https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61578
--- Comment #20 from Vladimir Makarov <vmakarov at gcc dot gnu.org> ---
(In reply to Fredrik Hederstierna from comment #19)
> I'm not sure why bug 59535 was closed, same problem might still exist, quote:
>
> > Zhenqiang Chen 2014-09-03 06:17:44 UTC
> >
> > Here is a small case to show lra introduces one more register copy (tested
> > with trunk and 4.9).
>
> int isascii (int c)
> {
> return c >= 0 && c < 128;
> }
> With options: -Os -mthumb -mcpu=cortex-m0, I got
>
> isascii:
> mov r3, #0
> mov r2, #127
> mov r1, r3 //???
> cmp r2, r0
> adc r1, r1, r3
> mov r0, r1
> bx lr
>
> With options: -Os -mthumb -mcpu=cortex-m0 -mno-lra, I got
>
> isascii:
> mov r2, #127
> mov r3, #0
> cmp r2, r0
> adc r3, r3, r3
> mov r0, r3
> bx lr
>
> Testing 4.8.5 and 5.2.0 still still produces same bigger code in GCC 5.2.
> So something adds a register copy in this small case.
Thanks for providing a small test case. I've started to work on the PR. I
hope to provide a fix for the case today.
