crosstool-ng/scripts/build/arch/sparc.sh

# Compute sparc-specific values
CT_DoArchTupleValues() {
    # That's the only thing to override
    CT_TARGET_ARCH="sparc${target_bits_64}${CT_ARCH_SUFFIX}"

    # By default, sparc64-*-linux is configured with -mcpu=v9. However,
    # according to https://sourceware.org/ml/libc-alpha/2005-12/msg00027.html,
    # "There is no Linux sparc64 port that runs on non-UltraSPARC-I+ ISA CPUs."
    # There is a patch that would change the default to -mcpu=ultrasparc for
    # sparc64-*-linux configuration: https://patchwork.ozlabs.org/patch/409424/
    # but that patch has not been integrated (yet). One concern raised about
    # this patch was that -mcpu=ultrasparc can suboptimally schedule instructions
    # for newer SPARC CPUs. So, override to -mcpu=ultrasparc and warn the user.
    if [ "${CT_KERNEL}" = "linux" -a "${CT_ARCH_64}" = "y" -a -z "${CT_ARCH_CPU}" ]; then
        CT_DoLog WARN "Setting CPU to UltraSPARC-I for sparc64-linux. Set CT_ARCH_CPU if a different CPU is desired."
        CT_ARCH_WITH_CPU="--with-cpu=ultrasparc"
    fi
}