aboutsummaryrefslogtreecommitdiff
path: root/arch/avr32/lib/memcpy.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/avr32/lib/memcpy.S')
-rw-r--r--arch/avr32/lib/memcpy.S62
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/avr32/lib/memcpy.S b/arch/avr32/lib/memcpy.S
new file mode 100644
index 00000000000..0abb26142b6
--- /dev/null
+++ b/arch/avr32/lib/memcpy.S
@@ -0,0 +1,62 @@
+/*
+ * 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.
+ */
+
+ /*
+ * void *memcpy(void *to, const void *from, unsigned long n)
+ *
+ * This implementation does word-aligned loads in the main loop,
+ * possibly sacrificing alignment of stores.
+ *
+ * Hopefully, in most cases, both "to" and "from" will be
+ * word-aligned to begin with.
+ */
+ .text
+ .global memcpy
+ .type memcpy, @function
+memcpy:
+ mov r9, r11
+ andl r9, 3, COH
+ brne 1f
+
+ /* At this point, "from" is word-aligned */
+2: sub r10, 4
+ mov r9, r12
+ brlt 4f
+
+3: ld.w r8, r11++
+ sub r10, 4
+ st.w r12++, r8
+ brge 3b
+
+4: neg r10
+ reteq r9
+
+ /* Handle unaligned count */
+ lsl r10, 2
+ add pc, pc, r10
+ ld.ub r8, r11++
+ st.b r12++, r8
+ ld.ub r8, r11++
+ st.b r12++, r8
+ ld.ub r8, r11++
+ st.b r12++, r8
+ retal r9
+
+ /* Handle unaligned "from" pointer */
+1: sub r10, 4
+ brlt 4b
+ add r10, r9
+ lsl r9, 2
+ add pc, pc, r9
+ ld.ub r8, r11++
+ st.b r12++, r8
+ ld.ub r8, r11++
+ st.b r12++, r8
+ ld.ub r8, r11++
+ st.b r12++, r8
+ rjmp 2b