Use Propeller profile information to optimize the build target.A propeller profile must consist of at least one of two files, a cc profile and a ld profile. This flag accepts a build label which must refer to the propeller profile input files. For example, the BUILD file that defines the label, in a/b/BUILD:propeller_optimize( name = "propeller_profile", cc_profile = "propeller_cc_profile.txt", ld_profile = "propeller_ld_profile.txt",) An exports_files directive may have to be added to the corresponding package to make these files visible to Bazel. The option must be used as: -- propeller_optimize=//a/b:propeller_profile