[PATCH 5/6] combine: handle REG_UNUSED in reg_dead_at_p (PR59278)

[Jeff Law]

On 11/27/14 18:44, Segher Boessenkool wrote:
> Currently reg_dead_at_p returns 0 for registers that are set but never
> used.  This patch repairs that oversight.  This fixes PR59278.
>
>
> 2014-11-27  Segher Boessenkool  <segher@kernel.crashing.org>
>
> gcc/
> 	PR rtl-optimization/59278
> 	combine (reg_dead_at_p): Consider REG_UNUSED notes.
OK with a testcase.  ISTM you can just create an SH specific testcase 
from the code in the BZ.  Pre-approved with suitable testcase.

jeff