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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/109057] Does GCC interpret assembly when deciding to
 optimize away a variable?
Date: Tue, 07 Mar 2023 17:32:53 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109057

--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #5)
> (In reply to Andrew Pinski from comment #2)
> > No it is not. you just don't notice it there because goldbolt is hiding
> > things because it thinks it is unused.
>=20
> This actually isn't godbolt hiding anything (which it does sometimes), but
> because
> nothing is printed in the asm nothing needs to be printed into the assemb=
ly
> output.
> It still acts as a black box to the compiler.
Kinda.

>More importantly, the entire static array LUT was optimized away from the =
object file.=20
the asm code still has LUT array (godbolt does hide unused lables by defaul=
t).
Using the original code we do get:

        .type   LUT, @object
        .size   LUT, 8
LUT:
        .string "\001\005\003"
        .ascii  "\002\007\001\002"=