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* add ReplaceInstWithInst 

* Add support for pointer indexing
* Fix minor bugs that are majorly annoying

llvm-svn: 1467
This commit is contained in:
Chris Lattner 2001-12-14 16:38:59 +00:00
parent b3364fc169
commit 9dedd32ff4
1 changed files with 25 additions and 26 deletions
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51
llvm/lib/Transforms/TransformInternals.cpp
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@ -11,6 +11,7 @@
#include "llvm/ConstantVals.h"
#include "llvm/Analysis/Expressions.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
@ -59,6 +60,15 @@ void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
--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);
}
// 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
@ -74,16 +84,13 @@ void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
vector<Value*> &Offsets,
bool StopEarly = true) {
if (!isa<CompositeType>(Ty) ||
(Offset == 0 && StopEarly && !Offsets.empty())) {
Offset = 0; // Return the offset that we were able to acheive
if (Offset == 0 && StopEarly && !Offsets.empty())
return Ty; // Return the leaf type
}
unsigned ThisOffset;
const Type *NextType;
if (const StructType *STy = dyn_cast<StructType>(Ty)) {
assert(Offset < TD.getTypeSize(Ty) && "Offset not in composite!");
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()
@ -99,15 +106,16 @@ const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
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!");
} 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);
Offsets.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
}
unsigned SubOffs = Offset - ThisOffset;
@ -124,7 +132,7 @@ const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
const Type *ConvertableToGEP(const Type *Ty, Value *OffsetVal,
vector<Value*> &Indices,
BasicBlock::iterator *BI = 0) {
const CompositeType *CompTy = getPointedToComposite(Ty);
const CompositeType *CompTy = dyn_cast<CompositeType>(Ty);
if (CompTy == 0) return 0;
// See if the cast is of an integer expression that is either a constant,
@ -132,10 +140,6 @@ const Type *ConvertableToGEP(const Type *Ty, Value *OffsetVal,
//
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;
@ -153,13 +157,6 @@ const Type *ConvertableToGEP(const Type *Ty, Value *OffsetVal,
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.
//
@ -173,10 +170,11 @@ const Type *ConvertableToGEP(const Type *Ty, Value *OffsetVal,
const StructLayout *SL = TD.getStructLayout(StructTy);
unsigned ActualOffset = Offset;
NextTy = getStructOffsetType(StructTy, ActualOffset, Indices);
if (StructTy == NextTy && ActualOffset == 0) return 0; // No progress. :(
Offset -= ActualOffset;
} else {
const ArrayType *AT = cast<ArrayType>(CompTy);
const Type *ElTy = AT->getElementType();
const Type *ElTy = cast<SequentialType>(CompTy)->getElementType();
if (!ElTy->isSized()) return 0; // Type is unreasonable... escape!
unsigned ElSize = TD.getTypeSize(ElTy);
// See if the user is indexing into a different cell of this array...
@ -188,7 +186,7 @@ const Type *ConvertableToGEP(const Type *Ty, Value *OffsetVal,
unsigned ScaleAmt = Scale/ElSize;
if (Scale-ScaleAmt*ElSize)
return 0; // Didn't scale by a multiple of element size, bail out
Scale = ElSize;
Scale = 0; // Scale is consumed
unsigned Index = Offset/ElSize; // is zero unless Offset > ElSize
Offset -= Index*ElSize; // Consume part of the offset
@ -227,18 +225,19 @@ const Type *ConvertableToGEP(const Type *Ty, Value *OffsetVal,
}
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 {
} else if (!isa<PointerType>(CompTy) || CompTy == Ty) {
// 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;
}