On 2026/07/09 10:50 AM, Peter Maydell wrote:
> The helper_lscbx() function isn't called anywhere. It used to be
> used by the PPC 601 CPU support; we removed that in commit 005b69fdcc
> in 2022 but missed this helper function.
>
> Fixes: 005b69fdcc ("target/ppc: Remove PowerPC 601 CPUs")
> Signed-off-by: Peter Maydell <[email protected]>
> ---
> This came to my attention because Coverity reported a
> "shifts into sign bit" issue in the function: CID 1663681
> ---
> target/ppc/helper.h | 1 -
> target/ppc/mem_helper.c | 28 ----------------------------
> 2 files changed, 29 deletions(-)
"git grep lscbx" returns only the declaration in helper.h and the
definition in mem_helper.c -- no TCG translator references, no
gen_lscbx, nothing in translate.c. Confirmed dead code with zero
callers. Thanks for the cleanup.
Reviewed-by: Amit Machhiwal <[email protected]>
Thanks,
Amit
>
> diff --git a/target/ppc/helper.h b/target/ppc/helper.h
> index e99c8c824b..6b2d19a3ad 100644
> --- a/target/ppc/helper.h
> +++ b/target/ppc/helper.h
> @@ -54,7 +54,6 @@ DEF_HELPER_FLAGS_2(dcbzl, TCG_CALL_NO_WG, void, env, tl)
> #endif
> DEF_HELPER_FLAGS_2(icbi, TCG_CALL_NO_WG, void, env, tl)
> DEF_HELPER_FLAGS_2(icbiep, TCG_CALL_NO_WG, void, env, tl)
> -DEF_HELPER_5(lscbx, tl, env, tl, i32, i32, i32)
>
> #if defined(TARGET_PPC64)
> DEF_HELPER_4(DIVDEU, i64, env, i64, i64, i32)
> diff --git a/target/ppc/mem_helper.c b/target/ppc/mem_helper.c
> index 119dc1df23..787ba2cdec 100644
> --- a/target/ppc/mem_helper.c
> +++ b/target/ppc/mem_helper.c
> @@ -367,34 +367,6 @@ void helper_icbiep(CPUPPCState *env, target_ulong addr)
> #endif
> }
>
> -/* XXX: to be tested */
> -target_ulong helper_lscbx(CPUPPCState *env, target_ulong addr, uint32_t reg,
> - uint32_t ra, uint32_t rb)
> -{
> - int i, c, d;
> -
> - d = 24;
> - for (i = 0; i < xer_bc; i++) {
> - c = cpu_ldub_data_ra(env, addr, GETPC());
> - addr = addr_add(env, addr, 1);
> - /* ra (if not 0) and rb are never modified */
> - if (likely(reg != rb && (ra == 0 || reg != ra))) {
> - env->gpr[reg] = (env->gpr[reg] & ~(0xFF << d)) | (c << d);
> - }
> - if (unlikely(c == xer_cmp)) {
> - break;
> - }
> - if (likely(d != 0)) {
> - d -= 8;
> - } else {
> - d = 24;
> - reg++;
> - reg = reg & 0x1F;
> - }
> - }
> - return i;
> -}
> -
>
> /*****************************************************************************/
> /* Altivec extension helpers */
> #if HOST_BIG_ENDIAN
> --
> 2.43.0
>
>
