On 2/21/06, Jeffrey A Law <[EMAIL PROTECTED]> wrote: > On Mon, 2006-02-20 at 22:00 +0100, Richard Guenther wrote: > > On 2/20/06, Jeffrey A Law <[EMAIL PROTECTED]> wrote: > > > On Sun, 2006-02-19 at 20:43 +0100, Laurent GUERBY wrote: > > > > 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
Is the final "conversion" a checked conversion or an unchecked conversion? I.e. are we supposed to check for overflow using 'Valid on the final result? Or will the value be truncated or a runtime error raised? Richard.
