------- Comment #6 from dberlin at gcc dot gnu dot org 2006-08-29 14:59 ------- SCCVN comes up with
Value numbers: d_2 = c_1 c_7 = b_6 d_8 = b_6 c_10 = a_9 d_11 = a_9 where # PRED: 3 (fallthru,exec) 4 (fallthru,exec) # dD.1526_2 = PHI <dD.1526_11(3), dD.1526_8(4)>; # cD.1525_1 = PHI <cD.1525_10(3), cD.1525_7(4)>; ... As a result, once integrated into PRE/FRE, it will eliminate uses of the d_2 phi with the c_1 phi, which is what you want. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28868
