> On Sep 19, 2017, at 5:25 PM, Alexander Monakov <amona...@ispras.ru> wrote:
>
> On Tue, 19 Sep 2017, Maxim Kuvyrkov wrote:
>> How about the following:
>> 1. if both instructions are "irrelevant", then return "0".
>> 2. if one instruction is "relevant" and another is "irrelevant", then
>> "relevant" instruction is always greater (or lesser) than the non-relevant.
>> 3. if both instructions are "relevant", then call autopref_rank_data.
>
> Sounds good, the following patch implements this (with 'relevant' greater).
>
>> I don't have immediate answer on whether "relevant" or "irrelevant"
>> instructions should be pushed towards beginning of the ready list. Possibly,
>> we want to delay "relevant" instructions and push "irrelevant" towards
>> beginning of ready list so that more "relevant" instructions can enter ready
>> list as their dependencies are resolved from scheduling "irrelevant"
>> instructions.
>>
>> WDYT?
>
> *nod*, this makes sense.
>
> (bootstrap/regtest running on x86-64)
>
> Thanks!
>
> * haifa-sched.c (autopref_rank_for_schedule): Order 'irrelevant' insns
> first, always call autopref_rank_data otherwise.
>
> diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
> index af0ed27b18f..8f006de2319 100644
> --- a/gcc/haifa-sched.c
> +++ b/gcc/haifa-sched.c
> @@ -5707,7 +5707,8 @@ autopref_rank_data (autopref_multipass_data_t data1,
> static int
> autopref_rank_for_schedule (const rtx_insn *insn1, const rtx_insn *insn2)
> {
> - for (int write = 0; write < 2; ++write)
> + int r = 0;
> + for (int write = 0; write < 2 && !r; ++write)
> {
> autopref_multipass_data_t data1
> = &INSN_AUTOPREF_MULTIPASS_DATA (insn1)[write];
> @@ -5716,21 +5717,20 @@ autopref_rank_for_schedule (const rtx_insn *insn1,
> const rtx_insn *insn2)
>
> if (data1->status == AUTOPREF_MULTIPASS_DATA_UNINITIALIZED)
> autopref_multipass_init (insn1, write);
> - if (data1->status == AUTOPREF_MULTIPASS_DATA_IRRELEVANT)
> - continue;
>
> if (data2->status == AUTOPREF_MULTIPASS_DATA_UNINITIALIZED)
> autopref_multipass_init (insn2, write);
> - if (data2->status == AUTOPREF_MULTIPASS_DATA_IRRELEVANT)
> - continue;
>
> - if (!rtx_equal_p (data1->base, data2->base))
> - continue;
> + int irrel1 = data1->status == AUTOPREF_MULTIPASS_DATA_IRRELEVANT;
> + int irrel2 = data2->status == AUTOPREF_MULTIPASS_DATA_IRRELEVANT;
>
> - return autopref_rank_data (data1, data2);
> + if (!irrel1 && !irrel2)
> + r = autopref_rank_data (data1, data2);
> + else
> + r = irrel2 - irrel1;I'd like to keep read/write processing balanced. In the above "read" analysis has greater weight than "write" analysis. Also, autopref_rank_data() should not be called if !rtx_equal_p (data1->base, data2->base). How about the attached patch? -- Maxim Kuvyrkov www.linaro.org
autopref_rank-fix.patch
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