[Bug tree-optimization/35164] [4.3 regression] Unable to coalesce ab SSA_NAMEs

[rakdver at gcc dot gnu dot org]

------- Comment #5 from rakdver at gcc dot gnu dot org  2008-02-15 02:59 -------
forwprop3 changes

SR.40_22 = &D.2672_11(ab)->D.2242;
# D.2672_315(ab) = PHI <D.2672_11(ab)(14), D.2672_11(ab)(19),
D.2672_11(ab)(17)>
SR.40_27 = SR.40_22;
D.2705_29 = &SR.40_27->D.2120;

(where the life ranges of D_11 and D_315 do not overlap)

to

SR.40_22 = &D.2672_11(ab)->D.2242;
# D.2672_315(ab) = PHI <D.2672_11(ab)(14), D.2672_11(ab)(19),
D.2672_11(ab)(17)>
SR.40_27 = SR.40_22;
D.2705_29 = &D.2672_11(ab)->D.2242.D.2120;

(where the life ranges of D_11 and D_315 do overlap).
Fwprop probably misses the check for abnormal ssa names, somewhere.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35164