Hi,
On Mon, Aug 18 2025, Richard Biener wrote:
> 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.
>
> Bootstrapped on x86_64-unknown-linux-gnu with all languages enabled,
> testing in progress.
>
> OK if that went OK?
Unfortunately i don't remember what the exact issue with Ada was in
2009. I'll be happy to get rid of the special-casing in this way if we
can.
Thanks for looking into the issue while I was away.
Martin
>
> Thanks,
> Richard.
>
> 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.
> ---
> gcc/tree-sra.cc | 20 ++++++--------------
> 1 file changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
> index 032f2770484..24ed2b2aea0 100644
> --- 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)
> --
> 2.43.0
