Index: llvm/cmake/config-ix.cmake
===================================================================
--- llvm/cmake/config-ix.cmake
+++ llvm/cmake/config-ix.cmake
@@ -29,6 +29,7 @@
 check_include_file(fcntl.h HAVE_FCNTL_H)
 check_include_file(link.h HAVE_LINK_H)
 check_include_file(malloc/malloc.h HAVE_MALLOC_MALLOC_H)
+check_include_file(malloc_np.h HAVE_MALLOC_NP_H)
 if( NOT PURE_WINDOWS )
   check_include_file(pthread.h HAVE_PTHREAD_H)
 endif()
@@ -200,7 +201,12 @@
 set(CMAKE_REQUIRED_DEFINITIONS "-D_LARGEFILE64_SOURCE")
 check_symbol_exists(lseek64 "sys/types.h;unistd.h" HAVE_LSEEK64)
 set(CMAKE_REQUIRED_DEFINITIONS "")
-check_symbol_exists(mallctl malloc_np.h HAVE_MALLCTL)
+if(HAVE_MALLOC_NP_H)
+  check_symbol_exists(mallctl malloc_np.h HAVE_MALLCTL)
+else()
+  # NetBSD has mallctl() in malloc.h
+  check_symbol_exists(mallctl malloc.h HAVE_MALLCTL)
+endif()
 check_symbol_exists(mallinfo malloc.h HAVE_MALLINFO)
 check_symbol_exists(malloc_zone_statistics malloc/malloc.h
                     HAVE_MALLOC_ZONE_STATISTICS)
Index: llvm/lib/Support/Unix/Process.inc
===================================================================
--- llvm/lib/Support/Unix/Process.inc
+++ llvm/lib/Support/Unix/Process.inc
@@ -36,7 +36,11 @@
 #include <malloc.h>
 #endif
 #if defined(HAVE_MALLCTL)
-#include <malloc_np.h>
+#  if defined(HAVE_MALLOC_NP_H)
+#    include <malloc_np.h>
+#  else
+#    include <malloc.h>
+#  endif
 #endif
 #ifdef HAVE_MALLOC_MALLOC_H
 #include <malloc/malloc.h>