[Bug tree-optimization/32230] [4.3 Regression] Segfault in set_bb_for_stmt with -O -ftree-vectorize

["irar at il dot ibm dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #6 from irar at il dot ibm dot com  2007-06-28 11:41 -------
((float*) (&((sbuf_header_t *) ((buf) == &(buf)->buf[0]))->buf[0]))[i] = val;

is (after ommiting the casts)

*(1B + (i * 4)) = val;

Is that legal?

Vectorizer assumes that every data-ref has base_address. In the above case we
get the following data-ref structure:
        base_address: 0B
        offset from base address: 0
        constant offset from base address: 1
        step: 4
        aligned to: 128
        base_object: *0B
        symbol tag: SMT.5

therefore, creating an empty stmt for the first access of the data-ref in the
loop.

Before Zdenek's rewrite of data-refs analysis, it failed to create a dr here,
and thus no segfault occurred.

Ira


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32230