tree-optimization/121527 - wrong SRA with aggregate copy

SRA handles outermost VIEW_CONVERT_EXPRs but it wrongly ignores
those when building an access which leads to the wrong size
used when the VIEW_CONVERT_EXPR does not have the same size as
its operand which is valid GENERIC and is used by Ada upcasting.

	PR tree-optimization/121527
	* tree-sra.cc (build_access_from_expr_1): Do not strip an
	outer VIEW_CONVERT_EXPR as it's relevant for the size of
	the access.
	(get_access_for_expr): Likewise.

(cherry picked from commit 1d0a0173cd3e48f1c7c7e98893d440527fc198d0)

diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
index aac5d733aa7b503706a5a9f6c6ef62ddb24bf7b4..a0106085ebc255c5400e69324bab5d41ad3fe7ab 100644 (file)
--- a/gcc/tree-sra.cc
+++ b/gcc/tree-sra.cc
@@ -1291,19 +1291,16 @@ build_access_from_expr_1 (tree expr, gimple *stmt, bool write)
       return NULL;
     }
 
-  /* We need to dive through V_C_Es in order to get the size of its parameter
-     and not the result type.  Ada produces such statements.  We are also
-     capable of handling the topmost V_C_E but not any of those buried in other
-     handled components.  */
-  if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
-    expr = TREE_OPERAND (expr, 0);
-
-  if (contains_view_convert_expr_p (expr))
+  /* We are capable of handling the topmost V_C_E but not any of those
+     buried in other handled components.  */
+  if (contains_view_convert_expr_p (TREE_CODE (expr) == VIEW_CONVERT_EXPR
+                                   ? TREE_OPERAND (expr, 0) : expr))
     {
       disqualify_base_of_expr (expr, "V_C_E under a different handled "
                               "component.");
       return NULL;
     }
+
   if (TREE_THIS_VOLATILE (expr))
     {
       disqualify_base_of_expr (expr, "part of a volatile reference.");
@@ -1323,6 +1320,7 @@ build_access_from_expr_1 (tree expr, gimple *stmt, bool write)
     case ARRAY_REF:
     case ARRAY_RANGE_REF:
     case BIT_FIELD_REF:
+    case VIEW_CONVERT_EXPR:
       ret = create_access (expr, stmt, write);
       break;
 
@@ -4086,12 +4084,6 @@ get_access_for_expr (tree expr)
   tree base;
   bool reverse;
 
-  /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
-     a different size than the size of its argument and we need the latter
-     one.  */
-  if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
-    expr = TREE_OPERAND (expr, 0);
-
   base = get_ref_base_and_extent (expr, &poffset, &psize, &pmax_size,
                                  &reverse);
   if (!known_size_p (pmax_size)