-//===-- TransformInternals.cpp - Implement shared functions for transforms --=//
+//===- TransformInternals.cpp - Implement shared functions for transforms -===//
+//
+// 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 defines shared functions used by the different components of the
// Transforms library.
//===----------------------------------------------------------------------===//
#include "TransformInternals.h"
-#include "llvm/Method.h"
#include "llvm/Type.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
-// though, just use this, because it happens to match the model that GCC uses.
-//
-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
- }
+#include "llvm/Function.h"
+#include "llvm/Instructions.h"
+using namespace llvm;
+
+static const Type *getStructOffsetStep(const StructType *STy, uint64_t &Offset,
+ std::vector<Value*> &Indices,
+ const TargetData &TD) {
+ 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::UIntTy, i));
+ Offset = SL->MemberOffsets[i];
+ return STy->getContainedType(i);
}
-// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
-// with a value, then remove and delete the original instruction.
+// 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
+// can. Note that it is possible that we cannot get exactly to Offset, in which
+// case we update offset to be the offset we actually obtained. The resultant
+// leaf type is returned.
//
-void ReplaceInstWithValue(BasicBlock::InstListType &BIL,
- BasicBlock::iterator &BI, Value *V) {
- Instruction *I = *BI;
- // Replaces all of the uses of the instruction with uses of the value
- I->replaceAllUsesWith(V);
-
- // Remove the unneccesary instruction now...
- BIL.remove(BI);
-
- // Make sure to propogate a name if there is one already...
- if (I->hasName() && !V->hasName())
- V->setName(I->getName(), BIL.getParent()->getSymbolTable());
-
- // Remove the dead instruction now...
- delete I;
-}
-
-
-// ReplaceInstWithInst - Replace the instruction specified by BI with the
-// instruction specified by I. The original instruction is deleted and BI is
-// updated to point to the new instruction.
+// If StopEarly is set to true (the default), the first object with the
+// specified type is returned, even if it is a struct type itself. In this
+// case, this routine will not drill down to the leaf type. Set StopEarly to
+// false if you want a leaf
//
-void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
- BasicBlock::iterator &BI, Instruction *I) {
- assert(I->getParent() == 0 &&
- "ReplaceInstWithInst: Instruction already inserted into basic block!");
-
- // Insert the new instruction into the basic block...
- BI = BIL.insert(BI, I)+1;
-
- // Replace all uses of the old instruction, and delete it.
- ReplaceInstWithValue(BIL, BI, I);
+const Type *llvm::getStructOffsetType(const Type *Ty, unsigned &Offset,
+ std::vector<Value*> &Indices,
+ const TargetData &TD, bool StopEarly) {
+ if (Offset == 0 && StopEarly && !Indices.empty())
+ return Ty; // Return the leaf type
+
+ uint64_t ThisOffset;
+ const Type *NextType;
+ if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+ if (STy->getNumElements()) {
+ Offset = 0;
+ return STy;
+ }
+
+ ThisOffset = Offset;
+ NextType = getStructOffsetStep(STy, ThisOffset, Indices, TD);
+ } else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+ assert(Offset == 0 || Offset < TD.getTypeSize(ATy) &&
+ "Offset not in composite!");
+
+ NextType = ATy->getElementType();
+ unsigned ChildSize = (unsigned)TD.getTypeSize(NextType);
+ if (ConstantSInt::isValueValidForType(Type::IntTy, Offset/ChildSize))
+ Indices.push_back(ConstantSInt::get(Type::IntTy, Offset/ChildSize));
+ else
+ Indices.push_back(ConstantSInt::get(Type::LongTy, Offset/ChildSize));
+ ThisOffset = (Offset/ChildSize)*ChildSize;
+ } else {
+ Offset = 0; // Return the offset that we were able to achieve
+ return Ty; // Return the leaf type
+ }
- // Reexamine the instruction just inserted next time around the cleanup pass
- // loop.
- --BI;
+ unsigned SubOffs = unsigned(Offset - ThisOffset);
+ const Type *LeafTy = getStructOffsetType(NextType, SubOffs,
+ Indices, TD, StopEarly);
+ Offset = unsigned(ThisOffset + SubOffs);
+ return LeafTy;
}
-
-