#include "TransformInternals.h"
#include "llvm/Method.h"
#include "llvm/Type.h"
-#include "llvm/ConstPoolVals.h"
+#include "llvm/ConstantVals.h"
+#include "llvm/Analysis/Expressions.h"
+#include "llvm/iOther.h"
// 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.
//
// false if you want a leaf
//
const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
- vector<ConstPoolVal*> &Offsets,
+ vector<Value*> &Offsets,
bool StopEarly = true) {
- if (!isa<StructType>(Ty) || (Offset == 0 && StopEarly && !Offsets.empty())) {
+ if (!isa<CompositeType>(Ty) ||
+ (Offset == 0 && StopEarly && !Offsets.empty())) {
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);
-
- // 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;
+ unsigned ThisOffset;
+ const Type *NextType;
+ if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+ assert(Offset < TD.getTypeSize(Ty) && "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...
- Offsets.push_back(ConstPoolUInt::get(Type::UByteTy, i));
+ assert(Offset >= SL->MemberOffsets[i] &&
+ (i == SL->MemberOffsets.size()-1 || Offset <SL->MemberOffsets[i+1]));
+
+ // Make sure to save the current index...
+ Offsets.push_back(ConstantUInt::get(Type::UByteTy, i));
+ ThisOffset = SL->MemberOffsets[i];
+ NextType = STy->getElementTypes()[i];
+ } else {
+ const ArrayType *ATy = cast<ArrayType>(Ty);
+ assert(ATy->isUnsized() || Offset < TD.getTypeSize(Ty) &&
+ "Offset not in composite!");
+
+ NextType = ATy->getElementType();
+ unsigned ChildSize = TD.getTypeSize(NextType);
+ Offsets.push_back(ConstantUInt::get(Type::UIntTy, Offset/ChildSize));
+ ThisOffset = (Offset/ChildSize)*ChildSize;
+ }
- unsigned SubOffs = Offset - SL->MemberOffsets[i];
- const Type *LeafTy = getStructOffsetType(STy->getElementTypes()[i], SubOffs,
- Offsets);
- Offset = SL->MemberOffsets[i] + SubOffs;
+ unsigned SubOffs = Offset - ThisOffset;
+ const Type *LeafTy = getStructOffsetType(NextType, SubOffs, Offsets);
+ Offset = ThisOffset + SubOffs;
return LeafTy;
}
+
+// 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,
+ vector<Value*> &Indices,
+ BasicBlock::iterator *BI = 0) {
+ const CompositeType *CompTy = getPointedToComposite(Ty);
+ if (CompTy == 0) return 0;
+
+ // 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);
+
+ // The expression must either be a constant, or a scaled index to be useful
+ if (!Expr.Offset && !Expr.Scale)
+ return 0;
+
+ // Get the offset and scale now...
+ unsigned Offset = 0, Scale = Expr.Var != 0;
+
+ // Get the offset value if it exists...
+ if (Expr.Offset) {
+ int Val = getConstantValue(Expr.Offset);
+ if (Val < 0) return false; // Don't mess with negative offsets
+ Offset = (unsigned)Val;
+ }
+
+ // Get the scale value if it exists...
+ if (Expr.Scale) {
+ int Val = getConstantValue(Expr.Scale);
+ if (Val < 0) return false; // Don't mess with negative scales
+ Scale = (unsigned)Val;
+ }
+
+ // Check to make sure the offset is not negative or really large, outside the
+ // scope of this structure...
+ //
+ if (!isa<ArrayType>(CompTy) || cast<ArrayType>(CompTy)->isSized())
+ if (Offset >= TD.getTypeSize(CompTy))
+ return 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)) {
+ const StructLayout *SL = TD.getStructLayout(StructTy);
+ unsigned ActualOffset = Offset;
+ NextTy = getStructOffsetType(StructTy, ActualOffset, Indices);
+ Offset -= ActualOffset;
+ } else {
+ const ArrayType *AT = cast<ArrayType>(CompTy);
+ const Type *ElTy = AT->getElementType();
+ unsigned ElSize = TD.getTypeSize(ElTy);
+
+ // See if the user is indexing into a different cell of this array...
+ if (Scale && Scale >= ElSize) {
+ // 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.
+ //
+ unsigned ScaleAmt = Scale/ElSize;
+ if (Scale-ScaleAmt*ElSize)
+ return 0; // Didn't scale by a multiple of element size, bail out
+ Scale = ElSize;
+
+ unsigned 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 (Scale > ElSize) { // If we have to scale up our index, do so now
+ Value *ScaleAmtVal = ConstantUInt::get(Type::UIntTy, 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, 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);
+ Scale = 0; // Consume scale factor!
+ } else if (Offset >= 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 -= Index*ElSize; // Consume part of the offset
+
+ } else {
+ // 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));
+ }
+ NextTy = ElTy;
+ }
+ } while (Offset || Scale); // Go until we're done!
+
+ return NextTy;
+}