Pu Lehui <pulehui@xxxxxxxxxxxxxxx> writes:
>>> @@ -252,10 +220,7 @@ static void __build_epilogue(bool is_tail_call, struct rv_jit_context *ctx)
>>> emit_ld(RV_REG_S5, store_offset, RV_REG_SP, ctx);
>>> store_offset -= 8;
>>> }
>>> - if (seen_reg(RV_REG_S6, ctx)) {
>>> - emit_ld(RV_REG_S6, store_offset, RV_REG_SP, ctx);
>>> - store_offset -= 8;
>>> - }
>>> + emit_ld(RV_REG_TCC, store_offset, RV_REG_SP, ctx);
>>
>> Why do you need to restore RV_REG_TCC? We're passing RV_REG_TCC (a6) as
>> an argument at all call-sites, and for tailcalls we're loading from the
>> stack.
>>
>> Is this to fake the a6 argument for the tail-call? If so, it's better to
>> move it to emit_bpf_tail_call(), instead of letting all programs pay for
>> it.
>
> Yes, we can remove this duplicate load. will do that at next version.
Hmm, no remove, but *move* right? Otherwise a6 can contain gargabe on
entering the tailcall?
Move it before __emit_epilogue() in the tailcall, no?
Björn
