[Analysis] Add Scalable field in MemoryLocation.h

  This is the first of a series of patch to improve Alias Analysis on
Scalable quantities.
  Keep Scalable information from TypeSize which
will be used in Alias Analysis.

Author: harviniriawan

llvm/include/llvm/Analysis/MemoryLocation.h

@@ -159,7 +159,7 @@ class LocationSize {
       return beforeOrAfterPointer();
     if (Value == AfterPointer || Other.Value == AfterPointer)
       return afterPointer();
-    if (isScalable() != Other.isScalable())
+    if (isScalable() || Other.isScalable())
       return afterPointer();
 
     return upperBound(std::max(getValue(), Other.getValue()));

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

@@ -2531,7 +2531,8 @@ static int64_t getKnownNonNullAndDerefBytesForUse(
   }
 
   std::optional<MemoryLocation> Loc = MemoryLocation::getOrNone(I);
-  if (!Loc || Loc->Ptr != UseV || !Loc->Size.isPrecise() || I->isVolatile())
+  if (!Loc || Loc->Ptr != UseV || !Loc->Size.isPrecise() ||
+      Loc->Size.isScalable() || I->isVolatile())
     return 0;
 
   int64_t Offset;

llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp

@@ -984,6 +984,10 @@ struct DSEState {
     const bool AnyScalable =
         DeadSize.isScalable() || KillingLocSize.isScalable();
 
+    // TODO: Remove AnyScalable constraint once alias analysis fully support
+    // scalable quantities
+    if (AnyScalable)
+      return OW_Unknown;
     // Query the alias information
     AliasResult AAR = BatchAA.alias(KillingLoc, DeadLoc);
 

llvm/test/Transforms/LICM/memloc-vscale.ll renamed to llvm/test/Analysis/AliasSet/memloc-vscale.ll

@@ -25,6 +25,14 @@ define void @ss(ptr %p) {
   ret void
 }
 
+; CHECK-LABEL: Alias sets for function 'ss2':
+; CHECK: AliasSet[{{.*}}, 1] must alias, Mod       Pointers: (ptr %p, unknown after)
+define void @ss2(ptr %p) {
+  store <vscale x 2 x i64> zeroinitializer, ptr %p, align 2
+  store <vscale x 2 x i64> zeroinitializer, ptr %p, align 2
+  store <vscale x 4 x i64> zeroinitializer, ptr %p, align 2
+  ret void
+}
 ; CHECK-LABEL: Alias sets for function 'son':
 ; CHECK: AliasSet[{{.*}}, 2] may alias, Mod       Pointers: (ptr %g, LocationSize::precise(vscale x 16)), (ptr %p, LocationSize::precise(8))
 define void @son(ptr %p) {