[Bug rtl-optimization/21676] [4.0/4.1/4.2/4.3 Regression] Optimizer regression: SciMark sparse matrix benchmark

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #12 from ubizjak at gmail dot com  2007-12-16 23:49 -------
(In reply to comment #11)
> Open regression with no activity since February 14.  Ping?

Current 4.3 SVN produces (-O3 -march=pentium4):

.L8:
        movl    (%ebx), %eax    #* ivtmp.33, tmp84
        fldl    (%edi,%eax,8)   #
        fmull   (%ecx)  #* ivtmp.35
        faddp   %st, %st(1)     #,
        addl    $1, %edx        #, i
        addl    $4, %ebx        #, ivtmp.33
        addl    $8, %ecx        #, ivtmp.35
        cmpl    %edx, %esi      # i, rowRp1
        jg      .L8     #,

(+ -fno-ivopts):

.L8:
        movl    (%esi,%edx,4), %eax     #, tmp76
        fldl    (%edi,%eax,8)   #* x
        movl    16(%ebp), %eax  # val,                  <-----here
        fmull   (%eax,%edx,8)   #
        faddp   %st, %st(1)     #,
        addl    $1, %edx        #, i
        cmpl    %edx, %ecx      # i, rowRp1
        jg      .L8     #,

We regressed vs. 4.2 in this case; "val" is loaded inside the loop.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676