ICE in change_address at emit_rtl.c

[Richard Kenner]

    > Right, but note I said *performance*.  Even if we do that, we'd lose
    > optimization potential in knowing the form of the values.

    Why?  Can you give a simple example?

No.  I said *complex* objects.

Basically if you can look inside a SAVE_EXPR you may be able to deduce that
the value is always a multiple of some power-of-two.  Or you may be
able to simplify the expression by merging some divides and multiplies.
It's this sort of thing I'm talking about.