tree-optimization/95272 - add SLP_TREE_REPRESENTATIVE

diff --git a/gcc/testsuite/gcc.dg/vect/pr95272.c b/gcc/testsuite/gcc.dg/vect/pr95272.c
new file mode 100644
index 00000000000..47698ff3e56
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr95272.c
@@ -0,0 +1,18 @@ 
+/* { dg-do compile } */
+
+enum { a = 5, b };
+typedef struct {
+  int c[b];
+} d;
+extern d e[];
+int f;
+int g[6];
+void h() {
+  int i;
+  for (; f; f++) {
+    i = 0;
+    for (; i < b; i++)
+      if (e[f].c[i])
+        g[i] = e[f].c[i];
+  }
+}
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 4f94b4baad9..3c5c0ea9ebc 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -6192,9 +6192,9 @@  vectorizable_reduction (loop_vec_info loop_vinfo,
     {
       slp_for_stmt_info = slp_node_instance->root;
       /* And then there's reduction chain with a conversion ...  */
-      if (SLP_TREE_SCALAR_STMTS (slp_for_stmt_info)[0] != stmt_info)
+      if (SLP_TREE_REPRESENTATIVE (slp_for_stmt_info) != stmt_info)
 	slp_for_stmt_info = SLP_TREE_CHILDREN (slp_for_stmt_info)[0];
-      gcc_assert (SLP_TREE_SCALAR_STMTS (slp_for_stmt_info)[0] == stmt_info);
+      gcc_assert (SLP_TREE_REPRESENTATIVE (slp_for_stmt_info) == stmt_info);
     }
   slp_tree *slp_op = XALLOCAVEC (slp_tree, op_type);
   for (i = 0; i < op_type; i++)
@@ -7952,6 +7952,10 @@  vectorizable_live_operation (loop_vec_info loop_vinfo,
 	     all involved stmts together.  */
 	  else if (slp_index != 0)
 	    return true;
+	  else
+	    /* For SLP reductions the meta-info is attached to
+	       the representative.  */
+	    stmt_info = SLP_TREE_REPRESENTATIVE (slp_node);
 	}
       stmt_vec_info reduc_info = info_for_reduction (loop_vinfo, stmt_info);
       gcc_assert (reduc_info->is_reduc_info);
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 5976e91cf62..836defce990 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -61,6 +61,7 @@  _slp_tree::_slp_tree ()
   SLP_TREE_TWO_OPERATORS (this) = false;
   SLP_TREE_DEF_TYPE (this) = vect_uninitialized_def;
   SLP_TREE_VECTYPE (this) = NULL_TREE;
+  SLP_TREE_REPRESENTATIVE (this) = NULL;
   this->refcnt = 1;
   this->max_nunits = 1;
 }
@@ -132,6 +133,7 @@  vect_create_new_slp_node (vec<stmt_vec_info> scalar_stmts, unsigned nops)
   SLP_TREE_SCALAR_STMTS (node) = scalar_stmts;
   SLP_TREE_CHILDREN (node).create (nops);
   SLP_TREE_DEF_TYPE (node) = vect_internal_def;
+  SLP_TREE_REPRESENTATIVE (node) = scalar_stmts[0];
 
   unsigned i;
   stmt_vec_info stmt_info;
@@ -1741,6 +1743,7 @@  slp_copy_subtree (slp_tree node, hash_map<slp_tree, slp_tree> &map)
   slp_tree copy = copy_ref;
   SLP_TREE_DEF_TYPE (copy) = SLP_TREE_DEF_TYPE (node);
   SLP_TREE_VECTYPE (copy) = SLP_TREE_VECTYPE (node);
+  SLP_TREE_REPRESENTATIVE (copy) = SLP_TREE_REPRESENTATIVE (node);
   copy->max_nunits = node->max_nunits;
   copy->refcnt = 0;
   if (SLP_TREE_SCALAR_STMTS (node).exists ())
@@ -1786,14 +1789,6 @@  vect_slp_rearrange_stmts (slp_tree node, unsigned int group_size,
   if (SLP_TREE_SCALAR_STMTS (node).exists ())
     {
       gcc_assert (group_size == SLP_TREE_SCALAR_STMTS (node).length ());
-      /* ???  Computation nodes are isomorphic and need no rearrangement.
-	 This is a quick hack to cover those where rearrangement breaks
-	 semantics because only the first stmt is guaranteed to have the
-	 correct operation code due to others being swapped or inverted.  */
-      stmt_vec_info first = SLP_TREE_SCALAR_STMTS (node)[0];
-      if (is_gimple_assign (first->stmt)
-	  && gimple_assign_rhs_code (first->stmt) == COND_EXPR)
-	return;
       vec<stmt_vec_info> tmp_stmts;
       tmp_stmts.create (group_size);
       tmp_stmts.quick_grow (group_size);
@@ -2664,7 +2659,7 @@  vect_slp_analyze_node_operations_1 (vec_info *vinfo, slp_tree node,
 				    slp_instance node_instance,
 				    stmt_vector_for_cost *cost_vec)
 {
-  stmt_vec_info stmt_info = SLP_TREE_SCALAR_STMTS (node)[0];
+  stmt_vec_info stmt_info = SLP_TREE_REPRESENTATIVE (node);
   gcc_assert (STMT_SLP_TYPE (stmt_info) != loop_vect);
 
   /* Calculate the number of vector statements to be created for the
@@ -4079,7 +4074,7 @@  vect_schedule_slp_instance (vec_info *vinfo,
 	  STMT_VINFO_DEF_TYPE (child_stmt_info) = SLP_TREE_DEF_TYPE (child);
       }
 
-  stmt_vec_info stmt_info = SLP_TREE_SCALAR_STMTS (node)[0];
+  stmt_vec_info stmt_info = SLP_TREE_REPRESENTATIVE (node);
 
   /* VECTYPE is the type of the destination.  */
   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
index 2bde71760e5..5a5648b3784 100644
--- a/gcc/tree-vectorizer.h
+++ b/gcc/tree-vectorizer.h
@@ -128,6 +128,9 @@  struct _slp_tree {
   vec<stmt_vec_info> stmts;
   /* A group of scalar operands to be vectorized together.  */
   vec<tree> ops;
+  /* The representative that should be used for analysis and
+     code generation.  */
+  stmt_vec_info representative;
 
   /* Load permutation relative to the stores, NULL if there is no
      permutation.  */
@@ -193,6 +196,7 @@  public:
 #define SLP_TREE_TWO_OPERATORS(S)		 (S)->two_operators
 #define SLP_TREE_DEF_TYPE(S)			 (S)->def_type
 #define SLP_TREE_VECTYPE(S)			 (S)->vectype
+#define SLP_TREE_REPRESENTATIVE(S)		 (S)->representative
 
 /* Key for map that records association between
    scalar conditions and corresponding loop mask, and