Re: [PATCH] LoongArch: gas: Add LVZ and LBT instructions support

[WANG Xuerui <i.swmail@xen0n.name>]

On 2023/6/29 17:08, mengqinggang wrote:
> gas/ChangeLog:
> 
> 	* testsuite/gas/loongarch/uleb128.d: Regenerated.
> 	* testsuite/gas/loongarch/lvz-lbt.d: New test.
> 	* testsuite/gas/loongarch/lvz-lbt.s: New test.
> 
> opcodes/ChangeLog:
> 
> 	* loongarch-opc.c (struct loongarch_ase): Add LVZ and LBT instructions.
> ---
>   gas/testsuite/gas/loongarch/lvz-lbt.d | 196 ++++++++++++++++++++++++
>   gas/testsuite/gas/loongarch/lvz-lbt.s | 186 +++++++++++++++++++++++
>   gas/testsuite/gas/loongarch/uleb128.d |  52 +++----
>   opcodes/loongarch-opc.c               | 205 +++++++++++++++++++++++++-
>   4 files changed, 611 insertions(+), 28 deletions(-)
>   create mode 100644 gas/testsuite/gas/loongarch/lvz-lbt.d
>   create mode 100644 gas/testsuite/gas/loongarch/lvz-lbt.s
> 
> [snip]
>
> diff --git a/opcodes/loongarch-opc.c b/opcodes/loongarch-opc.c
> index bd104465ca7..202614390db 100644
> --- a/opcodes/loongarch-opc.c
> +++ b/opcodes/loongarch-opc.c
> @@ -1646,6 +1646,7 @@ static struct loongarch_opcode loongarch_lsx_opcodes[] =
>     { 0x73e40000, 0xfffc0000, "vpermi.w", "v0:5,v5:5,u10:8", 0, 0, 0, 0},
>     { 0, 0, 0, 0, 0, 0, 0, 0 } /* Terminate the list.  */
>   };
> +
>   static struct loongarch_opcode loongarch_lasx_opcodes[] =
>   {
>   /* match,    mask,       name, format, macro, include, exclude, pinfo.  */
> @@ -2321,6 +2322,204 @@ static struct loongarch_opcode loongarch_lasx_opcodes[] =
>     { 0, 0, 0, 0, 0, 0, 0, 0 } /* Terminate the list.  */
>   };
>   
> +static struct loongarch_opcode loongarch_lvz_opcodes[] =
> +{
> +  /* match,    mask,       name,     format, macro, include, exclude, pinfo.  */
> +  {0x05000000, 0xff0003e0, "gcsrrd", "r0:5,u10:14", 0, 0, 0, 0},
> +  {0x05000020, 0xff0003e0, "gcsrwr", "r0:5,u10:14", 0, 0, 0, 0},
> +  {0x05000000, 0xff000000, "gcsrxchg", "r0:5,r5:5,u10:14", 0, 0, 0, 0},
> +  {0x06482801, 0xffffffff, "gtlbsrch", "", 0, 0, 0, 0},
> +  {0x06482c01, 0xffffffff, "gtlbrd", "", 0, 0, 0, 0},
> +  {0x06483001, 0xffffffff, "gtlbwr", "", 0, 0, 0, 0},
> +  {0x06483401, 0xffffffff, "gtlbfill", "", 0, 0, 0, 0},
> +  {0x06482001, 0xffffffff, "gtlbclr", "", 0, 0, 0, 0},
> +  {0x06482401, 0xffffffff, "gtlbflush", "", 0, 0, 0, 0},
> +  {0x002b8000, 0xffff8000, "hvcl", "u0:15", 0, 0, 0, 0},
> +  { 0, 0, 0, 0, 0, 0, 0, 0 } /* Terminate the list.  */
> +};
> +
> +static struct loongarch_opcode loongarch_lbt_opcodes[] =
> +{
> +  /* match,    mask,       name,     format, macro, include, exclude, pinfo.  */
> +  {0x00000800, 0xfffffc1c, "gr2scr", "cr0:2,r5:5", 0, 0, 0, 0},
> +  {0x00000c00, 0xffffff80, "scr2gr", "r0:5,cr5:2", 0, 0, 0, 0},

Hmm why aren't this couple of instructions named "movgr2scr" and 
"movscr2gr", like other similar ones? I remember suggesting this a while 
ago (in the now-deleted loongson/linux GitHub repo) but seems the 
suggestion wasn't taken.

If compatibility with older in-house code is what you intend, maybe we 
can add the more consistent names alongside, so the overall symmetry of 
transfer-between-banks instruction mnemonics is preserved.

> [snip]

The rest looks good (though I obviously have no means to verify the 
encodings). Thanks very much for posting this so we're finally going to 
have the entirety of LA64 v1.00 supported in 2.41.