diff --git a/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp b/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
--- a/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
+++ b/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
@@ -95,6 +95,9 @@
         return false;
       if (!onlyUsedByLifetimeMarkers(GEPI))
         return false;
+    } else if (const AddrSpaceCastInst *ASCI = dyn_cast<AddrSpaceCastInst>(U)) {
+      if (!onlyUsedByLifetimeMarkers(ASCI))
+        return false;
     } else {
       return false;
     }
diff --git a/llvm/test/Transforms/SROA/alloca_addrspace.ll b/llvm/test/Transforms/SROA/alloca_addrspace.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/SROA/alloca_addrspace.ll
@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -sroa -S | FileCheck %s
+; RUN: opt < %s -passes=sroa -S | FileCheck %s
+; RUN: opt < %s -mem2reg -S | FileCheck %s
+; RUN: opt < %s -passes=mem2reg -S | FileCheck %s
+
+; Do not crash ;)
+
+target datalayout = "e-p:64:64-p5:32:32-A5"
+
+define amdgpu_kernel void @addressspace_alloca() {
+; CHECK-LABEL: @addressspace_alloca(
+; CHECK-NEXT:    ret void
+;
+  %alloca = alloca i8, align 8, addrspace(5)
+  %cast = addrspacecast i8 addrspace(5)* %alloca to i8*
+  call void @llvm.lifetime.start.p0i8(i64 2, i8* %cast)
+  ret void
+}
+
+declare void @llvm.lifetime.start.p0i8(i64 %size, i8* nocapture %ptr)