diff options
Diffstat (limited to 'arch/sh/lib/memset.S')
| -rw-r--r-- | arch/sh/lib/memset.S | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/sh/lib/memset.S b/arch/sh/lib/memset.S new file mode 100644 index 000000000..c97648a4a --- /dev/null +++ b/arch/sh/lib/memset.S @@ -0,0 +1,72 @@ +! Taken from newlib-1.8.0 + +! +! Fast SH memset +! +! by Toshiyasu Morita (tm@netcom.com) +! +! Entry: r4: destination pointer +! r5: fill value +! r6: byte count +! +! Exit: r0-r3: trashed +! +#include <linux/linkage.h> + +ENTRY(memset) + mov r4,r3 ! Save return value + + mov r6,r0 ! Check explicitly for zero + cmp/eq #0,r0 + bt L_exit + + mov #12,r0 ! Check for small number of bytes + cmp/gt r6,r0 + bt L_store_byte_loop + + neg r4,r0 ! Align destination + add #4,r0 + and #3,r0 + tst r0,r0 + bt L_dup_bytes + .balignw 4,0x0009 +L_align_loop: + mov.b r5,@r4 + add #-1,r6 + add #1,r4 + dt r0 + bf L_align_loop + +L_dup_bytes: + extu.b r5,r5 ! Duplicate bytes across longword + swap.b r5,r0 + or r0,r5 + swap.w r5,r0 + or r0,r5 + + mov r6,r2 ! Calculate number of double longwords + shlr2 r2 + shlr r2 + + .balignw 4,0x0009 +L_store_long_loop: + mov.l r5,@r4 ! Store double longs to memory + dt r2 + mov.l r5,@(4,r4) + add #8,r4 + bf L_store_long_loop + + mov #7,r0 + and r0,r6 + tst r6,r6 + bt L_exit + .balignw 4,0x0009 +L_store_byte_loop: + mov.b r5,@r4 ! Store bytes to memory + add #1,r4 + dt r6 + bf L_store_byte_loop + +L_exit: + rts + mov r3,r0 |