re PR tree-optimization/82397 (qsort comparator non-negative on sorted output: 1...

2017-10-09  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/82397
	* tree-data-ref.c (data_ref_compare_tree): Make sure to return
	equality only for semantically equal trees.

From-SVN: r253547

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 44ca159117a1c402ef96468f96fbdb11229dc36a..26e6063130102f02fbb2179bb1d1e909b874c48f 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-10-09  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/82397
+       * tree-data-ref.c (data_ref_compare_tree): Make sure to return
+       equality only for semantically equal trees.
+
 2017-10-09  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/82449

diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index a414fbfe0f2a00c80073ee3fc69b7701788fe1ee..72cc8de59e875847956e7320be8d610883e57468 100644 (file)
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -1207,35 +1207,28 @@ data_ref_compare_tree (tree t1, tree t2)
   if (t2 == NULL)
     return 1;
 
-  STRIP_NOPS (t1);
-  STRIP_NOPS (t2);
+  STRIP_USELESS_TYPE_CONVERSION (t1);
+  STRIP_USELESS_TYPE_CONVERSION (t2);
+  if (t1 == t2)
+    return 0;
 
-  if (TREE_CODE (t1) != TREE_CODE (t2))
+  if (TREE_CODE (t1) != TREE_CODE (t2)
+      && ! (CONVERT_EXPR_P (t1) && CONVERT_EXPR_P (t2)))
     return TREE_CODE (t1) < TREE_CODE (t2) ? -1 : 1;
 
   code = TREE_CODE (t1);
   switch (code)
     {
-    /* For const values, we can just use hash values for comparisons.  */
     case INTEGER_CST:
-    case REAL_CST:
-    case FIXED_CST:
+      return tree_int_cst_compare (t1, t2);
+
     case STRING_CST:
-    case COMPLEX_CST:
-    case VECTOR_CST:
-      {
-       hashval_t h1 = iterative_hash_expr (t1, 0);
-       hashval_t h2 = iterative_hash_expr (t2, 0);
-       if (h1 != h2)
-         return h1 < h2 ? -1 : 1;
-       break;
-      }
+      if (TREE_STRING_LENGTH (t1) != TREE_STRING_LENGTH (t2))
+       return TREE_STRING_LENGTH (t1) < TREE_STRING_LENGTH (t2) ? -1 : 1;
+      return memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
+                    TREE_STRING_LENGTH (t1));
 
     case SSA_NAME:
-      cmp = data_ref_compare_tree (SSA_NAME_VAR (t1), SSA_NAME_VAR (t2));
-      if (cmp != 0)
-       return cmp;
-
       if (SSA_NAME_VERSION (t1) != SSA_NAME_VERSION (t2))
        return SSA_NAME_VERSION (t1) < SSA_NAME_VERSION (t2) ? -1 : 1;
       break;
@@ -1243,22 +1236,26 @@ data_ref_compare_tree (tree t1, tree t2)
     default:
       tclass = TREE_CODE_CLASS (code);
 
-      /* For var-decl, we could compare their UIDs.  */
+      /* For decls, compare their UIDs.  */
       if (tclass == tcc_declaration)
        {
          if (DECL_UID (t1) != DECL_UID (t2))
            return DECL_UID (t1) < DECL_UID (t2) ? -1 : 1;
          break;
        }
-
-      /* For expressions with operands, compare their operands recursively.  */
-      for (i = TREE_OPERAND_LENGTH (t1) - 1; i >= 0; --i)
+      /* For expressions, compare their operands recursively.  */
+      else if (IS_EXPR_CODE_CLASS (tclass))
        {
-         cmp = data_ref_compare_tree (TREE_OPERAND (t1, i),
-                                      TREE_OPERAND (t2, i));
-         if (cmp != 0)
-           return cmp;
+         for (i = TREE_OPERAND_LENGTH (t1) - 1; i >= 0; --i)
+           {
+             cmp = data_ref_compare_tree (TREE_OPERAND (t1, i),
+                                          TREE_OPERAND (t2, i));
+             if (cmp != 0)
+               return cmp;
+           }
        }
+      else
+       gcc_unreachable ();
     }
 
   return 0;