[mlir][sroa] Update name of subelement types in destructurable slots (llvm#97226)

The `elementPtrs` has changed meaning over time and the name is now
outdated which may be confusing. This PR updates it to a name
representative of current usage.

Author: Moxinilian

mlir/include/mlir/Interfaces/MemorySlotInterfaces.h

@@ -27,7 +27,7 @@ struct MemorySlot {
 /// Memory slot attached with information about its destructuring procedure.
 struct DestructurableMemorySlot : public MemorySlot {
   /// Maps an index within the memory slot to the corresponding subelement type.
-  DenseMap<Attribute, Type> elementPtrs;
+  DenseMap<Attribute, Type> subelementTypes;
 };
 
 /// Returned by operation promotion logic requesting the deletion of an

mlir/lib/Dialect/LLVMIR/IR/LLVMMemorySlot.cpp

@@ -841,12 +841,12 @@ bool LLVM::GEPOp::canRewire(const DestructurableMemorySlot &slot,
     return false;
   auto indexAttr =
       IntegerAttr::get(IntegerType::get(getContext(), 32), accessInfo->index);
-  assert(slot.elementPtrs.contains(indexAttr));
+  assert(slot.subelementTypes.contains(indexAttr));
   usedIndices.insert(indexAttr);
 
   // The remainder of the subslot should be accesses in-bounds. Thus, we create
   // a dummy slot with the size of the remainder.
-  Type subslotType = slot.elementPtrs.lookup(indexAttr);
+  Type subslotType = slot.subelementTypes.lookup(indexAttr);
   uint64_t slotSize = dataLayout.getTypeSize(subslotType);
   LLVM::LLVMArrayType remainingSlotType =
       getByteArrayType(getContext(), slotSize - accessInfo->subslotOffset);
@@ -923,7 +923,7 @@ static bool definitelyWritesOnlyWithinSlot(MemIntr op, const MemorySlot &slot,
 /// into them.
 static bool areAllIndicesI32(const DestructurableMemorySlot &slot) {
   Type i32 = IntegerType::get(slot.ptr.getContext(), 32);
-  return llvm::all_of(llvm::make_first_range(slot.elementPtrs),
+  return llvm::all_of(llvm::make_first_range(slot.subelementTypes),
                       [&](Attribute index) {
                         auto intIndex = dyn_cast<IntegerAttr>(index);
                         return intIndex && intIndex.getType() == i32;
@@ -1159,7 +1159,7 @@ static bool memcpyCanRewire(MemcpyLike op, const DestructurableMemorySlot &slot,
     return false;
 
   if (op.getSrc() == slot.ptr)
-    for (Attribute index : llvm::make_first_range(slot.elementPtrs))
+    for (Attribute index : llvm::make_first_range(slot.subelementTypes))
       usedIndices.insert(index);
 
   return true;
@@ -1211,7 +1211,7 @@ memcpyRewire(MemcpyLike op, const DestructurableMemorySlot &slot,
   // It was previously checked that index types are consistent, so this type can
   // be fetched now.
   Type indexType = cast<IntegerAttr>(subslots.begin()->first).getType();
-  for (size_t i = 0, e = slot.elementPtrs.size(); i != e; i++) {
+  for (size_t i = 0, e = slot.subelementTypes.size(); i != e; i++) {
     Attribute index = IntegerAttr::get(indexType, i);
     if (!subslots.contains(index))
       continue;

mlir/lib/Dialect/MemRef/IR/MemRefMemorySlot.cpp

@@ -277,7 +277,7 @@ bool memref::StoreOp::canRewire(const DestructurableMemorySlot &slot,
     return false;
   Attribute index = getAttributeIndexFromIndexOperands(
       getContext(), getIndices(), getMemRefType());
-  if (!index || !slot.elementPtrs.contains(index))
+  if (!index || !slot.subelementTypes.contains(index))
     return false;
   usedIndices.insert(index);
   return true;

mlir/lib/Transforms/SROA.cpp

@@ -146,11 +146,11 @@ static void destructureSlot(
       allocator.destructure(slot, info.usedIndices, builder, newAllocators);
 
   if (statistics.slotsWithMemoryBenefit &&
-      slot.elementPtrs.size() != info.usedIndices.size())
+      slot.subelementTypes.size() != info.usedIndices.size())
     (*statistics.slotsWithMemoryBenefit)++;
 
   if (statistics.maxSubelementAmount)
-    statistics.maxSubelementAmount->updateMax(slot.elementPtrs.size());
+    statistics.maxSubelementAmount->updateMax(slot.subelementTypes.size());
 
   SetVector<Operation *> usersToRewire;
   for (Operation *user : llvm::make_first_range(info.userToBlockingUses))

mlir/test/lib/Dialect/Test/TestOpDefs.cpp

@@ -1321,7 +1321,7 @@ DenseMap<Attribute, MemorySlot> TestMultiSlotAlloca::destructure(
   DenseMap<Attribute, MemorySlot> slotMap;
 
   for (Attribute usedIndex : usedIndices) {
-    Type elemType = slot.elementPtrs.lookup(usedIndex);
+    Type elemType = slot.subelementTypes.lookup(usedIndex);
     MemRefType elemPtr = MemRefType::get({}, elemType);
     auto subAlloca = builder.create<TestMultiSlotAlloca>(getLoc(), elemPtr);
     newAllocators.push_back(subAlloca);