https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85234
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Here are some testcases dealing with this and showing what still needs to be
done:
```
#define N 3
#define unsigned int
#define cmp !=
_Bool rshift(unsigned x, int t)
{
return (x << N) cmp 0;
}
_Bool rshift1(unsigned x, int t)
{
return (x & (-1u>>N)) cmp 0;
}
_Bool lshift(unsigned x, int t)
{
return (x >> N) cmp 0;
}
_Bool lshift1(unsigned x, int t)
{
return (x & (-1u<<N)) cmp 0;
}
_Bool lshift2(unsigned x, int t)
{
return (x >= (1u<<N)) cmp 0;
}
```
GCC handles lshift1 to lshift2 just fine.
But not lshift to lshift1 and rshift to rshift1.
Note GCC does the correct thing rshift/rshift1 even for riscv32 where forming
an constant for the and is hard.
