[Bug rtl-optimization/110587] [14 regression] 96% pr28071.c compile time regression since r14-2337-g37a231cc7594d1

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110587

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Roger Sayle <sayle@gcc.gnu.org>:

https://gcc.gnu.org/g:8125b12f846b41f26e58c0fe3b218d654f65d1c8

commit r14-2730-g8125b12f846b41f26e58c0fe3b218d654f65d1c8
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Sat Jul 22 21:52:55 2023 +0100

    i386: Don't use insvti_{high,low}part with -O0 (for compile-time).

    This patch attempts to help with PR rtl-optimization/110587, a regression
    of -O0 compile time for the pathological pr28071.c.  My recent patch helps
    a bit, but hasn't returned -O0 compile-time to where it was before my
    ix86_expand_move changes.  The obvious solution/workaround is to guard
    these new TImode parameter passing optimizations with "&& optimize", so
    they don't trigger when compiling with -O0.  The very minor complication
    is that "&& optimize" alone leads to the regression of pr110533.c, where
    our improved TImode parameter passing fixes a wrong-code issue with naked
    functions, importantly, when compiling with -O0.  This should explain
    the one line fix below "&& (optimize || ix86_function_naked (cfun))".

    I've an additional fix/tweak or two for this compile-time issue, but
    this change eliminates the part of the regression that I've caused.

    2023-07-22  Roger Sayle  <roger@nextmovesoftware.com>

    gcc/ChangeLog
            * config/i386/i386-expand.cc (ix86_expand_move): Disable the
            64-bit insertions into TImode optimizations with -O0, unless
            the function has the "naked" attribute (for PR target/110533).