svga: eliminiate unnecessary constant buffer updates

Currently if the texture binding is changed, emit_fs_consts()
is triggered to update texture scaling factor for
rectangle texture or texture buffer size in the constant buffer.
But the update is only relevant if the texture binding includes
a rectangle texture or a texture buffer.

To eliminate the unnecessary constant buffer updates due to other texture
binding changes, a new flag SVGA_NEW_TEXTURE_CONSTS will be used
to trigger fragment shader constant buffer update when a rectangle texture
or a texture buffer is bound.

With this patch, the number of constant buffer updates in Lightsmark2008
reduces from hundreds per frame to about 28 per frame.

Reviewed-by: Brian Paul <[email protected]>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/gallium/drivers/svga/svga_context.h b/src/gallium/drivers/svga/svga_context.h
index b485485f0be..007d5bc3b51 100644
--- a/src/gallium/drivers/svga/svga_context.h
+++ b/src/gallium/drivers/svga/svga_context.h
@@ -291,6 +291,8 @@ struct svga_state
    struct {
       unsigned flag_1d;
       unsigned flag_srgb;
+      unsigned flag_rect;  /* sampler views with rectangular texture target */
+      unsigned flag_buf;   /* sampler views with texture buffer target */
    } tex_flags;
 
    unsigned sample_mask;
@@ -586,6 +588,7 @@ struct svga_context
 #define SVGA_NEW_GS                  0x10000000
 #define SVGA_NEW_GS_CONST_BUFFER     0x20000000
 #define SVGA_NEW_GS_VARIANT          0x40000000
+#define SVGA_NEW_TEXTURE_CONSTS      0x80000000