> Am 18.12.2024 um 14:35 schrieb Alexandre Oliva <ol...@adacore.com>:
>
> On Dec 17, 2024, Alexandre Oliva <ol...@adacore.com> wrote:
>
>> diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
>> index 92f02ddd77408..06913d57f8aec 100644
>> --- a/gcc/gimple-fold.cc
>> +++ b/gcc/gimple-fold.cc
>> @@ -7554,13 +7554,10 @@ decode_field_reference (tree *pexp, HOST_WIDE_INT
>> *pbitsize,
>> narrowing then widening casts, or vice-versa, for those that are not
>> essential for the compare have already been optimized out at this
>> point. */
>> - if (gimple_convert_def_p (exp, res_ops))
>> + if (!outer_type && gimple_convert_def_p (exp, res_ops))
>
> Oops, I failed to update the comment.
> Please consider it combined with this patchlet.
Ok
Richard
> diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
> index d8f0df97b8f53..9ee854bec4dc6 100644
> --- a/gcc/gimple-fold.cc
> +++ b/gcc/gimple-fold.cc
> @@ -7313,10 +7313,14 @@ decode_field_reference (tree *pexp, HOST_WIDE_INT
> *pbitsize,
> if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
> return NULL_TREE;
>
> - /* Drop casts, only save the outermost type. We need not worry about
> - narrowing then widening casts, or vice-versa, for those that are not
> - essential for the compare have already been optimized out at this
> - point. */
> + /* Drop casts, saving only the outermost type, effectively used in
> + the compare. We can deal with at most one conversion, and it may
> + appear at various points in the chain of recognized preparation
> + statements. Earlier optimizers will often have already dropped
> + unneeded extensions, but they may survive, as in PR118046. ???
> + Can we do better and allow multiple conversions, perhaps taking
> + note of the narrowest intermediate type, sign extensions and
> + whatnot? */
> if (!outer_type && gimple_convert_def_p (exp, res_ops))
> {
> outer_type = TREE_TYPE (exp);
>
>
> --
> Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
> Free Software Activist GNU Toolchain Engineer
> More tolerance and less prejudice are key for inclusion and diversity
> Excluding neuro-others for not behaving ""normal"" is *not* inclusive
