钟居哲; gcc-patches
CC: rdapp.gcc; kito.cheng; kito.cheng; Jeff Law
Subject: Re: [PATCH] RISC-V: Switch RVV cost model to generic vector cost model
> Current generic cost model makes dynamic-lmul2-7.c generate inferior codegen.
>
> I found if I tweak the cost a little bit then dynamic-lmul2-7
> Current generic cost model makes dynamic-lmul2-7.c generate inferior codegen.
>
> I found if I tweak the cost a little bit then dynamic-lmul2-7.c codegen can
> be recovered.
> However, it makes other tests failed
> It's complicated story
Ok, makes sense. So the plan seems to be:
have regressions on current testsuite with the new cost model. So I
switch the cost model.
juzhe.zh...@rivai.ai
From: Robin Dapp
Date: 2024-01-10 23:04
To: 钟居哲; gcc-patches
CC: rdapp.gcc; kito.cheng; kito.cheng; Jeff Law
Subject: Re: [PATCH] RISC-V: Switch RVV cost model to generic vector cost
On 1/10/24 15:40, 钟居哲 wrote:
> I need to add these costs for segment load/stores:
>
> /* Generic costs for VLA vector operations. */
> static const scalable_vector_cost generic_vla_vector_cost = {
> {
> 1,/* int_stmt_cost */
> 1,/* fp_stmt_cost */
> 1,/* gather_load_cost */
>
: Switch RVV cost model to generic vector cost model
Hi Juzhe,
> The reason we want to switch to generic vector cost model is the default
> cost model generates inferior codegen for various benchmarks.
>
> For example, PR113247, we have performance bug that we end up having over 70%
&
to fall back to default vector cost model.
Could you tell me how to fix the XFAILs of slp-*.c tests ?
juzhe.zh...@rivai.ai
From: Robin Dapp
Date: 2024-01-10 22:11
To: Juzhe-Zhong; gcc-patches
CC: rdapp.gcc; kito.cheng; kito.cheng; jeffreyalaw
Subject: Re: [PATCH] RISC-V: Switch RVV cost m
Hi Juzhe,
> The reason we want to switch to generic vector cost model is the default
> cost model generates inferior codegen for various benchmarks.
>
> For example, PR113247, we have performance bug that we end up having over 70%
> performance drop of SHA256. Currently, no matter how we adapt
This patch is preparing patch for the following cost model tweak.
Since we don't have vector cost model in default tune info (rocket),
we set the cost model default as generic cost model by default.
The reason we want to switch to generic vector cost model is the default
cost model generates
