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!
! Fast SH memset
!
! by Toshiyasu Morita (tm@netcom.com)
!
! Entry: r4: destination pointer
! r5: fill value
! r6: byte count
!
! Exit: r0-r3: trashed
!
! This assumes that the first four bytes of the address space (0..3) are
! reserved - usually by the linker script. Otherwise, we would had to check
! for the case of objects of the size 12..15 at address 0..3 .
#include "asm.h"
ENTRY(memset)
mov #12,r0 ! Check for small number of bytes
cmp/gt r6,r0
mov r4,r0
SL(bt, L_store_byte_loop_check0, add r4,r6)
tst #3,r0 ! Align destination
SL(bt, L_dup_bytes, extu.b r5,r5)
.balignw 4,0x0009
L_align_loop:
mov.b r5,@r0
add #1,r0
tst #3,r0
bf L_align_loop
L_dup_bytes:
swap.b r5,r2 ! Duplicate bytes across longword
or r2,r5
swap.w r5,r2
or r2,r5
add #-16,r6
.balignw 4,0x0009
L_store_long_loop:
mov.l r5,@r0 ! Store double longs to memory
cmp/hs r6,r0
mov.l r5,@(4,r0)
SL(bf, L_store_long_loop, add #8,r0)
add #16,r6
L_store_byte_loop_check0:
cmp/eq r6,r0
bt L_exit
.balignw 4,0x0009
L_store_byte_loop:
mov.b r5,@r0 ! Store bytes to memory
add #1,r0
cmp/eq r6,r0
bf L_store_byte_loop
L_exit:
rts
mov r4,r0
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