Index: lib/Target/AArch64/AArch64ISelLowering.cpp
===================================================================
--- lib/Target/AArch64/AArch64ISelLowering.cpp
+++ lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -220,6 +220,10 @@
   // AArch64 lacks both left-rotate and popcount instructions.
   setOperationAction(ISD::ROTL, MVT::i32, Expand);
   setOperationAction(ISD::ROTL, MVT::i64, Expand);
+  for (MVT VT : MVT::vector_valuetypes()) {
+    setOperationAction(ISD::ROTL, VT, Expand);
+    setOperationAction(ISD::ROTR, VT, Expand);
+  }
 
   // AArch64 doesn't have {U|S}MUL_LOHI.
   setOperationAction(ISD::UMUL_LOHI, MVT::i64, Expand);
Index: lib/Target/ARM/ARMISelLowering.cpp
===================================================================
--- lib/Target/ARM/ARMISelLowering.cpp
+++ lib/Target/ARM/ARMISelLowering.cpp
@@ -718,7 +718,11 @@
   }
 
   // ARM does not have ROTL.
-  setOperationAction(ISD::ROTL,  MVT::i32, Expand);
+  setOperationAction(ISD::ROTL, MVT::i32, Expand);
+  for (MVT VT : MVT::vector_valuetypes()) {
+    setOperationAction(ISD::ROTL, VT, Expand);
+    setOperationAction(ISD::ROTR, VT, Expand);
+  }
   setOperationAction(ISD::CTTZ,  MVT::i32, Custom);
   setOperationAction(ISD::CTPOP, MVT::i32, Expand);
   if (!Subtarget->hasV5TOps() || Subtarget->isThumb1Only())
Index: test/CodeGen/AArch64/rotate.ll
===================================================================
--- /dev/null
+++ test/CodeGen/AArch64/rotate.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s -mtriple=aarch64--linux-gnueabihf | FileCheck %s
+
+;; This used to cause a backend crash about not being able to
+;; select ROTL. Make sure if generates the basic ushr/shl.
+define <2 x i64> @testcase(<2 x i64>* %in) {
+; CHECK-LABEL: testcase
+; CHECK: ushr {{v[0-9]+}}.2d
+; CHECK: shl  {{v[0-9]+}}.2d
+  %1 = load <2 x i64>, <2 x i64>* %in
+  %2 = lshr <2 x i64> %1, <i64 8, i64 8>
+  %3 = shl <2 x i64> %1, <i64 56, i64 56>
+  %4 = or <2 x i64> %2, %3
+  ret <2 x i64> %4
+}
Index: test/CodeGen/ARM/rotate.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/rotate.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s -mtriple=thumbv8--linux-gnueabihf | FileCheck %s
+
+;; This used to cause a backend crash about not being able to
+;; select ROTL. Make sure if generates the basic VSHL/VSHR.
+define <2 x i64> @testcase(<2 x i64>* %in) {
+; CHECK-LABEL: testcase
+; CHECK: vshl.i64
+; CHECK: vshr.u64
+  %1 = load <2 x i64>, <2 x i64>* %in
+  %2 = lshr <2 x i64> %1, <i64 8, i64 8>
+  %3 = shl <2 x i64> %1, <i64 56, i64 56>
+  %4 = or <2 x i64> %2, %3
+  ret <2 x i64> %4
+}