349 lines
14 KiB
C
349 lines
14 KiB
C
/****************************************************************************
|
|
* File: libc/string/lib_vikmemcpy.c
|
|
*
|
|
* This is version of the optimized memcpy by Daniel Vik, adapted to the
|
|
* NuttX environment.
|
|
*
|
|
* Copyright (C) 1999-2010 Daniel Vik
|
|
*
|
|
* Adaptations include:
|
|
* - File name change
|
|
* - Use of types defined in stdint.h
|
|
* - Integration with the NuttX configuration system
|
|
* - Other cosmetic changes for consistency with NuttX coding standards
|
|
*
|
|
* This software is provided 'as-is', without any express or implied
|
|
* warranty. In no event will the authors be held liable for any
|
|
* damages arising from the use of this software.
|
|
* Permission is granted to anyone to use this software for any
|
|
* purpose, including commercial applications, and to alter it and
|
|
* redistribute it freely, subject to the following restrictions:
|
|
*
|
|
* 1. The origin of this software must not be misrepresented; you
|
|
* must not claim that you wrote the original software. If you
|
|
* use this software in a product, an acknowledgment in the
|
|
* use this software in a product, an acknowledgment in the
|
|
* product documentation would be appreciated but is not
|
|
* required.
|
|
*
|
|
* 2. Altered source versions must be plainly marked as such, and
|
|
* must not be misrepresented as being the original software.
|
|
*
|
|
* 3. This notice may not be removed or altered from any source
|
|
* distribution.
|
|
*
|
|
* Description: Implementation of the standard library function memcpy.
|
|
* This implementation of memcpy() is ANSI-C89 compatible.
|
|
*
|
|
* The following configuration options can be set:
|
|
*
|
|
* CONFIG_ENDIAN_BIG
|
|
* Uses processor with big endian addressing. Default is little endian.
|
|
*
|
|
* CONFIG_MEMCPY_PRE_INC_PTRS
|
|
* Use pre increment of pointers. Default is post increment of pointers.
|
|
*
|
|
* CONFIG_MEMCPY_INDEXED_COPY
|
|
* Copying data using array indexing. Using this option, disables the
|
|
* CONFIG_MEMCPY_PRE_INC_PTRS option.
|
|
*
|
|
* CONFIG_MEMCPY_64BIT - Compiles memcpy for 64 bit architectures
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Configuration definitions.
|
|
****************************************************************************/
|
|
|
|
#define CONFIG_MEMCPY_INDEXED_COPY
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
#include <nuttx/compiler.h>
|
|
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/* Can't support CONFIG_MEMCPY_64BIT if the platform does not have 64-bit
|
|
* integer types.
|
|
*/
|
|
|
|
#ifndef CONFIG_HAVE_LONG_LONG
|
|
# undef CONFIG_MEMCPY_64BIT
|
|
#endif
|
|
|
|
/* Remove definitions when CONFIG_MEMCPY_INDEXED_COPY is defined */
|
|
|
|
#if defined (CONFIG_MEMCPY_INDEXED_COPY)
|
|
# if defined (CONFIG_MEMCPY_PRE_INC_PTRS)
|
|
# undef CONFIG_MEMCPY_PRE_INC_PTRS
|
|
# endif /* CONFIG_MEMCPY_PRE_INC_PTRS */
|
|
#endif /* CONFIG_MEMCPY_INDEXED_COPY */
|
|
|
|
/* Definitions for pre and post increment of pointers */
|
|
|
|
#if defined (CONFIG_MEMCPY_PRE_INC_PTRS)
|
|
|
|
# define START_VAL(x) (x)--
|
|
# define INC_VAL(x) *++(x)
|
|
# define CAST_TO_U8(p, o) ((uint8_t*)p + o + TYPE_WIDTH)
|
|
# define WHILE_DEST_BREAK (TYPE_WIDTH - 1)
|
|
# define PRE_LOOP_ADJUST - (TYPE_WIDTH - 1)
|
|
# define PRE_SWITCH_ADJUST + 1
|
|
|
|
#else /* CONFIG_MEMCPY_PRE_INC_PTRS */
|
|
|
|
# define START_VAL(x)
|
|
# define INC_VAL(x) *(x)++
|
|
# define CAST_TO_U8(p, o) ((uint8_t*)p + o)
|
|
# define WHILE_DEST_BREAK 0
|
|
# define PRE_LOOP_ADJUST
|
|
# define PRE_SWITCH_ADJUST
|
|
|
|
#endif /* CONFIG_MEMCPY_PRE_INC_PTRS */
|
|
|
|
/* Definitions for endian-ness */
|
|
|
|
#ifdef CONFIG_ENDIAN_BIG
|
|
|
|
# define SHL <<
|
|
# define SHR >>
|
|
|
|
#else /* CONFIG_ENDIAN_BIG */
|
|
|
|
# define SHL >>
|
|
# define SHR <<
|
|
|
|
#endif /* CONFIG_ENDIAN_BIG */
|
|
|
|
/****************************************************************************
|
|
* Macros for copying words of different alignment.
|
|
* Uses incremening pointers.
|
|
****************************************************************************/
|
|
|
|
#define CP_INCR() \
|
|
{ \
|
|
INC_VAL(dstN) = INC_VAL(srcN); \
|
|
}
|
|
|
|
#define CP_INCR_SH(shl, shr) \
|
|
{ \
|
|
dstWord = srcWord SHL shl; \
|
|
srcWord = INC_VAL(srcN); \
|
|
dstWord |= srcWord SHR shr; \
|
|
INC_VAL(dstN) = dstWord; \
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Macros for copying words of different alignment.
|
|
* Uses array indexes.
|
|
****************************************************************************/
|
|
|
|
#define CP_INDEX(idx) \
|
|
{ \
|
|
dstN[idx] = srcN[idx]; \
|
|
}
|
|
|
|
#define CP_INDEX_SH(x, shl, shr) \
|
|
{ \
|
|
dstWord = srcWord SHL shl; \
|
|
srcWord = srcN[x]; \
|
|
dstWord |= srcWord SHR shr; \
|
|
dstN[x] = dstWord; \
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Macros for copying words of different alignment.
|
|
* Uses incremening pointers or array indexes depending on
|
|
* configuration.
|
|
****************************************************************************/
|
|
|
|
#if defined (CONFIG_MEMCPY_INDEXED_COPY)
|
|
|
|
# define CP(idx) CP_INDEX(idx)
|
|
# define CP_SH(idx, shl, shr) CP_INDEX_SH(idx, shl, shr)
|
|
|
|
# define INC_INDEX(p, o) ((p) += (o))
|
|
|
|
#else /* CONFIG_MEMCPY_INDEXED_COPY */
|
|
|
|
# define CP(idx) CP_INCR()
|
|
# define CP_SH(idx, shl, shr) CP_INCR_SH(shl, shr)
|
|
|
|
# define INC_INDEX(p, o)
|
|
|
|
#endif /* CONFIG_MEMCPY_INDEXED_COPY */
|
|
|
|
#define COPY_REMAINING(count) \
|
|
{ \
|
|
START_VAL(dst8); \
|
|
START_VAL(src8); \
|
|
\
|
|
switch (count) \
|
|
{ \
|
|
case 7: INC_VAL(dst8) = INC_VAL(src8); \
|
|
case 6: INC_VAL(dst8) = INC_VAL(src8); \
|
|
case 5: INC_VAL(dst8) = INC_VAL(src8); \
|
|
case 4: INC_VAL(dst8) = INC_VAL(src8); \
|
|
case 3: INC_VAL(dst8) = INC_VAL(src8); \
|
|
case 2: INC_VAL(dst8) = INC_VAL(src8); \
|
|
case 1: INC_VAL(dst8) = INC_VAL(src8); \
|
|
case 0: \
|
|
default: break; \
|
|
} \
|
|
}
|
|
|
|
#define COPY_NO_SHIFT() \
|
|
{ \
|
|
UIntN* dstN = (UIntN*)(dst8 PRE_LOOP_ADJUST); \
|
|
UIntN* srcN = (UIntN*)(src8 PRE_LOOP_ADJUST); \
|
|
size_t length = count / TYPE_WIDTH; \
|
|
\
|
|
while (length & 7) \
|
|
{ \
|
|
CP_INCR(); \
|
|
length--; \
|
|
} \
|
|
\
|
|
length /= 8; \
|
|
\
|
|
while (length--) \
|
|
{ \
|
|
CP(0); \
|
|
CP(1); \
|
|
CP(2); \
|
|
CP(3); \
|
|
CP(4); \
|
|
CP(5); \
|
|
CP(6); \
|
|
CP(7); \
|
|
\
|
|
INC_INDEX(dstN, 8); \
|
|
INC_INDEX(srcN, 8); \
|
|
} \
|
|
\
|
|
src8 = CAST_TO_U8(srcN, 0); \
|
|
dst8 = CAST_TO_U8(dstN, 0); \
|
|
\
|
|
COPY_REMAINING(count & (TYPE_WIDTH - 1)); \
|
|
\
|
|
return dest; \
|
|
}
|
|
|
|
#define COPY_SHIFT(shift) \
|
|
{ \
|
|
UIntN* dstN = (UIntN*)((((UIntN)dst8) PRE_LOOP_ADJUST) & \
|
|
~(TYPE_WIDTH - 1)); \
|
|
UIntN* srcN = (UIntN*)((((UIntN)src8) PRE_LOOP_ADJUST) & \
|
|
~(TYPE_WIDTH - 1)); \
|
|
size_t length = count / TYPE_WIDTH; \
|
|
UIntN srcWord = INC_VAL(srcN); \
|
|
UIntN dstWord; \
|
|
\
|
|
while (length & 7) \
|
|
{ \
|
|
CP_INCR_SH(8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
length--; \
|
|
} \
|
|
\
|
|
length /= 8; \
|
|
\
|
|
while (length--) \
|
|
{ \
|
|
CP_SH(0, 8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
CP_SH(1, 8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
CP_SH(2, 8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
CP_SH(3, 8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
CP_SH(4, 8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
CP_SH(5, 8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
CP_SH(6, 8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
CP_SH(7, 8 * shift, 8 * (TYPE_WIDTH - shift)); \
|
|
\
|
|
INC_INDEX(dstN, 8); \
|
|
INC_INDEX(srcN, 8); \
|
|
} \
|
|
\
|
|
src8 = CAST_TO_U8(srcN, (shift - TYPE_WIDTH)); \
|
|
dst8 = CAST_TO_U8(dstN, 0); \
|
|
\
|
|
COPY_REMAINING(count & (TYPE_WIDTH - 1)); \
|
|
\
|
|
return dest; \
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Type Definitions
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_MEMCPY_64BIT
|
|
typedef uint64_t UIntN;
|
|
# define TYPE_WIDTH 8L
|
|
#else
|
|
typedef uint32_t UIntN;
|
|
# define TYPE_WIDTH 4L
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
/****************************************************************************
|
|
* Name: memcpy
|
|
*
|
|
* Description:
|
|
* Copies count bytes from src to dest. No overlap check is performed.
|
|
*
|
|
* Input Parameters:
|
|
* dest - pointer to destination buffer
|
|
* src - pointer to source buffer
|
|
* count - number of bytes to copy
|
|
*
|
|
* Returned Value:
|
|
* A pointer to destination buffer
|
|
*
|
|
****************************************************************************/
|
|
|
|
FAR void *memcpy(FAR void *dest, FAR const void *src, size_t count)
|
|
{
|
|
FAR uint8_t *dst8 = (FAR uint8_t *)dest;
|
|
FAR uint8_t *src8 = (FAR uint8_t *)src;
|
|
|
|
if (count < 8)
|
|
{
|
|
COPY_REMAINING(count);
|
|
return dest;
|
|
}
|
|
|
|
START_VAL(dst8);
|
|
START_VAL(src8);
|
|
|
|
while (((UIntN)dst8 & (TYPE_WIDTH - 1)) != WHILE_DEST_BREAK)
|
|
{
|
|
INC_VAL(dst8) = INC_VAL(src8);
|
|
count--;
|
|
}
|
|
|
|
switch ((((UIntN)src8) PRE_SWITCH_ADJUST) & (TYPE_WIDTH - 1))
|
|
{
|
|
case 0: COPY_NO_SHIFT(); break;
|
|
case 1: COPY_SHIFT(1); break;
|
|
case 2: COPY_SHIFT(2); break;
|
|
case 3: COPY_SHIFT(3); break;
|
|
#if TYPE_WIDTH > 4
|
|
case 4: COPY_SHIFT(4); break;
|
|
case 5: COPY_SHIFT(5); break;
|
|
case 6: COPY_SHIFT(6); break;
|
|
case 7: COPY_SHIFT(7); break;
|
|
#endif
|
|
}
|
|
|
|
return dest;
|
|
}
|