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-rw-r--r--arch/blackfin/lib/memset.S87
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/blackfin/lib/memset.S b/arch/blackfin/lib/memset.S
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+/*
+ * Copyright 2004-2009 Analog Devices Inc.
+ *
+ * Licensed under the ADI BSD license or the GPL-2 (or later)
+ */
+
+#include <linux/linkage.h>
+
+.align 2
+
+#ifdef CONFIG_MEMSET_L1
+.section .l1.text
+#else
+.text
+#endif
+
+/*
+ * C Library function MEMSET
+ * R0 = address (leave unchanged to form result)
+ * R1 = filler byte
+ * R2 = count
+ * Favours word aligned data.
+ * The strncpy assumes that I0 and I1 are not used in this function
+ */
+
+ENTRY(_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;
+
+ENDPROC(_memset)