[Bug tree-optimization/33136] [4.1/4.2/4.3 Regression] -Os generated code grew almost twice 4.2.1 versus 4.1.1

[rguenth at gcc dot gnu dot org]

------- Comment #12 from rguenth at gcc dot gnu dot org  2007-08-22 15:15 
-------
Indeed.

<bb 2>:
  # s_13 = VDEF <s_12(D)>
  s = 0B;
  goto <bb 4>;

<bb 4>:
  # p_1 = PHI <&s(2), p_5(3)>
  # VUSE <HEAP.5_14(D), SMT.7_15(D)>
  D.2019_3 = *p_1;

is wrong alias info (from trunk salias dump).  The load from *p_1 misses
a use of s_13 - or the assignment to s should use SMT.7 instead.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dberlin at gcc dot gnu dot
                   |                            |org
           Keywords|missed-optimization         |alias, wrong-code
            Summary|[4.2/4.3 Regression] -Os    |[4.1/4.2/4.3 Regression] -Os
                   |generated code grew almost  |generated code grew almost
                   |twice 4.2.1 versus 4.1.1    |twice 4.2.1 versus 4.1.1
   Target Milestone|4.2.2                       |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33136