aboutsummaryrefslogtreecommitdiff
path: root/nuttx/libc/string/lib_vikmemcpy.c
diff options
context:
space:
mode:
Diffstat (limited to 'nuttx/libc/string/lib_vikmemcpy.c')
-rw-r--r--nuttx/libc/string/lib_vikmemcpy.c348
1 files changed, 348 insertions, 0 deletions
diff --git a/nuttx/libc/string/lib_vikmemcpy.c b/nuttx/libc/string/lib_vikmemcpy.c
new file mode 100644
index 000000000..28bf4a4ce
--- /dev/null
+++ b/nuttx/libc/string/lib_vikmemcpy.c
@@ -0,0 +1,348 @@
+/****************************************************************************
+ * 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
+ *
+ *******************************************************************/
+
+void *memcpy(void *dest, const void *src, size_t count)
+{
+ uint8_t *dst8 = (uint8_t*)dest;
+ uint8_t *src8 = (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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-01 11:30:29 +0000