Re: Re: [PATCH] RISC-V: Fix VLMAX AVL incorrect local anticipate [VSETVL PASS]

["juzhe.zhong@rivai.ai" <juzhe.zhong@rivai.ai>]

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Yes. I think so. Will backport GCC 13 soon.



juzhe.zhong@rivai.ai
 
From: Jeff Law
Date: 2023-08-10 01:01
To: Juzhe-Zhong; gcc-patches
CC: kito.cheng; kito.cheng; rdapp.gcc
Subject: Re: [PATCH] RISC-V: Fix VLMAX AVL incorrect local anticipate [VSETVL PASS]
 
 
On 8/9/23 04:51, Juzhe-Zhong wrote:
> Realize we have a bug in VSETVL PASS which is triggered by strided_load_run-1.c in RV32 system.
> 
> FAIL: gcc.target/riscv/rvv/autovec/gather-scatter/strided_load_run-1.c execution test
> FAIL: gcc.target/riscv/rvv/autovec/gather-scatter/strided_load_run-1.c execution test
> FAIL: gcc.target/riscv/rvv/autovec/gather-scatter/strided_load_run-1.c execution test
> FAIL: gcc.target/riscv/rvv/autovec/gather-scatter/strided_load_run-1.c execution test
> 
> This is because VSETVL PASS incorrect hoist vsetvl instruction:
> 
> ...
>     10156: 0d9075d7          vsetvli a1,zero,e64,m2,ta,ma ---> pollute 'a1' register which will be used by following insns.
>     1015a: 01d586b3          add a3,a1,t4  --------> use 'a1'
>     1015e: 5e070257          vmv.v.v v4,v14
>     10162: b7032257          vmacc.vv v4,v6,v16
>     10166: 26440257          vand.vv v4,v4,v8
>     1016a: 22880227          vs2r.v v4,(a6)
>     1016e: 00b6b7b3          sltu a5,a3,a1
>     10172: 22888227          vs2r.v v4,(a7)
>     10176: 9e60b157          vmv2r.v v2,v6
>     1017a: 97ba                add a5,a5,a4
>     1017c: a6a62157          vmadd.vv v2,v12,v10
>     10180: 26240157          vand.vv v2,v2,v8
>     10184: 22830127          vs2r.v v2,(t1)
>     10188: 873e                mv a4,a5
>     1018a: 982a                add a6,a6,a0
>     1018c: 98aa                add a7,a7,a0
>     1018e: 932a                add t1,t1,a0
>     10190: 85b6                mv a1,a3       -----> set 'a1'
> ...
> 
> gcc/ChangeLog:
> 
>          * config/riscv/riscv-vsetvl.cc (anticipatable_occurrence_p): Fix incorrect anticipate info.
> 
> gcc/testsuite/ChangeLog:
> 
>          * gcc.target/riscv/rvv/autovec/gather-scatter/strided_load_run-1.c: Adapt test.
>          * gcc.target/riscv/rvv/vsetvl/vlmax_back_prop-24.c: Ditto.
>          * gcc.target/riscv/rvv/vsetvl/vlmax_back_prop-25.c: Ditto.
>          * gcc.target/riscv/rvv/vsetvl/vlmax_back_prop-26.c: Ditto.
>          * gcc.target/riscv/rvv/vsetvl/vlmax_back_prop-36.c: Ditto.
>          * gcc.target/riscv/rvv/vsetvl/vlmax_switch_vtype-14.c: Ditto.
>          * gcc.target/riscv/rvv/vsetvl/vlmax_switch_vtype-15.c: Ditto.
OK.
 
Do we need to backport this to gcc-13?
 
jeff