> -----Original Message-----
> From: Uros Bizjak <ubiz...@gmail.com>
> Sent: Wednesday, June 25, 2025 12:53 AM
> To: gcc-patches@gcc.gnu.org
> Cc: Cui, Lili <lili....@intel.com>
> Subject: [committed] i386: Convert LEA stack adjust insn to SUB when
> FLAGS_REG is dead
>
> ADD/SUB is faster than LEA for most processors. Also, there are several
> peephole2 patterns available that convert prologue esp subtractions to pushes
> (at the end of i386.md). These process only patterns with flags reg clobber,
> so
> they are ineffective with clobber-less stack ptr adjustments, introduced by
> r16-
> 1551
> ("x86: Enable separate shrink wrapping").
>
> Introduce a peephole2 pattern that adds a clobber to a clobber-less stack ptr
> adjustments when FLAGS_REG is dead.
>
> gcc/ChangeLog:
>
> * config/i386/i386.md
> (@pro_epilogue_adjust_stack_add_nocc<mode>): Add type attribute.
> (pro_epilogue_adjust_stack_add_nocc peephole2 pattern):
> Convert pro_epilogue_adjust_stack_add_nocc variant to
> pro_epilogue_adjust_stack_add when FLAGS_REG is dead.
>
> Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.
>
Great, thanks!
Lili.
> Uros.
