re PR middle-end/42834 (memcpy folding overeager)

[thirdparty/gcc.git] / gcc / tree-scalar-evolution.c

diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c
index 13d897fd5ced418451fdc7f2bf709638288ac261..0e372567c8954e677e03026b93ac80b13d7dadd8 100644 (file)
--- a/gcc/tree-scalar-evolution.c
+++ b/gcc/tree-scalar-evolution.c
@@ -1170,6 +1170,24 @@ follow_ssa_edge_expr (struct loop *loop, gimple at_stmt, tree expr,
                                    halting_phi, evolution_of_loop, limit);
       break;
 
+    case ADDR_EXPR:
+      /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR.  */
+      if (TREE_CODE (TREE_OPERAND (expr, 0)) == MEM_REF)
+       {
+         expr = TREE_OPERAND (expr, 0);
+         rhs0 = TREE_OPERAND (expr, 0);
+         rhs1 = TREE_OPERAND (expr, 1);
+         type = TREE_TYPE (rhs0);
+         STRIP_USELESS_TYPE_CONVERSION (rhs0);
+         STRIP_USELESS_TYPE_CONVERSION (rhs1);
+         res = follow_ssa_edge_binary (loop, at_stmt, type,
+                                       rhs0, POINTER_PLUS_EXPR, rhs1,
+                                       halting_phi, evolution_of_loop, limit);
+       }
+      else
+       res = t_false;
+      break;
+
     case ASSERT_EXPR:
       /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>"
         It must be handled as a copy assignment of the form a_1 = a_2.  */