aboutsummaryrefslogtreecommitdiff
path: root/arch/blackfin/lib/memmove.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/blackfin/lib/memmove.S')
-rw-r--r--arch/blackfin/lib/memmove.S103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/blackfin/lib/memmove.S b/arch/blackfin/lib/memmove.S
new file mode 100644
index 00000000000..2e5fb7f8df1
--- /dev/null
+++ b/arch/blackfin/lib/memmove.S
@@ -0,0 +1,103 @@
+/*
+ * File: arch/blackfin/lib/memmove.S
+ * Based on:
+ * Author:
+ *
+ * Created:
+ * Description:
+ *
+ * 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
+ */
+
+#include <linux/linkage.h>
+
+.align 2
+
+/*
+ * C Library function MEMMOVE
+ * R0 = To Address (leave unchanged to form result)
+ * R1 = From Address
+ * R2 = count
+ * Data may overlap
+ */
+
+ENTRY(_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