Hello All:
Addressed below review comments in the version 11 of the patch.
Please review and please let me know if its ok for trunk.
Thanks & Regards
Ajit
On 22/10/23 12:56 am, rep.dot....@gmail.com wrote:
> On 21 October 2023 01:56:16 CEST, Vineet Gupta <vine...@rivosinc.com> wrote:
>> On 10/19/23 23:50, Ajit Agarwal wrote:
>>> Hello All:
>>>
>>> This version 9 of the patch uses abi interfaces to remove zero and sign
>>> extension elimination.
>>> Bootstrapped and regtested on powerpc-linux-gnu.
>>>
>>> In this version (version 9) of the patch following review comments are
>>> incorporated.
>>>
>>> a) Removal of hard code zero_extend and sign_extend in abi interfaces.
>>> b) Source and destination with different registers are considered.
>>> c) Further enhancements.
>>> d) Added sign extension elimination using abi interfaces.
>>
>> As has been trend in the past, I don't think all the review comments have
>> been addressed.
>
> And apart from that, may I ask if this is just me, or does anybody else think
> that it might be worthwhile to actually read a patch before (re-)posting?
>
> Seeing e.g. the proposed abi_extension_candidate_p as written in a first POC
> would deserve some manual CSE, if nothing more then for clarity and
> conciseness?
>
> Just curious from a meta perspective..
>
> And:
>
>>> ree: Improve ree pass for rs6000 target using defined abi interfaces
>
> mentioning powerpc like this, and then changing generic code could be
> interpreted as misleading, IMHO.
>
>>>
>>> For rs6000 target we see redundant zero and sign extension and done
>>> to improve ree pass to eliminate such redundant zero and sign extension
>>> using defined ABI interfaces.
>
> Mentioning powerpc in the body as one of the affected target(s) is of course
> fine.
>
>
>>> +/* Return TRUE if target mode is equal to source mode of zero_extend
>>> + or sign_extend otherwise false. */
>
> , false otherwise.
>
> But I'm not a native speaker
>
>
>>> +/* Return TRUE if the candidate insn is zero extend and regno is
>>> + a return registers. */
>>> +
>>> +static bool
>>> +abi_extension_candidate_return_reg_p (/*rtx_insn *insn, */int regno)
>
> Leftover debug comment.
>
>>> +{
>>> + if (targetm.calls.function_value_regno_p (regno))
>>> + return true;
>>> +
>>> + return false;
>>> +}
>>> +
>
> As said, I don't see why the below was not cleaned up before the V1
> submission.
> Iff it breaks when manually CSEing, I'm curious why?
>
>>> +/* Return TRUE if reg source operand of zero_extend is argument registers
>>> + and not return registers and source and destination operand are same
>>> + and mode of source and destination operand are not same. */
>>> +
>>> +static bool
>>> +abi_extension_candidate_p (rtx_insn *insn)
>>> +{
>>> + rtx set = single_set (insn);
>>> + machine_mode dst_mode = GET_MODE (SET_DEST (set));
>>> + rtx orig_src = XEXP (SET_SRC (set), 0);
>>> +
>>> + if (!FUNCTION_ARG_REGNO_P (REGNO (orig_src))
>>> + || abi_extension_candidate_return_reg_p (/*insn,*/ REGNO (orig_src)))
>
> On top, debug leftover.
>
>>> + return false;
>>> +
>>> + /* Mode of destination and source should be different. */
>>> + if (dst_mode == GET_MODE (orig_src))
>>> + return false;
>>> +
>>> + machine_mode mode = GET_MODE (XEXP (SET_SRC (set), 0));
>>> + bool promote_p = abi_target_promote_function_mode (mode);
>>> +
>>> + /* REGNO of source and destination should be same if not
>>> + promoted. */
>>> + if (!promote_p && REGNO (SET_DEST (set)) != REGNO (orig_src))
>>> + return false;
>>> +
>>> + return true;
>>> +}
>>> +
>
> As said, please also rephrase the above (and everything else if it obviously
> looks akin the above).
>
> The rest, mentioned below, should largely be covered by following the coding
> convention.
>
>>> +/* Return TRUE if the candidate insn is zero extend and regno is
>>> + an argument registers. */
>
> Singular register.
>
>>> +
>>> +static bool
>>> +abi_extension_candidate_argno_p (/*rtx_code code, */int regno)
>
> Debug leftover.
> I would probably have inlined this function manually, with a respective
> comment.
> Did not look how often it is used, admittedly.
>
>>> +{
>>> + if (FUNCTION_ARG_REGNO_P (regno))
>>> + return true;
>>> +
>>> + return false;
>>> +}
> []
>>> +
>>> /* This function goes through all reaching defs of the source
>
> s/This function goes/Go/
>
>>> of the candidate for elimination (CAND) and tries to combine
>
> (of, ?didn't look) candidate CAND for eliminating
>
>>> the extension with the definition instruction. The changes
>
> defining
>
> Pre-existing, I know.
> But you could fix those in a preparatory patch while you touch surrounding
> code.
> This is not a requirement, of course, just good habit, IMHO.
>
>>> @@ -770,6 +889,11 @@ combine_reaching_defs (ext_cand *cand, const_rtx
>>> set_pat, ext_state *state)
>>> state->defs_list.truncate (0);
>>> state->copies_list.truncate (0);
>>> + rtx orig_src = XEXP (SET_SRC (cand->expr),0);
>>> +
>>> + if (abi_extension_candidate_p (cand->insn)
>>> + && (!get_defs (cand->insn, orig_src, NULL)))
>
> Excess braces.
> Hopefully check_gnu_style would have complained.
>
>>> + return abi_handle_regs (cand->insn);
>>> outcome = make_defs_and_copies_lists (cand->insn, set_pat, state);
>>> @@ -1036,6 +1160,15 @@ combine_reaching_defs (ext_cand *cand, const_rtx
>>> set_pat, ext_state *state)
>>> }
>>> }
>>> + rtx insn_set = single_set (cand->insn);
>>> +
>>> + machine_mode mode = (GET_MODE (XEXP (SET_SRC (insn_set), 0)));
>
> Excess braces.
> Also in a lot of other spots in your patch.
> Please read the coding conventions and the patch, once again, before
> submission?
> thanks
