1 files changed, 100 insertions, 0 deletions
diff --git a/lib_blackfin/memcmp.S b/lib_blackfin/memcmp.S
new file mode 100644
index 0000000..9b58832
--- /dev/null
+++ b/lib_blackfin/memcmp.S
@@ -0,0 +1,100 @@
+/*
+ * File: memcmp.S
+ *
+ * Copyright 2004-2007 Analog Devices Inc.
+ * 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 MEMCMP
+ * R0 = First Address
+ * R1 = Second Address
+ * R2 = count
+ * Favours word aligned data.
+ */
+
+.globl _memcmp;
+_memcmp:
+	I1 = P3;
+	P0 = R0;			/* P0 = s1 address */
+	P3 = R1;			/* P3 = s2 Address  */
+	P2 = R2 ;			/* P2 = count */
+	CC = R2 <= 7(IU);
+	IF CC JUMP  .Ltoo_small;
+	I0 = R1;			/* s2 */
+	R1 = R1 | R0;		/* OR addresses together */
+	R1 <<= 30;		/* check bottom two bits */
+	CC =  AZ;			/* AZ set if zero. */
+	IF !CC JUMP  .Lbytes ;	/* Jump if addrs not aligned. */
+
+	P1 = P2 >> 2;		/* count = n/4 */
+	R3 =  3;
+	R2 = R2 & R3;		/* remainder */
+	P2 = R2;			/* set remainder */
+
+	LSETUP (.Lquad_loop_s , .Lquad_loop_e) LC0=P1;
+.Lquad_loop_s:
+	NOP;
+	R0 = [P0++];
+	R1 = [I0++];
+	CC = R0 == R1;
+	IF !CC JUMP .Lquad_different;
+.Lquad_loop_e:
+	NOP;
+
+	P3 = I0;			/* s2 */
+.Ltoo_small:
+	CC = P2 == 0;		/* Check zero count*/
+	IF CC JUMP .Lfinished;	/* very unlikely*/
+
+.Lbytes:
+	LSETUP (.Lbyte_loop_s , .Lbyte_loop_e) LC0=P2;
+.Lbyte_loop_s:
+	R1 = B[P3++](Z);	/* *s2 */
+	R0 = B[P0++](Z);	/* *s1 */
+	CC = R0 == R1;
+	IF !CC JUMP .Ldifferent;
+.Lbyte_loop_e:
+	NOP;
+
+.Ldifferent:
+	R0 = R0 - R1;
+	P3 = I1;
+	RTS;
+
+.Lquad_different:
+/* We've read two quads which don't match.
+ * Can't just compare them, because we're
+ * a little-endian machine, so the MSBs of
+ * the regs occur at later addresses in the
+ * string.
+ * Arrange to re-read those two quads again,
+ * byte-by-byte.
+ */
+	P0 += -4;		/* back up to the start of the */
+	P3 = I0;		/* quads, and increase the*/
+	P2 += 4;		/* remainder count*/
+	P3 += -4;
+	JUMP .Lbytes;
+
+.Lfinished:
+	R0 = 0;
+	P3 = I1;
+	RTS;