switch goppc64 {
		case "power10":
			asmArgs = append(asmArgs, "-D", "GOPPC64_power10")
			fallthrough
		case "power9":
			asmArgs = append(asmArgs, "-D", "GOPPC64_power9")
			fallthrough
		default: // This should always be power8.
			asmArgs = append(asmArgs, "-D", "GOPPC64_power8")
		}
	}
	if goarch == "riscv64" {
		// Define GORISCV64_value from goriscv64