Hi! While trying to implement folding of &a +- cst to &a[c] I came along the C frontend, which for
int a[4]; int *p = &a[-1]; produces p = &a + (int *)-4; so my new transformation gets <integer_cst 0x401b5738 type <pointer_type 0x401559b4> constant invariant 4294967292> as (int *)-4. But of course trying to fold the index back into an ARRAY_REF, thereby adjusting for the element size does not preserve the unsigned pointer overflow behavior and I get &a[-4U/4] from &a[-1] which is of course not the same. Any idea how to avoid this kind of mess and still fold &a + cst to an ARRAY_REF if appropriate? Thanks, Richard. -- Richard Guenther <richard dot guenther at uni-tuebingen dot de> WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/
