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From: "ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/113106] Missing CSE with cast to volatile
Date: Thu, 21 Dec 2023 12:57:11 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113106

--- Comment #4 from Uro=C5=A1 Bizjak <ubizjak at gmail dot com> ---
(In reply to Richard Biener from comment #3)
> The situation with address-spaces isn't valid as we need to preserve the
> second load because it's volatile.  I think we simply refuse to combine
> volatile loads out of caution in the first case.

int __seg_gs b;
return *(volatile __seg_gs int *) &b + b;

But the above is the same w.r.t to volatile as:

int a;
return *(volatile int *) &a + a;

?

BTW: I also checked with clang, and it creates expected code in all cases.=