[Mesa-dev] [PATCH 4/5] radv/gfx10: do not enable NGG if a pipeline uses XFB

[Samuel Pitoiset]

NGG GS for streamout requires a bunch of work, so enable it with
the legacy path only for now.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/vulkan/radv_pipeline.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/amd/vulkan/radv_pipeline.c b/src/amd/vulkan/radv_pipeline.c
index a7ff0e2d139..0903e5abf37 100644
--- a/src/amd/vulkan/radv_pipeline.c
+++ b/src/amd/vulkan/radv_pipeline.c
@@ -33,6 +33,7 @@
 #include "radv_shader.h"
 #include "nir/nir.h"
 #include "nir/nir_builder.h"
+#include "nir/nir_xfb_info.h"
 #include "spirv/nir_spirv.h"
 #include "vk_util.h"
 
@@ -2269,6 +2270,16 @@ radv_generate_graphics_pipeline_key(struct radv_pipeline *pipeline,
 	return key;
 }
 
+static bool
+radv_nir_stage_uses_xfb(const nir_shader *nir)
+{
+	nir_xfb_info *xfb = nir_gather_xfb_info(nir, NULL);
+	bool uses_xfb = !!xfb;
+
+	ralloc_free(xfb);
+	return uses_xfb;
+}
+
 static void
 radv_fill_shader_keys(struct radv_device *device,
 		      struct radv_shader_variant_key *keys,
@@ -2321,6 +2332,23 @@ radv_fill_shader_keys(struct radv_device *device,
 			 */
 			keys[MESA_SHADER_TESS_EVAL].vs_common_out.as_ngg = false;
 		}
+
+		/* TODO: Implement streamout support for NGG. */
+		bool uses_xfb = false;
+		if ((nir[MESA_SHADER_VERTEX] &&
+		     radv_nir_stage_uses_xfb(nir[MESA_SHADER_VERTEX])) ||
+		    (nir[MESA_SHADER_TESS_EVAL] &&
+		     radv_nir_stage_uses_xfb(nir[MESA_SHADER_TESS_EVAL])) ||
+		    (nir[MESA_SHADER_GEOMETRY] &&
+		     radv_nir_stage_uses_xfb(nir[MESA_SHADER_GEOMETRY])))
+			uses_xfb = true;
+
+		if (uses_xfb) {
+			if (nir[MESA_SHADER_TESS_CTRL])
+				keys[MESA_SHADER_TESS_EVAL].vs_common_out.as_ngg = false;
+			else
+				keys[MESA_SHADER_VERTEX].vs_common_out.as_ngg = false;
+		}
 	}
 
 	for(int i = 0; i < MESA_SHADER_STAGES; ++i)
-- 
2.22.0