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From: "siarhei.siamashka at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/47759] New: _mm_empty() intrinsic fails to serve as a boundary between MMX and x87 code due to optimizations Date: Tue, 15 Feb 2011 21:58:00 -0000 [thread overview] Message-ID: <bug-47759-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47759 Summary: _mm_empty() intrinsic fails to serve as a boundary between MMX and x87 code due to optimizations Product: gcc Version: 4.5.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target AssignedTo: unassigned@gcc.gnu.org ReportedBy: siarhei.siamashka@gmail.com Host: i686-pc-linux-gnu Created attachment 23355 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23355 mm_empty_testcase.c The attached testcase fails when compiled with -O2 or -O3 optimizations, but works with -O1. I'm actually not precisely sure how this code is expected to behave because intrinsics are x86 architecture specific and C standard can't be used as a reference. But my guess is that if the optimizer would not be allowed to arbitrarily move code across _mm_empty() boundary, then the problem would disappear.
next reply other threads:[~2011-02-15 21:52 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-02-15 21:58 siarhei.siamashka at gmail dot com [this message] 2011-02-15 21:58 ` [Bug target/47759] " pinskia at gcc dot gnu.org 2011-02-15 22:21 ` pinskia at gcc dot gnu.org
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