Richard,
If you agree, I'd like to update the conversion section of
the poly_int manual to make the conversion to make it clearer
that the to_constant() function can be used even with class
types like offset_int besides scalars.
Also, when testing this I also tried converting poly64_int
into wide_int but that doesn't work. Is there a way to do
that?
Thanks
Martin
gcc/ChangeLog:
* doc/poly-int.texi (is_constant): Expand.
Index: gcc/doc/poly-int.texi
===================================================================
--- gcc/doc/poly-int.texi (revision 258004)
+++ gcc/doc/poly-int.texi (working copy)
@@ -836,9 +836,24 @@ Return true if @code{poly_int} @var{value} is a co
@item @var{value}.is_constant (&@var{c1})
Return true if @code{poly_int} @var{value} is a compile-time constant,
-storing it in @var{c1} if so. @var{c1} must be able to hold all
-constant values of @var{value} without loss of precision.
+storing it in @var{c1} if so. @var{c1} may be a scalar or a wide int
+class type capable of holding all constant values of @var{value} without
+loss of precision. The following example illustrates using the function
+to convert a @code{poly64_int} to @code{HOST_WIDE_INT} and to
+@code{offset_int}.
+@smallexample
+void f (poly64_int pi)
+@{
+ HOST_WIDE_INT hwi;
+ if (pi.is_constant (&hwi))
+ ; // Use hwi...
+ offset_int off;
+ if (pi.is_constant (&off))
+ ; // Use off...
+@}
+@end smallexample
+
@item @var{value}.to_constant ()
Assert that @var{value} is a compile-time constant and return its value.
When using this function, please add a comment explaining why the
