From a9063cad0f0190ff88cd20fbad5aa87bf1a943f6 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Wed, 24 Mar 2010 20:49:12 -0600 Subject: llvmpipe: optimize the lp_setup_fence() function Avoid emitting fences when not needed. Speeds up glReadPixels quite a bit when reading image row by row. --- src/gallium/drivers/llvmpipe/lp_setup.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/src/gallium/drivers/llvmpipe/lp_setup.c b/src/gallium/drivers/llvmpipe/lp_setup.c index 76a8b87a30..4eeb98621f 100644 --- a/src/gallium/drivers/llvmpipe/lp_setup.c +++ b/src/gallium/drivers/llvmpipe/lp_setup.c @@ -318,16 +318,30 @@ lp_setup_fence( struct lp_setup_context *setup ) { struct lp_scene *scene = lp_setup_get_current_scene(setup); const unsigned rank = lp_scene_get_num_bins( scene ); /* xxx */ - struct lp_fence *fence = lp_fence_create(rank); + struct lp_fence *fence; LP_DBG(DEBUG_SETUP, "%s rank %u\n", __FUNCTION__, rank); - set_scene_state( setup, SETUP_ACTIVE ); + if (setup->state == SETUP_FLUSHED) { + /* We're in a flushed state so there's nothing in the bins. + * No need to wait on a fence. + */ + fence = NULL; + } + else { + /* There's material in the bins. Emit the fence into the bins. + * When the rasterizer(s) find the fence, they'll signal on it. + */ + fence = lp_fence_create(rank); + + set_scene_state( setup, SETUP_ACTIVE ); - /* insert the fence into all command bins */ - lp_scene_bin_everywhere( scene, - lp_rast_fence, - lp_rast_arg_fence(fence) ); + /* insert the fence into all command bins */ + lp_scene_bin_everywhere( scene, + lp_rast_fence, + lp_rast_arg_fence(fence) ); + + } return (struct pipe_fence_handle *) fence; } -- cgit v1.2.3