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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/114688] repeat load argument of an inline function
Date: Thu, 11 Apr 2024 07:06:18 +0000	[thread overview]
Message-ID: <bug-114688-4-jDlKg42nMY@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-114688-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114688

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2024-04-11
           Keywords|                            |missed-optimization, ra
     Ever confirmed|0                           |1
             Target|                            |x86_64-*-*
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
char g;
int v;

static inline __attribute__((always_inline)) void foo(char p_17);
void func_1() { foo(g); }

static inline void foo(char c) { 
    v = (char)(2 - c) & c; 
}

shows that with -Os we get

func_1:
.LFB0:
        .cfi_startproc
        movb    g(%rip), %dl
        movb    $2, %al
        subl    %edx, %eax
        andl    %edx, %eax
        movsbl  %al, %eax
        movl    %eax, v(%rip)
        ret

I think we have duplicate bugs that show we're too happy replicating
memory operands to multiple instructions.  That might be a target cost
thing in the end.

  reply	other threads:[~2024-04-11  7:06 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-11  6:56 [Bug rtl-optimization/114688] New: " absoler at smail dot nju.edu.cn
2024-04-11  7:06 ` rguenth at gcc dot gnu.org [this message]
2024-04-11  7:07 ` [Bug rtl-optimization/114688] " pinskia at gcc dot gnu.org

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