[RFC PATCH 1/6] RISC-V: Add Zvkb ISA extension support

[Jeff Law]

On 12/21/22 10:07, Christoph Muellner wrote:
> From: Christoph Müllner <christoph.muellner@vrull.eu>
> 
> This commit adds the Zvkb ISA extension instructions, which are part
> of the vector crypto extensions.
> 
> Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
> ---
>   bfd/elfxx-riscv.c              |  5 ++++
>   gas/config/tc-riscv.c          | 13 ++++++++++
>   gas/testsuite/gas/riscv/zvkb.d | 36 ++++++++++++++++++++++++++++
>   gas/testsuite/gas/riscv/zvkb.s | 28 ++++++++++++++++++++++
>   include/opcode/riscv-opc.h     | 44 ++++++++++++++++++++++++++++++++++
>   include/opcode/riscv.h         |  5 ++++
>   opcodes/riscv-dis.c            |  4 ++++
>   opcodes/riscv-opc.c            | 16 +++++++++++++
>   8 files changed, 151 insertions(+)
>   create mode 100644 gas/testsuite/gas/riscv/zvkb.d
>   create mode 100644 gas/testsuite/gas/riscv/zvkb.s
It all looks quite sensible to me.


> +/* Zvkb instructions.  */
> +#define MATCH_VCLMULVV 0x30002057
> +#define MASK_VCLMULVV 0xfc00707f
I'm just going to trust you got these right and that the MATCH value in 
particular might need adjustment if the encodings change.



> +DECLARE_INSN(vclmulvv, MATCH_VCLMULVV, MASK_VCLMULVV)
So IIRC, these are only used in GDB's prologue/epilogue scanning code -- 
and we're quite unlikely to ever need any of these instructions for 
prologues/epilogues.  I'm guessing convention is to go ahead and add the 
DECLARE_INSN instances for each instruction, even if they aren't likely 
to be show up in a prologue or epilogue?

Jeff