[PATCH] powerpc: emulate power5 popcntb instruction

[Kumar Gala]

On Aug 18, 2006, at 2:05 PM, Arnd Bergmann wrote:

> On Friday 18 August 2006 20:11, Will Schmidt wrote:
>> +#define INST_POPCNTB           0x7c0000f4
>> +
>
>> +       /* Emulate the popcntb (Population Count Bytes)  
>> instruction. */
>> +       if ((instword & INST_POPCNTB) == INST_POPCNTB) {
>> +               return emulate_popcntb_inst(regs, instword);
>> +       }
>> +
>
> Is that the right check? The other similar traps check against a
> mask of 0x7c0007fe.

I agree with Arnd here, its better to check with a larger mask to  
ensure that bits that should be '0' in the minor opcode are.

For example, if you had an instruction that was 0x7c0000f7 it would  
match.

- kumar