On 2024/7/31 17:38, Alistair Francis wrote:
On Thu, Jul 25, 2024 at 11:53 AM LIU Zhiwei
<zhiwei_...@linux.alibaba.com> wrote:
On 2024/7/23 13:59, Richard Henderson wrote:
On 7/23/24 15:29, LIU Zhiwei wrote:
The more detailed information about its meaning is in priviledged
1.13 specification. More exactly, in 3.6.4. Misaligned Atomicity
Granule PMA.
The specification said:
"The misaligned atomicity granule PMA applies only to AMOs, loads and
stores defined in the base
ISAs, and loads and stores of no more than MXLEN bits defined in the
F, D, and Q extensions. For an
instruction in that set, if all accessed bytes lie within the same
misaligned atomicity granule, the
instruction will not raise an exception for reasons of address
alignment, and the instruction will give
rise to only one memory operation for the purposes of RVWMO—i.e., it
will execute atomically."
That's the reason why I do not apply zama16b to compressed instructions.
Given the non-specificity of this paragraph, I think not specifically
calling out compressed forms of the base ISA is simply a documentation
error. In general, the compressed ISA is supposed to be a smaller
encoding of the exact same instruction as the standard ISA.
Yes, it's a documentation error. We will fix in the specification.
https://github.com/riscv/riscv-isa-manual/pull/1557
Thanks for getting that clarified
What's the status of a followup patch? We should fix this before the release
I will send the follow patch as soon as possible. And resolve another
comment Richard gives later as it need some work on PBMT(I think).
Thanks,
Zhiwei
Alistair
