+++ /dev/null
-/* Copyright (C) 2013 - Adam Green (https://github.com/adamgreen)
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-*/
-#if defined(TOOLCHAIN_GCC) && defined(__thumb2__)
-
-#include <stdio.h>
-
-
-/* This is a hand written Thumb-2 assembly language version of the
- standard C memcpy() function that can be used by the lwIP networking
- stack to improve its performance. It copies 4 bytes at a time and
- unrolls the loop to perform 4 of these copies per loop iteration.
-*/
-__attribute__((naked)) void thumb2_memcpy(void* pDest, const void* pSource, size_t length)
-{
- __asm (
- ".syntax unified\n"
- ".thumb\n"
-
- // Copy 16 bytes at a time first.
- " lsrs r3, r2, #4\n"
- " beq.n 2$\n"
- "1$: ldr r12, [r1], #4\n"
- " str r12, [r0], #4\n"
- " ldr r12, [r1], #4\n"
- " str r12, [r0], #4\n"
- " ldr r12, [r1], #4\n"
- " str r12, [r0], #4\n"
- " ldr r12, [r1], #4\n"
- " str r12, [r0], #4\n"
- " subs r3, #1\n"
- " bne 1$\n"
-
- // Copy byte by byte for what is left.
- "2$:\n"
- " ands r3, r2, #0xf\n"
- " beq.n 4$\n"
- "3$: ldrb r12, [r1], #1\n"
- " strb r12, [r0], #1\n"
- " subs r3, #1\n"
- " bne 3$\n"
-
- // Return to caller.
- "4$: bx lr\n"
- );
-}
-
-#endif