//===----------------------------------------------------------------------===//
#include "TransformInternals.h"
-#include "llvm/Method.h"
#include "llvm/Type.h"
-#include "llvm/ConstPoolVals.h"
+#include "llvm/Analysis/Expressions.h"
+#include "llvm/Function.h"
+#include "llvm/iOther.h"
+#include <algorithm>
// TargetData Hack: Eventually we will have annotations given to us by the
// backend so that we know stuff about type size and alignments. For now
//
const TargetData TD("LevelRaise: Should be GCC though!");
-// losslessCastableTypes - Return true if the types are bitwise equivalent.
-// This predicate returns true if it is possible to cast from one type to
-// another without gaining or losing precision, or altering the bits in any way.
-//
-bool losslessCastableTypes(const Type *T1, const Type *T2) {
- if (!T1->isPrimitiveType() && !T1->isPointerType()) return false;
- if (!T2->isPrimitiveType() && !T2->isPointerType()) return false;
-
- if (T1->getPrimitiveID() == T2->getPrimitiveID())
- return true; // Handles identity cast, and cast of differing pointer types
-
- // Now we know that they are two differing primitive or pointer types
- switch (T1->getPrimitiveID()) {
- case Type::UByteTyID: return T2 == Type::SByteTy;
- case Type::SByteTyID: return T2 == Type::UByteTy;
- case Type::UShortTyID: return T2 == Type::ShortTy;
- case Type::ShortTyID: return T2 == Type::UShortTy;
- case Type::UIntTyID: return T2 == Type::IntTy;
- case Type::IntTyID: return T2 == Type::UIntTy;
- case Type::ULongTyID:
- case Type::LongTyID:
- case Type::PointerTyID:
- return T2 == Type::ULongTy || T2 == Type::LongTy ||
- T2->getPrimitiveID() == Type::PointerTyID;
- default:
- return false; // Other types have no identity values
- }
-}
-
-
// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
// with a value, then remove and delete the original instruction.
//
"ReplaceInstWithInst: Instruction already inserted into basic block!");
// Insert the new instruction into the basic block...
- BI = BIL.insert(BI, I)+1;
+ BI = BIL.insert(BI, I)+1; // Increment BI to point to instruction to delete
// Replace all uses of the old instruction, and delete it.
ReplaceInstWithValue(BIL, BI, I);
- // Reexamine the instruction just inserted next time around the cleanup pass
- // loop.
+ // Move BI back to point to the newly inserted instruction
--BI;
}
+void ReplaceInstWithInst(Instruction *From, Instruction *To) {
+ BasicBlock *BB = From->getParent();
+ BasicBlock::InstListType &BIL = BB->getInstList();
+ BasicBlock::iterator BI = find(BIL.begin(), BIL.end(), From);
+ assert(BI != BIL.end() && "Inst not in it's parents BB!");
+ ReplaceInstWithInst(BIL, BI, To);
+}
+
+// InsertInstBeforeInst - Insert 'NewInst' into the basic block that 'Existing'
+// is already in, and put it right before 'Existing'. This instruction should
+// only be used when there is no iterator to Existing already around. The
+// returned iterator points to the new instruction.
+//
+BasicBlock::iterator InsertInstBeforeInst(Instruction *NewInst,
+ Instruction *Existing) {
+ BasicBlock *BB = Existing->getParent();
+ BasicBlock::InstListType &BIL = BB->getInstList();
+ BasicBlock::iterator BI = find(BIL.begin(), BIL.end(), Existing);
+ assert(BI != BIL.end() && "Inst not in it's parents BB!");
+ return BIL.insert(BI, NewInst);
+}
+
+
+
+static const Type *getStructOffsetStep(const StructType *STy, unsigned &Offset,
+ std::vector<Value*> &Indices) {
+ assert(Offset < TD.getTypeSize(STy) && "Offset not in composite!");
+ const StructLayout *SL = TD.getStructLayout(STy);
+
+ // This loop terminates always on a 0 <= i < MemberOffsets.size()
+ unsigned i;
+ for (i = 0; i < SL->MemberOffsets.size()-1; ++i)
+ if (Offset >= SL->MemberOffsets[i] && Offset < SL->MemberOffsets[i+1])
+ break;
+
+ assert(Offset >= SL->MemberOffsets[i] &&
+ (i == SL->MemberOffsets.size()-1 || Offset < SL->MemberOffsets[i+1]));
+
+ // Make sure to save the current index...
+ Indices.push_back(ConstantUInt::get(Type::UByteTy, i));
+ Offset = SL->MemberOffsets[i];
+ return STy->getContainedType(i);
+}
+
// getStructOffsetType - Return a vector of offsets that are to be used to index
// into the specified struct type to get as close as possible to index as we
// false if you want a leaf
//
const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
- vector<ConstPoolVal*> &Offsets,
+ std::vector<Value*> &Indices,
bool StopEarly = true) {
- if (!isa<StructType>(Ty) || (Offset == 0 && StopEarly && !Offsets.empty())) {
+ if (Offset == 0 && StopEarly && !Indices.empty())
+ return Ty; // Return the leaf type
+
+ unsigned ThisOffset;
+ const Type *NextType;
+ if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+ ThisOffset = Offset;
+ NextType = getStructOffsetStep(STy, ThisOffset, Indices);
+ } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+ assert(Offset < TD.getTypeSize(ATy) && "Offset not in composite!");
+
+ NextType = ATy->getElementType();
+ unsigned ChildSize = TD.getTypeSize(NextType);
+ Indices.push_back(ConstantUInt::get(Type::UIntTy, Offset/ChildSize));
+ ThisOffset = (Offset/ChildSize)*ChildSize;
+ } else {
Offset = 0; // Return the offset that we were able to acheive
return Ty; // Return the leaf type
}
- assert(Offset < TD.getTypeSize(Ty) && "Offset not in struct!");
- const StructType *STy = cast<StructType>(Ty);
- const StructLayout *SL = TD.getStructLayout(STy);
+ unsigned SubOffs = Offset - ThisOffset;
+ const Type *LeafTy = getStructOffsetType(NextType, SubOffs,
+ Indices, StopEarly);
+ Offset = ThisOffset + SubOffs;
+ return LeafTy;
+}
- // This loop terminates always on a 0 <= i < MemberOffsets.size()
- unsigned i;
- for (i = 0; i < SL->MemberOffsets.size()-1; ++i)
- if (Offset >= SL->MemberOffsets[i] && Offset < SL->MemberOffsets[i+1])
- break;
-
- assert(Offset >= SL->MemberOffsets[i] &&
- (i == SL->MemberOffsets.size()-1 || Offset < SL->MemberOffsets[i+1]));
+// ConvertableToGEP - This function returns true if the specified value V is
+// a valid index into a pointer of type Ty. If it is valid, Idx is filled in
+// with the values that would be appropriate to make this a getelementptr
+// instruction. The type returned is the root type that the GEP would point to
+//
+const Type *ConvertableToGEP(const Type *Ty, Value *OffsetVal,
+ std::vector<Value*> &Indices,
+ BasicBlock::iterator *BI = 0) {
+ const CompositeType *CompTy = dyn_cast<CompositeType>(Ty);
+ if (CompTy == 0) return 0;
- // Make sure to save the current index...
- Offsets.push_back(ConstPoolUInt::get(Type::UByteTy, i));
+ // 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 SubOffs = Offset - SL->MemberOffsets[i];
- const Type *LeafTy = getStructOffsetType(STy->getElementTypes()[i], SubOffs,
- Offsets);
- Offset = SL->MemberOffsets[i] + SubOffs;
- return LeafTy;
+ // Get the offset and scale values if they exists...
+ // A scale of zero with Expr.Var != 0 means a scale of 1.
+ //
+ int Offset = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
+ int Scale = Expr.Scale ? getConstantValue(Expr.Scale) : 0;
+
+ if (Expr.Var && Scale == 0) Scale = 1; // Scale != 0 if Expr.Var != 0
+
+ // Loop over the Scale and Offset values, filling in the Indices vector for
+ // our final getelementptr instruction.
+ //
+ const Type *NextTy = CompTy;
+ do {
+ if (!isa<CompositeType>(NextTy))
+ return 0; // Type must not be ready for processing...
+ CompTy = cast<CompositeType>(NextTy);
+
+ if (const StructType *StructTy = dyn_cast<StructType>(CompTy)) {
+ // Step into the appropriate element of the structure...
+ unsigned ActualOffset = (Offset < 0) ? 0 : (unsigned)Offset;
+ NextTy = getStructOffsetStep(StructTy, ActualOffset, Indices);
+ Offset -= ActualOffset;
+ } else {
+ const Type *ElTy = cast<SequentialType>(CompTy)->getElementType();
+ if (!ElTy->isSized())
+ return 0; // Type is unreasonable... escape!
+ unsigned ElSize = TD.getTypeSize(ElTy);
+ int ElSizeS = (int)ElSize;
+
+ // See if the user is indexing into a different cell of this array...
+ if (Scale && (Scale >= ElSizeS || -Scale >= ElSizeS)) {
+ // A scale n*ElSize might occur if we are not stepping through
+ // array by one. In this case, we will have to insert math to munge
+ // the index.
+ //
+ int ScaleAmt = Scale/ElSizeS;
+ if (Scale-ScaleAmt*ElSizeS)
+ return 0; // Didn't scale by a multiple of element size, bail out
+ Scale = 0; // Scale is consumed
+
+ int Index = Offset/ElSize; // is zero unless Offset > ElSize
+ Offset -= Index*ElSize; // Consume part of the offset
+
+ if (BI) { // Generate code?
+ BasicBlock *BB = (**BI)->getParent();
+ if (Expr.Var->getType() != Type::UIntTy) {
+ CastInst *IdxCast = new CastInst(Expr.Var, Type::UIntTy);
+ if (Expr.Var->hasName())
+ IdxCast->setName(Expr.Var->getName()+"-idxcast");
+ *BI = BB->getInstList().insert(*BI, IdxCast)+1;
+ Expr.Var = IdxCast;
+ }
+
+ if (ScaleAmt && ScaleAmt != 1) {
+ // If we have to scale up our index, do so now
+ Value *ScaleAmtVal = ConstantUInt::get(Type::UIntTy,
+ (unsigned)ScaleAmt);
+ Instruction *Scaler = BinaryOperator::create(Instruction::Mul,
+ Expr.Var, ScaleAmtVal);
+ if (Expr.Var->hasName())
+ Scaler->setName(Expr.Var->getName()+"-scale");
+
+ *BI = BB->getInstList().insert(*BI, Scaler)+1;
+ Expr.Var = Scaler;
+ }
+
+ if (Index) { // Add an offset to the index
+ Value *IndexAmt = ConstantUInt::get(Type::UIntTy, (unsigned)Index);
+ Instruction *Offseter = BinaryOperator::create(Instruction::Add,
+ Expr.Var, IndexAmt);
+ if (Expr.Var->hasName())
+ Offseter->setName(Expr.Var->getName()+"-offset");
+ *BI = BB->getInstList().insert(*BI, Offseter)+1;
+ Expr.Var = Offseter;
+ }
+ }
+
+ Indices.push_back(Expr.Var);
+ Expr.Var = 0;
+ } else if (Offset >= (int)ElSize || -Offset >= (int)ElSize) {
+ // Calculate the index that we are entering into the array cell with
+ unsigned Index = Offset/ElSize;
+ Indices.push_back(ConstantUInt::get(Type::UIntTy, Index));
+ Offset -= (int)(Index*ElSize); // Consume part of the offset
+
+ } else if (isa<ArrayType>(CompTy) || Indices.empty()) {
+ // Must be indexing a small amount into the first cell of the array
+ // Just index into element zero of the array here.
+ //
+ Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
+ } else {
+ return 0; // Hrm. wierd, can't handle this case. Bail
+ }
+ NextTy = ElTy;
+ }
+ } while (Offset || Scale); // Go until we're done!
+
+ return NextTy;
}
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