On Wed, Oct 19, 2022 at 12:55:12PM -0400, Andrew MacLeod via Gcc-patches wrote:
> > Not sure I understand this part. op is whatever we pass as the ith
> > argument to IFN_ASSUME. I'd expect that at this point one needs to
> > remap that to the (i-1)th PARM_DECL of assume_id (so e.g. when you
> > have the above loop you could as well start with DECL_ARGUMENTS and move
> > that to DECL_CHAIN at the end of every iteration. And then
> > query ssa_default_def (DECL_STRUCT_FUNCTION (assume_id), parm)
> > in each case and get global range of what that returns.
>
> OK, this is the bit of code I dont know how to write :-)
>
> yes, op is the name of the value within this current function, and yes, that
> needs to be mapped to the argument decl in the assume function. Then we
> need to query what range was given to that name during the assume pass.
> when that is returned, the add_range (op, range) will inject it as a side
> effect.
>
> Can you write that loop?
I meant something like (untested code):
&& gimple_call_internal_fn (s) == IFN_ASSUME)
{
tree assume_id = gimple_call_arg (s, 0);
- for (unsigned i = 1; i < gimple_call_num_args (s); i++)
+ tree parm = DECL_ARGUMENTS (assume_id);
+ struct function *fun = DECL_STRUCT_FUNCTION (assume_id);
+ for (unsigned i = 1;
+ i < gimple_call_num_args (s) && parm;
+ i++, parm = DECL_CHAIN (parm))
{
tree op = gimple_call_arg (s, i);
tree type = TREE_TYPE (op);
+ tree arg = ssa_default_def (fun, parm);
+ if (arg == NULL_TREE)
+ continue;
if (gimple_range_ssa_p (op) && Value_Range::supports_type_p (type))
{
Value_Range assume_range (type);
and querying SSA_NAME_RANGE_INFO of arg rather than op.
>
> >
> > > + for (unsigned x= 0; x < gimple_phi_num_args (phi); x++)
> > for (unsigned x = 0; ...
> > ?
> >
> > > @@ -4345,6 +4345,30 @@ execute_ranger_vrp (struct function *fun, bool
> > > warn_array_bounds_p)
> > > scev_initialize ();
> > > calculate_dominance_info (CDI_DOMINATORS);
> > > + assume_query *r2 = new assume_query ();
> > > + for (unsigned i = 0; i < num_ssa_names; i++)
> > > + {
> > > + tree name = ssa_name (i);
> > > + if (!name || !gimple_range_ssa_p (name))
> > > + continue;
> > > + tree type = TREE_TYPE (name);
> > > + if (!Value_Range::supports_type_p (type))
> > > + continue;
> > > + Value_Range assume_range (type);
> > > + if (r2->assume_range_p (assume_range, name))
> > > + {
> > > + if (dump_file)
> > > + {
> > > + fprintf (dump_file, "for an assume function, ");
> > > + print_generic_expr (dump_file, name, TDF_SLIM);
> > > + fprintf (dump_file, " would have a range of ");
> > > + assume_range.dump (dump_file);
> > > + fputc ('\n', dump_file);
> > > + }
> > > + }
> > > + }
> > > + delete r2;
> > I have expected (but tell me if that isn't possible) this could be something
> > done in the new pass_assumptions::execute () rather than vrp and you'd
> > create the assume_query there (i.e. just for assume_functions) and then
> > query it solely for ssa_default_def of the parameters and save in
> > SSA_NAME_RANGE_INFO.
>
> I just discovered the assumption pass, and I have moved it to there.
>
> I dont know much about managing the parameters, but presumably yes, we'd
> only query it for the parameters........... I was showing the query for
> every name just to show what its producing.
Inside of the assume function (cfun->assume_function being true)
one could again walk DECL_ARGUMENTS and for arguments with types
which ranger is able to cope with and they are reg types,
ssa_default_def (cfun, parm) to get the SSA_NAME of the default def (if
any).
> --- a/gcc/tree-vrp.cc
> +++ b/gcc/tree-vrp.cc
> @@ -4465,6 +4465,35 @@ public:
> bool gate (function *fun) final override { return fun->assume_function; }
Regarding your second mail, see above gate, this pass is only run for
assume functions and nothing else.
> unsigned int execute (function *) final override
> {
> + assume_query query;
> + if (dump_file)
> + fprintf (dump_file, "Assumptions :\n--------------\n");
> + for (unsigned i = 0; i < num_ssa_names; i++)
> + {
> + tree name = ssa_name (i);
> + if (!name || !gimple_range_ssa_p (name))
> + continue;
> + tree type = TREE_TYPE (name);
> + if (!Value_Range::supports_type_p (type))
> + continue;
> + Value_Range assume_range (type);
> + if (query.assume_range_p (assume_range, name))
> + {
> + set_range_info (name, assume_range);
> + if (dump_file)
> + {
> + print_generic_expr (dump_file, name, TDF_SLIM);
> + fprintf (dump_file, " -> ");
> + assume_range.dump (dump_file);
> + fputc ('\n', dump_file);
> + }
> + }
> + }
> + if (dump_file)
> + {
> + fputc ('\n', dump_file);
> + gimple_dump_cfg (dump_file, dump_flags);
> + }
> return TODO_discard_function;
> }
Jakub
