Re: [PATCH] RISC-V: Don't emit cm.popret when zcmp + zicfiss is enabled [PR125217]

[Jeffrey Law]

On 5/8/2026 12:27 PM, Michiel Derhaeg wrote:

Currently when -fcf-protection=return and zcmp are enabled this code is
generated:

        sspush ra
        cm.push {ra, s0-s1}, -32
        ..
        cm.popret {ra, s0-s1}, 32

riscv_expand_epilogue will skip emitting sspopchk when cm.popret is
emitted. After this patch we will no longer emit cm.popret and instead
use cm.pop + sspopchk + a regular return:

        sspush  ra
        cm.push {ra, s0-s1}, -32
        ..
        cm.pop {ra, s0-s1}, 32
        sspopchk ra
        jr ra

Regtested for rv32g & rv64g.

        PR target/125217

gcc/ChangeLog:

        * config/riscv/riscv.cc (riscv_gen_multi_pop_insn): Rename variable.
        (riscv_expand_epilogue): Don't emit cm.popret with shadow stack.

gcc/testsuite/ChangeLog:

        * gcc.target/riscv/ssp-zcmp.c: New test.

Thanks.  I've pushed this to the trunk.

jeff