84 lines
1.9 KiB
ArmAsm
84 lines
1.9 KiB
ArmAsm
/*
|
|
* File: memmove.S
|
|
*
|
|
* Copyright 2004-2007 Analog Devices Inc.
|
|
* Enter bugs at http://blackfin.uclinux.org/
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
.align 2
|
|
|
|
/*
|
|
* C Library function MEMMOVE
|
|
* R0 = To Address (leave unchanged to form result)
|
|
* R1 = From Address
|
|
* R2 = count
|
|
* Data may overlap
|
|
*/
|
|
|
|
.globl _memmove;
|
|
.type _memmove, STT_FUNC;
|
|
_memmove:
|
|
I1 = P3;
|
|
P0 = R0; /* P0 = To address */
|
|
P3 = R1; /* P3 = From Address */
|
|
P2 = R2 ; /* P2 = count */
|
|
CC = P2 == 0; /* Check zero count*/
|
|
IF CC JUMP .Lfinished; /* very unlikely */
|
|
|
|
CC = R1 < R0 (IU); /* From < To */
|
|
IF !CC JUMP .Lno_overlap;
|
|
R3 = R1 + R2;
|
|
CC = R0 <= R3 (IU); /* (From+len) >= To */
|
|
IF CC JUMP .Loverlap;
|
|
.Lno_overlap:
|
|
R3 = 11;
|
|
CC = R2 <= R3;
|
|
IF CC JUMP .Lbytes;
|
|
R3 = R1 | R0; /* OR addresses together */
|
|
R3 <<= 30; /* check bottom two bits */
|
|
CC = AZ; /* AZ set if zero.*/
|
|
IF !CC JUMP .Lbytes ; /* Jump if addrs not aligned.*/
|
|
|
|
I0 = P3;
|
|
P1 = P2 >> 2; /* count = n/4 */
|
|
P1 += -1;
|
|
R3 = 3;
|
|
R2 = R2 & R3; /* remainder */
|
|
P2 = R2; /* set remainder */
|
|
R1 = [I0++];
|
|
|
|
LSETUP (.Lquad_loop , .Lquad_loop) LC0=P1;
|
|
.Lquad_loop: MNOP || [P0++] = R1 || R1 = [I0++];
|
|
[P0++] = R1;
|
|
|
|
CC = P2 == 0; /* any remaining bytes? */
|
|
P3 = I0; /* Ammend P3 to updated ptr. */
|
|
IF !CC JUMP .Lbytes;
|
|
P3 = I1;
|
|
RTS;
|
|
|
|
.Lbytes: LSETUP (.Lbyte2_s , .Lbyte2_e) LC0=P2;
|
|
.Lbyte2_s: R1 = B[P3++](Z);
|
|
.Lbyte2_e: B[P0++] = R1;
|
|
|
|
.Lfinished: P3 = I1;
|
|
RTS;
|
|
|
|
.Loverlap:
|
|
P2 += -1;
|
|
P0 = P0 + P2;
|
|
P3 = P3 + P2;
|
|
R1 = B[P3--] (Z);
|
|
CC = P2 == 0;
|
|
IF CC JUMP .Lno_loop;
|
|
LSETUP (.Lol_s, .Lol_e) LC0 = P2;
|
|
.Lol_s: B[P0--] = R1;
|
|
.Lol_e: R1 = B[P3--] (Z);
|
|
.Lno_loop: B[P0] = R1;
|
|
P3 = I1;
|
|
RTS;
|
|
|
|
.size _memmove, .-_memmove
|