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-rw-r--r--arch/avr32/lib/csum_partial.S47
1 files changed, 47 insertions, 0 deletions
diff --git a/arch/avr32/lib/csum_partial.S b/arch/avr32/lib/csum_partial.S
new file mode 100644
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--- /dev/null
+++ b/arch/avr32/lib/csum_partial.S
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * 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.
+ */
+
+ /*
+ * unsigned int csum_partial(const unsigned char *buff,
+ * int len, unsigned int sum)
+ */
+ .text
+ .global csum_partial
+ .type csum_partial,"function"
+ .align 1
+csum_partial:
+ /* checksum complete words, aligned or not */
+3: sub r11, 4
+ brlt 5f
+4: ld.w r9, r12++
+ add r10, r9
+ acr r10
+ sub r11, 4
+ brge 4b
+
+ /* return if we had a whole number of words */
+5: sub r11, -4
+ reteq r10
+
+ /* checksum any remaining bytes at the end */
+ mov r9, 0
+ mov r8, 0
+ cp r11, 2
+ brlt 6f
+ ld.uh r9, r12++
+ sub r11, 2
+ breq 7f
+ lsl r9, 16
+6: ld.ub r8, r12++
+ lsl r8, 8
+7: or r9, r8
+ add r10, r9
+ acr r10
+
+ retal r10
+ .size csum_partial, . - csum_partial