On Thu, 2022-08-18 at 11:54 +0800, Lulu Cheng wrote:
> Sorry, I have already added the code of cmodel=extreme, and I am sorting out
> the code and test cases.
> I still insist on using __attribute__(model(extreme)) to describe the
> variables of precpu.
> I will send my patch today.
Ok, I can live with it.
A possible enhancement (we can add it later or abandon it if it won't
really produce any benefit):
The address of a per-CPU variable is
per_cpu_buf_addr + cpu_offset + var_offset
Or, B + C + V as an abbreviation. Currently we have $r21 = C, and the
faked address of per-cpu symbol is (B + V). As (B + V) is large, we
have to use five (PC-rel) or four (Absolute) instructions to address it.
But in the future we can make $r21 = B + C, and the faked address V. As
V <= 2GiB we can add model(low) and use a lu12i/addi pair to address V.
--
Xi Ruoyao <xry...@xry111.site>
School of Aerospace Science and Technology, Xidian University
