[SROA] NFC: Look at TypeStoreSize scalable property, rather than at t…

…ype directly.

Some places in the code have checks for isa<ScalableVectorType> and use
that to bail out of the code. It's also possible to look directly at the
allocated type-size and check if the size is scalable. This means it's
possible to also support other scalable types that are not vectors (i.e.
TargetExtType).

This is split out from D136861.

llvm/lib/Transforms/Scalar/SROA.cpp

@@ -956,11 +956,12 @@ class AllocaSlices::SliceBuilder : public PtrUseVisitor<SliceBuilder> {
     if (!IsOffsetKnown)
       return PI.setAborted(&LI);
 
-    if (isa<ScalableVectorType>(LI.getType()))
+    TypeSize Size = DL.getTypeStoreSize(LI.getType());
+    if (Size.isScalable())
       return PI.setAborted(&LI);
 
-    uint64_t Size = DL.getTypeStoreSize(LI.getType()).getFixedValue();
-    return handleLoadOrStore(LI.getType(), LI, Offset, Size, LI.isVolatile());
+    return handleLoadOrStore(LI.getType(), LI, Offset, Size.getFixedValue(),
+                             LI.isVolatile());
   }
 
   void visitStoreInst(StoreInst &SI) {
@@ -970,10 +971,11 @@ class AllocaSlices::SliceBuilder : public PtrUseVisitor<SliceBuilder> {
     if (!IsOffsetKnown)
       return PI.setAborted(&SI);
 
-    if (isa<ScalableVectorType>(ValOp->getType()))
+    TypeSize StoreSize = DL.getTypeStoreSize(ValOp->getType());
+    if (StoreSize.isScalable())
       return PI.setAborted(&SI);
 
-    uint64_t Size = DL.getTypeStoreSize(ValOp->getType()).getFixedValue();
+    uint64_t Size = StoreSize.getFixedValue();
 
     // If this memory access can be shown to *statically* extend outside the
     // bounds of the allocation, it's behavior is undefined, so simply
@@ -4864,8 +4866,9 @@ SROAPass::runOnAlloca(AllocaInst &AI) {
 
   // Skip alloca forms that this analysis can't handle.
   auto *AT = AI.getAllocatedType();
-  if (AI.isArrayAllocation() || !AT->isSized() || isa<ScalableVectorType>(AT) ||
-      DL.getTypeAllocSize(AT).getFixedValue() == 0)
+  TypeSize Size = DL.getTypeAllocSize(AT);
+  if (AI.isArrayAllocation() || !AT->isSized() || Size.isScalable() ||
+      Size.getFixedValue() == 0)
     return {Changed, CFGChanged};
 
   // First, split any FCA loads and stores touching this alloca to promote
@@ -4993,16 +4996,16 @@ PreservedAnalyses SROAPass::runImpl(Function &F, DomTreeUpdater &RunDTU,
   DTU = &RunDTU;
   AC = &RunAC;
 
+  const DataLayout &DL = F.getParent()->getDataLayout();
   BasicBlock &EntryBB = F.getEntryBlock();
   for (BasicBlock::iterator I = EntryBB.begin(), E = std::prev(EntryBB.end());
        I != E; ++I) {
     if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
-      if (isa<ScalableVectorType>(AI->getAllocatedType())) {
-        if (isAllocaPromotable(AI))
-          PromotableAllocas.push_back(AI);
-      } else {
+      if (DL.getTypeAllocSize(AI->getAllocatedType()).isScalable() &&
+          isAllocaPromotable(AI))
+        PromotableAllocas.push_back(AI);
+      else
         Worklist.insert(AI);
-      }
     }
   }