mesa: Track maximum CurrentTexUnit to reduce glDeleteTextures() overhead.

No more walking 96*6 pointers looking to see if they're the current
texture, when we only use the first 2 out of 96 units.  -6.26002% +/-
1.87817% effect on cairo runtime on no-fbo-cache glamor (n=36).

Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/mesa/main/texstate.c b/src/mesa/main/texstate.c
index 3a7e2273f90..000af94c6ed 100644
--- a/src/mesa/main/texstate.c
+++ b/src/mesa/main/texstate.c
@@ -108,6 +108,10 @@ _mesa_copy_texture_state( const struct gl_context *src, struct gl_context *dst )
          for (tex = 0; tex < NUM_TEXTURE_TARGETS; tex++) {
             _mesa_reference_texobj(&dst->Texture.Unit[u].CurrentTex[tex],
                                    src->Texture.Unit[u].CurrentTex[tex]);
+            if (src->Texture.Unit[u].CurrentTex[tex]) {
+               dst->Texture.NumCurrentTexUsed =
+                  MAX2(dst->Texture.NumCurrentTexUsed, u + 1);
+            }
          }
          _mesa_unlock_context_textures(dst);
       }
@@ -912,6 +916,8 @@ _mesa_init_texture(struct gl_context *ctx)
    _mesa_reference_buffer_object(ctx, &ctx->Texture.BufferObject,
                                  ctx->Shared->NullBufferObj);
 
+   ctx->Texture.NumCurrentTexUsed = 0;
+
    return GL_TRUE;
 }