i965/gen6/gs: Fix binding table clash between TF surfaces and textures.

For gen6 geometry shaders we use the first BRW_MAX_SOL_BINDINGS entries of the
binding table for transform feedback surfaces. However, vec4_visitor will
setup the binding table so that textures use the same space in the binding
table. This is done when calling assign_common_binding_table_offsets(0) as
part if its run() method.

To fix this clash we add a virtual method to the vec4_visitor hierarchy to
assign the binding table offsets, so that we can change this behavior
specifically for gen6 geometry shaders by mapping textures right after the
first BRW_MAX_SOL_BINDINGS entries.

Also, when there is no user-provided geometry shader, we only need to upload
the binding table if we have transform feedback, however, in the case of a
user-provided geometry shader, we can't only look into transform feedback
to make that decision.

This fixes multiple piglit tests for textureSize() and texelFetch() when these
functions are called from a geometry shader in gen6, like these:

bin/textureSize gs sampler2D -fbo -auto
bin/texelFetch gs usampler2D -fbo -auto

Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/gen6_gs_visitor.cpp b/src/mesa/drivers/dri/i965/gen6_gs_visitor.cpp
index 704a02f..d16cc6e 100644
--- a/src/mesa/drivers/dri/i965/gen6_gs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/gen6_gs_visitor.cpp
@@ -36,6 +36,15 @@ const unsigned MAX_GS_INPUT_VERTICES = 6;
 namespace brw {
 
 void
+gen6_gs_visitor::assign_binding_table_offsets()
+{
+   /* In gen6 we reserve the first BRW_MAX_SOL_BINDINGS entries for transform
+    * feedback surfaces.
+    */
+   assign_common_binding_table_offsets(BRW_MAX_SOL_BINDINGS);
+}
+
+void
 gen6_gs_visitor::emit_prolog()
 {
    vec4_gs_visitor::emit_prolog();