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.macro GET_FRONT_BITS rx ry
#ifdef __cskyLE__
lsr \rx, \ry
#else
lsl \rx, \ry
#endif
.endm
.macro GET_AFTER_BITS rx ry
#ifdef __cskyLE__
lsl \rx, \ry
#else
lsr \rx, \ry
#endif
.endm
#ifdef WANT_WIDE
# define Wmemcpy wmemcpy
#else
# define Wmemcpy memcpy
#endif
/* void *memcpy(void *dest, const void *src, size_t n); */
.text
.align 2
.global Wmemcpy
.type Wmemcpy, @function
Wmemcpy:
mov r3, r0
cmplti r2, 4 /* If len less than 4 bytes */
jbt .L_copy_by_byte
mov r12, r0
andi r12, 3
bnez r12, .L_dest_not_aligned /* If dest is not 4 bytes aligned */
.L0:
mov r12, r1
andi r12, 3
bnez r12, .L_dest_aligned_but_src_not_aligned /* If dest is aligned, but src is not aligned */
cmplti r2, 16 /* dest and src are all aligned */
jbt .L_aligned_and_len_less_16bytes /* If len less than 16 bytes */
.L_aligned_and_len_larger_16bytes: /* src and dst are all aligned, and len > 16 bytes */
ldw r18, (r1, 0)
ldw r19, (r1, 4)
ldw r20, (r1, 8)
ldw r21, (r1, 12)
stw r18, (r3, 0)
stw r19, (r3, 4)
stw r20, (r3, 8)
stw r21, (r3, 12)
subi r2, 16
addi r1, 16
addi r3, 16
cmplti r2, 16
jbf .L_aligned_and_len_larger_16bytes
.L_aligned_and_len_less_16bytes:
cmplti r2, 4
jbt .L_copy_by_byte
ldw r18, (r1, 0)
stw r18, (r3, 0)
subi r2, 4
addi r1, 4
addi r3, 4
jbr .L_aligned_and_len_less_16bytes
.L_copy_by_byte: /* len less than 4 bytes */
cmpnei r2, 0
jbf .L_return
ldb r18, (r1, 0)
stb r18, (r3, 0)
subi r2, 1
addi r1, 1
addi r3, 1
jbr .L_copy_by_byte
.L_return:
rts
/* If dest is not aligned, just copying some bytes makes the dest align.
After that, we judge whether the src is aligned. */
.L_dest_not_aligned:
rsub r13, r1, r3 /* consider overlapped case */
abs r13, r13
cmplt r13, r2
jbt .L_copy_by_byte
.L1:
ldb r18, (r1, 0) /* makes the dest align. */
stb r18, (r3, 0)
addi r12, 1
subi r2, 1
addi r1, 1
addi r3, 1
cmpnei r12, 4
jbt .L1
cmplti r2, 4
jbt .L_copy_by_byte
jbf .L0 /* judge whether the src is aligned. */
.L_dest_aligned_but_src_not_aligned:
rsub r13, r1, r3 /* consider overlapped case */
abs r13, r13
cmplt r13, r2
jbt .L_copy_by_byte
bclri r1, 0
bclri r1, 1
ldw r18, (r1, 0)
addi r1, 4
movi r13, 8
mult r13, r12
mov r24, r13 /* r12 is used to store the misaligned bits */
rsubi r13, 32
mov r25, r13
cmplti r2, 16
jbt .L_not_aligned_and_len_less_16bytes
.L_not_aligned_and_len_larger_16bytes:
ldw r20, (r1, 0)
ldw r21, (r1, 4)
ldw r22, (r1, 8)
ldw r23, (r1, 12)
GET_FRONT_BITS r18 r24 /* little or big endian? */
mov r19, r20
GET_AFTER_BITS r20 r25
or r20, r18
GET_FRONT_BITS r19 r24
mov r18, r21
GET_AFTER_BITS r21 r13
or r21, r19
GET_FRONT_BITS r18 r24
mov r19, r22
GET_AFTER_BITS r22 r25
or r22, r18
GET_FRONT_BITS r19 r24
mov r18, r23
GET_AFTER_BITS r23 r25
or r23, r19
stw r20, (r3, 0)
stw r21, (r3, 4)
stw r22, (r3, 8)
stw r23, (r3, 12)
subi r2, 16
addi r1, 16
addi r3, 16
cmplti r2, 16
jbf .L_not_aligned_and_len_larger_16bytes
.L_not_aligned_and_len_less_16bytes:
cmplti r2, 4
jbf .L2
rsubi r12, 4 /* r12 is used to stored the misaligned bits */
subu r1, r12 /* initial the position */
jbr .L_copy_by_byte
.L2:
ldw r21, (r1, 0)
GET_FRONT_BITS r18 r24
mov r19, r18
mov r18, r21
GET_AFTER_BITS r21 r25
or r21, r19
stw r21, (r3, 0)
subi r2, 4
addi r1, 4
addi r3, 4
jbr .L_not_aligned_and_len_less_16bytes
.size Wmemcpy, .-Wmemcpy
libc_hidden_def(Wmemcpy)
.weak Wmemcpy
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