-DVIXL_DEBUG \
-UNDEBUG
+# The latest clang update trips over many of the files in art and never finishes
+# compiling for aarch64 with -O3 (or -O2). Drop back to -O1 while we investigate
+# to stop punishing the build server.
+ifeq ($(TARGET_ARCH),arm64)
+ ifeq ($(USE_CLANG_PLATFORM_BUILD),true)
+ art_debug_cflags += -O1
+ art_non_debug_cflags += -O1
+ endif
+endif
+
art_host_non_debug_cflags := $(art_non_debug_cflags)
art_target_non_debug_cflags := $(art_non_debug_cflags)