[Qemu-devel] sparc smul problem

[Vince Weaver]

Hello!

I've been stuck on this all weekend, as I can't find where the actual 
problem is. I might be completely missing it, but I've tried a lot of 
things and can't make it work.

On SPARC, the "smul" instruction multiplies two numbers, puts the result 
in the result register but also puts the top 32-bits of the 64-bit result 
into the "Y" register.

As the attached code shows, the value of "Y" is wrong.  Somehow after the 
multiply, the top 32 bits of the product rae all zeros.  I've played 
around with the code generated by translate.c, and it looks like the shift 
and other instructions all work properly, but the 64-bit multiply the 
result is somehow being truncated.  But I've looked at the generated code 
(on x86_64) and it looks like it is doing the right thing.

So anyway, I'll have to take a look at this again later, but in case 
anyone else wants to look at it in case I am missing anything obvious.

Thanks

Vince

smul.s
Description: Text document

smul
Description: Binary data