Fail early when SLP instance build fails

The following makes us fail earlier when parts of the SLP build fails.
Currently we rely on hybrid stmt detection later to discover not all
stmts are covered by SLP, but this code should go away.  I've also
seen a case of a missed gcond SLP build that went undetected.  So
the following makes us fail during vect_analyze_slp if any of the
SLP instances we expect to discover fails.

	* tree-vect-slp.cc (vect_analyze_slp): When analyzing a loop
	and slp instance discovery fails, immediately fail the whole
	process.

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index ca14a2deed2b97918c61ae670856221bee1f3e5e..3f3a509ff30114d0b6ac10ae89e883d6d30d73bc 100644 (file)
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -4888,9 +4888,11 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
 
   /* Find SLP sequences starting from groups of grouped stores.  */
   FOR_EACH_VEC_ELT (vinfo->grouped_stores, i, first_element)
-    vect_analyze_slp_instance (vinfo, bst_map, first_element,
-                              slp_inst_kind_store, max_tree_size, &limit,
-                              force_single_lane);
+    if (! vect_analyze_slp_instance (vinfo, bst_map, first_element,
+                                    slp_inst_kind_store, max_tree_size, &limit,
+                                    force_single_lane)
+       && loop_vinfo)
+      return opt_result::failure_at (vect_location, "SLP build failed.\n");
 
   /* For loops also start SLP discovery from non-grouped stores.  */
   if (loop_vinfo)
@@ -4908,9 +4910,12 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
            vec<tree> remain = vNULL;
            stmts.create (1);
            stmts.quick_push (stmt_info);
-           vect_build_slp_instance (vinfo, slp_inst_kind_store,
-                                    stmts, roots, remain, max_tree_size,
-                                    &limit, bst_map, NULL, force_single_lane);
+           if (! vect_build_slp_instance (vinfo, slp_inst_kind_store,
+                                          stmts, roots, remain, max_tree_size,
+                                          &limit, bst_map, NULL,
+                                          force_single_lane))
+             return opt_result::failure_at (vect_location,
+                                            "SLP build failed.\n");
          }
     }
 
@@ -5002,12 +5007,14 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
                      vec<tree> remain = vNULL;
                      stmts.create (1);
                      stmts.quick_push (next_info);
-                     vect_build_slp_instance (vinfo,
-                                              slp_inst_kind_reduc_group,
-                                              stmts, roots, remain,
-                                              max_tree_size, &limit,
-                                              bst_map, NULL,
-                                              force_single_lane);
+                     if (! vect_build_slp_instance (vinfo,
+                                                    slp_inst_kind_reduc_group,
+                                                    stmts, roots, remain,
+                                                    max_tree_size, &limit,
+                                                    bst_map, NULL,
+                                                    force_single_lane))
+                       return opt_result::failure_at (vect_location,
+                                                      "SLP build failed.\n");
                    }
                }
            }
@@ -5032,11 +5039,14 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
                  vec<tree> remain = vNULL;
                  stmts.create (1);
                  stmts.quick_push (vect_stmt_to_vectorize (stmt_info));
-                 vect_build_slp_instance (vinfo,
-                                          slp_inst_kind_reduc_group,
-                                          stmts, roots, remain,
-                                          max_tree_size, &limit,
-                                          bst_map, NULL, force_single_lane);
+                 if (! vect_build_slp_instance (vinfo,
+                                                slp_inst_kind_reduc_group,
+                                                stmts, roots, remain,
+                                                max_tree_size, &limit,
+                                                bst_map, NULL,
+                                                force_single_lane))
+                   return opt_result::failure_at (vect_location,
+                                                  "SLP build failed.\n");
                }
            }
          saved_stmts.release ();
@@ -5065,11 +5075,14 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
                vec<tree> remain = vNULL;
                stmts.create (1);
                stmts.quick_push (vect_stmt_to_vectorize (stmt_info));
-               vect_build_slp_instance (vinfo,
-                                        slp_inst_kind_reduc_group,
-                                        stmts, roots, remain,
-                                        max_tree_size, &limit,
-                                        bst_map, NULL, force_single_lane);
+               if (! vect_build_slp_instance (vinfo,
+                                              slp_inst_kind_reduc_group,
+                                              stmts, roots, remain,
+                                              max_tree_size, &limit,
+                                              bst_map, NULL,
+                                              force_single_lane))
+                 return opt_result::failure_at (vect_location,
+                                                "SLP build failed.\n");
              }
          }
 
@@ -5092,7 +5105,8 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
              || !integer_zerop (args1))
            {
              roots.release ();
-             continue;
+             return opt_result::failure_at (vect_location,
+                                            "SLP build failed.\n");
            }
 
          /* An argument without a loop def will be codegened from vectorizing the
@@ -5110,7 +5124,11 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
                                         stmts, roots, remain,
                                         max_tree_size, &limit,
                                         bst_map, NULL, force_single_lane))
-           roots.release ();
+           {
+             roots.release ();
+             return opt_result::failure_at (vect_location,
+                                            "SLP build failed.\n");
+           }
        }
 
        /* Find and create slp instances for inductions that have been forced
@@ -5128,10 +5146,13 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
              {
                stmts.create (1);
                stmts.quick_push (vect_stmt_to_vectorize (lc_info));
-               vect_build_slp_instance (vinfo, slp_inst_kind_reduc_group,
-                                        stmts, roots, remain,
-                                        max_tree_size, &limit,
-                                        bst_map, NULL, force_single_lane);
+               if (! vect_build_slp_instance (vinfo, slp_inst_kind_reduc_group,
+                                              stmts, roots, remain,
+                                              max_tree_size, &limit,
+                                              bst_map, NULL,
+                                              force_single_lane))
+                 return opt_result::failure_at (vect_location,
+                                                "SLP build failed.\n");
              }
            /* When the latch def is from a different cycle this can only
               be a induction.  Build a simple instance for this.
@@ -5144,10 +5165,13 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
              {
                stmts.create (1);
                stmts.quick_push (stmt_info);
-               vect_build_slp_instance (vinfo, slp_inst_kind_reduc_group,
-                                        stmts, roots, remain,
-                                        max_tree_size, &limit,
-                                        bst_map, NULL, force_single_lane);
+               if (! vect_build_slp_instance (vinfo, slp_inst_kind_reduc_group,
+                                              stmts, roots, remain,
+                                              max_tree_size, &limit,
+                                              bst_map, NULL,
+                                              force_single_lane))
+                 return opt_result::failure_at (vect_location,
+                                                "SLP build failed.\n");
              }
          }
     }