[Mesa-dev] [PATCH] i965: Trim

[Matt Turner]

On Wed, Feb 7, 2018 at 11:41 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>    text    data     bss     dec     hex filename
> 8852169  388752  671064 9911985  973eb1 lib/i965_dri.so
> 8852017  388752  671064 9911833  973e19
> ---
>  src/mesa/drivers/dri/i965/intel_tiled_memcpy.c | 48 +++++++++-----------------
>  1 file changed, 16 insertions(+), 32 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/intel_tiled_memcpy.c b/src/mesa/drivers/dri/i965/intel_tiled_memcpy.c
> index 53a5679691..a8157b5232 100644
> --- a/src/mesa/drivers/dri/i965/intel_tiled_memcpy.c
> +++ b/src/mesa/drivers/dri/i965/intel_tiled_memcpy.c
> @@ -468,26 +468,22 @@ linear_to_xtiled_faster(uint32_t x0, uint32_t x1, uint32_t x2, uint32_t x3,
>        if (mem_copy == memcpy)
>           return linear_to_xtiled(0, 0, xtile_width, xtile_width, 0, xtile_height,
>                                   dst, src, src_pitch, swizzle_bit, memcpy, memcpy);
> -      else if (mem_copy == rgba8_copy)
> +      else /* if (mem_copy == rgba8_copy) */
>           return linear_to_xtiled(0, 0, xtile_width, xtile_width, 0, xtile_height,
>                                   dst, src, src_pitch, swizzle_bit,
>                                   rgba8_copy, rgba8_copy_aligned_dst);
> -      else
> -         unreachable("not reached");
>     } else {
>        if (mem_copy == memcpy)
>           return linear_to_xtiled(x0, x1, x2, x3, y0, y1,
>                                   dst, src, src_pitch, swizzle_bit,
>                                   memcpy, memcpy);
> -      else if (mem_copy == rgba8_copy)
> +      else /* if (mem_copy == rgba8_copy) */
>           return linear_to_xtiled(x0, x1, x2, x3, y0, y1,
>                                   dst, src, src_pitch, swizzle_bit,
>                                   rgba8_copy, rgba8_copy_aligned_dst);
> -      else
> -         unreachable("not reached");

This should be a no-op. I'd expect the presence of 'else unreachable'
to allow the compiler to remove the previous conditional.

>     }
> -   linear_to_xtiled(x0, x1, x2, x3, y0, y1,
> -                    dst, src, src_pitch, swizzle_bit, mem_copy, mem_copy);
> +
> +   unreachable("not reached");

I would expect this is what causes the change. If that's the case,
let's just make this change. What do you think?