[PATCH] Modify simplify_truncation to handle extended CONST_INT.

[Jim Wilson]

On Thu, Oct 10, 2019 at 1:46 AM Richard Sandiford
<richard.sandiford@arm.com> wrote:
> subst tries to avoid creating invalid (zero_extend:DI (const_int N)):
>
>               else if (CONST_SCALAR_INT_P (new_rtx)
>                        && (GET_CODE (x) == ZERO_EXTEND
>                            || GET_CODE (x) == FLOAT
>                            || GET_CODE (x) == UNSIGNED_FLOAT))
>
> Does adding SIGN_EXTEND to the list fix the bug?

I missed that.  I tried that, and it does work.  This looks like a
better solution.  I'm sending a new patch.

Jim