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+/*
+ * File: arch/blackfin/lib/memset.S
+ * Based on:
+ * Author:
+ *
+ * Created:
+ * Description:
+ *
+ * Rev: $Id: memset.S 2769 2007-02-19 16:45:53Z hennerich $
+ *
+ * Modified:
+ * Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs: Enter bugs at http://blackfin.uclinux.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+.align 2
+
+/*
+ * C Library function MEMSET
+ * R0 = address (leave unchanged to form result)
+ * R1 = filler byte
+ * R2 = count
+ * Favours word aligned data.
+ */
+
+.globl _memset;
+_memset:
+ P0 = R0 ; /* P0 = address */
+ P2 = R2 ; /* P2 = count */
+ R3 = R0 + R2; /* end */
+ CC = R2 <= 7(IU);
+ IF CC JUMP .Ltoo_small;
+ R1 = R1.B (Z); /* R1 = fill char */
+ R2 = 3;
+ R2 = R0 & R2; /* addr bottom two bits */
+ CC = R2 == 0; /* AZ set if zero. */
+ IF !CC JUMP .Lforce_align ; /* Jump if addr not aligned. */
+
+.Laligned:
+ P1 = P2 >> 2; /* count = n/4 */
+ R2 = R1 << 8; /* create quad filler */
+ R2.L = R2.L + R1.L(NS);
+ R2.H = R2.L + R1.H(NS);
+ P2 = R3;
+
+ LSETUP (.Lquad_loop , .Lquad_loop) LC0=P1;
+.Lquad_loop:
+ [P0++] = R2;
+
+ CC = P0 == P2;
+ IF !CC JUMP .Lbytes_left;
+ RTS;
+
+.Lbytes_left:
+ R2 = R3; /* end point */
+ R3 = P0; /* current position */
+ R2 = R2 - R3; /* bytes left */
+ P2 = R2;
+
+.Ltoo_small:
+ CC = P2 == 0; /* Check zero count */
+ IF CC JUMP .Lfinished; /* Unusual */
+
+.Lbytes:
+ LSETUP (.Lbyte_loop , .Lbyte_loop) LC0=P2;
+.Lbyte_loop:
+ B[P0++] = R1;
+
+.Lfinished:
+ RTS;
+
+.Lforce_align:
+ CC = BITTST (R0, 0); /* odd byte */
+ R0 = 4;
+ R0 = R0 - R2;
+ P1 = R0;
+ R0 = P0; /* Recover return address */
+ IF !CC JUMP .Lskip1;
+ B[P0++] = R1;
+.Lskip1:
+ CC = R2 <= 2; /* 2 bytes */
+ P2 -= P1; /* reduce count */
+ IF !CC JUMP .Laligned;
+ B[P0++] = R1;
+ B[P0++] = R1;
+ JUMP .Laligned;