Index: lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -2028,6 +2028,7 @@
     // is reasonable to treat their delta as a 32-bit value.
     LLVM_FALLTHROUGH;
   case Instruction::BitCast:
+  case Instruction::AddrSpaceCast:
     return lowerConstant(CE->getOperand(0));
 
   case Instruction::IntToPtr: {
Index: test/CodeGen/X86/constant-with-addrspace-cast.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/constant-with-addrspace-cast.ll
@@ -0,0 +1,8 @@
+; RUN: llc -filetype=asm -mtriple x86_64 < %s
+
+; Check that the code below successfully compiled without getting
+; "LLVM ERROR: Unsupported expression in static initializer: addrspacecast"
+
+@__block_literal_global = external addrspace(1) constant { i32, i32, i8 addrspace(4)* }, align 4
+
+@block_A = addrspace(1) constant void (i8 addrspace(3)*) addrspace(4)* addrspacecast (void (i8 addrspace(3)*) addrspace(1)* bitcast ({ i32, i32, i8 addrspace(4)* } addrspace(1)* @__block_literal_global to void (i8 addrspace(3)*) addrspace(1)*) to void (i8 addrspace(3)*) addrspace(4)*), align 4