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From: "tbptbp at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/19252] New: sub optimal use of fpu comparisons in SSE code
Date: Tue, 04 Jan 2005 12:38:00 -0000	[thread overview]
Message-ID: <20050104123832.19252.tbptbp@gmail.com> (raw)

Somehow fpu comparisons are used in SSE heavy code with -mfpmath=sse.

Case in point (not from the testcase):
 401447:       fldz
[snip lots of SSE only operations]
 401535:       movss  %xmm2,0xc(%esp)
 40153b:       flds   0xc(%esp)
 40153f:       fcomip %st(1),%st
 401541:       jbe    401650

I couldn't reduce further the attached testcase, but it's really obvious
something's wrong the generated code for fp_compare vs pristine_intersection.

Switches: -O3 -march=k8 -mfpmath=sse -ffast-math -fomit-frame-pointer

-- 
           Summary: sub optimal use of fpu comparisons in SSE code
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tbptbp at gmail dot com
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: cygwin


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19252


             reply	other threads:[~2005-01-04 12:38 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-01-04 12:38 tbptbp at gmail dot com [this message]
2005-01-04 12:39 ` [Bug rtl-optimization/19252] " tbptbp at gmail dot com
2005-01-04 13:00 ` [Bug target/19252] " uros at kss-loka dot si
2005-01-04 14:05 ` uros at kss-loka dot si
2005-01-04 15:24 ` kcook at gcc dot gnu dot org
2005-01-06 14:41 ` bangerth at dealii dot org
2005-01-07 11:32 ` uros at kss-loka dot si
2005-01-11 22:35 ` pinskia at gcc dot gnu dot org
2005-01-12  2:48 ` rth at gcc dot gnu dot org
2005-01-14  0:34 ` cvs-commit at gcc dot gnu dot org
2005-01-14  0:55 ` rth at gcc dot gnu dot org
2005-01-14  0:56 ` pinskia at gcc dot gnu dot org

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