[SCEV] Use object size for allocas as well

The object size and alignment based restriction on the possible
allocation range also applies to allocas, not just globals, so
handle them as well.

We shouldn't really need any type restriction here at all, but
for now stay conservative.

llvm/lib/Analysis/ScalarEvolution.cpp

@@ -6815,22 +6815,22 @@ const ConstantRange &ScalarEvolution::getRangeRef(
           RangeType);
 
     if (U->getType()->isPointerTy() && SignHint == HINT_RANGE_UNSIGNED) {
-      // Strengthen the range if the underlying IR value is a global using the
-      // size of the global.
+      // Strengthen the range if the underlying IR value is a global/alloca
+      // using the size of the object.
       ObjectSizeOpts Opts;
       Opts.RoundToAlign = false;
       Opts.NullIsUnknownSize = true;
       uint64_t ObjSize;
-      auto *GV = dyn_cast<GlobalVariable>(V);
-      if (GV && getObjectSize(V, ObjSize, DL, &TLI, Opts) && ObjSize > 1) {
+      if ((isa<GlobalVariable>(V) || isa<AllocaInst>(V)) &&
+          getObjectSize(V, ObjSize, DL, &TLI, Opts) && ObjSize > 1) {
         // The highest address the object can start is ObjSize bytes before the
         // end (unsigned max value). If this value is not a multiple of the
         // alignment, the last possible start value is the next lowest multiple
         // of the alignment. Note: The computations below cannot overflow,
         // because if they would there's no possible start address for the
         // object.
         APInt MaxVal = APInt::getMaxValue(BitWidth) - APInt(BitWidth, ObjSize);
-        uint64_t Align = GV->getAlign().valueOrOne().value();
+        uint64_t Align = U->getValue()->getPointerAlignment(DL).value();
         uint64_t Rem = MaxVal.urem(Align);
         MaxVal -= APInt(BitWidth, Rem);
         ConservativeResult = ConservativeResult.intersectWith(

llvm/test/Analysis/ScalarEvolution/nsw.ll

@@ -276,7 +276,7 @@ define void @test4(i32 %arg) {
 ; CHECK-LABEL: 'test4'
 ; CHECK-NEXT:  Classifying expressions for: @test4
 ; CHECK-NEXT:    %array = alloca [10 x i32], align 4
-; CHECK-NEXT:    --> %array U: [0,-3) S: [-9223372036854775808,9223372036854775805)
+; CHECK-NEXT:    --> %array U: [0,-43) S: [-9223372036854775808,9223372036854775805)
 ; CHECK-NEXT:    %index = phi i32 [ %inc5, %for.body ], [ %arg, %entry ]
 ; CHECK-NEXT:    --> {%arg,+,1}<nsw><%for.body> U: full-set S: full-set Exits: (-1 + (10 smax (1 + %arg)<nsw>))<nsw> LoopDispositions: { %for.body: Computable }
 ; CHECK-NEXT:    %sub = add nsw i32 %index, -2

llvm/test/Analysis/ScalarEvolution/sdiv.ll

@@ -8,9 +8,9 @@ define dso_local void @_Z4loopi(i32 %width) local_unnamed_addr #0 {
 ; CHECK-LABEL: '_Z4loopi'
 ; CHECK-NEXT:  Classifying expressions for: @_Z4loopi
 ; CHECK-NEXT:    %storage = alloca [2 x i32], align 4
-; CHECK-NEXT:    --> %storage U: [0,-3) S: [-9223372036854775808,9223372036854775805)
+; CHECK-NEXT:    --> %storage U: [0,-11) S: [-9223372036854775808,9223372036854775805)
 ; CHECK-NEXT:    %0 = bitcast ptr %storage to ptr
-; CHECK-NEXT:    --> %storage U: [0,-3) S: [-9223372036854775808,9223372036854775805)
+; CHECK-NEXT:    --> %storage U: [0,-11) S: [-9223372036854775808,9223372036854775805)
 ; CHECK-NEXT:    %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
 ; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%for.cond> U: [0,-2147483648) S: [0,-2147483648) Exits: %width LoopDispositions: { %for.cond: Computable }
 ; CHECK-NEXT:    %rem = sdiv i32 %i.0, 2

llvm/test/Analysis/ScalarEvolution/srem.ll

@@ -8,17 +8,17 @@ define dso_local void @_Z4loopi(i32 %width) local_unnamed_addr #0 {
 ; CHECK-LABEL: '_Z4loopi'
 ; CHECK-NEXT:  Classifying expressions for: @_Z4loopi
 ; CHECK-NEXT:    %storage = alloca [2 x i32], align 4
-; CHECK-NEXT:    --> %storage U: [0,-3) S: [-9223372036854775808,9223372036854775805)
+; CHECK-NEXT:    --> %storage U: [0,-11) S: [-9223372036854775808,9223372036854775805)
 ; CHECK-NEXT:    %0 = bitcast ptr %storage to ptr
-; CHECK-NEXT:    --> %storage U: [0,-3) S: [-9223372036854775808,9223372036854775805)
+; CHECK-NEXT:    --> %storage U: [0,-11) S: [-9223372036854775808,9223372036854775805)
 ; CHECK-NEXT:    %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
 ; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%for.cond> U: [0,-2147483648) S: [0,-2147483648) Exits: %width LoopDispositions: { %for.cond: Computable }
 ; CHECK-NEXT:    %rem = srem i32 %i.0, 2
 ; CHECK-NEXT:    --> (zext i1 {false,+,true}<%for.cond> to i32) U: [0,2) S: [0,2) Exits: (zext i1 (trunc i32 %width to i1) to i32) LoopDispositions: { %for.cond: Computable }
 ; CHECK-NEXT:    %idxprom = sext i32 %rem to i64
 ; CHECK-NEXT:    --> (zext i1 {false,+,true}<%for.cond> to i64) U: [0,2) S: [0,2) Exits: (zext i1 (trunc i32 %width to i1) to i64) LoopDispositions: { %for.cond: Computable }
 ; CHECK-NEXT:    %arrayidx = getelementptr inbounds [2 x i32], ptr %storage, i64 0, i64 %idxprom
-; CHECK-NEXT:    --> ((4 * (zext i1 {false,+,true}<%for.cond> to i64))<nuw><nsw> + %storage) U: [0,-3) S: [-9223372036854775808,9223372036854775805) Exits: ((4 * (zext i1 (trunc i32 %width to i1) to i64))<nuw><nsw> + %storage) LoopDispositions: { %for.cond: Computable }
+; CHECK-NEXT:    --> ((4 * (zext i1 {false,+,true}<%for.cond> to i64))<nuw><nsw> + %storage) U: [0,-7) S: [-9223372036854775808,9223372036854775805) Exits: ((4 * (zext i1 (trunc i32 %width to i1) to i64))<nuw><nsw> + %storage) LoopDispositions: { %for.cond: Computable }
 ; CHECK-NEXT:    %1 = load i32, ptr %arrayidx, align 4
 ; CHECK-NEXT:    --> %1 U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %for.cond: Variant }
 ; CHECK-NEXT:    %call = call i32 @_Z3adji(i32 %1)