export RUSTFLAGS="$BASE_RUSTFLAGS -C target-cpu=sandybridge"
export CFLAGS_$ENV_TARGET="$BASE_HOST_CFLAGS -march=sandybridge -mcpu=sandybridge -mtune=sandybridge"
;;
+ "aarch64_apple_darwin")
+ export RUSTFLAGS="$BASE_RUSTFLAGS -C target-cpu=apple-a14"
+ export CFLAGS_$ENV_TARGET="$BASE_HOST_CFLAGS -mcpu=apple-a14"
+ ;;
*)
# Assume this isn't targeted at another host and build for the host's CPU.
export RUSTFLAGS="$BASE_RUSTFLAGS -C target-cpu=native"