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From: Glen Nakamura <glen@imodulo.com> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, Subject: Re: c/10226: unsigned short promotion with bitwise inversion Date: Wed, 26 Mar 2003 20:36:00 -0000 [thread overview] Message-ID: <20030326201600.5713.qmail@sources.redhat.com> (raw) The following reply was made to PR c/10226; it has been noted by GNATS. From: Glen Nakamura <glen@imodulo.com> To: gcc-gnats@gcc.gnu.org, gcc-bugs@gcc.gnu.org, mmarks@internetmachines.com Cc: Subject: Re: c/10226: unsigned short promotion with bitwise inversion Date: Wed, 26 Mar 2003 10:06:02 -1000 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10226 > unsigned short A = 0xDEAD; > unsigned short B; > B = ~A; > if ( B == ~A) { > printf("Pass\n"); > } > else { > printf("Fail\n"); > } I'll leave the final decision to the language lawyers, but I don't think this is a bug in GCC. The ~ operator is subject to integer promotion, so with the implicit conversions the expression becomes: if ((int) B == ~((int) A)) which is indeed false in the example above. In fact, I see the following warning when compiling with -Wall (GCC 3.3): warning: comparison of promoted ~unsigned with unsigned Perhaps "if (B == (unsigned short) ~A)" will behave as you expect. - glen
next reply other threads:[~2003-03-26 20:16 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2003-03-26 20:36 Glen Nakamura [this message] -- strict thread matches above, loose matches on Subject: below -- 2003-03-27 0:16 Michael Marks 2003-03-26 23:06 Falk Hueffner 2003-03-26 22:36 Glen Nakamura 2003-03-26 22:26 Falk Hueffner 2003-03-26 22:26 Glen Nakamura 2003-03-26 22:06 Michael Marks 2003-03-26 21:56 Glen Nakamura 2003-03-26 21:56 Falk Hueffner 2003-03-26 21:16 Michael Marks 2003-03-26 21:16 ebotcazou 2003-03-26 19:56 Michael Marks 2003-03-26 18:26 Falk Hueffner 2003-03-26 18:16 mmarks
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