Re: [PATCH v2] target/ppc: Fix 64-bit decrementer

[Richard Henderson]

On 9/14/21 6:43 AM, Cédric Le Goater wrote:
> and then another sign calculation on a target_ulong
>
>         ...
>         && !(decr & (1ULL << (nr_bits - 1))))) {

I was wondering if that was supposed to be an unsigned test for a "small" value (i.e. decr 
< MAKE_64BIT_MASK(0, nr_bits)?  Certainly decr should never be negative, since the 
decrementer never increments, and I can't figure out what it's supposed to mean otherwise.


> We should introduce intermediate 'int64_t' variables to extract the
> sign values from the target_ulong. That would be cleaner.

Yes it would.  The underflow test becomes easier for certain.

r~