RFA; MN10300: Fix AM33 clzsi2 pattern

[Richard Henderson]

On 06/25/2011 01:18 AM, Nick Clifton wrote:
> Hi Alex, Hi Jeff, Hi Richard,
> 
>   The clzsi2/bsch patterns in the MN10300 backend do not work.  There
>   are two problems - firstly the starting bit-search position for the
>   BSCH instruction is not set. 

Yes it is.  What do you think that "unused" second operand does?


> Secondly the BSCH instruction returns
>   the bit position of the highest set bit, not the number of leading
>   zeros.

Ah, I do see that.  I recommend you put the xor in the clz expander
rather than cluttering up the "bsch" pattern.


r~