------- Additional Comments From rguenth at gcc dot gnu dot org 2005-07-15 13:29 ------- One easy to locate problem (and possibly the one blocking other optimizers like IVOPTs do anything useful) is aliasing. From the .vars dump we can see
<L2>:; D.215486.D.81558.D.81253.domain_m[0].D.80426.D.50706.D.50587.domain_m = i0.4405; D.215486.D.81558.D.81253.domain_m[1].D.80426.D.50706.D.50587.domain_m = i1.4406; D.215486.D.81558.D.81253.domain_m[2].D.80426.D.50706.D.50587.domain_m = i2; D.215914 = D.215486.D.81558.D.81253.domain_m[0].D.80426.D.50706.D.50587.domain_m; D.215816 = D.215486.D.81558.D.81253.domain_m[1].D.80426.D.50706.D.50587.domain_m; D.215629 = *(D.215772 + (double *) ((unsigned int) (D.215808 + D.215914 + D.215816 * D.215806) * 8)); The structure containing an 3-dimensional index into an array D.215486 is assigned from the integer variables i0, i1, i2 which control a three-level nested loops. You can see easily that in the inner loop (whose head you can see) operations on indices i1 and i2 are not hoisted out of the loop because aliasing thinks the stores to the structure alias. Which also causes us not to propagate the assignments from i0, i1, i2 to the final use in the memory access. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22501
