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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug ipa/97264] [11 Regression] -fpa-modref breaks va_arg on glibc Date: Thu, 01 Oct 2020 11:31:31 +0000 [thread overview] Message-ID: <bug-97264-4-50KYQ3dBub@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-97264-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97264 --- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Andreas Schwab from comment #5) > Why doesn't gcc warn about that? It does: unsigned char **q; void foo (char *p) { q = (unsigned char **)&p; } > gcc t.c -fstrict-aliasing -Wstrict-aliasing=2 -S t.i: In function 'foo': t.i:4:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] q = (unsigned char **)&p; ^ note the default level of -Wstrict-aliasing when enabled is 3 which will not warn when the pointer is not dereferenced in the same expression.
next prev parent reply other threads:[~2020-10-01 11:31 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-10-01 8:37 [Bug ipa/97264] New: " slyfox at gcc dot gnu.org 2020-10-01 8:38 ` [Bug ipa/97264] " slyfox at gcc dot gnu.org 2020-10-01 9:41 ` rguenth at gcc dot gnu.org 2020-10-01 9:50 ` slyfox at gcc dot gnu.org 2020-10-01 9:53 ` rguenther at suse dot de 2020-10-01 10:57 ` schwab@linux-m68k.org 2020-10-01 11:31 ` rguenth at gcc dot gnu.org [this message] 2020-10-16 12:09 ` rguenth at gcc dot gnu.org
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