re PR tree-optimization/92461 (ICE: verify_ssa failed (error: excess use operand for statement))

2019-11-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/92461
	* tree-vect-loop.c (vect_create_epilog_for_reduction): Update
	stmt after propagation.

	* gcc.dg/torture/pr92461.c: New testcase.

From-SVN: r278093

gcc/ChangeLog

+2019-11-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/92461
+	* tree-vect-loop.c (vect_create_epilog_for_reduction): Update
+	stmt after propagation.
+
 2019-11-12  Martin Liska  <mliska@suse.cz>
 
 	* config/i386/i386-options.c (ix86_recompute_optlev_based_flags):

gcc/testsuite/ChangeLog

+2019-11-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/92461
+	* gcc.dg/torture/pr92461.c: New testcase.
+
 2019-11-12  Martin Liska  <mliska@suse.cz>
 
 	* gcc.dg/completion-3.c: Append = to all expected

gcc/testsuite/gcc.dg/torture/pr92461.c

+/* { dg-do compile } */
+/* { dg-additional-options "-ftree-vectorize" } */
+
+short int zb;
+
+void
+gs (void)
+{
+  while (zb < 1)
+    {
+      int at;
+
+      zb %= 1;
+
+      for (at = 0; at < 56; ++at)
+	zb += zb;
+
+      ++zb;
+    }
+}

gcc/tree-vect-loop.c

@@ -5299,8 +5299,11 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
           orig_name = PHI_RESULT (exit_phi);
           scalar_result = scalar_results[k];
           FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, orig_name)
-            FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
-              SET_USE (use_p, scalar_result);
+	    {
+	      FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
+		SET_USE (use_p, scalar_result);
+	      update_stmt (use_stmt);
+	    }
         }
 
       phis.release ();