Re: [PATCH v2] xtensa: Optimize stack frame adjustment more

[Max Filippov <jcmvbkbc@gmail.com>]

On Fri, Jan 6, 2023 at 6:55 PM Takayuki 'January June' Suwa
<jjsuwa_sys3175@yahoo.co.jp> wrote:
>
> This patch introduces a convenient helper function for integer immediate
> addition with scratch register as needed, that splits and emits either
> up to two ADDI/ADDMI machine instructions or an addition by register
> following an integer immediate load (which may later be transformed by
> constantsynth).
>
> By using the helper function, it makes stack frame adjustment logic
> simplified and instruction count less in some cases.
>
> gcc/ChangeLog:
>
>         * config/xtensa/xtensa.cc
>         (xtensa_split_imm_two_addends, xtensa_emit_add_imm):
>         New helper functions.
>         (xtensa_set_return_address, xtensa_output_mi_thunk):
>         Change to use the helper function.
>         (xtensa_emit_adjust_stack_ptr): Ditto.
>         And also change to try reusing the content of scratch register
>         A9 if the register is not modified in the function body.
> ---
>  gcc/config/xtensa/xtensa.cc | 151 +++++++++++++++++++++++++-----------
>  1 file changed, 106 insertions(+), 45 deletions(-)

Regtested for target=xtensa-linux-uclibc, no new regressions.
Committed to master.

-- 
Thanks.
-- Max