svga: try to emit fewer buffer rebind commands

If a consecutive sequence of drawing commands references the same
vertex/index buffers, there should be no need to rebind the surfaces
for the second and subsequent drawing commands.

Apps that use multiple display lists benefit from this since the vertex
data for several display lists is often stored in one buffer.

In the case of the legacy E&S Glaze demo, this reduces the size of our
command buffers from 91KB to 44KB.  One WSI Fusion trace shows a 33%
reduction in command buffer sizes.

Tested with full piglit run.

Reviewed-by: Charmaine Lee <charmainel@vmware.com>

diff --git a/src/gallium/drivers/svga/svga_cmd.c b/src/gallium/drivers/svga/svga_cmd.c
index e45b3e72aebf9ed25bf8e367a2d702287625b0b1..ecf2e9d2ca0cb876186d0c0f29b775763a735518 100644 (file)
--- a/src/gallium/drivers/svga/svga_cmd.c
+++ b/src/gallium/drivers/svga/svga_cmd.c
@@ -119,6 +119,8 @@ SVGA3D_FIFOReserve(struct svga_winsys_context *swc,
    header->id = cmd;
    header->size = cmdSize;
 
+   swc->last_command = cmd;
+
    return &header[1];
 }
 

diff --git a/src/gallium/drivers/svga/svga_cmd.h b/src/gallium/drivers/svga/svga_cmd.h
index 06e1b4a325396f1914bd9d53fb1975bfc5953c00..47a33ec3932660afdddad987a5d83d38db7cc3b9 100644 (file)
--- a/src/gallium/drivers/svga/svga_cmd.h
+++ b/src/gallium/drivers/svga/svga_cmd.h
@@ -35,6 +35,7 @@
 
 
 #include "svga_types.h"
+#include "svga_winsys.h"
 #include "svga_reg.h"
 #include "svga3d_reg.h"
 
@@ -60,6 +61,25 @@ SVGA3D_FIFOReserve(struct svga_winsys_context *swc, uint32 cmd, uint32 cmdSize,
 void
 SVGA_FIFOCommitAll(struct svga_winsys_context *swc);
 
+/**
+ * Return the last command id put in the command buffer.
+ */
+static inline SVGAFifo3dCmdId
+SVGA3D_GetLastCommand(const struct svga_winsys_context *swc)
+{
+   return swc->last_command;
+}
+
+/**
+ * Reset/clear the last command put in the command buffer.
+ * To be called when buffer is flushed.
+ */
+static inline void
+SVGA3D_ResetLastCommand(struct svga_winsys_context *swc)
+{
+   swc->last_command = 0;
+}
+
 
 /*
  * Context Management

diff --git a/src/gallium/drivers/svga/svga_context.c b/src/gallium/drivers/svga/svga_context.c
index f498e839aa2f11a26969df7a588cfb00889e4323..1ed0f3d1b78226497884fc84258d440138ee7b73 100644 (file)
--- a/src/gallium/drivers/svga/svga_context.c
+++ b/src/gallium/drivers/svga/svga_context.c
@@ -338,6 +338,8 @@ void svga_context_flush( struct svga_context *svga,
 
    svga_screen_cache_flush(svgascreen, fence);
 
+   SVGA3D_ResetLastCommand(svga->swc);
+
    /* To force the re-emission of rendertargets and texture sampler bindings on
     * the next command buffer.
     */

diff --git a/src/gallium/drivers/svga/svga_draw.c b/src/gallium/drivers/svga/svga_draw.c
index f8d3ae543ef764f9d87f951efb19ff42539b70cf..988267b8df1e2f021f14502c89176ecd8833bbf8 100644 (file)
--- a/src/gallium/drivers/svga/svga_draw.c
+++ b/src/gallium/drivers/svga/svga_draw.c
@@ -427,6 +427,32 @@ validate_constant_buffers(struct svga_context *svga)
 }
 
 
+/**
+ * Was the last command put into the command buffer a drawing command?
+ * We use this to determine if we can skip emitting buffer re-bind
+ * commands when we have a sequence of drawing commands that use the
+ * same vertex/index buffers with no intervening commands.
+ *
+ * The first drawing command will bind the vertex/index buffers.  If
+ * the immediately following command is also a drawing command using the
+ * same buffers, we shouldn't have to rebind them.
+ */
+static bool
+last_command_was_draw(const struct svga_context *svga)
+{
+   switch (SVGA3D_GetLastCommand(svga->swc)) {
+   case SVGA_3D_CMD_DX_DRAW:
+   case SVGA_3D_CMD_DX_DRAW_INDEXED:
+   case SVGA_3D_CMD_DX_DRAW_INSTANCED:
+   case SVGA_3D_CMD_DX_DRAW_INDEXED_INSTANCED:
+   case SVGA_3D_CMD_DX_DRAW_AUTO:
+      return true;
+   default:
+      return false;
+   }
+}
+
+
 static enum pipe_error
 draw_vgpu10(struct svga_hwtnl *hwtnl,
             const SVGA3dPrimitiveRange *range,
@@ -583,7 +609,7 @@ draw_vgpu10(struct svga_hwtnl *hwtnl,
           * command, we still need to reference the vertex buffers surfaces.
           */
          for (i = 0; i < vbuf_count; i++) {
-            if (vbuffer_handles[i]) {
+            if (vbuffer_handles[i] && !last_command_was_draw(svga)) {
                ret = svga->swc->resource_rebind(svga->swc, vbuffer_handles[i],
                                                 NULL, SVGA_RELOC_READ);
                if (ret != PIPE_OK)
@@ -626,10 +652,12 @@ draw_vgpu10(struct svga_hwtnl *hwtnl,
          /* Even though we can avoid emitting the redundant SetIndexBuffer
           * command, we still need to reference the index buffer surface.
           */
-         ret = svga->swc->resource_rebind(svga->swc, ib_handle,
-                                          NULL, SVGA_RELOC_READ);
-         if (ret != PIPE_OK)
-            return ret;
+         if (!last_command_was_draw(svga)) {
+            ret = svga->swc->resource_rebind(svga->swc, ib_handle,
+                                             NULL, SVGA_RELOC_READ);
+            if (ret != PIPE_OK)
+               return ret;
+         }
       }
 
       if (instance_count > 1) {

diff --git a/src/gallium/drivers/svga/svga_winsys.h b/src/gallium/drivers/svga/svga_winsys.h
index a7b25ab7b44c69536d19e61b3ef75e2d6b0c4de1..901a73eba0ae785be8423657ecca07bb194f4f0f 100644 (file)
--- a/src/gallium/drivers/svga/svga_winsys.h
+++ b/src/gallium/drivers/svga/svga_winsys.h
@@ -424,6 +424,9 @@ struct svga_winsys_context
 
    /** To report perf/conformance/etc issues to the state tracker */
    struct pipe_debug_callback *debug_callback;
+
+   /** The more recent command issued to command buffer */
+   SVGAFifo3dCmdId last_command;
 };