------- Comment #2 from pinskia at gcc dot gnu dot org 2006-12-07 18:18 -------
Actually this is a PRE opertunity.
if we look into .102t.final_cleanup, we notice we did the load PRE:
<L2>:;
prephitmp.32 = *data;
prephitmp.38 = *(data + 12B);
i = 1;
goto <bb 5> (<L1>);
<L0>:;
*((int *) ((unsigned int) *(data + 8B) * 4) + data) = 2;
prephitmp.32 = *data;
prephitmp.38 = *(data + 12B);
i = prephitmp.32 + 1 + prephitmp.38;
<L1>:;
*(data + 16B) = prephitmp.38 + prephitmp.32;
but did not do the other part of the pre for the add.
I think this is a reassiocation issue:
<L0>:
...
j_15 = D.1620_12 + 1;
i_16 = j_15 + D.1622_14;
# prephitmp.32_37 = PHI <pretmp.31_36(5), D.1622_14(3)>;
# prephitmp.32_35 = PHI <pretmp.31_34(5), D.1620_12(3)>;
# prephitmp.30_33 = PHI <pretmp.29_32(5), D.1621_13(3)>;
# i_1 = PHI <1(5), i_16(3)>;
<L1>:;
....
D.1620_18 = prephitmp.32_35;
D.1621_19 = prephitmp.30_33;
D.1622_20 = prephitmp.32_37;
D.1624_21 = D.1622_20 + D.1620_18;
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|missed code hoisting |missed PRE (add)
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30105
