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[Bug middle-end/38671] [4.4 Regression] extra code for setting up loops



------- Comment #4 from pinskia at gcc dot gnu dot org  2008-12-31 08:10 -------
  D.45587 = VIEW_CONVERT_EXPR<__v4si>(x);
  D.45589 = __builtin_ia32_pcmpeqd128 (D.45587, D.45587);
  D.45591 = __builtin_ia32_psrldi128 (D.45589, 25);
  D.45594 = __builtin_ia32_pslldi128 (D.45591, 23);
  one = VIEW_CONVERT_EXPR<__m128>(VIEW_CONVERT_EXPR<__m128i>(D.45594));
  D.45644 = (long unsigned int) ((n >> 2) + 4294967295) + 1 * 16;
  ivtmp.516 = 0;


So the inner loop is not the issue, only the setup code.

The extra subtract/add comes from D.45644.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |middle-end
            Summary|[4.4 Regression] speed      |[4.4 Regression] extra code
                   |regression with sse         |for setting up loops
                   |intrinsics                  |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38671


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