[PATCH] powerpc: emulate power5 popcntb instruction

[segher at gate.crashing.org]

>> +static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
>> +{
>> +	u32 ra,rs;
>> +	unsigned long tmp;
>> +
>> +	ra = (instword >> 16) & 0x1f;
>> +	rs = (instword >> 21) & 0x1f;
>> +
>> +	tmp = regs->gpr[rs];
>> +	tmp = tmp - ((tmp >> 1) & 0x5555555555555555);
>> +	tmp = (tmp & 0x3333333333333333) + ((tmp >> 2) &
>> 0x3333333333333333);
>> +	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0f;
>> +	regs->gpr[ra] = tmp;
>> +
>> +	return 0;
>> +}
>
> This is going to give warnings on ppc32 kernel compiles, maybe
> something like:
>
> (unsigned long) 0x5555555555555555ull

Nah, just make "tmp" an u64.  And/or don't do this emulation on
32-bit machines at all.

And if the compiler warns about the non-qualified constants --
well, we should compile with -std=gnu99 anyway, eh?


Segher