https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69526
--- Comment #15 from rdapp at linux dot vnet.ibm.com ---
Thanks for the suggestions. The omission of the inner op was actually more or
less on purpose as I intended to capture the
(convert @inner)
in order to access @inner's value range as a whole rather than re-calculating
what VRP already figured out.
Is there a simple method to access @inner when
capturing
(outer_op (convert (inner_op SSA_NAME@0 INTEGER_CST@1)) INTEGER_CST@2))
^---------------------------------^
@inner
or, even-better both, @inner as well as @0 and @1, at the same time? (Apart
from looking through use stmts)
In my case VRP determines @0's range as ~[0,0] and @inner's as [0,INT_MAX-1].
VRP probably canonicalized the anti-range to a normal range and performed other
simplifications in order to arrive at [0,INT_MAX-1]. If I cannot get @inner's
VRP info with the capture above, would there be another way to obtain it?
The TREE_OVERFLOW/const_binop code is copied from the (A +- CST) +- CST -> A +
CST pattern and the result of const_binop is used in the final simplification.
The overflow check could of course be done via wi::add/sub but wouldn't I just
replicate what int_const_binop_1 is doing on top of it when I need the result
anyway?
