* tree-affine.c (tree_to_aff_combination): Handle (T1)(X + X).

From-SVN: r248956

gcc/ChangeLog

 2017-06-07  Bin Cheng  <bin.cheng@arm.com>
 
+	* tree-affine.c (tree_to_aff_combination): Handle (T1)(X + X).
+
+2017-06-07  Bin Cheng  <bin.cheng@arm.com>
+
 	(aff_combination_expand): Move (T1)(X *+- CST) simplification to ...
 	(tree_to_aff_combination): ... here.
 

gcc/tree-affine.c

@@ -375,19 +375,26 @@ tree_to_aff_combination (tree expr, tree type, aff_tree *comb)
 	if ((icode == PLUS_EXPR || icode == MINUS_EXPR || icode == MULT_EXPR)
 	    && TREE_CODE (itype) == INTEGER_TYPE
 	    && TREE_CODE (otype) == INTEGER_TYPE
-	    && TYPE_PRECISION (otype) > TYPE_PRECISION (itype)
-	    && TYPE_OVERFLOW_UNDEFINED (itype)
-	    && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST)
-	  {
-	    /* Convert (T1)(X *+- CST) into (T1)X *+- (T1)CST if X's type has
-	       undefined overflow behavior.  */
-	    tree op0 = fold_convert (otype, TREE_OPERAND (inner, 0));
-	    tree op1 = fold_convert (otype, TREE_OPERAND (inner, 1));
+	    && TYPE_PRECISION (otype) > TYPE_PRECISION (itype))
+	  {
+	    tree op0 = TREE_OPERAND (inner, 0), op1 = TREE_OPERAND (inner, 1);
+
+	    /* If inner type has undefined overflow behavior, fold conversion
+	       for below two cases:
+		 (T1)(X *+- CST) -> (T1)X *+- (T1)CST
+		 (T1)(X + X)     -> (T1)X + (T1)X.  */
+	    if (TYPE_OVERFLOW_UNDEFINED (itype)
+		&& (TREE_CODE (op1) == INTEGER_CST
+		    || (icode == PLUS_EXPR && operand_equal_p (op0, op1, 0))))
+	      {
+		op0 = fold_convert (otype, op0);
+		op1 = fold_convert (otype, op1);
 		expr = fold_build2 (icode, otype, op0, op1);
 		tree_to_aff_combination (expr, type, comb);
 		return;
 	      }
 	  }
+      }
       break;
 
     default: