Re: [PATCH] ppc: Fix 'calli' when floating-point arguments are passed

[Paul Cercueil]

Hi Paulo,

Le jeu., sept. 8 2022 at 14:52:28 -0300, Paulo César Pereira de 
Andrade <paulo.cesar.pereira.de.andrade@gmail.com> a écrit :
> Em qui., 8 de set. de 2022 às 14:18, Paulo César Pereira de Andrade
> <paulo.cesar.pereira.de.andrade@gmail.com> escreveu:
>
> [snip]
>
> >  > The problem now is that r26 should be live at L2 but is not 
> > detected as
> >  > such.
> >  > This causes Lightning to use r26 as a temporary for the andi line 
> > 34
> >  > (lines 153-155 in the generated code).
> >
> >    What code you use to access 'r10' and 'r3'? It is possible to use
> >  JIT_R(5) and JIT_R(12) as I did in the C code, but it is an ugly 
> > hack,
> >  taking advantage that it does not check bounds. The 
> > check/lightning.c
> >  code need to be patched to accept it...
> >
> >    Can you create a reproducer in C, starting with the above sample?
>
>   Well, the most likely cause is that it did happen because of a 
> lightning
> build without the last 3 commits, and is a side effect of the jumps 
> to a
> raw address:
>
>     jmpi 0x20000d0c

I can assure you I triple-checked that. I removed the library in my 
toolchain, my program would complain that liblightning.so.0 is missing, 
then I just "make clean install" with the proper path, my program picks 
up the library just fine. And I'm at the latest origin/master, clean, 
no local changes. Also, others can reproduce my issue with my program + 
Lightning master.

Now what's really triggering me, is that I have a C program that 
produces the *exact* same Lightning output (see attachment). It is 
exactly the same, the *only* differences are the jmpi addresses, and my 
test program does not have the r26 missing in L2.

So even with the exact same code in a test example, I cannot reproduce 
it. Yet my regular program shows the bug with the exact same Lightning 
calls. I have absolutely no idea what's going on.

-Paul

test.c
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