[IR] GetUnderlyingObject(), stripPointerCastsAndOffsets(): don't cras…

…h on `bitcast <1 x i8*> to i8*`

I'm not sure how to write standalone tests for each of two changes here.
If either one of these two fixes is missing, the test fill crash.

llvm/lib/Analysis/ValueTracking.cpp

@@ -4147,6 +4147,8 @@ Value *llvm::GetUnderlyingObject(Value *V, const DataLayout &DL,
     } else if (Operator::getOpcode(V) == Instruction::BitCast ||
                Operator::getOpcode(V) == Instruction::AddrSpaceCast) {
       V = cast<Operator>(V)->getOperand(0);
+      if (!V->getType()->isPointerTy())
+        return V;
     } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
       if (GA->isInterposable())
         return V;

llvm/lib/IR/Value.cpp

@@ -552,6 +552,8 @@ static const Value *stripPointerCastsAndOffsets(
       V = GEP->getPointerOperand();
     } else if (Operator::getOpcode(V) == Instruction::BitCast) {
       V = cast<Operator>(V)->getOperand(0);
+      if (!V->getType()->isPointerTy())
+        return V;
     } else if (StripKind != PSK_ZeroIndicesSameRepresentation &&
                Operator::getOpcode(V) == Instruction::AddrSpaceCast) {
       // TODO: If we know an address space cast will not change the

llvm/test/Transforms/InstSimplify/icmp.ll

@@ -0,0 +1,14 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+
+target datalayout = "e-p:64:64:64-p1:16:16:16-p2:32:32:32-p3:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+
+declare void @usei8ptr(i8* %ptr)
+
+; Ensure that we do not crash when looking at such a weird bitcast.
+define i1 @bitcast_from_single_element_pointer_vector_to_pointer(<1 x i8*> %ptr1vec, i8* %ptr2) {
+  %ptr1 = bitcast <1 x i8*> %ptr1vec to i8*
+  call void @usei8ptr(i8* %ptr1)
+  %cmp = icmp eq i8* %ptr1, %ptr2
+  ret i1 %cmp
+}