https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59535
Zhenqiang Chen <zhenqiang.chen at arm dot com> changed:
What |Removed |Added
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CC| |zhenqiang.chen at arm dot com
--- Comment #20 from Zhenqiang Chen <zhenqiang.chen at arm dot com> ---
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
