On Sat, Sep 3, 2011 at 11:24 AM, Eric Botcazou <ebotca...@adacore.com> wrote: >> Well, even when sign-extended there is a constant you can't negate >> without overflow. I would start digging for a testcase with >> such case - but as said, testcases involving TYPE_IS_SIZETYPE are >> very hard to generate for me. > > We run thousands of Ada tests every night on many platforms and never detected > a problem here, so finding a testcase with the unpatched compiler is probably > very hard - if there is really something to be found, which I doubt.
Well, for real-world code I believe that. But see all the recent testcases for corner-cases of our signed-overflow stuff, they all require hand-crafted testcases involving INT_MIN, no inlining and even -ftrapv. What I meant to say is, given Ada can construct arbitrary layouted types it should be possible to have testcases for all the corner-cases - after all you cannot have both, undefined overflow and wrapping overflow, at the same time. That extract_muldiv_1 code is wrong for TYPE_OVERFLOW_UNDEFINED types as well, btw. >> Well, but I'd expect you can have a set of Ada types, a function that >> returns just its size and some scan-tree-dumps that check those sizes >> are folded to a constant. Or to just N statements. > > We probably should, but we don't have them (yet). Like for the vast majority > of the transformations made by the folder I guess, so... > >> If you insist I can revert the patch and apply it together with the >> sign-extension change. > > Yes, IMHO it should be part of the final patch. Ok, I'll revert it on monday. Richard. > -- > Eric Botcazou >
