Improve -fopt-info-vec for basic-block vectorization

We currently dump notes like

flow_lam.f:65:72: optimized: basic block part vectorized using 32 byte vectors
flow_lam.f:65:72: optimized: basic block part vectorized using 32 byte vectors
flow_lam.f:65:72: optimized: basic block part vectorized using 32 byte vectors
flow_lam.f:65:72: optimized: basic block part vectorized using 32 byte vectors
..

repeating the same location for multiple instances because we
clobber vect_location during BB vectorization.  The following
avoids this, improving things to

flow_lam.f:15:72: optimized: basic block part vectorized using 32 byte vectors
flow_lam.f:16:72: optimized: basic block part vectorized using 32 byte vectors
flow_lam.f:17:72: optimized: basic block part vectorized using 32 byte vectors
flow_lam.f:18:72: optimized: basic block part vectorized using 32 byte vectors
...

	* tree-vect-slp.cc (vect_slp_region): Save/restore vect_location
	around dumping code.

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index a1b153035e100867814d6c9ef1fbfce6ccdcab2c..eab3dcd40ec1aed00941affccf0f26c5a703f382 100644 (file)
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -7496,6 +7496,7 @@ vect_slp_region (vec<basic_block> bbs, vec<data_reference_p> datarefs,
              if (instance->subgraph_entries.is_empty ())
                continue;
 
+             dump_user_location_t saved_vect_location = vect_location;
              vect_location = instance->location ();
              if (!unlimited_cost_model (NULL)
                  && !vect_bb_vectorization_profitable_p
@@ -7505,9 +7506,11 @@ vect_slp_region (vec<basic_block> bbs, vec<data_reference_p> datarefs,
                    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
                                     "not vectorized: vectorization is not "
                                     "profitable.\n");
+                 vect_location = saved_vect_location;
                  continue;
                }
 
+             vect_location = saved_vect_location;
              if (!dbg_cnt (vect_slp))
                continue;
 
@@ -7557,6 +7560,9 @@ vect_slp_region (vec<basic_block> bbs, vec<data_reference_p> datarefs,
                                 "using SLP\n");
              vectorized = true;
 
+             dump_user_location_t saved_vect_location = vect_location;
+             vect_location = instance->location ();
+
              vect_schedule_slp (bb_vinfo, instance->subgraph_entries);
 
              unsigned HOST_WIDE_INT bytes;
@@ -7572,6 +7578,8 @@ vect_slp_region (vec<basic_block> bbs, vec<data_reference_p> datarefs,
                                     "basic block part vectorized using "
                                     "variable length vectors\n");
                }
+
+             vect_location = saved_vect_location;
            }
        }
       else