radeonsi: generate GS prolog to (partially) fix triangle strip adjacency rotation

Fixes GL45-CTS.geometry_shader.adjacency.adjacency_indiced_triangle_strip and
others.

This leaves the case of triangle strips with adjacency and primitive restarts
open. It seems that the only thing that cares about that is a piglit test.
Fixing this efficiently would be really involved, and I don't want to use the
hammer of degrading to software handling of indices because there may well
be software that uses this draw mode (without caring about the precise
rotation of triangles).

v2:
- skip the GS prolog entirely if workaround is not needed
- only check for TES (TES is always non-null when tessellation is used)

Reviewed-by: Marek Olšák <[email protected]>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index e7617bc4975..8e6a94deade 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -96,6 +96,7 @@ struct si_screen {
 	struct si_shader_part		*vs_prologs;
 	struct si_shader_part		*vs_epilogs;
 	struct si_shader_part		*tcs_epilogs;
+	struct si_shader_part		*gs_prologs;
 	struct si_shader_part		*ps_prologs;
 	struct si_shader_part		*ps_epilogs;
 
@@ -319,6 +320,7 @@ struct si_context {
 	unsigned		last_sc_line_stipple;
 	int			last_vtx_reuse_depth;
 	int			current_rast_prim; /* primitive type after TES, GS */
+	bool			gs_tri_strip_adj_fix;
 	unsigned		last_gsvs_itemsize;
 
 	/* Scratch buffer */