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Re: a warning to implement
- From: Gabriel Dos Reis <gdr at codesourcery dot com>
- To: Joe Buck <jbuck at synopsys dot com>
- Cc: dewar at gnat dot com (Robert Dewar), gdr at codesourcery dot com, aoliva at redhat dot com, gcc at gcc dot gnu dot org, phil at jaj dot com
- Date: 06 Feb 2002 21:29:10 +0100
- Subject: Re: a warning to implement
- Organization: CodeSourcery, LLC
- References: <200202062020.MAA05376@atrus.synopsys.com>
Joe Buck <firstname.lastname@example.org> writes:
| Robert writes:
| > But Gaby, right now, the construct
| > int a = a;
| > produces an undefined result, so no one can use it. It might suppress
| > warnings in one version of gcc, but then someone might submit a patch
| > that causes it to have some disastrous effect, and no one would have
| > a right to complain, since if they are using this, they are using an
| > undocumented behavior, and have no right to count on it.
| One possible disasterous effect is that
| float a = a;
| with debugging off might generate an actual load and store, and if it
| reads stack noise that looks like a signalling NaN, boom.
It is defined to copy a signalling NaN.