https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108360
--- Comment #11 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I have a patch which gets us to:
```
short int b.2_1;
...
b.2_1 = b;
_2 = b.2_1 <= 0;
_4 = (char) _2;
f = _4;
f.5_5 = (unsigned char) _2;
_6 = f.5_5 << 4;
e = _6;
_19 = b.2_1 <= 0;
_7 = (short int) _19;
_21 = _7 << 4;
if (b.2_1 == _21)
```
Which is closer.
```
int f(short b)
{
auto _19 = b <= 0;
auto _7 = (short int) _19;
auto _21 = _7 << 4;
return b == _21;
}
```
is just `return false;` as _21's range is `[0,4]` but it is only 0 when `b > 0`
And then maybe:
(simplify
(eq:c @0 (rshift (convert (le @0 integer_zero_p)) INTEGER_CST@1))
(if (wi::to_wide(@1) < element_precision (TREE_TYPE (@0)) - 1)
( { false_value; } ))
Is this worth this pattern, I don't know ...
