https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50856
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|target |tree-optimization
Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot
gnu.org
Status|NEW |ASSIGNED
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is a generic issue and not really arm related.
In phiopt4 for absolute_difference1 we have:
_14 = (int) b_7(D);
_12 = (int) a_6(D);
if (a_6(D) > b_7(D))
goto <bb 3>; [50.00%]
else
goto <bb 4>; [50.00%]
<bb 3> [local count: 536870913]:
iftmp.0_9 = _12 - _14;
goto <bb 5>; [100.00%]
<bb 4> [local count: 536870913]:
iftmp.0_8 = _14 - _12;
<bb 5> [local count: 1073741824]:
# iftmp.0_5 = PHI <iftmp.0_9(3), iftmp.0_8(4)>
While for absolute_difference2 we have in phiopt1
tmp_4 = (int) a_3(D);
_1 = (int) b_5(D);
tmp_6 = tmp_4 - _1;
if (tmp_6 < 0)
goto <bb 3>; [INV]
else
goto <bb 4>; [INV]
<bb 3> :
tmp_8 = _1 - tmp_4;
<bb 4> :
# tmp_2 = PHI <tmp_6(2), tmp_8(3)>
absolute_difference2 is easier to handle, let me try to handle both cases/
The second case we have:
(a - b) < 0 ? (b - a) : (a - b)
Or:
(cond (lt (minus@0 @1 @2) zero_p) (minus @2 @1) @0)
The first case we have is more complex.
