summaryrefslogtreecommitdiff
path: root/ports/sysdeps/powerpc/powerpc32/405/memcpy.S
diff options
context:
space:
mode:
Diffstat (limited to 'ports/sysdeps/powerpc/powerpc32/405/memcpy.S')
-rw-r--r--ports/sysdeps/powerpc/powerpc32/405/memcpy.S132
1 files changed, 132 insertions, 0 deletions
diff --git a/ports/sysdeps/powerpc/powerpc32/405/memcpy.S b/ports/sysdeps/powerpc/powerpc32/405/memcpy.S
new file mode 100644
index 0000000000..61025cf818
--- /dev/null
+++ b/ports/sysdeps/powerpc/powerpc32/405/memcpy.S
@@ -0,0 +1,132 @@
+/* Optimized memcpy implementation for PowerPC476.
+ Copyright (C) 2010 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+#include <bp-sym.h>
+#include <bp-asm.h>
+
+/* memcpy
+
+ r0:return address
+ r3:destination address
+ r4:source address
+ r5:byte count
+
+ Save return address in r0.
+ If destinationn and source are unaligned and copy count is greater than 256
+ then copy 0-3 bytes to make destination aligned.
+ If 32 or more bytes to copy we use 32 byte copy loop.
+ Finaly we copy 0-31 extra bytes. */
+
+EALIGN (BP_SYM (memcpy), 5, 0)
+/* Check if bytes to copy are greater than 256 and if
+ source and destination are unaligned */
+ cmpwi r5,0x0100
+ addi r0,r3,0
+ ble L(string_count_loop)
+ neg r6,r3
+ clrlwi. r6,r6,30
+ beq L(string_count_loop)
+ neg r6,r4
+ clrlwi. r6,r6,30
+ beq L(string_count_loop)
+ mtctr r6
+ subf r5,r6,r5
+
+L(unaligned_bytecopy_loop): /* Align destination by coping 0-3 bytes */
+ lbz r8,0x0(r4)
+ addi r4,r4,1
+ stb r8,0x0(r3)
+ addi r3,r3,1
+ bdnz L(unaligned_bytecopy_loop)
+ srwi. r7,r5,5
+ beq L(preword2_count_loop)
+ mtctr r7
+
+L(word8_count_loop_no_dcbt): /* Copy 32 bytes at a time */
+ lwz r6,0(r4)
+ lwz r7,4(r4)
+ lwz r8,8(r4)
+ lwz r9,12(r4)
+ subi r5,r5,0x20
+ stw r6,0(r3)
+ stw r7,4(r3)
+ stw r8,8(r3)
+ stw r9,12(r3)
+ lwz r6,16(r4)
+ lwz r7,20(r4)
+ lwz r8,24(r4)
+ lwz r9,28(r4)
+ addi r4,r4,0x20
+ stw r6,16(r3)
+ stw r7,20(r3)
+ stw r8,24(r3)
+ stw r9,28(r3)
+ addi r3,r3,0x20
+ bdnz L(word8_count_loop_no_dcbt)
+
+L(preword2_count_loop): /* Copy remaining 0-31 bytes */
+ clrlwi. r12,r5,27
+ beq L(end_memcpy)
+ mtxer r12
+ lswx r5,0,r4
+ stswx r5,0,r3
+ mr r3,r0
+ blr
+
+L(string_count_loop): /* Copy odd 0-31 bytes */
+ clrlwi. r12,r5,28
+ add r3,r3,r5
+ add r4,r4,r5
+ beq L(pre_string_copy)
+ mtxer r12
+ subf r4,r12,r4
+ subf r3,r12,r3
+ lswx r6,0,r4
+ stswx r6,0,r3
+
+L(pre_string_copy): /* Check how many 32 byte chunck to copy */
+ srwi. r7,r5,4
+ beq L(end_memcpy)
+ mtctr r7
+
+L(word4_count_loop_no_dcbt): /* Copy 32 bytes at a time */
+ lwz r6,-4(r4)
+ lwz r7,-8(r4)
+ lwz r8,-12(r4)
+ lwzu r9,-16(r4)
+ stw r6,-4(r3)
+ stw r7,-8(r3)
+ stw r8,-12(r3)
+ stwu r9,-16(r3)
+ bdz L(end_memcpy)
+ lwz r6,-4(r4)
+ lwz r7,-8(r4)
+ lwz r8,-12(r4)
+ lwzu r9,-16(r4)
+ stw r6,-4(r3)
+ stw r7,-8(r3)
+ stw r8,-12(r3)
+ stwu r9,-16(r3)
+ bdnz L(word4_count_loop_no_dcbt)
+
+L(end_memcpy):
+ mr r3,r0
+ blr
+END (BP_SYM (memcpy))
+libc_hidden_builtin_def (memcpy)