https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94892
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Last reconfirmed| |2021-12-15
Status|UNCONFIRMED |NEW
Component|target |tree-optimization
Severity|normal |enhancement
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.
Testcase:
inline int sign(int x)
{
return (x >> 31) | ((unsigned)-x >> 31);
}
bool f1(int x)
{
return sign(x) > -1;
}
bool f3(int x)
{
return (x>>31)+1;
}
void f1(void);
void f2(void);
void f(int x)
{
if (sign(x) > -1)
f1();
else
f2();
}
void f0(int x)
{
if (f3(x))
f1();
else
f2();
}
void fn1(int x)
{
if (x>0)
f1();
else
f2();
}
f, f0 and fn1 should all produce the same result on the gimple level but don't.
(x >> 31) | ((unsigned)-x >> 31) is the same as x == 0 ? 0 : -(x < 0) really.
Which we should simplify into.
Though COND_EXPR is not as well handled by the rest of GCC really.
