[Bug tree-optimization/37421] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2008-09-08 15:14 -------
It actually is the correct fix.  We valueize expressions in-place, and
copy visiting doesn't follow the chain up until a constant.  So we have

a = 0;
  = VIEW_CONVERT_EXPR <a>;
b = a;
  = VIEW_CONVERT_EXPR <b>;

we first insert VIEW_CONVERT_EXPR <0> in the table, then during processing
of VIEW_CONVERT_EXPR <b> we valueize it to VIEW_CONVERT_EXPR <a> which is
not in the table.  During insertion we valueize again, now getting
VIEW_CONVERT_EXPR <0> which is already in the table so we hit the assert.

Bootstrapping and testing the fix now.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421