Move the folding of gep null, 0, 0, 0 to a place where it can be shared and

enjoyed by all, fixing a fixme.  Add an assert

llvm-svn: 11505
This commit is contained in:
Chris Lattner 2004-02-16 20:46:13 +00:00
parent 4dd7a7245f
commit 04b60fe5ad
2 changed files with 20 additions and 14 deletions

View File

@ -927,8 +927,21 @@ Constant *llvm::ConstantFoldGetElementPtr(const Constant *C,
(IdxList.size() == 1 && IdxList[0]->isNullValue()))
return const_cast<Constant*>(C);
// TODO If C is null and all idx's are null, return null of the right type.
if (C->isNullValue()) {
bool isNull = true;
for (unsigned i = 0, e = IdxList.size(); i != e; ++i)
if (!IdxList[i]->isNullValue()) {
isNull = false;
break;
}
if (isNull) {
std::vector<Value*> VIdxList(IdxList.begin(), IdxList.end());
const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), VIdxList,
true);
assert(Ty != 0 && "Invalid indices for GEP!");
return ConstantPointerNull::get(PointerType::get(Ty));
}
}
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(const_cast<Constant*>(C))) {
// Combine Indices - If the source pointer to this getelementptr instruction

View File

@ -1081,11 +1081,15 @@ Constant *ConstantExpr::getShiftTy(const Type *ReqTy, unsigned Opcode,
Constant *ConstantExpr::getGetElementPtrTy(const Type *ReqTy, Constant *C,
const std::vector<Constant*> &IdxList) {
assert(GetElementPtrInst::getIndexedType(C->getType(),
std::vector<Value*>(IdxList.begin(), IdxList.end()), true) &&
"GEP indices invalid!");
if (Constant *FC = ConstantFoldGetElementPtr(C, IdxList))
return FC; // Fold a few common cases...
assert(isa<PointerType>(C->getType()) &&
"Non-pointer type for constant GetElementPtr expression");
// Look up the constant in the table first to ensure uniqueness
std::vector<Constant*> argVec(1, C);
argVec.insert(argVec.end(), IdxList.begin(), IdxList.end());
@ -1101,17 +1105,6 @@ Constant *ConstantExpr::getGetElementPtr(Constant *C,
const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), VIdxList,
true);
assert(Ty && "GEP indices invalid!");
if (C->isNullValue()) {
bool isNull = true;
for (unsigned i = 0, e = IdxList.size(); i != e; ++i)
if (!IdxList[i]->isNullValue()) {
isNull = false;
break;
}
if (isNull) return ConstantPointerNull::get(PointerType::get(Ty));
}
return getGetElementPtrTy(PointerType::get(Ty), C, IdxList);
}