tree-loop-distribution.c: Adjust the general comment.

	* tree-loop-distribution.c: Adjust the general comment.
	(NUM_PARTITION_THRESHOLD): New macro.
	(ssa_name_has_uses_outside_loop_p): Support loop nest distribution.
	(classify_partition): Skip builtin pattern of loop nest's inner loop.
	(merge_dep_scc_partitions): New parameter ignore_alias_p and use it
	in call to build_partition_graph.
	(finalize_partitions): New parameter.  Make loop distribution more
	conservative by fusing more partitions.
	(distribute_loop): Don't do runtime alias check in case of loop nest
	distribution.
	(find_seed_stmts_for_distribution): New function.
	(prepare_perfect_loop_nest): New function.
	(pass_loop_distribution::execute): Refactor code finding seed stmts
	and loop nest into above functions.  Support loop nest distribution.
	Adjust dump information accordingly.

	gcc/testsuite
	* gcc.dg/tree-ssa/ldist-7.c: Adjust test string.
	* gcc.dg/tree-ssa/ldist-16.c: Ditto.
	* gcc.dg/tree-ssa/ldist-25.c: Ditto.
	* gcc.dg/tree-ssa/ldist-33.c: New test.

From-SVN: r253679

gcc/ChangeLog

 2017-10-12  Bin Cheng  <bin.cheng@arm.com>
 
+	* tree-loop-distribution.c: Adjust the general comment.
+	(NUM_PARTITION_THRESHOLD): New macro.
+	(ssa_name_has_uses_outside_loop_p): Support loop nest distribution.
+	(classify_partition): Skip builtin pattern of loop nest's inner loop.
+	(merge_dep_scc_partitions): New parameter ignore_alias_p and use it
+	in call to build_partition_graph.
+	(finalize_partitions): New parameter.  Make loop distribution more
+	conservative by fusing more partitions.
+	(distribute_loop): Don't do runtime alias check in case of loop nest
+	distribution.
+	(find_seed_stmts_for_distribution): New function.
+	(prepare_perfect_loop_nest): New function.
+	(pass_loop_distribution::execute): Refactor code finding seed stmts
+	and loop nest into above functions.  Support loop nest distribution.
+	Adjust dump information accordingly.
+
+2017-10-12  Bin Cheng  <bin.cheng@arm.com>
+
 	* tree-loop-distribution.c (break_alias_scc_partitions): Add comment
 	and set PTYPE_SEQUENTIAL for merged partition.
 

gcc/testsuite/ChangeLog

+2017-10-12  Bin Cheng  <bin.cheng@arm.com>
+
+	* gcc.dg/tree-ssa/ldist-7.c: Adjust test string.
+	* gcc.dg/tree-ssa/ldist-16.c: Ditto.
+	* gcc.dg/tree-ssa/ldist-25.c: Ditto.
+	* gcc.dg/tree-ssa/ldist-33.c: New test.
+
 2017-10-12  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/69728

gcc/testsuite/gcc.dg/tree-ssa/ldist-16.c

@@ -16,5 +16,5 @@ void foo (int n)
 
 /* We should not apply loop distribution and not generate a memset (0).  */
 
-/* { dg-final { scan-tree-dump "Loop 1 is the same" "ldist" } } */
+/* { dg-final { scan-tree-dump "Loop 1 not distributed" "ldist" } } */
 /* { dg-final { scan-tree-dump-times "generated memset zero" 0 "ldist" } } */

gcc/testsuite/gcc.dg/tree-ssa/ldist-25.c

@@ -22,4 +22,4 @@ foo (void)
     }
 }
 
-/* { dg-final { scan-tree-dump "Loop . is the same" "ldist" } } */
+/* { dg-final { scan-tree-dump "Loop . not distributed" "ldist" } } */

gcc/testsuite/gcc.dg/tree-ssa/ldist-33.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-loop-distribution -ftree-loop-distribute-patterns -fdump-tree-ldist-details" } */
+
+#define N (1024)
+double a[N][N], b[N][N], c[N][N];
+
+void
+foo (void)
+{
+  unsigned i, j, k;
+
+  for (i = 0; i < N; ++i)
+    for (j = 0; j < N; ++j)
+      {
+	c[i][j] = 0.0;
+	for (k = 0; k < N; ++k)
+	  c[i][j] += a[i][k] * b[k][j];
+      }
+}
+
+/* { dg-final { scan-tree-dump "Loop nest . distributed: split to 1 loops and 1 library" "ldist" } } */

gcc/testsuite/gcc.dg/tree-ssa/ldist-7.c

@@ -28,4 +28,4 @@ int loop1 (int k)
   return a[1000-2] + b[1000-1] + c[1000-2] + d[1000-2];
 }
 
-/* { dg-final { scan-tree-dump-times "distributed" 0 "ldist" } } */
+/* { dg-final { scan-tree-dump-times "distributed: " 0 "ldist" } } */