On Mon, 2006-02-27 at 20:26 +0100, Sebastian Pop wrote: > Jeffrey A Law wrote: > > On Fri, 2006-02-24 at 19:47 +0100, Sebastian Pop wrote: > > > Jeffrey A Law wrote: > > > > Another possibility is to simply not allow conversions between a > > > > subtype and basetype. > > > > > > Such a patch also solves the problem. But I'm not sure to understand > > > the impact on other codes. Is this kind of conversion between a type > > > and its basetype specific to Ada? > > My suspicions appear to be correct. This never triggers except for > > Ada code and it's relatively common in Ada code. No surprise since > > I don't think any other front-end abuses TYPE_MAX_VALUE in the way > > the Ada front-end does. This wouldn't be the first time we've had > > to hack up something in the generic optimizers to deal with the > > broken TYPE_MAX_VALUE. > > > > This is good to know, thanks. > > I was testing on amd64 this patch that was suggested by Zdenek, it > passed bootstrap, but is still not finished the test. As you said, > this is a little bit more computation inefficient, so probably the > other patch is preferable instead. I'm testing a patch which implements Zdenek's suggestion -- but in a way that's more computationally efficient than yours.
There's no need to use fold_build2, creating junk nodes in the process. We just get the bounds and use operand_equal_p to compare them to the type's min/max values. Jeff
