GOBIN                         = Getenv("GOBIN")
	GOMODCACHE, GOMODCACHEChanged = EnvOrAndChanged("GOMODCACHE", gopathDir("pkg/mod"))

	// Used in envcmd.MkEnv and build ID computations.
	GOARM64, goARM64Changed     = EnvOrAndChanged("GOARM64", fmt.Sprint(buildcfg.GOARM64))
	GOARM, goARMChanged         = EnvOrAndChanged("GOARM", fmt.Sprint(buildcfg.GOARM))
	GO386, go386Changed         = EnvOrAndChanged("GO386", buildcfg.GO386)

	GOARM64
		For GOARCH=arm64, the ARM64 architecture for which to compile.
		Valid values are v8.0 (default), v8.{1-9}, v9.{0-5}.
		The value can be followed by an option specifying extensions implemented by target hardware.
		Valid options are ,lse and ,crypto.
		Note that some extensions are enabled by default starting from a certain GOARM64 version;

			args = append(args, "-D", "GOARM_6")
			fallthrough
		default:
			args = append(args, "-D", "GOARM_5")
		}
	}

	if cfg.Goarch == "arm64" {
		g, err := buildcfg.ParseGoarm64(cfg.GOARM64)
		if err == nil && g.LSE {
			args = append(args, "-D", "GOARM64_LSE")
		}
	}

	return args
}

func (gcToolchain) asm(b *Builder, a *Action, sfiles []string) ([]string, error) {
	p := a.Package