https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108748
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
CC| |amacleod at redhat dot com
Last reconfirmed| |2023-02-10
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The GIMPLE we see sems to be
uint64_t foo (uint64_t x)
{
<bb 2> :
if (POLY_INT_CST [16, 16] == 2)
goto <bb 3>; [INV]
else
goto <bb 4>; [INV]
<bb 3> :
x_6 = x_5(D) + POLY_INT_CST [1600, 1600];
<bb 4> :
# x_4 = PHI <x_5(D)(2), x_6(3)>
return x_4;
so any such optimization would derive the TU wide constant(?) N that is
applied to all POLY_INT_CSTs? Is there a set_svcntb (..) intrinsic that
would clobber such knowledge?
That said, we'd track a "virtual" variables range here. For the above
I wonder why we cannot constant fold it - [16, 16] can never be 2, no?
