3 files changed, 63 insertions, 7 deletions
diff --git a/gcc/testsuite/gcc.dg/vect/pr107212-1.c b/gcc/testsuite/gcc.dg/vect/pr107212-1.c
new file mode 100644
index 0000000..5343f9b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr107212-1.c
@@ -0,0 +1,27 @@
+/* { dg-do run } */
+
+#include "tree-vect.h"
+
+int main()
+{
+  check_vect ();
+
+  unsigned int tab[6][2] = { {69, 73}, {36, 40}, {24, 16},
+        {16, 11}, {4, 5}, {3, 1} };
+
+  int sum_0 = 0;
+  int sum_1 = 0;
+
+  for(int t=0; t<6; t++) {
+      sum_0 += tab[t][0];
+      sum_1 += tab[t][1];
+  }
+
+  int x1 = (sum_0 < 100);
+  int x2 = (sum_0 > 200);
+
+  if (x1 || x2 || sum_1 != 146)
+    __builtin_abort ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/vect/pr107212-2.c b/gcc/testsuite/gcc.dg/vect/pr107212-2.c
new file mode 100644
index 0000000..109c2b9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr107212-2.c
@@ -0,0 +1,23 @@
+/* { dg-do run } */
+
+#include "tree-vect.h"
+
+int sum_1 = 0;
+
+int main()
+{
+  check_vect ();
+
+  unsigned int tab[6][2] = {{150, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}};
+  
+  int sum_0 = 0;
+  
+  for (int t = 0; t < 6; t++) {
+    sum_0 += tab[t][0];
+    sum_1 += tab[t][0];
+  }
+  
+  if (sum_0 < 100 || sum_0 > 200)
+    __builtin_abort();
+  return 0;
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 2536cc3..1996ecf 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -6822,10 +6822,20 @@ vectorizable_reduction (loop_vec_info loop_vinfo,
 	}
       if (!REDUC_GROUP_FIRST_ELEMENT (vdef))
 	only_slp_reduc_chain = false;
-      /* ???  For epilogue generation live members of the chain need
+      /* For epilogue generation live members of the chain need
          to point back to the PHI via their original stmt for
-	 info_for_reduction to work.  */
-      if (STMT_VINFO_LIVE_P (vdef))
+	 info_for_reduction to work.  For SLP we need to look at
+	 all lanes here - even though we only will vectorize from
+	 the SLP node with live lane zero the other live lanes also
+	 need to be identified as part of a reduction to be able
+	 to skip code generation for them.  */
+      if (slp_for_stmt_info)
+	{
+	  for (auto s : SLP_TREE_SCALAR_STMTS (slp_for_stmt_info))
+	    if (STMT_VINFO_LIVE_P (s))
+	      STMT_VINFO_REDUC_DEF (vect_orig_stmt (s)) = phi_info;
+	}
+      else if (STMT_VINFO_LIVE_P (vdef))
 	STMT_VINFO_REDUC_DEF (def) = phi_info;
       gimple_match_op op;
       if (!gimple_extract_op (vdef->stmt, &op))
@@ -9601,10 +9611,6 @@ vectorizable_live_operation (vec_info *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);