Re: RISC-V Bootstrap problems

[Jeff Law <jeffreyalaw@gmail.com>]

On 5/24/23 17:13, Palmer Dabbelt wrote:
> On Wed, 24 May 2023 16:12:20 PDT (-0700), Vineet Gupta wrote:

[ ... big snip ... ]

>>
>> Never mind. Looks like I found the issue - with just trial and error and
>> no idea of how this stuff works.
>> The torture-{init,finish} needs to be in riscv.exp not rvv.exp
>> Running full tests now.
> 
> Thanks!
Marginally related.  I was able to bisect the "hang" when 3-staging the 
trunk on RISC-V with qemu user mode emulation.

So it wasn't actually hanging, but after the introduction of segment 
intrinsics the compilation time for insn-emit explodes -- previously I 
could do a full 3-stage bootstrap, build the glibc & the kernel, then 
test c/c++/fortran in ~10 hours.

Now just building insn-emit.o alone takes ~10 hours in that environment. 
  I suspect (but have not yet confirmed) that we should see a huge 
compile-time spike in cross builds as well, though obviously it won't be 
as bad since we're not using qemu emulation.

Clearly something isn't scaling well.  I don't know if we've got a crazy 
large function in there, a crazy number of functions or something that's 
just triggering a compile-time scaling problem.  Whatever it is, we 
probably need to address it.

jeff