llvm/clang/test/CodeGen/2004-02-12-LargeAggregateCopy.c

// RUN: %clang_cc1  %s -emit-llvm -o - | FileCheck %s

struct X { int V[10000]; };
struct X Global1, Global2;
void test(void) {
  // CHECK: llvm.memcpy
  Global2 = Global1;
}