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From: Robin Dapp <rdapp.gcc@gmail.com>
To: pan2.li@intel.com, gcc-patches@gcc.gnu.org
Cc: rdapp.gcc@gmail.com, juzhe.zhong@rivai.ai, jeffreyalaw@gmail.com,
	yanzhang.wang@intel.com, kito.cheng@gmail.com
Subject: Re: [PATCH v2] RISC-V: Bugfix for vec_init repeating auto vectorization in RV32
Date: Wed, 14 Jun 2023 10:27:19 +0200	[thread overview]
Message-ID: <c7c28ac1-531b-10b1-c658-8ed3b1ee04bf@gmail.com> (raw)
In-Reply-To: <20230614072900.3698145-1-pan2.li@intel.com>

Hi Pan,

> This patch would like to fix one bug exported by RV32 test case
> multiple_rgroup_run-2.c. The mask should be restricted by elen in
> vector, and the condition between the vmv.s.x and the vmv.v.x should
> take inner_bits_size rather than constants.

exported -> exposed.

How about something like:

"When constructing a vector mask from individual elements we wrongly
assumed that we can broadcast BITS_PER_WORD (i.e. XLEN).  The maximum
is actually the vector element length (i.e. ELEN).  This patch fixes
this."?

> +  /* We restrict the limit to the elen of RVV. For example:
> +     -march=zve32*, the ELEN is 32.
> +     -march=zve64*, the ELEN is 64.
> +     The related vmv.v.x/vmv.s.x is restricted to ELEN as above, we cannot
> +     take care of case like below when ELEN=32
> +     vsetvil e64,m1
> +     vmv.v.x/vmv.s.x
> +   */

/* Here we construct a mask pattern that will later be broadcast
   to a vector register.  The maximum broadcast size for vmv.v.x/vmv.s.x
   is determined by the length of a vector element (ELEN) and not by
   XLEN so make sure we do not exceed it.  One example is -march=zve32*
   which mandates ELEN == 32 but can be combined with -march=rv64
   with XLEN == 64.  */

Regards
 Robin

  parent reply	other threads:[~2023-06-14  8:27 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-14  0:58 [PATCH v1] " pan2.li
2023-06-14  1:07 ` juzhe.zhong
2023-06-14  7:30   ` Li, Pan2
2023-06-14  7:29 ` [PATCH v2] " pan2.li
2023-06-14  7:43   ` juzhe.zhong
2023-06-14  8:27   ` Robin Dapp [this message]
2023-06-14  8:34     ` Li, Pan2
2023-06-14  9:00 ` [PATCH v3] " pan2.li
2023-06-14  9:01   ` juzhe.zhong
2023-06-14 18:56     ` Jeff Law
2023-06-15  1:05       ` Li, Pan2

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