svga: avoid emitting redundant SetSamplers() commands

This greatly reduces the number of SetSamplers() commands for some
applications.

Reviewed-by: José Fonseca <[email protected]>
Reviewed-by: Charmaine Lee <[email protected]>

2 files changed, 18 insertions, 7 deletions

diff --git a/src/gallium/drivers/svga/svga_context.h b/src/gallium/drivers/svga/svga_context.h
index db9491bc282..78e346a92b9 100644
--- a/src/gallium/drivers/svga/svga_context.h
+++ b/src/gallium/drivers/svga/svga_context.h
@@ -347,6 +347,9 @@ struct svga_hw_draw_state
    SVGA3dSurfaceFormat ib_format;
    unsigned ib_offset;
 
+   unsigned num_samplers[PIPE_SHADER_TYPES];
+   SVGA3dSamplerId samplers[PIPE_SHADER_TYPES][PIPE_MAX_SAMPLERS];
+
    /* used for rebinding */
    unsigned num_sampler_views[PIPE_SHADER_TYPES];
    unsigned default_constbuf_size[PIPE_SHADER_TYPES];
diff --git a/src/gallium/drivers/svga/svga_state_sampler.c b/src/gallium/drivers/svga/svga_state_sampler.c
index c5d52bbfd14..b070f65feaf 100644
--- a/src/gallium/drivers/svga/svga_state_sampler.c
+++ b/src/gallium/drivers/svga/svga_state_sampler.c
@@ -301,13 +301,21 @@ update_samplers(struct svga_context *svga, unsigned dirty )
       }
 
       if (count > 0) {
-         ret = SVGA3D_vgpu10_SetSamplers(svga->swc,
-                                         count,
-                                         0,                        /* start */
-                                         svga_shader_type(shader), /* type */
-                                         ids);
-         if (ret != PIPE_OK)
-            return ret;
+         if (count != svga->state.hw_draw.num_samplers[shader] ||
+             memcmp(ids, svga->state.hw_draw.samplers[shader],
+                    count * sizeof(ids[0])) != 0) {
+            /* HW state is really changing */
+            ret = SVGA3D_vgpu10_SetSamplers(svga->swc,
+                                            count,
+                                            0,                       /* start */
+                                            svga_shader_type(shader), /* type */
+                                            ids);
+            if (ret != PIPE_OK)
+               return ret;
+            memcpy(svga->state.hw_draw.samplers[shader], ids,
+                   count * sizeof(ids[0]));
+            svga->state.hw_draw.num_samplers[shader] = count;
+         }
       }
    }