i965/gen7: Prefer vertical alignment of 4 when possible.

Gen6+ allows for color buffers to use a vertical alignment of either 4
or 2.  Previously we defaulted to 2.  This may have caused problems on
Gen7 because Y-tiled render targets are not allowed to use a vertical
alignment of 2.

This patch changes the vertical alignment to 4 on Gen7, except for the
few formats where a vertical alignment of 2 is required.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit 6b40dd17cf)
This commit is contained in:
Paul Berry 2013-11-12 17:16:25 -08:00 committed by Carl Worth
parent 498853b9fd
commit b2f14a6284

View file

@ -105,11 +105,11 @@ intel_vertical_texture_alignment_unit(struct brw_context *brw,
* | Depth Buffer | 2 | 2 | 2 | 4 | 4 |
* | Separate Stencil Buffer | N/A | N/A | N/A | 4 | 8 |
* | Multisampled (4x or 8x) render target | N/A | N/A | N/A | 4 | 4 |
* | All Others | 2 | 2 | 2 | 2 | 2 |
* | All Others | 2 | 2 | 2 | * | * |
* +----------------------------------------------------------------------+
*
* On SNB+, non-special cases can be overridden by setting the SURFACE_STATE
* "Surface Vertical Alignment" field to VALIGN_2 or VALIGN_4.
* Where "*" means either VALIGN_2 or VALIGN_4 depending on the setting of
* the SURFACE_STATE "Surface Vertical Alignment" field.
*/
if (_mesa_is_format_compressed(format))
return 4;
@ -128,6 +128,25 @@ intel_vertical_texture_alignment_unit(struct brw_context *brw,
return 4;
}
if (brw->gen == 7) {
/* On Gen7, we prefer a vertical alignment of 4 when possible, because
* that allows Y tiled render targets.
*
* From the Ivy Bridge PRM, Vol4 Part1 2.12.2.1 (SURFACE_STATE for most
* messages), on p64, under the heading "Surface Vertical Alignment":
*
* Value of 1 [VALIGN_4] is not supported for format YCRCB_NORMAL
* (0x182), YCRCB_SWAPUVY (0x183), YCRCB_SWAPUV (0x18f), YCRCB_SWAPY
* (0x190)
*
* VALIGN_4 is not supported for surface format R32G32B32_FLOAT.
*/
if (base_format == GL_YCBCR_MESA || format == MESA_FORMAT_RGB_FLOAT32)
return 2;
return 4;
}
return 2;
}