https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95102
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
Last reconfirmed| |2021-07-20
Severity|normal |enhancement
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
One thing that should be done:
if (_1 < a_4(D))
goto <bb 4>; [50.00%]
else
goto <bb 3>; [50.00%]
<bb 3> [local count: 536870913]:
x_5 = BIT_INSERT_EXPR <x_3(D), a_4(D), 0>;
<bb 4> [local count: 1073741824]:
# x_2 = PHI <x_3(D)(2), x_5(3)>
Be converted to:
_1 = BIT_FIELD_REF <x_3(D), 32, 0>;
nt_6 = BIT_FIELD_REF <x_3(D), 32, 0>;
if (_1 < a_4(D))
goto <bb 4>; [50.00%]
else
goto <bb 3>; [50.00%]
<bb 3> [local count: 536870913]:
<bb 4> [local count: 1073741824]:
# nt_7 = PHI <nt_6(2), a_4(D)(3)>
x_2 = BIT_INSERT_EXPR <x_3(D), nt_7, 0>;
And then normal phiopt would convert it to:
_1 = BIT_FIELD_REF <x_3(D), 32, 0>;
nt_7 = MIN <_1, a_4(D);
x_2 = BIT_INSERT_EXPR <x_3(D), nt_7, 0>;
But this would require a new part of tree-ssa-phiopt which does this, this
can't be done in match as far as I can tell; I don't know how profitable this
transfomration is either.
