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From: "joseph at codesourcery dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/43128] [4.5 Regression] c-c++-common/pr41779.c doesn't work Date: Tue, 23 Feb 2010 00:30:00 -0000 [thread overview] Message-ID: <20100223002952.27241.qmail@sourceware.org> (raw) In-Reply-To: <bug-43128-682@http.gcc.gnu.org/bugzilla/> ------- Comment #19 from joseph at codesourcery dot com 2010-02-23 00:29 ------- Subject: Re: [4.5 Regression] c-c++-common/pr41779.c doesn't work On Mon, 22 Feb 2010, manu at gcc dot gnu dot org wrote: > ------- Comment #18 from manu at gcc dot gnu dot org 2010-02-22 23:56 ------- > (In reply to comment #17) > > suggest having a c_ep_convert_and_check or similar function that handles > > excess precision: it would take the result type, the semantic result type > > (the type that gets used eventually to build an EXCESS_PRECISION_EXPR) and > > the value to convert. It would just call convert_and_check, ignoring the > > semantic type, *except* when the operand has integer type *and* the > > semantic type is non-NULL; in that case, it would first convert to the > > semantic type them to the result type. > > Wouldn't that change the normal result of promotion rules? No. The present logic is: convert (with convert_and_check) both operands to a common type, which may have excess precision; then, later, after producing the tree for the result of the operation, wrap that in an EXCESS_PRECISION_EXPR, using the semantic type, if there is a semantic type different from the type with excess precision. The proposed logic is the same, *except* that the conversion to a common type goes via the semantic type, *if* there is excess precision involved *and* the operand being converted had integer type. > Also, why call convert_and_check ignoring the semantic type and not just call > convert? The excess precision type should be large enough to not cause any > problem that needs checking. Yes, you could just use convert for the second conversion (semantic type to type with excess precision). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43128
next prev parent reply other threads:[~2010-02-23 0:30 UTC|newest] Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-02-20 7:12 [Bug c/43128] New: " hjl dot tools at gmail dot com 2010-02-20 10:40 ` [Bug c/43128] " manu at gcc dot gnu dot org 2010-02-20 11:00 ` Andrew Pinski 2010-02-20 11:01 ` pinskia at gmail dot com 2010-02-20 11:51 ` manu at gcc dot gnu dot org 2010-02-20 11:51 ` manu at gcc dot gnu dot org 2010-02-20 13:52 ` rguenth at gcc dot gnu dot org 2010-02-20 15:53 ` hjl dot tools at gmail dot com 2010-02-21 15:39 ` hjl dot tools at gmail dot com 2010-02-21 15:56 ` hjl dot tools at gmail dot com 2010-02-21 16:16 ` hjl dot tools at gmail dot com 2010-02-21 16:46 ` [Bug c/43128] [4.5 Regression] " hjl dot tools at gmail dot com 2010-02-21 16:48 ` hjl dot tools at gmail dot com 2010-02-21 17:25 ` manu at gcc dot gnu dot org 2010-02-21 17:43 ` joseph at codesourcery dot com 2010-02-21 17:57 ` manu at gcc dot gnu dot org 2010-02-21 18:00 ` hjl dot tools at gmail dot com 2010-02-21 18:16 ` joseph at codesourcery dot com 2010-02-21 18:25 ` manu at gcc dot gnu dot org 2010-02-21 18:32 ` joseph at codesourcery dot com 2010-02-22 23:56 ` manu at gcc dot gnu dot org 2010-02-23 0:27 ` manu at gcc dot gnu dot org 2010-02-23 0:30 ` joseph at codesourcery dot com [this message] 2010-02-23 8:39 ` manu at gcc dot gnu dot org 2010-02-23 10:23 ` manu at gcc dot gnu dot org 2010-02-23 16:32 ` joseph at codesourcery dot com 2010-02-23 16:39 ` joseph at codesourcery dot com 2010-02-23 17:34 ` manu at gcc dot gnu dot org 2010-02-24 10:39 ` manu at gcc dot gnu dot org 2010-02-24 13:10 ` manu at gcc dot gnu dot org 2010-02-24 13:10 ` manu at gcc dot gnu dot org
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