On 03/25/06 09:12, Duncan Sands wrote:
> I'm quite interested in trying out this scheme. Unfortunately it's not clear
> to me how I would go about finding which variables are subroutine parameters,
> and adding ASSERT_EXPRs for them; any hints would be welcome.
>
Probably not a bad idea to test. You can recognize parameters with the
predicate TREE_CODE (sym) == PARM_DECL. The SSA name on which you want
to add the assertion is the so called "default definition" for that
PARM_DECL.
A default definition is an SSA name that is created for a variable SYM
when the very first reference to SYM is a load/read. For instance
foo (int i)
{
return i - 1;
}
The SSA form for the above is:
foo (int i)
{
return i_1 - 1;
}
i_1 is the "default definition" for 'i'. You find that out with the
predicate 'name == default_def (sym)'.
Start by looking at tree-vrp.c:infer_value_range.
