> > > I suppose there is > > > > > > *hv = (HOST_WIDE_INT) -(unsigned HOST_WIDE_INT) h1; > > > > > > to make it safe. > > > > Can't that conversion overflow? > > Not on a two's complement machine,
Then I'm confused about C's arithmetic rules. Suppose h1 is 1. It's cast to unsigned, so stays as 1. Now we do unary minus in unsigned. That's ~0 because it's done mod 2**32, but interpreted as a POSITIVE number. Now, that positive number overflows when converted to signed (the intent is for that overflow make it negative). Am I missing something (quite likely!)?
