Introduce vNULL to use as a nil initializer for vec<>.

This patch implements Jakub's idea of adding an empty struct with
a typecast operator that returns nil vectors.  This is useful to
shorten all the initializers when declaring vec instances or passing
nil vectors as function arguments.

2012-11-20  Diego Novillo  <dnovillo@google.com>
	    Jakub Jelinek  <jakub@redhat.com>

ChangeLog
	* vec.h (struct vnull): Declare.
	(vNULL): Declare.
	* vec.c (vNULL): Define.
	* bb-reorder.c: Replace all vec<T, A>() initializers with vNULL.
	* cfgexpand.c: Likewise.
	* cfgloop.c: Likewise.
	* cfgloopanal.c: Likewise.
	* cfgloopmanip.c: Likewise.
	* cgraph.c: Likewise.
	* config/c6x/c6x.c: Likewise.
	* config/i386/i386.c: Likewise.
	* df-core.c: Likewise.
	* dominance.c: Likewise.
	* dwarf2out.c: Likewise.
	* except.c: Likewise.
	* function.c: Likewise.
	* gcse.c: Likewise.
	* genautomata.c: Likewise.
	* graphds.c: Likewise.
	* graphite-scop-detection.c: Likewise.
	* graphite.c: Likewise.
	* haifa-sched.c: Likewise.
	* ifcvt.c: Likewise.
	* ipa-cp.c: Likewise.
	* ipa-inline-analysis.c: Likewise.
	* ipa-inline-transform.c: Likewise.
	* ipa-inline.c: Likewise.
	* ipa-prop.c: Likewise.
	* ipa-split.c: Likewise.
	* ipa-utils.c: Likewise.
	* ira-build.c: Likewise.
	* lto-cgraph.c: Likewise.
	* lto-streamer-in.c: Likewise.
	* lto-symtab.c: Likewise.
	* opts-global.c: Likewise.
	* passes.c: Likewise.
	* ree.c: Likewise.
	* sched-deps.c: Likewise.
	* sel-sched-ir.c: Likewise.
	* sel-sched-ir.h: Likewise.
	* sel-sched.c: Likewise.
	* stor-layout.c: Likewise.
	* trans-mem.c: Likewise.
	* tree-call-cdce.c: Likewise.
	* tree-cfg.c: Likewise.
	* tree-data-ref.c: Likewise.
	* tree-diagnostic.c: Likewise.
	* tree-eh.c: Likewise.
	* tree-loop-distribution.c: Likewise.
	* tree-predcom.c: Likewise.
	* tree-ssa-loop-im.c: Likewise.
	* tree-ssa-loop-ivcanon.c: Likewise.
	* tree-ssa-loop-manip.c: Likewise.
	* tree-ssa-loop-niter.c: Likewise.
	* tree-ssa-loop-prefetch.c: Likewise.
	* tree-ssa-math-opts.c: Likewise.
	* tree-ssa-phiopt.c: Likewise.
	* tree-ssa-pre.c: Likewise.
	* tree-ssa-propagate.c: Likewise.
	* tree-ssa-reassoc.c: Likewise.
	* tree-ssa-sccvn.c: Likewise.
	* tree-ssa-structalias.c: Likewise.
	* tree-ssa-threadedge.c: Likewise.
	* tree-ssa-uninit.c: Likewise.
	* tree-stdarg.c: Likewise.
	* tree-switch-conversion.c: Likewise.
	* tree-vect-data-refs.c: Likewise.
	* tree-vect-loop.c: Likewise.
	* tree-vect-slp.c: Likewise.
	* tree-vect-stmts.c: Likewise.
	* value-prof.c: Likewise.
	* varasm.c: Likewise.

ada/ChangeLog
	* gcc-interface/decl.c: Replace all vec<T,A>()
	initializers with vNULL.

cp/ChangeLog
	* name-lookup.c: Replace all vec<T, A>() initializers
	with vNULL.
	* semantics.c: Likewise.

fortran/ChangeLog
	* trans-openmp.c: Replace all vec<T, A>() initializers
	with vNULL.

lto/ChangeLog
	* lto.c: Replace all vec<T, A>() initializers with vNULL.

objc/ChangeLog
	* objc-act.c: Replace all vec<T, A>() initializers with vNULL.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@193677 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 5 insertions, 5 deletions

diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index e6f3da9bdfb..a4f537a8412 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -960,7 +960,7 @@ vect_build_slp_tree (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo,
 				   prologue_cost_vec, body_cost_vec))
         {
 	  if (child)
-	    oprnd_info->def_stmts = vec<gimple>();
+	    oprnd_info->def_stmts = vNULL;
 	  vect_free_slp_tree (child);
 	  vect_free_oprnd_info (oprnds_info);
    	  return false;
@@ -1058,7 +1058,7 @@ vect_supported_slp_permutation_p (slp_instance instance)
   slp_tree node = SLP_INSTANCE_LOADS (instance)[0];
   gimple stmt = SLP_TREE_SCALAR_STMTS (node)[0];
   gimple first_load = GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt));
-  vec<slp_tree> sorted_loads = vec<slp_tree>();
+  vec<slp_tree> sorted_loads = vNULL;
   int index;
   slp_tree *tmp_loads = NULL;
   int group_size = SLP_INSTANCE_GROUP_SIZE (instance), i, j;
@@ -1102,7 +1102,7 @@ vect_supported_slp_permutation_p (slp_instance instance)
   SLP_INSTANCE_LOADS (instance) = sorted_loads;
   free (tmp_loads);
 
-  if (!vect_transform_slp_perm_load (stmt, vec<tree>(), NULL,
+  if (!vect_transform_slp_perm_load (stmt, vNULL, NULL,
                                      SLP_INSTANCE_UNROLLING_FACTOR (instance),
                                      instance, true))
     return false;
@@ -1705,8 +1705,8 @@ vect_analyze_slp (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo)
 {
   unsigned int i;
   vec<gimple> grouped_stores;
-  vec<gimple> reductions = vec<gimple>();
-  vec<gimple> reduc_chains = vec<gimple>();
+  vec<gimple> reductions = vNULL;
+  vec<gimple> reduc_chains = vNULL;
   gimple first_element;
   bool ok = false;