invoke.texi: Document -ftree-loop-distribution.

	* doc/invoke.texi: Document -ftree-loop-distribution.
	* tree-loop-distribution.c: New.
	* tree-pass.h (pass_loop_distribution): New.
	* graphds.h (struct graph): Add htab_t indices.
	* timevar.def (TV_TREE_LOOP_DISTRIBUTION): New.
	* tree-vectorizer.c (rename_variables_in_loop): Extern.
	(slpeel_tree_duplicate_loop_to_edge_cfg): Init PENDING_STMT to NULL.
	* tree-vectorizer.h (tree_duplicate_loop_on_edge): Declared.
	* tree-data-ref.c (debug_data_dependence_relations): New.
	(dump_data_dependence_relation): Also print data references.
	(free_data_ref): Extern.
	(same_access_functions): Moved...
	(find_vertex_for_stmt): Renamed rdg_vertex_for_stmt.
	(dump_rdg_vertex, debug_rdg_vertex, dump_rdg_component,
	debug_rdg_component, dump_rdg, debug_rdg, dot_rdg_1, dot_rdg,
	struct rdg_vertex_info, rdg_vertex_for_stmt): New.
	(create_rdg_edge_for_ddr, create_rdg_vertices): Cleaned up.
	(stmts_from_loop): Skip LABEL_EXPR.
	(hash_stmt_vertex_info, eq_stmt_vertex_info, hash_stmt_vertex_del): New.
	(build_rdg): Initialize rdg->indices htab.
	(free_rdg, stores_from_loop, ref_base_address,
	rdg_defs_used_in_other_loops_p, have_similar_memory_accesses,
	have_similar_memory_accesses_1, ref_base_address_1,
	remove_similar_memory_refs): New.
	* tree-data-ref.h: Depend on tree-chrec.h.
	(debug_data_dependence_relations, free_data_ref): Declared.
	(same_access_functions): ... here.
	(ddr_is_anti_dependent, ddrs_have_anti_deps, ddr_dependence_level): New.
	(struct rdg_vertex): Add has_mem_write and has_mem_reads.
	(RDGV_HAS_MEM_WRITE, RDGV_HAS_MEM_READS, RDG_STMT,
	RDG_MEM_WRITE_STMT, RDG_MEM_READS_STMT): New.
	(dump_rdg_vertex, debug_rdg_vertex, dump_rdg_component,
	debug_rdg_component, dump_rdg, debug_rdg, dot_rdg,
	rdg_vertex_for_stmt): Declared.
	(struct rdg_edge): Add level.
	(RDGE_LEVEL): New.
	(free_rdg, stores_from_loop, remove_similar_memory_refs,
	rdg_defs_used_in_other_loops_p, have_similar_memory_accesses): Declared.
	(rdg_has_similar_memory_accesses): New.
	* tree-vect-analyze.c: Remove unused static decls.
	* lambda.h (dependence_level): New.
	* common.opt (ftree-loop-distribution): New.
	* tree-flow.h (mark_virtual_ops_in_bb, 
	slpeel_tree_duplicate_loop_to_edge_cfg,
	rename_variables_in_loop): Declared.
	* Makefile.in (TREE_DATA_REF_H): Depend on tree-chrec.h.
	(OBJS-common): Add tree-loop-distribution.o.
	(tree-loop-distribution.o): New rule.
	* tree-cfg.c (mark_virtual_ops_in_bb): New.
	(mark_virtual_ops_in_region): Use mark_virtual_ops_in_bb.
	* passes.c (init_optimization_passes): Schedule pass_loop_distribution.

	* testsuite/gcc.dg/tree-ssa/ldist-{1..12}.c: New.

From-SVN: r132745

1 files changed, 31 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ldist-2.c b/gcc/testsuite/gcc.dg/tree-ssa/ldist-2.c
new file mode 100644
index 0000000..de98ccc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ldist-2.c
@@ -0,0 +1,31 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O2 -ftree-loop-distribution -fdump-tree-ldist-all" } */
+
+void foo (int * __restrict__ a,
+	  int * __restrict__ b,
+	  int * __restrict__ c)
+{
+  int i;
+
+  for (i=1; i < 10; i++)
+    {
+      a[i] += c[i];
+      b[i] = a[i - 1] + 1;
+    }
+
+  /* This loop is not distributed because the cost of spliting it:
+
+     |  for (i=1; i < N; i++)
+     |    a[i] += c[i];
+     |
+     |  for (i=1; i < N; i++)
+     |    b[i] = a[i - 1] + 1;
+
+     is higher due to data in array A that is written and then read in
+     another task.  The cost model should forbid the transformation in
+     this case.
+  */
+}
+
+/* { dg-final { scan-tree-dump-times "distributed: split to 2 loops" 0 "ldist" } } */
+/* { dg-final { cleanup-tree-dump "ldist" } } */