[gcc r17-2620] Fix SLP scheduling in-region check

https://gcc.gnu.org/g:6581a831fd548819097b1172b9488cd7c7d82a41

commit r17-2620-g6581a831fd548819097b1172b9488cd7c7d82a41
Author: Richard Biener <[email protected]>
Date:   Wed Jul 22 12:58:47 2026 +0200

    Fix SLP scheduling in-region check
    
    This corrects assessing whether a stmt is inside the vector region,
    checking random stmt UIDs against -1 does not work for loop vectorization.
    
            * tree-vect-slp.cc (vect_schedule_slp_node): Correct in-region
            stmt check.

Diff:
---
 gcc/tree-vect-slp.cc | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index fe406a4cb6a4..7cb0c749fa32 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -11953,15 +11953,12 @@ vect_schedule_slp_node (vec_info *vinfo,
 	    unsigned j;
 	    tree def;
 	    FOR_EACH_VEC_ELT (SLP_TREE_SCALAR_OPS (child), j, def)
-	      if (TREE_CODE (def) == SSA_NAME
-		  && !SSA_NAME_IS_DEFAULT_DEF (def))
+	      /* If the stmt is not inside the region do not
+		 use it as possible insertion point.  */
+	      if (auto stmt_info = vinfo->lookup_def (def))
 		{
-		  gimple *stmt = SSA_NAME_DEF_STMT (def);
-		  if (gimple_uid (stmt) == -1u)
-		    /* If the stmt is not inside the region do not
-		       use it as possible insertion point.  */
-		    ;
-		  else if (!last_stmt)
+		  gimple *stmt = stmt_info->stmt;
+		  if (!last_stmt)
 		    last_stmt = stmt;
 		  else if (vect_stmt_dominates_stmt_p (last_stmt, stmt))
 		    last_stmt = stmt;