1 files changed, 92 insertions, 0 deletions
diff --git a/kernel/arch/blackfin/lib/memcmp.S b/kernel/arch/blackfin/lib/memcmp.S
new file mode 100644
index 000000000..2e1c9477f
--- /dev/null
+++ b/kernel/arch/blackfin/lib/memcmp.S
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2004-2009 Analog Devices Inc.
+ *
+ * Licensed under the Clear BSD license or the GPL-2 (or later)
+ */
+
+#include <linux/linkage.h>
+
+/* int memcmp(const void *s1, const void *s2, size_t n);
+ * R0 = First Address (s1)
+ * R1 = Second Address (s2)
+ * R2 = count (n)
+ *
+ * Favours word aligned data.
+ */
+
+.text
+
+.align 2
+
+ENTRY(_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:
+#if ANOMALY_05000202
+	R0 = [P0++];
+	R1 = [I0++];
+#else
+	MNOP || R0 = [P0++] || R1 = [I0++];
+#endif
+	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;
+
+ENDPROC(_memcmp)