On Fri, Oct 9, 2015 at 7:36 AM, Alexandre Oliva <aol...@redhat.com> wrote:
> This fixes fallout from the PR64164 expander revamp. On alpha, PARALLEL
> hard return values may be modeless, and this confuses the code that
> wants to copy the pseudo/s in the returned value to the return hard
> regs.
>
> It used to work because PARALLELs and CONCATs used to lead to DECL_RTL
> with the same mode, but now we try harder to create a pseudo or MEM with
> a reasonable mode.
>
> The solution was as simple as moving down the code that handled mode
> differences, so that PARALLELs and CONCATs are handled as they should.
> Since AFAICT they don't ever have to deal with mode promotion anyway, we
> should be fine with this simple change, that Uroš kindly tested with an
> alpha-linux-gnu regstrap. I tested it myself on x86_64-linux-gnu and
> i686-linux-gnu.
>
> Ok to install?
Ok.
Richard.
>
> [PR67766] reorder handling of parallels, concats and promoted values in return
>
> From: Alexandre Oliva <aol...@redhat.com>
>
> for gcc/ChangeLog
>
> PR middle-end/67766
> * function.c (expand_function_end): Move return value
> promotion past the handling of PARALLELs and CONCATs.
> ---
> gcc/function.c | 24 ++++++++++++------------
> 1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/gcc/function.c b/gcc/function.c
> index e76ba2b..d16d6d8 100644
> --- a/gcc/function.c
> +++ b/gcc/function.c
> @@ -5446,18 +5446,6 @@ expand_function_end (void)
> decl_rtl);
> shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
> }
> - /* If a named return value dumped decl_return to memory, then
> - we may need to re-do the PROMOTE_MODE signed/unsigned
> - extension. */
> - else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
> - {
> - int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
> - promote_function_mode (TREE_TYPE (decl_result),
> - GET_MODE (decl_rtl), &unsignedp,
> - TREE_TYPE (current_function_decl), 1);
> -
> - convert_move (real_decl_rtl, decl_rtl, unsignedp);
> - }
> else if (GET_CODE (real_decl_rtl) == PARALLEL)
> {
> /* If expand_function_start has created a PARALLEL for decl_rtl,
> @@ -5488,6 +5476,18 @@ expand_function_end (void)
> emit_move_insn (tmp, decl_rtl);
> emit_move_insn (real_decl_rtl, tmp);
> }
> + /* If a named return value dumped decl_return to memory, then
> + we may need to re-do the PROMOTE_MODE signed/unsigned
> + extension. */
> + else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
> + {
> + int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
> + promote_function_mode (TREE_TYPE (decl_result),
> + GET_MODE (decl_rtl), &unsignedp,
> + TREE_TYPE (current_function_decl), 1);
> +
> + convert_move (real_decl_rtl, decl_rtl, unsignedp);
> + }
> else
> emit_move_insn (real_decl_rtl, decl_rtl);
> }
>
>
> --
> Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
> You must be the change you wish to see in the world. -- Gandhi
> Be Free! -- http://FSFLA.org/ FSF Latin America board member
> Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer
