Re: [PATCH 1/4] ppc/amigaone: Simplify replacement dummy_fw

["Nicholas Piggin" <npiggin@gmail.com>]

On Sun Feb 23, 2025 at 3:52 AM AEST, BALATON Zoltan wrote:
> There's no need to do shift in a loop, doing it in one instruction
> works just as well, only the result is used.
>
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>

Resulting asm looks right to me.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

> ---
>  hw/ppc/amigaone.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/hw/ppc/amigaone.c b/hw/ppc/amigaone.c
> index b02792221c..4290d58613 100644
> --- a/hw/ppc/amigaone.c
> +++ b/hw/ppc/amigaone.c
> @@ -41,10 +41,7 @@
>  
>  /* AmigaOS calls this routine from ROM, use this if no firmware loaded */
>  static const char dummy_fw[] = {
> -    0x38, 0x00, 0x00, 0x08, /* li      r0,8 */
> -    0x7c, 0x09, 0x03, 0xa6, /* mtctr   r0 */
> -    0x54, 0x63, 0xf8, 0x7e, /* srwi    r3,r3,1 */
> -    0x42, 0x00, 0xff, 0xfc, /* bdnz    0x8 */
> +    0x54, 0x63, 0xc2, 0x3e, /* srwi    r3,r3,8 */
>      0x7c, 0x63, 0x18, 0xf8, /* not     r3,r3 */
>      0x4e, 0x80, 0x00, 0x20, /* blr */
>  };