2009-10-06 Sebastian Pop <sebastian.pop@amd.com>

	* graphite-dependences.c (reduction_dr_1): New.
	(reduction_dr_p): New.
	(graphite_legal_transform_dr): Call reduction_dr_p.
	(reduction_ddr): Renamed reduction_ddr_p.
	* graphite-poly.h (same_pdr_p): New.
	(number_of_write_pdrs): New.
	* graphite-sese-to-poly.c (nb_data_writes_in_bb): New.
	(split_reduction_stmt): Do not split reduction statements
	when there are no writes to memory.
	(translate_scalar_reduction_to_array_for_stmt): Insert the
	memory reduction statement just after the scalar reduction statement.

	* gcc.dg/graphite/interchange-10.c: Updated to differ from interchange-4.c.
	Un-XFAIL-ed.
	* gcc.dg/graphite/interchange-3.c: Un-XFAIL-ed.
	* gcc.dg/graphite/interchange-4.c: Un-XFAIL-ed.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@154564 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 22 insertions, 1 deletions

diff --git a/gcc/graphite-sese-to-poly.c b/gcc/graphite-sese-to-poly.c
index 807e287f622..75d10c69869 100644
--- a/gcc/graphite-sese-to-poly.c
+++ b/gcc/graphite-sese-to-poly.c
@@ -2213,6 +2213,22 @@ nb_pbbs_in_loops (scop_p scop)
   return res;
 }
 
+/* Return the number of data references in BB that write in
+   memory.  */
+
+static int
+nb_data_writes_in_bb (basic_block bb)
+{
+  int res = 0;
+  gimple_stmt_iterator gsi;
+
+  for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+    if (gimple_vdef (gsi_stmt (gsi)))
+      res++;
+
+  return res;
+}
+
 /* Splits STMT out of its current BB.  */
 
 static basic_block
@@ -2222,6 +2238,11 @@ split_reduction_stmt (gimple stmt)
   basic_block bb = gimple_bb (stmt);
   edge e;
 
+  /* Do not split basic blocks with no writes to memory: the reduction
+     will be the only write to memory.  */
+  if (nb_data_writes_in_bb (bb) == 0)
+    return bb;
+
   split_block (bb, stmt);
 
   gsi = gsi_last_bb (bb);
@@ -2444,7 +2465,7 @@ translate_scalar_reduction_to_array_for_stmt (tree red, gimple stmt,
   gsi_insert_before (&insert_gsi, assign, GSI_SAME_STMT);
 
   assign = gimple_build_assign (red, gimple_assign_lhs (stmt));
-  insert_gsi = gsi_last_bb (bb);
+  insert_gsi = gsi_for_stmt (stmt);
   gsi_insert_after (&insert_gsi, assign, GSI_SAME_STMT);
 }