[gcc r13-2060] xtensa: Turn on -fsplit-wide-types-early by default

[gcc r13-2060] xtensa: Turn on -fsplit-wide-types-early by default

[Max Filippov]

https://gcc.gnu.org/g:a2ff389099c325bc1244b1d72744a18c5fa6fda3

commit r13-2060-ga2ff389099c325bc1244b1d72744a18c5fa6fda3
Author: Takayuki 'January June' Suwa <jjsuwa_sys3175@yahoo.co.jp>
Date:   Sun Aug 14 18:29:33 2022 +0900

    xtensa: Turn on -fsplit-wide-types-early by default
    
    Since GCC10, the "subreg2" optimization pass was no longer tied to enabling
    "subreg1" unless -fsplit-wide-types-early was turned on (PR88233).  However
    on the Xtensa port, the lack of "subreg2" can degrade the quality of the
    output code, especially for those that produce many D[FC]mode pseudos.
    
    This patch turns on -fsplit-wide-types-early by default in order to restore
    the previous behavior.
    
    gcc/ChangeLog:
    
            * common/config/xtensa/xtensa-common.cc
            (xtensa_option_optimization_table): Add OPT_fsplit_wide_types_early
            for OPT_LEVELS_ALL in order to restore pre-GCC10 behavior.

Diff:
---
 gcc/common/config/xtensa/xtensa-common.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcc/common/config/xtensa/xtensa-common.cc b/gcc/common/config/xtensa/xtensa-common.cc
index fbbe9b0aad7..0f27763aa71 100644
--- a/gcc/common/config/xtensa/xtensa-common.cc
+++ b/gcc/common/config/xtensa/xtensa-common.cc
@@ -34,6 +34,8 @@ static const struct default_options xtensa_option_optimization_table[] =
        assembler, so GCC cannot do a good job of reordering blocks.
        Do not enable reordering unless it is explicitly requested.  */
     { OPT_LEVELS_ALL, OPT_freorder_blocks, NULL, 0 },
+    /* Split multi-word types early (pre-GCC10 behavior).  */
+    { OPT_LEVELS_ALL, OPT_fsplit_wide_types_early, NULL, 1 },
     { OPT_LEVELS_NONE, 0, NULL, 0 }
   };