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From: "tg at swox dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/12654] [3.3/3.4 regression] Incorrect comparison code generated for Alpha Date: Fri, 17 Oct 2003 23:29:00 -0000 [thread overview] Message-ID: <20031017230319.14395.qmail@sources.redhat.com> (raw) In-Reply-To: <20031017020801.12654.tg@swox.com> PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12654 ------- Additional Comments From tg at swox dot com 2003-10-17 23:03 ------- Subject: Re: [3.3/3.4 regression] Incorrect comparison code generated for Alpha "falk dot hueffner at student dot uni-tuebingen dot de" <gcc-bugzilla@gcc.gnu.org> writes: No, it isn't, since it is an unsigned value. But passing this value to a function taking a signed value is implementation defined. Passing an "unsigned long" value to a function accepting "long" is perfectly well-defined, as long as no signed overflow happens in the conversion. The value used doesn't cause overflow. > The bogus variant is actually slightly better WRT register pressure, so we > might want to retain it for int arguments. > > Huh? Not sure what you are suggesting. Adding and then comarping > to 0 is *wrong* also for int arguments when since the add risks to > overflow. Not if you do a 64-bit add. But it's probably not worth bothering. Yeah, I suppose you can do the trick in SImode by actually doing the operations in DImode, so to speak. Alpha is unusual in that it allowed larger immediate operands for addition (via lda) than comparison.
next prev parent reply other threads:[~2003-10-17 23:03 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2003-10-17 2:08 [Bug c/12654] New: " tg at swox dot com 2003-10-17 9:52 ` [Bug c/12654] [3.3/3.4 regression] " falk at debian dot org 2003-10-17 15:25 ` tg at swox dot com 2003-10-17 15:58 ` falk dot hueffner at student dot uni-tuebingen dot de 2003-10-17 21:01 ` falk at debian dot org 2003-10-17 22:01 ` [Bug target/12654] " pinskia at gcc dot gnu dot org 2003-10-17 23:29 ` tg at swox dot com [this message] 2003-10-18 14:23 ` falk dot hueffner at student dot uni-tuebingen dot de 2003-10-18 14:31 ` tg at swox dot com 2003-10-18 15:20 ` falk dot hueffner at student dot uni-tuebingen dot de 2003-10-19 7:08 ` tg at swox dot com 2003-10-20 8:05 ` cvs-commit at gcc dot gnu dot org 2003-10-20 8:35 ` falk at debian dot org 2003-10-23 0:23 ` wilson at specifixinc dot com 2003-10-27 20:56 ` cvs-commit at gcc dot gnu dot org 2003-10-27 22:04 ` tg at swox dot com 2003-10-27 23:12 ` falk dot hueffner at student dot uni-tuebingen dot de
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