[Mesa-dev] [PATCH] st/mesa: Reduce array updates due to current changes.

[Mathias.Froehlich at gmx.net]

From: Mathias Fröhlich <mathias.froehlich at web.de>

Hi Brian,

Following a small optimization in the gallium state tracker to
avoid flagging ST_NEW_VERTEX_ARRAYS a bit more often:

please review!

best

Mathias




Since using bitmasks we can easily check if we have any
current value that is potentially uploaded on array setup.
So check for any potential vertex program input that is not
already a vao enabled array. Only flag array update if there is
a potential overlap.

Signed-off-by: Mathias Fröhlich <Mathias.Froehlich at web.de>
---
 src/mesa/state_tracker/st_context.c | 2 +-
 src/mesa/state_tracker/st_context.h | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
index 0a0bd8ba1ca..45451531df9 100644
--- a/src/mesa/state_tracker/st_context.c
+++ b/src/mesa/state_tracker/st_context.c
@@ -224,7 +224,7 @@ st_invalidate_state(struct gl_context *ctx)
    if (new_state & _NEW_PIXEL)
       st->dirty |= ST_NEW_PIXEL_TRANSFER;
 
-   if (new_state & _NEW_CURRENT_ATTRIB)
+   if (new_state & _NEW_CURRENT_ATTRIB && st_vp_uses_current_values(ctx))
       st->dirty |= ST_NEW_VERTEX_ARRAYS;
 
    /* Update the vertex shader if ctx->Light._ClampVertexColor was changed. */
diff --git a/src/mesa/state_tracker/st_context.h b/src/mesa/state_tracker/st_context.h
index ed69e3d4873..324a7f24178 100644
--- a/src/mesa/state_tracker/st_context.h
+++ b/src/mesa/state_tracker/st_context.h
@@ -28,6 +28,7 @@
 #ifndef ST_CONTEXT_H
 #define ST_CONTEXT_H
 
+#include "main/arrayobj.h"
 #include "main/mtypes.h"
 #include "state_tracker/st_api.h"
 #include "main/fbobject.h"
@@ -398,6 +399,14 @@ st_user_clip_planes_enabled(struct gl_context *ctx)
           ctx->Transform.ClipPlanesEnabled;
 }
 
+
+static inline bool
+st_vp_uses_current_values(const struct gl_context *ctx)
+{
+   const uint64_t inputs = ctx->VertexProgram._Current->info.inputs_read;
+   return _mesa_draw_current_bits(ctx) & inputs;
+}
+
 /** clear-alloc a struct-sized object, with casting */
 #define ST_CALLOC_STRUCT(T)   (struct T *) calloc(1, sizeof(struct T))
 
-- 
2.20.1