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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/26/25 3:49 PM, Jan Beulich wrote: > On 26.02.2025 15:38, Oleksii Kurochko wrote: >> On 2/26/25 1:58 PM, Jan Beulich wrote: >>> On 20.02.2025 18:44, Oleksii Kurochko wrote: >>>> According to riscv/booting.txt, it is expected that Zbb should be supported. >>>> >>>> Signed-off-by: Oleksii Kurochko >>>> --- >>>> Changes in v7: >>>> - new patch. >>>> --- >>>> xen/arch/riscv/arch.mk | 7 ++----- >>>> 1 file changed, 2 insertions(+), 5 deletions(-) >>> Please can you also tidy asm/cmpxchg.h of ANDN_INSN() then? >> Sure, I can leave only: >> /* >> * To not face an issue that gas doesn't understand ANDN instruction >> * it is encoded using .insn directive. >> */ >> #define ANDN_INSN(rd, rs1, rs2) \ >> ".insn r OP, 0x7, 0x20, " rd ", " rs1 ", " rs2 "\n" > Wait, no - why would you? Patch 0.5 is supposed to be setting a baseline > where Zbb is known by the tool chain. With that proper "andn" can be used > wherever we like. I thought that Zbb in binutils (part of whic is gas) was added later then I mentioned in Patch 0.5 but Zbb was added starting from 2.37, so we can just really use `andn` instruction instead of `.insn` . Thanks for clarification. ~ Oleksii --------------7hkHssToVTlKRyzsfquaY0MN Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit


On 2/26/25 3:49 PM, Jan Beulich wrote:
On 26.02.2025 15:38, Oleksii Kurochko wrote:

On 2/26/25 1:58 PM, Jan Beulich wrote:

On 20.02.2025 18:44, Oleksii Kurochko wrote:

According to riscv/booting.txt, it is expected that Zbb should be supported.

Signed-off-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
---
Changes in v7:
  - new patch.
---
  xen/arch/riscv/arch.mk | 7 ++-----
  1 file changed, 2 insertions(+), 5 deletions(-)

Please can you also tidy asm/cmpxchg.h of ANDN_INSN() then?

Sure, I can leave only:
/*
  * To not face an issue that gas doesn't understand ANDN instruction
  * it is encoded using .insn directive.
  */
#define ANDN_INSN(rd, rs1, rs2)                 \
     ".insn r OP, 0x7, 0x20, " rd ", " rs1 ", " rs2 "\n"

Wait, no - why would you? Patch 0.5 is supposed to be setting a baseline
where Zbb is known by the tool chain. With that proper "andn" can be used
wherever we like.
I thought that Zbb in binutils (part of whic is gas) was added later then
I mentioned in Patch 0.5 but Zbb was added starting from 2.37, so we can
just really use `andn` instruction instead of `.insn` .

Thanks for clarification.

~ Oleksii
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