using namespace llvm;
-/// ComputeLinearIndex - Given an LLVM IR aggregate type and a sequence
-/// of insertvalue or extractvalue indices that identify a member, return
-/// the linearized index of the start of the member.
-///
+/// Compute the linearized index of a member in a nested aggregate/struct/array
+/// by recursing and accumulating CurIndex as long as there are indices in the
+/// index list.
unsigned llvm::ComputeLinearIndex(Type *Ty,
const unsigned *Indices,
const unsigned *IndicesEnd,
return ComputeLinearIndex(*EI, Indices+1, IndicesEnd, CurIndex);
CurIndex = ComputeLinearIndex(*EI, nullptr, nullptr, CurIndex);
}
+ assert(!Indices && "Unexpected out of bound");
return CurIndex;
}
// Given an array type, recursively traverse the elements.
else if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
Type *EltTy = ATy->getElementType();
- for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) {
- if (Indices && *Indices == i)
- return ComputeLinearIndex(EltTy, Indices+1, IndicesEnd, CurIndex);
- CurIndex = ComputeLinearIndex(EltTy, nullptr, nullptr, CurIndex);
+ unsigned NumElts = ATy->getNumElements();
+ // Compute the Linear offset when jumping one element of the array
+ unsigned EltLinearOffset = ComputeLinearIndex(EltTy, nullptr, nullptr, 0);
+ if (Indices) {
+ assert(*Indices < NumElts && "Unexpected out of bound");
+ // If the indice is inside the array, compute the index to the requested
+ // elt and recurse inside the element with the end of the indices list
+ CurIndex += EltLinearOffset* *Indices;
+ return ComputeLinearIndex(EltTy, Indices+1, IndicesEnd, CurIndex);
}
+ CurIndex += EltLinearOffset*NumElts;
return CurIndex;
}
// We haven't found the type we're looking for, so keep searching.