Re: [Qemu-devel] [PATCH 1/8] target-ppc: Bug Fix: rlwinm

[Richard Henderson]

On 08/11/2014 09:23 AM, Tom Musta wrote:
> The rlwinm specification includes the ROTL32 operation, which is defined
> to be a left rotation of two copies of the least significant 32 bits of
> the source GPR.
> 
> The current implementation is incorrect on 64-bit implementations in that
> it rotates a single copy of the least significant 32 bits, padding with
> zeroes in the most significant bits.

Yes, it does describe rotate_32 as a double-copy of the low 32 bits.  But it
also describes the mask as having "0 bits elsewhere".  Thus, post mask, I don't
see how you could distinguish the implementations.

Have you an example that doesn't work with the current code?


r~