From 214d514fafcd78cd54e4a4aa9ae08c89abf9cc57 Mon Sep 17 00:00:00 2001
From: Aldy Hernandez <aldyh@redhat.com>
Date: Thu, 8 Oct 2020 11:15:23 +0200
Subject: [PATCH] Fix PR97315 (part 1 of 2)

gcc/ChangeLog:

	PR tree-optimization/97315
	* gimple-ssa-evrp.c (hybrid_folder::choose_value): Removes the
	trap and instead annotates the listing.

gcc/testsuite/ChangeLog:

	* gcc.dg/pr97315-1.c: New test.
---
 gcc/gimple-ssa-evrp.c            | 48 ++++++++++++++++++--------------
 gcc/testsuite/gcc.dg/pr97315-1.c | 27 ++++++++++++++++++
 2 files changed, 54 insertions(+), 21 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr97315-1.c

diff --git a/gcc/gimple-ssa-evrp.c b/gcc/gimple-ssa-evrp.c
index 363e2ab6816..7688e4aa4bd 100644
--- a/gcc/gimple-ssa-evrp.c
+++ b/gcc/gimple-ssa-evrp.c
@@ -258,37 +258,43 @@ hybrid_folder::value_of_stmt (gimple *stmt, tree op)
 tree
 hybrid_folder::choose_value (tree evrp_val, tree ranger_val)
 {
-  if (!ranger_val)
-    {
-      // If neither returned a value, return NULL_TREE.
-      if (!evrp_val)
-	return NULL_TREE;
+  // If both found the same value, just return it.
+  if (evrp_val && ranger_val && !compare_values (evrp_val, ranger_val))
+    return evrp_val;
+
+  // If neither returned a value, return NULL_TREE.
+  if (!ranger_val && !evrp_val)
+    return NULL_TREE;
 
-      // Otherwise EVRP found something.
-      if (dump_file)
+  // Otherwise there is a discrepancy to flag.
+  if (dump_file)
+    {
+      if (evrp_val && ranger_val)
+	fprintf (dump_file, "EVRP:hybrid: Disagreement\n");
+      if (evrp_val)
 	{
 	  fprintf (dump_file, "EVRP:hybrid: EVRP found singleton ");
 	  print_generic_expr (dump_file, evrp_val);
 	  fprintf (dump_file, "\n");
 	}
-      return evrp_val;
+      if (ranger_val)
+	{
+	  fprintf (dump_file, "EVRP:hybrid: RVRP found singleton ");
+	  print_generic_expr (dump_file, ranger_val);
+	  fprintf (dump_file, "\n");
+	}
     }
 
-  // Otherwise ranger found a value, if they match we're good.
-  if (evrp_val && !compare_values (evrp_val, ranger_val))
+  // If one value was found, return it.
+  if (!evrp_val)
+    return ranger_val;
+  if (!ranger_val)
     return evrp_val;
 
-  // We should never get different singletons.
-  gcc_checking_assert (!evrp_val);
-
-  // Now ranger has found a value, but EVRP did not.
-  if (dump_file)
-    {
-      fprintf (dump_file, "EVRP:hybrid: RVRP found singleton ");
-      print_generic_expr (dump_file, ranger_val);
-      fprintf (dump_file, "\n");
-    }
-  return ranger_val;
+  // If values are different, return the first calculated value.
+  if ((param_evrp_mode & EVRP_MODE_RVRP_FIRST) == EVRP_MODE_RVRP_FIRST)
+    return ranger_val;
+  return evrp_val;
 }
 
 /* Main entry point for the early vrp pass which is a simplified non-iterative
diff --git a/gcc/testsuite/gcc.dg/pr97315-1.c b/gcc/testsuite/gcc.dg/pr97315-1.c
new file mode 100644
index 00000000000..250e0e9ecbb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr97315-1.c
@@ -0,0 +1,27 @@
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+typedef struct tree_node *tree;
+enum tree_code { RECORD_TYPE, QUAL_UNION_TYPE };
+enum tree_code_class {};
+struct tree_base {
+  tree_code code : 16;
+};
+struct tree_node {
+  tree_base base;
+};
+extern tree_code_class tree_code_type[];
+void tree_check_failed() __attribute__((__noreturn__));
+tree tree_check3(tree __t, tree_code __c1, tree_code __c3) {
+  if (__t->base.code != __c1 && __t->base.code != __c3)
+    tree_check_failed();
+  return __t;
+}
+tree add_type_duplicate_type;
+void add_type_duplicate() {
+  if (tree_code_type[add_type_duplicate_type->base.code])
+    if (add_type_duplicate_type->base.code == RECORD_TYPE)
+      for (;
+           tree_check3(add_type_duplicate_type, RECORD_TYPE, QUAL_UNION_TYPE);)
+        tree_check3(add_type_duplicate_type, RECORD_TYPE, QUAL_UNION_TYPE);
+}
-- 
2.30.2