radeonsi: do compilation from si_create_shader_selector asynchronously

Main shader parts and geometry shaders are compiled asynchronously
by util_queue. si_create_shader_selector doesn't wait and returns.
si_draw_vbo(si_shader_select) waits for completion.

This has the best effect when shaders are compiled at app-loading time.
It doesn't help much for shaders compiled on demand, even though
VS+PS compilation should take as much as time as the bigger one of the two.

If an app creates more shaders, at most 4 threads will be used to compile
them.

Debug output disables this for shader stats to be printed in the correct
order.

(We could go even further and build variants asynchronously too, then emit
draw calls without waiting and emit incomplete shader states, then force IB
chaining to give the compiler more time, then sync the compilation at the IB
flush and patch the IB with correct shader states. This is great for
compilation before draw calls, but there are some difficulties such as
scratch and tess states requiring the compiler output, and an on-disk shader
cache will likely be a much better and simpler solution.)

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index fc7e73e..1f63c12 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -27,6 +27,7 @@
 #define SI_PIPE_H
 
 #include "si_state.h"
+#include "util/u_queue.h"
 
 #include <llvm-c/TargetMachine.h>
 
@@ -110,6 +111,10 @@ struct si_screen {
 	 */
 	pipe_mutex			shader_cache_mutex;
 	struct hash_table		*shader_cache;
+
+	/* Shader compiler queue for multithreaded compilation. */
+	struct util_queue		shader_compiler_queue;
+	LLVMTargetMachineRef		tm[4]; /* used by the queue only */
 };
 
 struct si_blend_color {
@@ -207,7 +212,7 @@ struct si_context {
 
 	struct pipe_fence_handle	*last_gfx_fence;
 	struct si_shader_ctx_state	fixed_func_tcs_shader;
-	LLVMTargetMachineRef		tm;
+	LLVMTargetMachineRef		tm; /* only non-threaded compilation */
 	bool				gfx_flush_in_progress;
 
 	/* Atoms (direct states). */