The bug issue reported by google/highway project:
(set(..........)
(reg:QI s0)
(reg:DI s0))
The "avl" operand rtx = (reg:DI s0)
count_occurrences return 1 however the actual regno occurrences should be 2.
In this case, the VSETVL PASS will eliminate the use of (reg:DI s0) then file
assertion in RTL_SSA.
Instead, we should not eliminate "s0" dependency.
Thanks
juzhe.zh...@rivai.ai
From: Jeff Law
Date: 2023-04-19 08:56
To: Kito Cheng; juzhe.zhong; Richard Biener
CC: gcc-patches; palmer
Subject: Re: [PATCH] RISC-V: Fix bug reported by PR109535
On 4/18/23 18:18, Kito Cheng wrote:
> Hi Richard, Jeff:
>
> It's it possible to backport to GCC 13? highway is one of our
> important users for RISC-V vector stuff, and it has built in some
> distro, so we believe this bug fix is important to backport.
I want to see an explanation why count_occurrences isn't doing what you
want.
jeff
