On 8/11/21 7:03 PM, LIU Zhiwei wrote:
On 2021/8/12 下午12:42, Richard Henderson wrote:
On 8/11/21 12:40 PM, LIU Zhiwei wrote:
If the software doesn't use the high part, who cares the really value in high part? Do
you know the benefit? Thanks again.
I do not.
I simply presume that they already have the hardware, in the form of the addw
instruction, etc.
The mistake, I think, was changing the definition of "add" in the first place, which
required the addition of a different opcode "addw", which is then undefined for RV32.
Sorry, I don't get "the mistake" here. Do you think the specification is not
right.
I was critiquing the development of the risc-v specification, in that there are
complications in the current specification that could have been foreseen and avoided with
different choices years ago.
They should simply have had "addw" and "addq" as different opcodes that didn't change
behaviour. Etc.
I don't get this statement. Is it related to UXL32?
No. I was just musing. It's not important.
r~
