more readable code

src/core/dependencies/data_commute_concurrency.c

@@ -295,11 +295,15 @@ void _starpu_submit_job_enforce_commute_deps(struct _starpu_job *j, unsigned buf
 
 	for (idx_buf_commute = nb_non_commute_buff; idx_buf_commute < nbuffers; idx_buf_commute++)
 	{
-		if (idx_buf_commute && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute-1)==_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute)))
-			continue;
-		/* we post all commute  */
 		starpu_data_handle_t handle = _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute);
 		enum starpu_data_access_mode mode = _STARPU_JOB_GET_ORDERED_BUFFER_MODE(j, idx_buf_commute);
+
+		if (idx_buf_commute && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute-1)==handle))
+			/* We have already requested this data, skip it. This
+			 * depends on ordering putting writes before reads, see
+			 * _starpu_compar_handles.  */
+			continue;
+		/* we post all commute  */
 		STARPU_ASSERT(mode & STARPU_COMMUTE);
 
 		_starpu_spin_lock(&handle->header_lock);
@@ -324,10 +328,11 @@ void _starpu_submit_job_enforce_commute_deps(struct _starpu_job *j, unsigned buf
 		unsigned idx_buf_cancel;
 		for (idx_buf_cancel = nb_non_commute_buff; idx_buf_cancel < idx_buf_commute ; idx_buf_cancel++)
 		{
-			if (idx_buf_cancel && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_cancel-1)==_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_cancel)))
+			starpu_data_handle_t cancel_handle = _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_cancel);
+
+			if (idx_buf_cancel && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_cancel-1)==cancel_handle))
 				continue;
 
-			starpu_data_handle_t cancel_handle = _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_cancel);
 			_starpu_spin_lock(&cancel_handle->header_lock);
 			/* reset the counter because finally we do not take the data */
 			STARPU_ASSERT(cancel_handle->refcnt == 1);
@@ -415,7 +420,11 @@ void _starpu_notify_commute_dependencies(starpu_data_handle_t handle)
 		/* find the position of commute buffers */
 		for (nb_non_commute_buff = 0; nb_non_commute_buff < nbuffers; nb_non_commute_buff++)
 		{
-			if (nb_non_commute_buff && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, nb_non_commute_buff-1) == _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, nb_non_commute_buff)))
+			starpu_data_handle_t handle_commute = _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, nb_non_commute_buff);
+			if (nb_non_commute_buff && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, nb_non_commute_buff-1) == handle_commute))
+				/* We have already requested this data, skip it. This
+				 * depends on ordering putting writes before reads, see
+				 * _starpu_compar_handles.  */
 				continue;
 			enum starpu_data_access_mode mode = _STARPU_JOB_GET_ORDERED_BUFFER_MODE(j, nb_non_commute_buff);
 			if(mode & STARPU_COMMUTE)
@@ -429,10 +438,13 @@ void _starpu_notify_commute_dependencies(starpu_data_handle_t handle)
 
 		for (idx_buf_commute = nb_non_commute_buff; idx_buf_commute < nbuffers; idx_buf_commute++)
 		{
-			if (idx_buf_commute && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute-1)==_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute)))
+			starpu_data_handle_t handle_commute = _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute);
+			if (idx_buf_commute && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute-1)==handle_commute))
+				/* We have already requested this data, skip it. This
+				 * depends on ordering putting writes before reads, see
+				 * _starpu_compar_handles.  */
 				continue;
 			/* we post all commute  */
-			starpu_data_handle_t handle_commute = _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute);
 			enum starpu_data_access_mode mode = _STARPU_JOB_GET_ORDERED_BUFFER_MODE(j, idx_buf_commute);
 			STARPU_ASSERT(mode & STARPU_COMMUTE);
 
@@ -454,10 +466,10 @@ void _starpu_notify_commute_dependencies(starpu_data_handle_t handle)
 		{
 			for (idx_buf_commute = nb_non_commute_buff; idx_buf_commute < nbuffers; idx_buf_commute++)
 			{
-				if (idx_buf_commute && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute-1)==_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute)))
+				starpu_data_handle_t handle_commute = _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute);
+				if (idx_buf_commute && (_STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute-1)==handle_commute))
 					continue;
 				/* we post all commute  */
-				starpu_data_handle_t handle_commute = _STARPU_JOB_GET_ORDERED_BUFFER_HANDLE(j, idx_buf_commute);
 				enum starpu_data_access_mode mode = _STARPU_JOB_GET_ORDERED_BUFFER_MODE(j, idx_buf_commute);
 				STARPU_ASSERT(mode & STARPU_COMMUTE);