);