aboutsummaryrefslogtreecommitdiff
path: root/arch/arm26/lib/memset.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm26/lib/memset.S')
-rw-r--r--arch/arm26/lib/memset.S80
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/arm26/lib/memset.S b/arch/arm26/lib/memset.S
new file mode 100644
index 000000000000..aedec10b58f5
--- /dev/null
+++ b/arch/arm26/lib/memset.S
@@ -0,0 +1,80 @@
+/*
+ * linux/arch/arm26/lib/memset.S
+ *
+ * Copyright (C) 1995-2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * ASM optimised string functions
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+ .text
+ .align 5
+ .word 0
+
+1: subs r2, r2, #4 @ 1 do we have enough
+ blt 5f @ 1 bytes to align with?
+ cmp r3, #2 @ 1
+ strltb r1, [r0], #1 @ 1
+ strleb r1, [r0], #1 @ 1
+ strb r1, [r0], #1 @ 1
+ add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3))
+/*
+ * The pointer is now aligned and the length is adjusted. Try doing the
+ * memzero again.
+ */
+
+ENTRY(memset)
+ ands r3, r0, #3 @ 1 unaligned?
+ bne 1b @ 1
+/*
+ * we know that the pointer in r0 is aligned to a word boundary.
+ */
+ orr r1, r1, r1, lsl #8
+ orr r1, r1, r1, lsl #16
+ mov r3, r1
+ cmp r2, #16
+ blt 4f
+/*
+ * We need an extra register for this loop - save the return address and
+ * use the LR
+ */
+ str lr, [sp, #-4]!
+ mov ip, r1
+ mov lr, r1
+
+2: subs r2, r2, #64
+ stmgeia r0!, {r1, r3, ip, lr} @ 64 bytes at a time.
+ stmgeia r0!, {r1, r3, ip, lr}
+ stmgeia r0!, {r1, r3, ip, lr}
+ stmgeia r0!, {r1, r3, ip, lr}
+ bgt 2b
+ LOADREGS(eqfd, sp!, {pc}) @ Now <64 bytes to go.
+/*
+ * No need to correct the count; we're only testing bits from now on
+ */
+ tst r2, #32
+ stmneia r0!, {r1, r3, ip, lr}
+ stmneia r0!, {r1, r3, ip, lr}
+ tst r2, #16
+ stmneia r0!, {r1, r3, ip, lr}
+ ldr lr, [sp], #4
+
+4: tst r2, #8
+ stmneia r0!, {r1, r3}
+ tst r2, #4
+ strne r1, [r0], #4
+/*
+ * When we get here, we've got less than 4 bytes to zero. We
+ * may have an unaligned pointer as well.
+ */
+5: tst r2, #2
+ strneb r1, [r0], #1
+ strneb r1, [r0], #1
+ tst r2, #1
+ strneb r1, [r0], #1
+ RETINSTR(mov,pc,lr)