On Sun, 2006-02-19 at 14:23 -0500, Richard Kenner wrote: > "Second, for a given integer type (such as > natural___XDLU_0_2147483647), the type for the nodes in TYPE_MIN_VALUE > and TYPE_MAX_VALUE really should be a natural___XDLU_0_2147483647. > ie, the type of an integer constant should be the same as the type of > its min/max values." > > No, the type of the bounds of a subtype should be the *base type*. That's > how the tree has always looked, as far back as I can remember.
This is because intermediate computations can produce results outside the subtype range but within the base type range (RM 3.5(6)), right? type T1 is range 0 .. 127; -- Compiler will choose some type for T'Base, likely to be -128..127 -- but could be Integer (implementation dependant) subtype T is T1 range 0 .. 100; R : T := 100+X-X; -- guaranteed work as long 100+X<=T'Base'Last and 100-X>=T'Base'First Laurent
