if find(goos, okgoos) < 0 {
		fatalf("unknown $GOOS %s", goos)
	}

	b = os.Getenv("GOARM")
	if b == "" {
		b = xgetgoarm()
	}
	goarm = b

	b = os.Getenv("GOARM64")
	if b == "" {
		b = "v8.0"
	}
	goarm64 = b

	b = os.Getenv("GO386")
	if b == "" {
		b = "sse2"
	}
	go386 = b

	b = os.Getenv("GOAMD64")
	if b == "" {
		b = "v1"
	}
	goamd64 = b

	archVariants = map[string][]string{
		"386":     {"GO386", "sse2", "softfloat"},
		"amd64":   {"GOAMD64", "v1", "v2", "v3", "v4"},
		"arm":     {"GOARM", "5", "6", "7", "7,softfloat"},
		"arm64":   {"GOARM64", "v8.0", "v8.1"},
		"loong64": {},
		"mips":    {"GOMIPS", "hardfloat", "softfloat"},
		"mips64":  {"GOMIPS64", "hardfloat", "softfloat"},
		"ppc64":   {"GOPPC64", "power8", "power9", "power10"},