https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62233
Oleg Endo <olegendo at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |olegendo at gcc dot gnu.org
--- Comment #4 from Oleg Endo <olegendo at gcc dot gnu.org> ---
Looks like with GCC 13 it now converts the loop into a memset call.
typedef struct {
int l;
int b[258];
} S;
void clear2 (S* s )
{
int i;
int len = s->l;
int* p = s->b;
for (i = 0; i < len; i++)
p[i] = 0;
}
compiling with GCC 13 -mlra -m2 -ml -O2:
mov.l @r4+,r6 ! 6 [c=1 l=2] movsi_i/5
cmp/pl r6 ! 10 [c=4 l=2] cmpgtsi_t/0
bf.s .L1 ! 11 [c=17 l=2] *cbranch_t
shll2 r6 ! 16 [c=4 l=2] ashlsi3_k/1
mov.l .L5,r0 ! 19 [c=10 l=2] movsi_i/0
jmp @r0 ! 20 [c=5 l=2] sibcall_valuei
mov #0,r5 ! 17 [c=4 l=2] movsi_i/2
.align 1
.L1:
rts
nop ! 41 [c=0 l=4] *return_i
.L6:
.align 2
.L5:
.long _memset
However, compiling with GCC 13 -mlra -m2 -ml -O2 -fno-builtin results in pretty
much the same code as in comment #2
