diff --git a/libc/Android.bp b/libc/Android.bp
index 242963476..93854b714 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -23,6 +23,7 @@ libc_common_src_files = [
     "bionic/system_properties_compat.c",
     "stdio/findfp.c",
     "stdio/fread.c",
+    "stdio/refill.c",
     "stdio/snprintf.c",
     "stdio/sprintf.c",
     "stdio/stdio.c",
@@ -168,10 +169,12 @@ cc_library_static {
 
     cflags: libc_common_cflags + [
         "-fvisibility=hidden",
+        "-Wno-unused-parameter",
         // Don't use ridiculous amounts of stack.
         "-DALL_STATE",
         // Include tzsetwall, timelocal, timegm, time2posix, and posix2time.
         "-DSTD_INSPIRED",
+        "-DTHREAD_SAFE",
         // The name of the tm_gmtoff field in our struct tm.
         "-DTM_GMTOFF=tm_gmtoff",
         // Where we store our tzdata.
@@ -292,28 +295,26 @@ cc_library_static {
         "upstream-freebsd/lib/libc/string/wcpcpy.c",
         "upstream-freebsd/lib/libc/string/wcpncpy.c",
         "upstream-freebsd/lib/libc/string/wcscasecmp.c",
+        "upstream-freebsd/lib/libc/string/wcscat.c",
+        "upstream-freebsd/lib/libc/string/wcschr.c",
+        "upstream-freebsd/lib/libc/string/wcscmp.c",
+        "upstream-freebsd/lib/libc/string/wcscpy.c",
         "upstream-freebsd/lib/libc/string/wcscspn.c",
         "upstream-freebsd/lib/libc/string/wcsdup.c",
         "upstream-freebsd/lib/libc/string/wcslcat.c",
+        "upstream-freebsd/lib/libc/string/wcslen.c",
         "upstream-freebsd/lib/libc/string/wcsncasecmp.c",
         "upstream-freebsd/lib/libc/string/wcsncat.c",
         "upstream-freebsd/lib/libc/string/wcsncmp.c",
         "upstream-freebsd/lib/libc/string/wcsncpy.c",
         "upstream-freebsd/lib/libc/string/wcsnlen.c",
         "upstream-freebsd/lib/libc/string/wcspbrk.c",
+        "upstream-freebsd/lib/libc/string/wcsrchr.c",
         "upstream-freebsd/lib/libc/string/wcsspn.c",
         "upstream-freebsd/lib/libc/string/wcstok.c",
         "upstream-freebsd/lib/libc/string/wmemchr.c",
-        "upstream-freebsd/lib/libc/string/wmemset.c",
-
-        // May be overriden by per-arch optimized versions
-        "upstream-freebsd/lib/libc/string/wcscat.c",
-        "upstream-freebsd/lib/libc/string/wcschr.c",
-        "upstream-freebsd/lib/libc/string/wcscmp.c",
-        "upstream-freebsd/lib/libc/string/wcscpy.c",
-        "upstream-freebsd/lib/libc/string/wcslen.c",
-        "upstream-freebsd/lib/libc/string/wcsrchr.c",
         "upstream-freebsd/lib/libc/string/wmemcmp.c",
+        "upstream-freebsd/lib/libc/string/wmemset.c",
         "upstream-freebsd/lib/libc/string/wmemmove.c",
     ],
     arch: {
@@ -330,10 +331,15 @@ cc_library_static {
                 "upstream-freebsd/lib/libc/string/wcsrchr.c",
             ],
         },
-        x86_sse3: {
+        atom: {
+            exclude_srcs: [
+                "upstream-freebsd/lib/libc/string/wmemcmp.c",
+            ],
+        },
+        x86_ssse3: {
             exclude_srcs: [
-                "upstream-freebsd/lib/libc/string/wcscpy.c",
                 "upstream-freebsd/lib/libc/string/wcscat.c",
+                "upstream-freebsd/lib/libc/string/wcscpy.c",
             ],
         },
         x86_sse4: {
@@ -500,11 +506,9 @@ cc_library_static {
         "upstream-openbsd/lib/libc/locale/wctomb.c",
         "upstream-openbsd/lib/libc/net/htonl.c",
         "upstream-openbsd/lib/libc/net/htons.c",
-        "upstream-openbsd/lib/libc/net/inet_addr.c",
         "upstream-openbsd/lib/libc/net/inet_lnaof.c",
         "upstream-openbsd/lib/libc/net/inet_makeaddr.c",
         "upstream-openbsd/lib/libc/net/inet_netof.c",
-        "upstream-openbsd/lib/libc/net/inet_network.c",
         "upstream-openbsd/lib/libc/net/inet_ntoa.c",
         "upstream-openbsd/lib/libc/net/inet_ntop.c",
         "upstream-openbsd/lib/libc/net/inet_pton.c",
@@ -564,7 +568,6 @@ cc_library_static {
         "upstream-openbsd/lib/libc/stdio/puts.c",
         "upstream-openbsd/lib/libc/stdio/putwc.c",
         "upstream-openbsd/lib/libc/stdio/putwchar.c",
-        "upstream-openbsd/lib/libc/stdio/refill.c",
         "upstream-openbsd/lib/libc/stdio/remove.c",
         "upstream-openbsd/lib/libc/stdio/rewind.c",
         "upstream-openbsd/lib/libc/stdio/rget.c",
@@ -685,7 +688,6 @@ cc_library_static {
         "upstream-openbsd/lib/libc/string/stpcpy.c",
         "upstream-openbsd/lib/libc/string/stpncpy.c",
         "upstream-openbsd/lib/libc/string/strcat.c",
-        "upstream-openbsd/lib/libc/string/strcmp.c",
         "upstream-openbsd/lib/libc/string/strcpy.c",
         "upstream-openbsd/lib/libc/string/strlcat.c",
         "upstream-openbsd/lib/libc/string/strlcpy.c",
@@ -703,7 +705,6 @@ cc_library_static {
     arch: {
         arm: {
             exclude_srcs: [
-                "upstream-openbsd/lib/libc/string/strcmp.c",
                 "upstream-openbsd/lib/libc/string/strcpy.c",
             ],
         },
@@ -721,6 +722,13 @@ cc_library_static {
                 "upstream-openbsd/lib/libc/string/strcat.c",
             ],
         },
+        cortex_a53_a57: {
+            exclude_srcs: [
+                "upstream-openbsd/lib/libc/string/memmove.c",
+                "upstream-openbsd/lib/libc/string/stpcpy.c",
+                "upstream-openbsd/lib/libc/string/strcat.c",
+            ],
+        },
         cortex_a8: {
             exclude_srcs: [
                 "upstream-openbsd/lib/libc/string/memmove.c",
@@ -762,24 +770,11 @@ cc_library_static {
                 "upstream-openbsd/lib/libc/string/memchr.c",
                 "upstream-openbsd/lib/libc/string/memmove.c",
                 "upstream-openbsd/lib/libc/string/stpcpy.c",
-                "upstream-openbsd/lib/libc/string/strcmp.c",
                 "upstream-openbsd/lib/libc/string/strcpy.c",
                 "upstream-openbsd/lib/libc/string/strncmp.c",
             ],
         },
 
-        mips: {
-            exclude_srcs: [
-                "upstream-openbsd/lib/libc/string/strcmp.c",
-            ],
-        },
-
-        mips64: {
-            exclude_srcs: [
-                "upstream-openbsd/lib/libc/string/strcmp.c",
-            ],
-        },
-
         x86: {
              exclude_srcs: [
                  "upstream-openbsd/lib/libc/string/memchr.c",
@@ -788,13 +783,12 @@ cc_library_static {
                  "upstream-openbsd/lib/libc/string/stpcpy.c",
                  "upstream-openbsd/lib/libc/string/stpncpy.c",
                  "upstream-openbsd/lib/libc/string/strcat.c",
-                 "upstream-openbsd/lib/libc/string/strcmp.c",
                  "upstream-openbsd/lib/libc/string/strcpy.c",
                  "upstream-openbsd/lib/libc/string/strncmp.c",
                  "upstream-openbsd/lib/libc/string/strncpy.c",
-                 ],
+             ],
         },
-        x86_sse3: {
+        x86_ssse3: {
              exclude_srcs: [
                  "upstream-openbsd/lib/libc/string/strlcat.c",
                  "upstream-openbsd/lib/libc/string/strlcpy.c",
@@ -808,7 +802,6 @@ cc_library_static {
                  "upstream-openbsd/lib/libc/string/stpcpy.c",
                  "upstream-openbsd/lib/libc/string/stpncpy.c",
                  "upstream-openbsd/lib/libc/string/strcat.c",
-                 "upstream-openbsd/lib/libc/string/strcmp.c",
                  "upstream-openbsd/lib/libc/string/strcpy.c",
                  "upstream-openbsd/lib/libc/string/strlcat.c",
                  "upstream-openbsd/lib/libc/string/strlcpy.c",
@@ -933,174 +926,7 @@ cc_library_static {
         "bionic/sysconf.cpp",
         "bionic/vdso.cpp",
         "bionic/setjmp_cookie.cpp",
-    ],
-    cflags: libc_common_cflags + ["-Wframe-larger-than=2048"],
 
-    arch: {
-        x86_64: {
-            clang: use_clang_x86_64,
-        },
-    },
-
-    conlyflags: libc_common_conlyflags,
-    cppflags: libc_common_cppflags + ["-Wold-style-cast"],
-    product_variables: libc_common_product_variables,
-    include_dirs: ["bionic/libstdc++/include"],
-    name: "libc_bionic",
-
-    stl: "none",
-    system_shared_libs: [],
-    sanitize: ["never"],
-    native_coverage: bionic_coverage,
-
-}
-
-// ========================================================
-// libc_bionic_ndk.a- The portions of libc_bionic that can
-// be safely used in libc_ndk.a (no troublesome global data
-// or constructors).
-// ========================================================
-cc_library_static {
-    srcs: [
-        "bionic/abort.cpp",
-        "bionic/accept.cpp",
-        "bionic/accept4.cpp",
-        "bionic/access.cpp",
-        "bionic/assert.cpp",
-        "bionic/atof.cpp",
-        "bionic/bionic_systrace.cpp",
-        "bionic/bionic_time_conversions.cpp",
-        "bionic/brk.cpp",
-        "bionic/c16rtomb.cpp",
-        "bionic/c32rtomb.cpp",
-        "bionic/chmod.cpp",
-        "bionic/chown.cpp",
-        "bionic/clearenv.cpp",
-        "bionic/clock.cpp",
-        "bionic/clock_getcpuclockid.cpp",
-        "bionic/clock_nanosleep.cpp",
-        "bionic/clone.cpp",
-        "bionic/close.cpp",
-        "bionic/__cmsg_nxthdr.cpp",
-        "bionic/connect.cpp",
-        "bionic/ctype.cpp",
-        "bionic/dirent.cpp",
-        "bionic/dup2.cpp",
-        "bionic/epoll_create.cpp",
-        "bionic/epoll_pwait.cpp",
-        "bionic/epoll_wait.cpp",
-        "bionic/__errno.cpp",
-        "bionic/error.cpp",
-        "bionic/eventfd_read.cpp",
-        "bionic/eventfd_write.cpp",
-        "bionic/faccessat.cpp",
-        "bionic/fchmod.cpp",
-        "bionic/fchmodat.cpp",
-        "bionic/ffs.cpp",
-        "bionic/fgetxattr.cpp",
-        "bionic/flistxattr.cpp",
-        "bionic/flockfile.cpp",
-        "bionic/fpclassify.cpp",
-        "bionic/fsetxattr.cpp",
-        "bionic/ftruncate.cpp",
-        "bionic/futimens.cpp",
-        "bionic/getcwd.cpp",
-        "bionic/gethostname.cpp",
-        "bionic/getpgrp.cpp",
-        "bionic/getpid.cpp",
-        "bionic/gettid.cpp",
-        "bionic/__gnu_basename.cpp",
-        "bionic/inotify_init.cpp",
-        "bionic/lchown.cpp",
-        "bionic/lfs64_support.cpp",
-        "bionic/__libc_current_sigrtmax.cpp",
-        "bionic/__libc_current_sigrtmin.cpp",
-        "bionic/libc_init_common.cpp",
-        "bionic/libc_logging.cpp",
-        "bionic/libgen.cpp",
-        "bionic/link.cpp",
-        "bionic/locale.cpp",
-        "bionic/lstat.cpp",
-        "bionic/malloc_info.cpp",
-        "bionic/mbrtoc16.cpp",
-        "bionic/mbrtoc32.cpp",
-        "bionic/mbstate.cpp",
-        "bionic/mempcpy.cpp",
-        "bionic/mkdir.cpp",
-        "bionic/mkfifo.cpp",
-        "bionic/mknod.cpp",
-        "bionic/mntent.cpp",
-        "bionic/NetdClientDispatch.cpp",
-        "bionic/open.cpp",
-        "bionic/pathconf.cpp",
-        "bionic/pause.cpp",
-        "bionic/pipe.cpp",
-        "bionic/poll.cpp",
-        "bionic/posix_fadvise.cpp",
-        "bionic/posix_fallocate.cpp",
-        "bionic/posix_madvise.cpp",
-        "bionic/posix_timers.cpp",
-        "bionic/ptrace.cpp",
-        "bionic/pty.cpp",
-        "bionic/raise.cpp",
-        "bionic/rand.cpp",
-        "bionic/readlink.cpp",
-        "bionic/reboot.cpp",
-        "bionic/recv.cpp",
-        "bionic/rename.cpp",
-        "bionic/rmdir.cpp",
-        "bionic/scandir.cpp",
-        "bionic/sched_getaffinity.cpp",
-        "bionic/sched_getcpu.cpp",
-        "bionic/semaphore.cpp",
-        "bionic/send.cpp",
-        "bionic/setegid.cpp",
-        "bionic/__set_errno.cpp",
-        "bionic/seteuid.cpp",
-        "bionic/setpgrp.cpp",
-        "bionic/sigaction.cpp",
-        "bionic/sigaddset.cpp",
-        "bionic/sigdelset.cpp",
-        "bionic/sigemptyset.cpp",
-        "bionic/sigfillset.cpp",
-        "bionic/sigismember.cpp",
-        "bionic/signal.cpp",
-        "bionic/signalfd.cpp",
-        "bionic/sigpending.cpp",
-        "bionic/sigprocmask.cpp",
-        "bionic/sigqueue.cpp",
-        "bionic/sigsuspend.cpp",
-        "bionic/sigtimedwait.cpp",
-        "bionic/sigwait.cpp",
-        "bionic/sigwaitinfo.cpp",
-        "bionic/socket.cpp",
-        "bionic/stat.cpp",
-        "bionic/statvfs.cpp",
-        "bionic/strchrnul.cpp",
-        "bionic/strerror.cpp",
-        "bionic/strerror_r.cpp",
-        "bionic/strsignal.cpp",
-        "bionic/strtold.cpp",
-        "bionic/stubs.cpp",
-        "bionic/symlink.cpp",
-        "bionic/sysinfo.cpp",
-        "bionic/syslog.cpp",
-        "bionic/sys_siglist.c",
-        "bionic/sys_signame.c",
-        "bionic/system_properties.cpp",
-        "bionic/tdestroy.cpp",
-        "bionic/termios.cpp",
-        "bionic/thread_private.cpp",
-        "bionic/tmpfile.cpp",
-        "bionic/umount.cpp",
-        "bionic/unlink.cpp",
-        "bionic/utimes.cpp",
-        "bionic/wait.cpp",
-        "bionic/wchar.cpp",
-        "bionic/wctype.cpp",
-        "bionic/wmempcpy.cpp",
-
-        // May be overriden by per-arch optimized versions
         "bionic/__memcpy_chk.cpp",
         "bionic/__memset_chk.cpp",
         "bionic/__strcat_chk.cpp",
@@ -1112,7 +938,6 @@ cc_library_static {
     cflags: libc_common_cflags + ["-Wframe-larger-than=2048"],
 
     arch: {
-
         arm: {
             srcs: [
                 "arch-arm/bionic/abort_arm.S",
@@ -1189,6 +1014,30 @@ cc_library_static {
                 "bionic/__strcpy_chk.cpp",
             ],
         },
+        cortex_a53_a57: {
+            srcs: [
+                "arch-arm/cortex-a15/bionic/memcpy.S",
+                "arch-arm/cortex-a15/bionic/memset.S",
+                "arch-arm/cortex-a15/bionic/stpcpy.S",
+                "arch-arm/cortex-a15/bionic/strcat.S",
+                "arch-arm/cortex-a15/bionic/__strcat_chk.S",
+                "arch-arm/cortex-a15/bionic/strcmp.S",
+                "arch-arm/cortex-a15/bionic/strcpy.S",
+                "arch-arm/cortex-a15/bionic/__strcpy_chk.S",
+                "arch-arm/cortex-a15/bionic/strlen.S",
+
+                "arch-arm/denver/bionic/memmove.S",
+            ],
+            exclude_srcs: [
+                "arch-arm/generic/bionic/memcpy.S",
+                "arch-arm/generic/bionic/memset.S",
+                "arch-arm/generic/bionic/strcmp.S",
+                "arch-arm/generic/bionic/strcpy.S",
+                "arch-arm/generic/bionic/strlen.c",
+                "bionic/__strcat_chk.cpp",
+                "bionic/__strcpy_chk.cpp",
+            ],
+        },
         cortex_a8: {
             srcs: [
                 "arch-arm/cortex-a15/bionic/memcpy.S",
@@ -1431,15 +1280,44 @@ cc_library_static {
                 "arch-x86/silvermont/string/sse2-strlen-slm.S",
                 "arch-x86/silvermont/string/sse2-strncpy-slm.S",
             ],
+
+            exclude_srcs: [
+                "bionic/strchr.cpp",
+                "bionic/strnlen.c",
+                "bionic/strrchr.cpp",
+            ],
         },
-        x86_sse3: {
+        atom: {
+            srcs: [
+                "arch-x86/atom/string/sse2-bzero-atom.S",
+                "arch-x86/atom/string/sse2-memset-atom.S",
+                "arch-x86/atom/string/sse2-strlen-atom.S",
+                "arch-x86/atom/string/ssse3-bcopy-atom.S",
+                "arch-x86/atom/string/ssse3-memcmp-atom.S",
+                "arch-x86/atom/string/ssse3-memmove-atom.S",
+                "arch-x86/atom/string/ssse3-strncpy-atom.S",
+                "arch-x86/atom/string/ssse3-wmemcmp-atom.S",
+            ],
+            exclude_srcs: [
+                "arch-x86/generic/string/memcmp.S",
+                "arch-x86/silvermont/string/sse2-bcopy-slm.S",
+                "arch-x86/silvermont/string/sse2-bzero-slm.S",
+                "arch-x86/silvermont/string/sse2-memcpy-slm.S",
+                "arch-x86/silvermont/string/sse2-memmove-slm.S",
+                "arch-x86/silvermont/string/sse2-memset-slm.S",
+                "arch-x86/silvermont/string/sse2-strcpy-slm.S",
+                "arch-x86/silvermont/string/sse2-strlen-slm.S",
+                "arch-x86/silvermont/string/sse2-strncpy-slm.S",
+            ],
+        },
+        x86_ssse3: {
             srcs: [
                 "arch-x86/atom/string/ssse3-strncat-atom.S",
                 "arch-x86/atom/string/ssse3-strlcat-atom.S",
                 "arch-x86/atom/string/ssse3-strlcpy-atom.S",
+                "arch-x86/atom/string/ssse3-strcat-atom.S",
                 "arch-x86/atom/string/ssse3-strcmp-atom.S",
                 "arch-x86/atom/string/ssse3-strncmp-atom.S",
-                "arch-x86/atom/string/ssse3-strcat-atom.S",
                 "arch-x86/atom/string/ssse3-wcscat-atom.S",
                 "arch-x86/atom/string/ssse3-wcscpy-atom.S",
             ],
@@ -1459,7 +1337,6 @@ cc_library_static {
             ],
         },
 
-
         x86_64: {
             clang: use_clang_x86_64,
             srcs: [
@@ -1488,7 +1365,173 @@ cc_library_static {
                 "arch-x86_64/string/ssse3-strncmp-slm.S",
             ],
         },
+    },
 
+    conlyflags: libc_common_conlyflags,
+    cppflags: libc_common_cppflags + ["-Wold-style-cast"],
+    product_variables: libc_common_product_variables,
+    include_dirs: ["bionic/libstdc++/include"],
+    name: "libc_bionic",
+
+    stl: "none",
+    system_shared_libs: [],
+    sanitize: ["never"],
+    native_coverage: bionic_coverage,
+
+}
+
+// ========================================================
+// libc_bionic_ndk.a- The portions of libc_bionic that can
+// be safely used in libc_ndk.a (no troublesome global data
+// or constructors).
+// ========================================================
+cc_library_static {
+    srcs: [
+        "bionic/abort.cpp",
+        "bionic/accept.cpp",
+        "bionic/accept4.cpp",
+        "bionic/access.cpp",
+        "bionic/arpa_inet.cpp",
+        "bionic/assert.cpp",
+        "bionic/atof.cpp",
+        "bionic/bionic_systrace.cpp",
+        "bionic/bionic_time_conversions.cpp",
+        "bionic/brk.cpp",
+        "bionic/c16rtomb.cpp",
+        "bionic/c32rtomb.cpp",
+        "bionic/chmod.cpp",
+        "bionic/chown.cpp",
+        "bionic/clearenv.cpp",
+        "bionic/clock.cpp",
+        "bionic/clock_getcpuclockid.cpp",
+        "bionic/clock_nanosleep.cpp",
+        "bionic/clone.cpp",
+        "bionic/close.cpp",
+        "bionic/__cmsg_nxthdr.cpp",
+        "bionic/connect.cpp",
+        "bionic/ctype.cpp",
+        "bionic/dirent.cpp",
+        "bionic/dup2.cpp",
+        "bionic/epoll_create.cpp",
+        "bionic/epoll_pwait.cpp",
+        "bionic/epoll_wait.cpp",
+        "bionic/__errno.cpp",
+        "bionic/error.cpp",
+        "bionic/eventfd_read.cpp",
+        "bionic/eventfd_write.cpp",
+        "bionic/faccessat.cpp",
+        "bionic/fchmod.cpp",
+        "bionic/fchmodat.cpp",
+        "bionic/ffs.cpp",
+        "bionic/fgetxattr.cpp",
+        "bionic/flistxattr.cpp",
+        "bionic/flockfile.cpp",
+        "bionic/fpclassify.cpp",
+        "bionic/fsetxattr.cpp",
+        "bionic/ftruncate.cpp",
+        "bionic/futimens.cpp",
+        "bionic/getcwd.cpp",
+        "bionic/gethostname.cpp",
+        "bionic/getpgrp.cpp",
+        "bionic/getpid.cpp",
+        "bionic/gettid.cpp",
+        "bionic/__gnu_basename.cpp",
+        "bionic/inotify_init.cpp",
+        "bionic/lchown.cpp",
+        "bionic/lfs64_support.cpp",
+        "bionic/__libc_current_sigrtmax.cpp",
+        "bionic/__libc_current_sigrtmin.cpp",
+        "bionic/libc_init_common.cpp",
+        "bionic/libc_logging.cpp",
+        "bionic/libgen.cpp",
+        "bionic/link.cpp",
+        "bionic/locale.cpp",
+        "bionic/lstat.cpp",
+        "bionic/malloc_info.cpp",
+        "bionic/mbrtoc16.cpp",
+        "bionic/mbrtoc32.cpp",
+        "bionic/mbstate.cpp",
+        "bionic/mempcpy.cpp",
+        "bionic/mkdir.cpp",
+        "bionic/mkfifo.cpp",
+        "bionic/mknod.cpp",
+        "bionic/mntent.cpp",
+        "bionic/NetdClientDispatch.cpp",
+        "bionic/open.cpp",
+        "bionic/pathconf.cpp",
+        "bionic/pause.cpp",
+        "bionic/pipe.cpp",
+        "bionic/poll.cpp",
+        "bionic/posix_fadvise.cpp",
+        "bionic/posix_fallocate.cpp",
+        "bionic/posix_madvise.cpp",
+        "bionic/posix_timers.cpp",
+        "bionic/ptrace.cpp",
+        "bionic/pty.cpp",
+        "bionic/raise.cpp",
+        "bionic/rand.cpp",
+        "bionic/readlink.cpp",
+        "bionic/reboot.cpp",
+        "bionic/recv.cpp",
+        "bionic/rename.cpp",
+        "bionic/rmdir.cpp",
+        "bionic/scandir.cpp",
+        "bionic/sched_getaffinity.cpp",
+        "bionic/sched_getcpu.cpp",
+        "bionic/semaphore.cpp",
+        "bionic/send.cpp",
+        "bionic/setegid.cpp",
+        "bionic/__set_errno.cpp",
+        "bionic/seteuid.cpp",
+        "bionic/setpgrp.cpp",
+        "bionic/sigaction.cpp",
+        "bionic/sigaddset.cpp",
+        "bionic/sigdelset.cpp",
+        "bionic/sigemptyset.cpp",
+        "bionic/sigfillset.cpp",
+        "bionic/sigismember.cpp",
+        "bionic/signal.cpp",
+        "bionic/signalfd.cpp",
+        "bionic/sigpending.cpp",
+        "bionic/sigprocmask.cpp",
+        "bionic/sigqueue.cpp",
+        "bionic/sigsuspend.cpp",
+        "bionic/sigtimedwait.cpp",
+        "bionic/sigwait.cpp",
+        "bionic/sigwaitinfo.cpp",
+        "bionic/socket.cpp",
+        "bionic/stat.cpp",
+        "bionic/statvfs.cpp",
+        "bionic/strchrnul.cpp",
+        "bionic/strerror.cpp",
+        "bionic/strerror_r.cpp",
+        "bionic/strsignal.cpp",
+        "bionic/strtold.cpp",
+        "bionic/stubs.cpp",
+        "bionic/symlink.cpp",
+        "bionic/sysinfo.cpp",
+        "bionic/syslog.cpp",
+        "bionic/sys_siglist.c",
+        "bionic/sys_signame.c",
+        "bionic/system_properties.cpp",
+        "bionic/tdestroy.cpp",
+        "bionic/termios.cpp",
+        "bionic/thread_private.cpp",
+        "bionic/tmpfile.cpp",
+        "bionic/umount.cpp",
+        "bionic/unlink.cpp",
+        "bionic/utimes.cpp",
+        "bionic/wait.cpp",
+        "bionic/wchar.cpp",
+        "bionic/wctype.cpp",
+        "bionic/wmempcpy.cpp",
+    ],
+    cflags: libc_common_cflags + ["-Wframe-larger-than=2048"],
+
+    arch: {
+        x86_64: {
+            clang: use_clang_x86_64,
+        },
     },
     multilib: {
         lib32: {
diff --git a/libc/Android.mk b/libc/Android.mk
index 140ec82d3..8db67453c 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -258,6 +258,15 @@ libc_bionic_src_files += bionic/sysconf.cpp
 libc_bionic_src_files += bionic/vdso.cpp
 libc_bionic_src_files += bionic/setjmp_cookie.cpp
 
+libc_bionic_src_files += \
+    bionic/__memcpy_chk.cpp \
+    bionic/__memset_chk.cpp \
+    bionic/__strcat_chk.cpp \
+    bionic/__strcpy_chk.cpp \
+    bionic/strchr.cpp \
+    bionic/strnlen.c \
+    bionic/strrchr.cpp \
+
 libc_cxa_src_files := \
     bionic/__cxa_guard.cpp \
     bionic/__cxa_pure_virtual.cpp \
@@ -274,18 +283,26 @@ libc_upstream_freebsd_src_files := \
     upstream-freebsd/lib/libc/string/wcpcpy.c \
     upstream-freebsd/lib/libc/string/wcpncpy.c \
     upstream-freebsd/lib/libc/string/wcscasecmp.c \
+    upstream-freebsd/lib/libc/string/wcscat.c \
+    upstream-freebsd/lib/libc/string/wcschr.c \
+    upstream-freebsd/lib/libc/string/wcscmp.c \
+    upstream-freebsd/lib/libc/string/wcscpy.c \
     upstream-freebsd/lib/libc/string/wcscspn.c \
     upstream-freebsd/lib/libc/string/wcsdup.c \
     upstream-freebsd/lib/libc/string/wcslcat.c \
+    upstream-freebsd/lib/libc/string/wcslen.c \
     upstream-freebsd/lib/libc/string/wcsncasecmp.c \
     upstream-freebsd/lib/libc/string/wcsncat.c \
     upstream-freebsd/lib/libc/string/wcsncmp.c \
     upstream-freebsd/lib/libc/string/wcsncpy.c \
     upstream-freebsd/lib/libc/string/wcsnlen.c \
     upstream-freebsd/lib/libc/string/wcspbrk.c \
+    upstream-freebsd/lib/libc/string/wcsrchr.c \
     upstream-freebsd/lib/libc/string/wcsspn.c \
     upstream-freebsd/lib/libc/string/wcstok.c \
     upstream-freebsd/lib/libc/string/wmemchr.c \
+    upstream-freebsd/lib/libc/string/wmemcmp.c \
+    upstream-freebsd/lib/libc/string/wmemmove.c \
     upstream-freebsd/lib/libc/string/wmemset.c \
 
 libc_upstream_netbsd_src_files := \
@@ -355,6 +372,20 @@ libc_upstream_openbsd_src_files := \
     upstream-openbsd/lib/libc/crypt/arc4random.c \
     upstream-openbsd/lib/libc/crypt/arc4random_uniform.c \
 
+libc_upstream_openbsd_src_files += \
+    upstream-openbsd/lib/libc/string/memchr.c \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/memrchr.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/stpncpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+    upstream-openbsd/lib/libc/string/strcpy.c \
+    upstream-openbsd/lib/libc/string/strlcat.c \
+    upstream-openbsd/lib/libc/string/strlcpy.c \
+    upstream-openbsd/lib/libc/string/strncat.c \
+    upstream-openbsd/lib/libc/string/strncmp.c \
+    upstream-openbsd/lib/libc/string/strncpy.c \
+
 libc_upstream_openbsd_ndk_src_files := \
     upstream-openbsd/lib/libc/compat-43/killpg.c \
     upstream-openbsd/lib/libc/gen/alarm.c \
@@ -794,7 +825,7 @@ LOCAL_SANITIZE := never
 LOCAL_NATIVE_COVERAGE := $(bionic_coverage)
 
 $(eval $(call patch-up-arch-specific-flags,LOCAL_CFLAGS,libc_common_cflags))
-$(eval $(call patch-up-arch-specific-flags,LOCAL_SRC_FILES,libc_freebsd_src_files))
+$(eval $(call patch-up-arch-specific-flags,LOCAL_SRC_FILES_EXCLUDE,libc_freebsd_src_files_exclude))
 include $(BUILD_STATIC_LIBRARY)
 
 
@@ -908,7 +939,7 @@ LOCAL_SANITIZE := never
 LOCAL_NATIVE_COVERAGE := $(bionic_coverage)
 
 $(eval $(call patch-up-arch-specific-flags,LOCAL_CFLAGS,libc_common_cflags))
-$(eval $(call patch-up-arch-specific-flags,LOCAL_SRC_FILES,libc_openbsd_src_files))
+$(eval $(call patch-up-arch-specific-flags,LOCAL_SRC_FILES_EXCLUDE,libc_openbsd_src_files_exclude))
 include $(BUILD_STATIC_LIBRARY)
 
 
@@ -972,6 +1003,7 @@ LOCAL_NATIVE_COVERAGE := $(bionic_coverage)
 
 $(eval $(call patch-up-arch-specific-flags,LOCAL_CFLAGS,libc_common_cflags))
 $(eval $(call patch-up-arch-specific-flags,LOCAL_SRC_FILES,libc_bionic_src_files))
+$(eval $(call patch-up-arch-specific-flags,LOCAL_SRC_FILES_EXCLUDE,libc_bionic_src_files_exclude))
 include $(BUILD_STATIC_LIBRARY)
 
 
diff --git a/libc/arch-arm/arm.mk b/libc/arch-arm/arm.mk
index 58c5eb662..76f465e81 100644
--- a/libc/arch-arm/arm.mk
+++ b/libc/arch-arm/arm.mk
@@ -1,33 +1,19 @@
 # 32-bit arm.
 
-#
-# Default implementations of functions that are commonly optimized.
-#
-
 libc_bionic_src_files_arm += \
-    bionic/strchr.cpp \
-    bionic/strnlen.c \
-    bionic/strrchr.cpp \
+    arch-arm/generic/bionic/memcmp.S \
+    arch-arm/generic/bionic/memcpy.S \
+    arch-arm/generic/bionic/memset.S \
+    arch-arm/generic/bionic/strcmp.S \
+    arch-arm/generic/bionic/strcpy.S \
+    arch-arm/generic/bionic/strlen.c \
 
-libc_freebsd_src_files_arm += \
-    upstream-freebsd/lib/libc/string/wcscat.c \
-    upstream-freebsd/lib/libc/string/wcschr.c \
-    upstream-freebsd/lib/libc/string/wcscmp.c \
-    upstream-freebsd/lib/libc/string/wcscpy.c \
-    upstream-freebsd/lib/libc/string/wcslen.c \
-    upstream-freebsd/lib/libc/string/wcsrchr.c \
-    upstream-freebsd/lib/libc/string/wmemcmp.c \
-    upstream-freebsd/lib/libc/string/wmemmove.c \
+libc_bionic_src_files_exclude_arm += \
+    bionic/__memcpy_chk.cpp \
+    bionic/__memset_chk.cpp \
 
-libc_openbsd_src_files_arm += \
-    upstream-openbsd/lib/libc/string/memchr.c \
-    upstream-openbsd/lib/libc/string/memrchr.c \
-    upstream-openbsd/lib/libc/string/stpncpy.c \
-    upstream-openbsd/lib/libc/string/strlcat.c \
-    upstream-openbsd/lib/libc/string/strlcpy.c \
-    upstream-openbsd/lib/libc/string/strncat.c \
-    upstream-openbsd/lib/libc/string/strncmp.c \
-    upstream-openbsd/lib/libc/string/strncpy.c \
+libc_openbsd_src_files_exclude_arm += \
+    upstream-openbsd/lib/libc/string/strcpy.c \
 
 #
 # Inherently architecture-specific code.
@@ -52,6 +38,7 @@ libc_arch_dynamic_src_files_arm := arch-arm/bionic/exidx_dynamic.c
 ifeq ($(strip $(TARGET_$(my_2nd_arch_prefix)CPU_VARIANT)),)
   $(warning TARGET_$(my_2nd_arch_prefix)ARCH is arm, but TARGET_$(my_2nd_arch_prefix)CPU_VARIANT is not defined)
 endif
+ifneq ($(TARGET_$(my_2nd_arch_prefix)CPU_VARIANT),generic)
 cpu_variant_mk := $(LOCAL_PATH)/arch-arm/$(TARGET_$(my_2nd_arch_prefix)CPU_VARIANT)/$(TARGET_$(my_2nd_arch_prefix)CPU_VARIANT).mk
 ifeq ($(wildcard $(cpu_variant_mk)),)
 $(error "TARGET_$(my_2nd_arch_prefix)CPU_VARIANT not set or set to an unknown value. Possible values are cortex-a7, cortex-a8, cortex-a9, cortex-a15, krait, denver. Use generic for devices that do not have a CPU similar to any of the supported cpu variants.")
@@ -60,6 +47,7 @@ include $(cpu_variant_mk)
 libc_common_additional_dependencies += $(cpu_variant_mk)
 
 cpu_variant_mk :=
+endif
 
 
 libc_crt_target_cflags_arm := \
diff --git a/libc/arch-arm/cortex-a15/cortex-a15.mk b/libc/arch-arm/cortex-a15/cortex-a15.mk
index 6fa327022..20202a7c6 100644
--- a/libc/arch-arm/cortex-a15/cortex-a15.mk
+++ b/libc/arch-arm/cortex-a15/cortex-a15.mk
@@ -1,3 +1,17 @@
+libc_openbsd_src_files_exclude_arm += \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+
+libc_bionic_src_files_exclude_arm += \
+    arch-arm/generic/bionic/memcpy.S \
+    arch-arm/generic/bionic/memset.S \
+    arch-arm/generic/bionic/strcmp.S \
+    arch-arm/generic/bionic/strcpy.S \
+    arch-arm/generic/bionic/strlen.c \
+    bionic/__strcat_chk.cpp \
+    bionic/__strcpy_chk.cpp \
+
 libc_bionic_src_files_arm += \
     arch-arm/cortex-a15/bionic/memcpy.S \
     arch-arm/cortex-a15/bionic/memset.S \
@@ -9,8 +23,5 @@ libc_bionic_src_files_arm += \
     arch-arm/cortex-a15/bionic/__strcpy_chk.S \
     arch-arm/cortex-a15/bionic/strlen.S \
 
-libc_bionic_src_files_arm += \
-    arch-arm/generic/bionic/memcmp.S \
-
 libc_bionic_src_files_arm += \
     arch-arm/denver/bionic/memmove.S \
diff --git a/libc/arch-arm/cortex-a53.a57/cortex-a53.a57.mk b/libc/arch-arm/cortex-a53.a57/cortex-a53.a57.mk
index 0eec165f1..6455d0480 100644
--- a/libc/arch-arm/cortex-a53.a57/cortex-a53.a57.mk
+++ b/libc/arch-arm/cortex-a53.a57/cortex-a53.a57.mk
@@ -3,6 +3,20 @@
 # The cortex-a7 optimized routines, and the cortex-a53 optimized routines
 # decrease performance on cortex-a57 processors by as much as 20%.
 
+libc_openbsd_src_files_exclude_arm += \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+
+libc_bionic_src_files_exclude_arm += \
+    arch-arm/generic/bionic/memcpy.S \
+    arch-arm/generic/bionic/memset.S \
+    arch-arm/generic/bionic/strcmp.S \
+    arch-arm/generic/bionic/strcpy.S \
+    arch-arm/generic/bionic/strlen.c \
+    bionic/__strcat_chk.cpp \
+    bionic/__strcpy_chk.cpp \
+
 libc_bionic_src_files_arm += \
     arch-arm/cortex-a15/bionic/memcpy.S \
     arch-arm/cortex-a15/bionic/memset.S \
@@ -14,8 +28,5 @@ libc_bionic_src_files_arm += \
     arch-arm/cortex-a15/bionic/__strcpy_chk.S \
     arch-arm/cortex-a15/bionic/strlen.S \
 
-libc_bionic_src_files_arm += \
-    arch-arm/generic/bionic/memcmp.S \
-
 libc_bionic_src_files_arm += \
     arch-arm/denver/bionic/memmove.S \
diff --git a/libc/arch-arm/cortex-a53/cortex-a53.mk b/libc/arch-arm/cortex-a53/cortex-a53.mk
index bb00433f5..9b431ae48 100644
--- a/libc/arch-arm/cortex-a53/cortex-a53.mk
+++ b/libc/arch-arm/cortex-a53/cortex-a53.mk
@@ -1,3 +1,17 @@
+libc_openbsd_src_files_exclude_arm += \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+
+libc_bionic_src_files_exclude_arm += \
+    arch-arm/generic/bionic/memcpy.S \
+    arch-arm/generic/bionic/memset.S \
+    arch-arm/generic/bionic/strcmp.S \
+    arch-arm/generic/bionic/strcpy.S \
+    arch-arm/generic/bionic/strlen.c \
+    bionic/__strcat_chk.cpp \
+    bionic/__strcpy_chk.cpp \
+
 libc_bionic_src_files_arm += \
     arch-arm/cortex-a53/bionic/memcpy.S \
     arch-arm/cortex-a53/bionic/__strcat_chk.S \
@@ -13,8 +27,5 @@ libc_bionic_src_files_arm += \
     arch-arm/cortex-a15/bionic/strcpy.S \
     arch-arm/cortex-a15/bionic/strlen.S \
 
-libc_bionic_src_files_arm += \
-    arch-arm/generic/bionic/memcmp.S \
-
 libc_bionic_src_files_arm += \
     arch-arm/denver/bionic/memmove.S \
diff --git a/libc/arch-arm/cortex-a7/cortex-a7.mk b/libc/arch-arm/cortex-a7/cortex-a7.mk
index b6af4dadb..f570d0f05 100644
--- a/libc/arch-arm/cortex-a7/cortex-a7.mk
+++ b/libc/arch-arm/cortex-a7/cortex-a7.mk
@@ -1,3 +1,17 @@
+libc_openbsd_src_files_exclude_arm += \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+
+libc_bionic_src_files_exclude_arm += \
+    arch-arm/generic/bionic/memcpy.S \
+    arch-arm/generic/bionic/memset.S \
+    arch-arm/generic/bionic/strcmp.S \
+    arch-arm/generic/bionic/strcpy.S \
+    arch-arm/generic/bionic/strlen.c \
+    bionic/__strcat_chk.cpp \
+    bionic/__strcpy_chk.cpp \
+
 libc_bionic_src_files_arm += \
     arch-arm/cortex-a7/bionic/memset.S \
 
@@ -11,8 +25,5 @@ libc_bionic_src_files_arm += \
     arch-arm/cortex-a15/bionic/__strcpy_chk.S \
     arch-arm/cortex-a15/bionic/strlen.S \
 
-libc_bionic_src_files_arm += \
-    arch-arm/generic/bionic/memcmp.S \
-
 libc_bionic_src_files_arm += \
     arch-arm/denver/bionic/memmove.S \
diff --git a/libc/arch-arm/cortex-a9/cortex-a9.mk b/libc/arch-arm/cortex-a9/cortex-a9.mk
index 7b38de15c..8a26d6b70 100644
--- a/libc/arch-arm/cortex-a9/cortex-a9.mk
+++ b/libc/arch-arm/cortex-a9/cortex-a9.mk
@@ -1,3 +1,18 @@
+libc_openbsd_src_files_exclude_arm += \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+    upstream-openbsd/lib/libc/string/strcpy.c \
+
+libc_bionic_src_files_exclude_arm += \
+    arch-arm/generic/bionic/memcpy.S \
+    arch-arm/generic/bionic/memset.S \
+    arch-arm/generic/bionic/strcmp.S \
+    arch-arm/generic/bionic/strcpy.S \
+    arch-arm/generic/bionic/strlen.c \
+    bionic/__strcat_chk.cpp \
+    bionic/__strcpy_chk.cpp \
+
 libc_bionic_src_files_arm += \
     arch-arm/cortex-a9/bionic/memcpy.S \
     arch-arm/cortex-a9/bionic/memset.S \
@@ -9,8 +24,5 @@ libc_bionic_src_files_arm += \
     arch-arm/cortex-a9/bionic/__strcpy_chk.S \
     arch-arm/cortex-a9/bionic/strlen.S \
 
-libc_bionic_src_files_arm += \
-    arch-arm/generic/bionic/memcmp.S \
-
 libc_bionic_src_files_arm += \
     arch-arm/denver/bionic/memmove.S \
diff --git a/libc/arch-arm/denver/denver.mk b/libc/arch-arm/denver/denver.mk
index 5fddf955a..f1679919b 100644
--- a/libc/arch-arm/denver/denver.mk
+++ b/libc/arch-arm/denver/denver.mk
@@ -1,5 +1,18 @@
+libc_openbsd_src_files_exclude_arm += \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+
+libc_bionic_src_files_exclude_arm += \
+    arch-arm/generic/bionic/memcpy.S \
+    arch-arm/generic/bionic/memset.S \
+    arch-arm/generic/bionic/strcmp.S \
+    arch-arm/generic/bionic/strcpy.S \
+    arch-arm/generic/bionic/strlen.c \
+    bionic/__strcat_chk.cpp \
+    bionic/__strcpy_chk.cpp \
+
 libc_bionic_src_files_arm += \
-    arch-arm/generic/bionic/memcmp.S \
     arch-arm/denver/bionic/memcpy.S \
     arch-arm/denver/bionic/memmove.S \
     arch-arm/denver/bionic/memset.S \
diff --git a/libc/arch-arm/generic/generic.mk b/libc/arch-arm/generic/generic.mk
deleted file mode 100644
index e49d6d200..000000000
--- a/libc/arch-arm/generic/generic.mk
+++ /dev/null
@@ -1,14 +0,0 @@
-libc_bionic_src_files_arm += \
-    arch-arm/generic/bionic/memcmp.S \
-    arch-arm/generic/bionic/memcpy.S \
-    arch-arm/generic/bionic/memset.S \
-    arch-arm/generic/bionic/strcmp.S \
-    arch-arm/generic/bionic/strcpy.S \
-    arch-arm/generic/bionic/strlen.c \
-    bionic/__strcat_chk.cpp \
-    bionic/__strcpy_chk.cpp \
-
-libc_openbsd_src_files_arm += \
-    upstream-openbsd/lib/libc/string/memmove.c \
-    upstream-openbsd/lib/libc/string/stpcpy.c \
-    upstream-openbsd/lib/libc/string/strcat.c \
diff --git a/libc/arch-arm/krait/krait.mk b/libc/arch-arm/krait/krait.mk
index 88b4d663c..f8e34529f 100644
--- a/libc/arch-arm/krait/krait.mk
+++ b/libc/arch-arm/krait/krait.mk
@@ -1,3 +1,18 @@
+libc_openbsd_src_files_exclude_arm += \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+
+libc_bionic_src_files_exclude_arm += \
+    arch-arm/generic/bionic/memcpy.S \
+    arch-arm/generic/bionic/memset.S \
+    arch-arm/generic/bionic/strcmp.S \
+    arch-arm/generic/bionic/strcpy.S \
+    arch-arm/generic/bionic/strlen.c \
+    bionic/__strcat_chk.cpp \
+    bionic/__strcpy_chk.cpp \
+
 libc_bionic_src_files_arm += \
     arch-arm/krait/bionic/memcpy.S \
     arch-arm/krait/bionic/memset.S \
@@ -12,8 +27,5 @@ libc_bionic_src_files_arm += \
     arch-arm/cortex-a15/bionic/strcpy.S \
     arch-arm/cortex-a15/bionic/strlen.S \
 
-libc_bionic_src_files_arm += \
-    arch-arm/generic/bionic/memcmp.S \
-
 libc_bionic_src_files_arm += \
     arch-arm/denver/bionic/memmove.S \
diff --git a/libc/arch-arm64/arm64.mk b/libc/arch-arm64/arm64.mk
index 470a03838..0811c960c 100644
--- a/libc/arch-arm64/arm64.mk
+++ b/libc/arch-arm64/arm64.mk
@@ -1,32 +1,38 @@
 # 64-bit arm.
 
 #
-# Default implementations of functions that are commonly optimized.
+# Generic arm64 optimizations, may be overriden by CPU variants.
 #
 
 libc_bionic_src_files_arm64 += \
-    bionic/__memset_chk.cpp \
-    bionic/__strcpy_chk.cpp \
-    bionic/__strcat_chk.cpp \
-    bionic/strrchr.cpp \
+    arch-arm64/generic/bionic/memchr.S \
+    arch-arm64/generic/bionic/memcmp.S \
+    arch-arm64/generic/bionic/memcpy.S \
+    arch-arm64/generic/bionic/memmove.S \
+    arch-arm64/generic/bionic/memset.S \
+    arch-arm64/generic/bionic/stpcpy.S \
+    arch-arm64/generic/bionic/strchr.S \
+    arch-arm64/generic/bionic/strcmp.S \
+    arch-arm64/generic/bionic/strcpy.S \
+    arch-arm64/generic/bionic/strlen.S \
+    arch-arm64/generic/bionic/strncmp.S \
+    arch-arm64/generic/bionic/strnlen.S \
+    arch-arm64/generic/bionic/wmemmove.S \
 
-libc_freebsd_src_files_arm64 += \
-    upstream-freebsd/lib/libc/string/wcscat.c \
-    upstream-freebsd/lib/libc/string/wcschr.c \
-    upstream-freebsd/lib/libc/string/wcscmp.c \
-    upstream-freebsd/lib/libc/string/wcscpy.c \
-    upstream-freebsd/lib/libc/string/wcslen.c \
-    upstream-freebsd/lib/libc/string/wcsrchr.c \
-    upstream-freebsd/lib/libc/string/wmemcmp.c \
+libc_bionic_src_files_exclude_arm64 += \
+    bionic/__memcpy_chk.cpp \
+    bionic/strchr.cpp \
+    bionic/strnlen.c \
 
-libc_openbsd_src_files_arm64 += \
-    upstream-openbsd/lib/libc/string/memrchr.c \
-    upstream-openbsd/lib/libc/string/stpncpy.c \
-    upstream-openbsd/lib/libc/string/strcat.c \
-    upstream-openbsd/lib/libc/string/strlcat.c \
-    upstream-openbsd/lib/libc/string/strlcpy.c \
-    upstream-openbsd/lib/libc/string/strncat.c \
-    upstream-openbsd/lib/libc/string/strncpy.c \
+libc_freebsd_src_files_exclude_arm64 += \
+    upstream-freebsd/lib/libc/string/wmemmove.c \
+
+libc_openbsd_src_files_exclude_arm64 += \
+    upstream-openbsd/lib/libc/string/memchr.c \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/strcpy.c \
+    upstream-openbsd/lib/libc/string/strncmp.c \
 
 #
 # Inherently architecture-specific code.
@@ -54,6 +60,7 @@ libc_crt_target_crtbegin_so_file_arm64 := \
 ifeq ($(strip $(TARGET_CPU_VARIANT)),)
   $(warning TARGET_ARCH is arm64, but TARGET_CPU_VARIANT is not defined)
 endif
+ifneq ($(TARGET_CPU_VARIANT),generic)
 cpu_variant_mk := $(LOCAL_PATH)/arch-arm64/$(TARGET_CPU_VARIANT)/$(TARGET_CPU_VARIANT).mk
 ifeq ($(wildcard $(cpu_variant_mk)),)
 $(error "TARGET_CPU_VARIANT not set or set to an unknown value. Possible values are generic, denver64. Use generic for devices that do not have a CPU similar to any of the supported cpu variants.")
@@ -62,3 +69,4 @@ include $(cpu_variant_mk)
 libc_common_additional_dependencies += $(cpu_variant_mk)
 
 cpu_variant_mk :=
+endif
diff --git a/libc/arch-arm64/cortex-a53/cortex-a53.mk b/libc/arch-arm64/cortex-a53/cortex-a53.mk
index 676e8860a..e69de29bb 100644
--- a/libc/arch-arm64/cortex-a53/cortex-a53.mk
+++ b/libc/arch-arm64/cortex-a53/cortex-a53.mk
@@ -1 +0,0 @@
-include bionic/libc/arch-arm64/generic/generic.mk
diff --git a/libc/arch-arm64/denver64/denver64.mk b/libc/arch-arm64/denver64/denver64.mk
index d619c1157..703af4550 100644
--- a/libc/arch-arm64/denver64/denver64.mk
+++ b/libc/arch-arm64/denver64/denver64.mk
@@ -1,14 +1,7 @@
 libc_bionic_src_files_arm64 += \
-    arch-arm64/generic/bionic/memchr.S \
-    arch-arm64/generic/bionic/memcmp.S \
     arch-arm64/denver64/bionic/memcpy.S \
-    arch-arm64/generic/bionic/memmove.S \
     arch-arm64/denver64/bionic/memset.S \
-    arch-arm64/generic/bionic/stpcpy.S \
-    arch-arm64/generic/bionic/strchr.S \
-    arch-arm64/generic/bionic/strcmp.S \
-    arch-arm64/generic/bionic/strcpy.S \
-    arch-arm64/generic/bionic/strlen.S \
-    arch-arm64/generic/bionic/strncmp.S \
-    arch-arm64/generic/bionic/strnlen.S \
-    arch-arm64/generic/bionic/wmemmove.S
+
+libc_bionic_src_files_exclude_arm64 += \
+    arch-arm64/generic/bionic/memcpy.S \
+    arch-arm64/generic/bionic/memset.S \
diff --git a/libc/arch-arm64/generic/generic.mk b/libc/arch-arm64/generic/generic.mk
deleted file mode 100644
index 1b595aacb..000000000
--- a/libc/arch-arm64/generic/generic.mk
+++ /dev/null
@@ -1,14 +0,0 @@
-libc_bionic_src_files_arm64 += \
-    arch-arm64/generic/bionic/memchr.S \
-    arch-arm64/generic/bionic/memcmp.S \
-    arch-arm64/generic/bionic/memcpy.S \
-    arch-arm64/generic/bionic/memmove.S \
-    arch-arm64/generic/bionic/memset.S \
-    arch-arm64/generic/bionic/stpcpy.S \
-    arch-arm64/generic/bionic/strchr.S \
-    arch-arm64/generic/bionic/strcmp.S \
-    arch-arm64/generic/bionic/strcpy.S \
-    arch-arm64/generic/bionic/strlen.S \
-    arch-arm64/generic/bionic/strncmp.S \
-    arch-arm64/generic/bionic/strnlen.S \
-    arch-arm64/generic/bionic/wmemmove.S
diff --git a/libc/arch-mips/mips.mk b/libc/arch-mips/mips.mk
index 05e719854..b184abb9a 100644
--- a/libc/arch-mips/mips.mk
+++ b/libc/arch-mips/mips.mk
@@ -1,45 +1,10 @@
 # 32-bit mips.
 
-#
-# Default implementations of functions that are commonly optimized.
-#
-
 libc_bionic_src_files_mips += \
     arch-mips/string/memcmp.c \
     arch-mips/string/memcpy.S \
     arch-mips/string/memset.S \
     arch-mips/string/strcmp.S \
-    bionic/__memcpy_chk.cpp \
-    bionic/__memset_chk.cpp \
-    bionic/__strcpy_chk.cpp \
-    bionic/__strcat_chk.cpp \
-    bionic/strchr.cpp \
-    bionic/strnlen.c \
-    bionic/strrchr.cpp \
-
-libc_freebsd_src_files_mips += \
-    upstream-freebsd/lib/libc/string/wcscat.c \
-    upstream-freebsd/lib/libc/string/wcschr.c \
-    upstream-freebsd/lib/libc/string/wcscmp.c \
-    upstream-freebsd/lib/libc/string/wcscpy.c \
-    upstream-freebsd/lib/libc/string/wcslen.c \
-    upstream-freebsd/lib/libc/string/wcsrchr.c \
-    upstream-freebsd/lib/libc/string/wmemcmp.c \
-    upstream-freebsd/lib/libc/string/wmemmove.c \
-
-libc_openbsd_src_files_mips += \
-    upstream-openbsd/lib/libc/string/memchr.c \
-    upstream-openbsd/lib/libc/string/memmove.c \
-    upstream-openbsd/lib/libc/string/memrchr.c \
-    upstream-openbsd/lib/libc/string/stpcpy.c \
-    upstream-openbsd/lib/libc/string/stpncpy.c \
-    upstream-openbsd/lib/libc/string/strcat.c \
-    upstream-openbsd/lib/libc/string/strcpy.c \
-    upstream-openbsd/lib/libc/string/strlcat.c \
-    upstream-openbsd/lib/libc/string/strlcpy.c \
-    upstream-openbsd/lib/libc/string/strncat.c \
-    upstream-openbsd/lib/libc/string/strncmp.c \
-    upstream-openbsd/lib/libc/string/strncpy.c \
 
 #
 # Inherently architecture-specific code.
diff --git a/libc/arch-mips64/mips64.mk b/libc/arch-mips64/mips64.mk
index 77573851c..20ee639ee 100644
--- a/libc/arch-mips64/mips64.mk
+++ b/libc/arch-mips64/mips64.mk
@@ -1,46 +1,11 @@
 # 64-bit mips.
 
-#
-# Default implementations of functions that are commonly optimized.
-#
-
 libc_bionic_src_files_mips64 += \
     arch-mips/string/memcmp.c \
     arch-mips/string/memcpy.S \
     arch-mips/string/memset.S \
     arch-mips/string/strcmp.S \
     arch-mips/string/strlen.c \
-    bionic/__memcpy_chk.cpp \
-    bionic/__memset_chk.cpp \
-    bionic/__strcpy_chk.cpp \
-    bionic/__strcat_chk.cpp \
-    bionic/strchr.cpp \
-    bionic/strnlen.c \
-    bionic/strrchr.cpp \
-
-libc_freebsd_src_files_mips64 += \
-    upstream-freebsd/lib/libc/string/wcscat.c \
-    upstream-freebsd/lib/libc/string/wcschr.c \
-    upstream-freebsd/lib/libc/string/wcscmp.c \
-    upstream-freebsd/lib/libc/string/wcscpy.c \
-    upstream-freebsd/lib/libc/string/wcslen.c \
-    upstream-freebsd/lib/libc/string/wcsrchr.c \
-    upstream-freebsd/lib/libc/string/wmemcmp.c \
-    upstream-freebsd/lib/libc/string/wmemmove.c \
-
-libc_openbsd_src_files_mips64 += \
-    upstream-openbsd/lib/libc/string/memchr.c \
-    upstream-openbsd/lib/libc/string/memmove.c \
-    upstream-openbsd/lib/libc/string/memrchr.c \
-    upstream-openbsd/lib/libc/string/stpcpy.c \
-    upstream-openbsd/lib/libc/string/stpncpy.c \
-    upstream-openbsd/lib/libc/string/strcat.c \
-    upstream-openbsd/lib/libc/string/strcpy.c \
-    upstream-openbsd/lib/libc/string/strlcat.c \
-    upstream-openbsd/lib/libc/string/strlcpy.c \
-    upstream-openbsd/lib/libc/string/strncat.c \
-    upstream-openbsd/lib/libc/string/strncmp.c \
-    upstream-openbsd/lib/libc/string/strncpy.c \
 
 #
 # Inherently architecture-specific code.
diff --git a/libc/arch-x86/atom/atom.mk b/libc/arch-x86/atom/atom.mk
index 3f28fb236..1afabaca0 100644
--- a/libc/arch-x86/atom/atom.mk
+++ b/libc/arch-x86/atom/atom.mk
@@ -1,32 +1,27 @@
 libc_bionic_src_files_x86 += \
     arch-x86/atom/string/sse2-bzero-atom.S \
-    arch-x86/atom/string/sse2-memchr-atom.S \
-    arch-x86/atom/string/sse2-memrchr-atom.S \
     arch-x86/atom/string/sse2-memset-atom.S \
-    arch-x86/atom/string/sse2-strchr-atom.S \
     arch-x86/atom/string/sse2-strlen-atom.S \
-    arch-x86/atom/string/sse2-strnlen-atom.S \
-    arch-x86/atom/string/sse2-strrchr-atom.S \
-    arch-x86/atom/string/sse2-wcschr-atom.S \
-    arch-x86/atom/string/sse2-wcsrchr-atom.S \
-    arch-x86/atom/string/sse2-wcslen-atom.S \
-    arch-x86/atom/string/sse2-wcscmp-atom.S \
     arch-x86/atom/string/ssse3-bcopy-atom.S \
     arch-x86/atom/string/ssse3-memcmp-atom.S \
     arch-x86/atom/string/ssse3-memcpy-atom.S \
     arch-x86/atom/string/ssse3-memmove-atom.S \
-    arch-x86/atom/string/ssse3-strcat-atom.S \
-    arch-x86/atom/string/ssse3-strcmp-atom.S \
     arch-x86/atom/string/ssse3-strcpy-atom.S \
-    arch-x86/atom/string/ssse3-strlcat-atom.S \
-    arch-x86/atom/string/ssse3-strlcpy-atom.S \
-    arch-x86/atom/string/ssse3-strncat-atom.S \
-    arch-x86/atom/string/ssse3-strncmp-atom.S \
     arch-x86/atom/string/ssse3-strncpy-atom.S \
-    arch-x86/atom/string/ssse3-wcscat-atom.S \
-    arch-x86/atom/string/ssse3-wcscpy-atom.S \
     arch-x86/atom/string/ssse3-wmemcmp-atom.S
 
-libc_bionic_src_files_x86 += \
-    arch-x86/silvermont/string/sse2-stpcpy-slm.S \
-    arch-x86/silvermont/string/sse2-stpncpy-slm.S
+libc_bionic_src_files_exclude_x86 += \
+    arch-x86/generic/string/memcmp.S \
+
+libc_bionic_src_files_exclude_x86 += \
+    arch-x86/silvermont/string/sse2-bcopy-slm.S \
+    arch-x86/silvermont/string/sse2-bzero-slm.S \
+    arch-x86/silvermont/string/sse2-memcpy-slm.S \
+    arch-x86/silvermont/string/sse2-memmove-slm.S \
+    arch-x86/silvermont/string/sse2-memset-slm.S \
+    arch-x86/silvermont/string/sse2-strcpy-slm.S \
+    arch-x86/silvermont/string/sse2-strlen-slm.S \
+    arch-x86/silvermont/string/sse2-strncpy-slm.S \
+
+libc_freebsd_src_files_exclude_x86 += \
+    upstream-freebsd/lib/libc/string/wmemcmp.c \
diff --git a/libc/arch-x86/generic/generic.mk b/libc/arch-x86/generic/generic.mk
deleted file mode 100644
index 4aee5dc63..000000000
--- a/libc/arch-x86/generic/generic.mk
+++ /dev/null
@@ -1,52 +0,0 @@
-libc_bionic_src_files_x86 += \
-    arch-x86/atom/string/sse2-memchr-atom.S \
-    arch-x86/atom/string/sse2-memrchr-atom.S \
-    arch-x86/atom/string/sse2-strchr-atom.S \
-    arch-x86/atom/string/sse2-strnlen-atom.S \
-    arch-x86/atom/string/sse2-strrchr-atom.S \
-    arch-x86/atom/string/sse2-wcschr-atom.S \
-    arch-x86/atom/string/sse2-wcsrchr-atom.S \
-    arch-x86/atom/string/sse2-wcslen-atom.S \
-    arch-x86/atom/string/sse2-wcscmp-atom.S \
-    arch-x86/silvermont/string/sse2-bcopy-slm.S \
-    arch-x86/silvermont/string/sse2-bzero-slm.S \
-    arch-x86/silvermont/string/sse2-memcpy-slm.S \
-    arch-x86/silvermont/string/sse2-memmove-slm.S \
-    arch-x86/silvermont/string/sse2-memset-slm.S \
-    arch-x86/silvermont/string/sse2-stpcpy-slm.S \
-    arch-x86/silvermont/string/sse2-stpncpy-slm.S \
-    arch-x86/silvermont/string/sse2-strcpy-slm.S \
-    arch-x86/silvermont/string/sse2-strlen-slm.S \
-    arch-x86/silvermont/string/sse2-strncpy-slm.S
-
-ifeq ($(ARCH_X86_HAVE_SSSE3),true)
-libc_bionic_src_files_x86 += \
-    arch-x86/atom/string/ssse3-strncat-atom.S \
-    arch-x86/atom/string/ssse3-strlcat-atom.S \
-    arch-x86/atom/string/ssse3-strlcpy-atom.S \
-    arch-x86/atom/string/ssse3-strcmp-atom.S \
-    arch-x86/atom/string/ssse3-strncmp-atom.S \
-    arch-x86/atom/string/ssse3-strcat-atom.S \
-    arch-x86/atom/string/ssse3-wcscat-atom.S \
-    arch-x86/atom/string/ssse3-wcscpy-atom.S
-else
-libc_bionic_src_files_x86 += \
-    arch-x86/generic/string/strcmp.S \
-    arch-x86/generic/string/strncmp.S \
-    arch-x86/generic/string/strcat.S \
-    upstream-freebsd/lib/libc/string/wcscpy.c \
-    upstream-freebsd/lib/libc/string/wcscat.c \
-    upstream-openbsd/lib/libc/string/strlcat.c \
-    upstream-openbsd/lib/libc/string/strlcpy.c \
-    upstream-openbsd/lib/libc/string/strncat.c
-endif
-
-ifeq ($(ARCH_X86_HAVE_SSE4),true)
- libc_bionic_src_files_x86 += \
-    arch-x86/silvermont/string/sse4-memcmp-slm.S \
-    arch-x86/silvermont/string/sse4-wmemcmp-slm.S
-else
-libc_bionic_src_files_x86 += \
-    arch-x86/generic/string/memcmp.S \
-    upstream-freebsd/lib/libc/string/wmemcmp.c
-endif
diff --git a/libc/arch-x86/silvermont/silvermont.mk b/libc/arch-x86/silvermont/silvermont.mk
index 176bee339..e69de29bb 100644
--- a/libc/arch-x86/silvermont/silvermont.mk
+++ b/libc/arch-x86/silvermont/silvermont.mk
@@ -1,32 +0,0 @@
-libc_bionic_src_files_x86 += \
-    arch-x86/silvermont/string/sse2-bcopy-slm.S \
-    arch-x86/silvermont/string/sse2-bzero-slm.S \
-    arch-x86/silvermont/string/sse2-memcpy-slm.S \
-    arch-x86/silvermont/string/sse2-memmove-slm.S \
-    arch-x86/silvermont/string/sse2-memset-slm.S \
-    arch-x86/silvermont/string/sse2-stpcpy-slm.S \
-    arch-x86/silvermont/string/sse2-stpncpy-slm.S \
-    arch-x86/silvermont/string/sse2-strcpy-slm.S \
-    arch-x86/silvermont/string/sse2-strlen-slm.S \
-    arch-x86/silvermont/string/sse2-strncpy-slm.S \
-    arch-x86/silvermont/string/sse4-memcmp-slm.S \
-    arch-x86/silvermont/string/sse4-wmemcmp-slm.S
-
-libc_bionic_src_files_x86 += \
-    arch-x86/atom/string/sse2-memchr-atom.S \
-    arch-x86/atom/string/sse2-memrchr-atom.S \
-    arch-x86/atom/string/sse2-strchr-atom.S \
-    arch-x86/atom/string/sse2-strrchr-atom.S \
-    arch-x86/atom/string/sse2-strnlen-atom.S \
-    arch-x86/atom/string/sse2-wcschr-atom.S \
-    arch-x86/atom/string/sse2-wcsrchr-atom.S \
-    arch-x86/atom/string/sse2-wcslen-atom.S \
-    arch-x86/atom/string/sse2-wcscmp-atom.S \
-    arch-x86/atom/string/ssse3-strncat-atom.S \
-    arch-x86/atom/string/ssse3-strlcat-atom.S \
-    arch-x86/atom/string/ssse3-strlcpy-atom.S \
-    arch-x86/atom/string/ssse3-strcmp-atom.S \
-    arch-x86/atom/string/ssse3-strncmp-atom.S \
-    arch-x86/atom/string/ssse3-strcat-atom.S \
-    arch-x86/atom/string/ssse3-wcscat-atom.S \
-    arch-x86/atom/string/ssse3-wcscpy-atom.S
diff --git a/libc/arch-x86/x86.mk b/libc/arch-x86/x86.mk
index e5d70a9d8..b4056bbbc 100644
--- a/libc/arch-x86/x86.mk
+++ b/libc/arch-x86/x86.mk
@@ -1,17 +1,103 @@
 # 32-bit x86.
 
 #
-# Default implementations of functions that are commonly optimized.
+# Generic x86 optimizations, may be overriden by CPU variants.
 #
 
-libc_common_src_files_x86 += \
-    bionic/__memcpy_chk.cpp \
-    bionic/__memset_chk.cpp \
-    bionic/__strcpy_chk.cpp \
-    bionic/__strcat_chk.cpp \
+libc_bionic_src_files_x86 += \
+    arch-x86/atom/string/sse2-memchr-atom.S \
+    arch-x86/atom/string/sse2-memrchr-atom.S \
+    arch-x86/atom/string/sse2-strchr-atom.S \
+    arch-x86/atom/string/sse2-strnlen-atom.S \
+    arch-x86/atom/string/sse2-strrchr-atom.S \
+    arch-x86/atom/string/sse2-wcschr-atom.S \
+    arch-x86/atom/string/sse2-wcsrchr-atom.S \
+    arch-x86/atom/string/sse2-wcslen-atom.S \
+    arch-x86/atom/string/sse2-wcscmp-atom.S \
+    arch-x86/silvermont/string/sse2-bcopy-slm.S \
+    arch-x86/silvermont/string/sse2-bzero-slm.S \
+    arch-x86/silvermont/string/sse2-memcpy-slm.S \
+    arch-x86/silvermont/string/sse2-memmove-slm.S \
+    arch-x86/silvermont/string/sse2-memset-slm.S \
+    arch-x86/silvermont/string/sse2-stpcpy-slm.S \
+    arch-x86/silvermont/string/sse2-stpncpy-slm.S \
+    arch-x86/silvermont/string/sse2-strcpy-slm.S \
+    arch-x86/silvermont/string/sse2-strlen-slm.S \
+    arch-x86/silvermont/string/sse2-strncpy-slm.S
 
-libc_freebsd_src_files_x86 += \
-    upstream-freebsd/lib/libc/string/wmemmove.c \
+libc_bionic_src_files_x86 += \
+    arch-x86/generic/string/memcmp.S \
+    arch-x86/generic/string/strcmp.S \
+    arch-x86/generic/string/strncmp.S \
+    arch-x86/generic/string/strcat.S
+
+ifeq ($(ARCH_X86_HAVE_SSSE3),true)
+libc_bionic_src_files_x86 += \
+    arch-x86/atom/string/ssse3-strncat-atom.S \
+    arch-x86/atom/string/ssse3-strlcat-atom.S \
+    arch-x86/atom/string/ssse3-strlcpy-atom.S \
+    arch-x86/atom/string/ssse3-strcmp-atom.S \
+    arch-x86/atom/string/ssse3-strncmp-atom.S \
+    arch-x86/atom/string/ssse3-strcat-atom.S \
+    arch-x86/atom/string/ssse3-wcscat-atom.S \
+    arch-x86/atom/string/ssse3-wcscpy-atom.S
+libc_bionic_src_files_exclude_x86 += \
+    arch-x86/generic/string/strcmp.S \
+    arch-x86/generic/string/strncmp.S \
+    arch-x86/generic/string/strcat.S
+endif
+
+ifeq ($(ARCH_X86_HAVE_SSE4),true)
+libc_bionic_src_files_x86 += \
+    arch-x86/silvermont/string/sse4-memcmp-slm.S \
+    arch-x86/silvermont/string/sse4-wmemcmp-slm.S
+libc_bionic_src_files_exclude_x86 += \
+    arch-x86/generic/string/memcmp.S
+endif
+
+#
+# Remove default implementations that we have optimized versions of.
+#
+
+libc_freebsd_src_files_exclude_x86 += \
+    upstream-freebsd/lib/libc/string/wcschr.c \
+    upstream-freebsd/lib/libc/string/wcscmp.c \
+    upstream-freebsd/lib/libc/string/wcslen.c \
+    upstream-freebsd/lib/libc/string/wcsrchr.c \
+
+ifeq ($(ARCH_X86_HAVE_SSSE3),true)
+libc_freebsd_src_files_exclude_x86 += \
+    upstream-freebsd/lib/libc/string/wcscat.c \
+    upstream-freebsd/lib/libc/string/wcscpy.c
+endif
+
+ifeq ($(ARCH_X86_HAVE_SSE4),true)
+libc_freebsd_src_files_exclude_x86 += \
+    upstream-freebsd/lib/libc/string/wmemcmp.c
+endif
+
+libc_openbsd_src_files_exclude_x86 += \
+    upstream-openbsd/lib/libc/string/memchr.c \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/memrchr.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/stpncpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+    upstream-openbsd/lib/libc/string/strcpy.c \
+    upstream-openbsd/lib/libc/string/strncmp.c \
+    upstream-openbsd/lib/libc/string/strncpy.c \
+
+ifeq ($(ARCH_X86_HAVE_SSSE3),true)
+libc_openbsd_src_files_exclude_x86 += \
+    upstream-openbsd/lib/libc/string/strlcat.c \
+    upstream-openbsd/lib/libc/string/strlcpy.c \
+    upstream-openbsd/lib/libc/string/strncat.c
+endif
+
+libc_bionic_src_files_exclude_x86 += \
+    bionic/strchr.cpp \
+    bionic/strnlen.c \
+    bionic/strrchr.cpp \
 
 #
 # Inherently architecture-specific functions.
@@ -30,12 +116,14 @@ libc_bionic_src_files_x86 += \
 ## ARCH variant specific source files
 arch_variant_mk := $(LOCAL_PATH)/arch-x86/$(TARGET_ARCH_VARIANT)/$(TARGET_ARCH_VARIANT).mk
 ifeq ($(wildcard $(arch_variant_mk)),)
-    arch_variant_mk := $(LOCAL_PATH)/arch-x86/generic/generic.mk
+    arch_variant_mk :=
 endif
+ifneq ($(arch_variant_mk),)
 include $(arch_variant_mk)
 libc_common_additional_dependencies += $(arch_variant_mk)
 
 arch_variant_mk :=
+endif
 
 libc_crt_target_cflags_x86 := \
     -m32 \
diff --git a/libc/arch-x86_64/x86_64.mk b/libc/arch-x86_64/x86_64.mk
index 06d318574..bbf5c8c5b 100644
--- a/libc/arch-x86_64/x86_64.mk
+++ b/libc/arch-x86_64/x86_64.mk
@@ -1,31 +1,20 @@
 # 64-bit x86.
 
 #
-# Default implementations of functions that are commonly optimized.
+# Remove default implementations that we have optimized versions of.
 #
 
-libc_bionic_src_files_x86_64 += \
-    bionic/__memcpy_chk.cpp \
-    bionic/__memset_chk.cpp \
-    bionic/__strcpy_chk.cpp \
-    bionic/__strcat_chk.cpp \
-    bionic/strchr.cpp \
-    bionic/strnlen.c \
-    bionic/strrchr.cpp \
-
-libc_freebsd_src_files_x86_64 += \
-    upstream-freebsd/lib/libc/string/wcscat.c \
-    upstream-freebsd/lib/libc/string/wcschr.c \
-    upstream-freebsd/lib/libc/string/wcscmp.c \
-    upstream-freebsd/lib/libc/string/wcscpy.c \
-    upstream-freebsd/lib/libc/string/wcslen.c \
-    upstream-freebsd/lib/libc/string/wcsrchr.c \
-    upstream-freebsd/lib/libc/string/wmemcmp.c \
-    upstream-freebsd/lib/libc/string/wmemmove.c \
-
-libc_openbsd_src_files_x86_64 += \
-    upstream-openbsd/lib/libc/string/memchr.c \
-    upstream-openbsd/lib/libc/string/memrchr.c \
+libc_openbsd_src_files_exclude_x86_64 += \
+    upstream-openbsd/lib/libc/string/memmove.c \
+    upstream-openbsd/lib/libc/string/stpcpy.c \
+    upstream-openbsd/lib/libc/string/stpncpy.c \
+    upstream-openbsd/lib/libc/string/strcat.c \
+    upstream-openbsd/lib/libc/string/strcpy.c \
+    upstream-openbsd/lib/libc/string/strlcat.c \
+    upstream-openbsd/lib/libc/string/strlcpy.c \
+    upstream-openbsd/lib/libc/string/strncat.c \
+    upstream-openbsd/lib/libc/string/strncmp.c \
+    upstream-openbsd/lib/libc/string/strncpy.c \
 
 #
 # Inherently architecture-specific code.