[Bug tree-optimization/36905] [4.3/4.4/4.5 Regression] IV-opts needs a little help with a[i+1]

[amonakov at gcc dot gnu dot org]

------- Comment #7 from amonakov at gcc dot gnu dot org  2010-02-16 17:43 
-------
(In reply to comment #6)

Looks like this has been fixed.  We do generate good code:

fred:
        li 0,100
        mtctr 0
.L2:
        sthu 3,2(4)
        bdnz .L2
        blr
        .size   fred, .-fred
        .ident  "GCC: (GNU) 4.5.0 20100215 (experimental)"

And ivopts dump is quite sane:

<bb 2>:
  ivtmp.13_17 = (unsigned int) out1_5(D);

<bb 3>:
  # i_13 = PHI <i_3(4), 0(2)>
  # ivtmp.13_15 = PHI <ivtmp.13_16(4), ivtmp.13_17(2)>
  i_3 = i_13 + 1;
  ivtmp.13_16 = ivtmp.13_15 + 2;
  D.2031_18 = (void *) ivtmp.13_16;
  MEM[base: D.2031_18] = in_7(D);
  if (i_3 != 100)
    goto <bb 4>;
  else
    goto <bb 5>;

<bb 4>:
  goto <bb 3>;


-- 

amonakov at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amonakov at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36905