#include <linux/string.h>
  #include <linux/module.h>
  
  #undef memcpy
  #undef memset
  
  __visible void *memcpy(void *to, const void *from, size_t n)
  {
  #ifdef CONFIG_X86_USE_3DNOW
  	return __memcpy3d(to, from, n);
  #else
  	return __memcpy(to, from, n);
  #endif
  }
  EXPORT_SYMBOL(memcpy);
  
  __visible void *memset(void *s, int c, size_t count)
  {
  	return __memset(s, c, count);
  }
  EXPORT_SYMBOL(memset);
  
  __visible void *memmove(void *dest, const void *src, size_t n)
  {
  	int d0,d1,d2,d3,d4,d5;
  	char *ret = dest;
  
  	__asm__ __volatile__(
  		/* Handle more 16 bytes in loop */
  		"cmp $0x10, %0
  \t"
  		"jb	1f
  \t"
  
  		/* Decide forward/backward copy mode */
  		"cmp %2, %1
  \t"
  		"jb	2f
  \t"
  
  		/*
  		 * movs instruction have many startup latency
  		 * so we handle small size by general register.
  		 */
  		"cmp  $680, %0
  \t"
  		"jb 3f
  \t"
  		/*
  		 * movs instruction is only good for aligned case.
  		 */
  		"mov %1, %3
  \t"
  		"xor %2, %3
  \t"
  		"and $0xff, %3
  \t"
  		"jz 4f
  \t"
  		"3:
  \t"
  		"sub $0x10, %0
  \t"
  
  		/*
  		 * We gobble 16 bytes forward in each loop.
  		 */
  		"3:
  \t"
  		"sub $0x10, %0
  \t"
  		"mov 0*4(%1), %3
  \t"
  		"mov 1*4(%1), %4
  \t"
  		"mov  %3, 0*4(%2)
  \t"
  		"mov  %4, 1*4(%2)
  \t"
  		"mov 2*4(%1), %3
  \t"
  		"mov 3*4(%1), %4
  \t"
  		"mov  %3, 2*4(%2)
  \t"
  		"mov  %4, 3*4(%2)
  \t"
  		"lea  0x10(%1), %1
  \t"
  		"lea  0x10(%2), %2
  \t"
  		"jae 3b
  \t"
  		"add $0x10, %0
  \t"
  		"jmp 1f
  \t"
  
  		/*
  		 * Handle data forward by movs.
  		 */
  		".p2align 4
  \t"
  		"4:
  \t"
  		"mov -4(%1, %0), %3
  \t"
  		"lea -4(%2, %0), %4
  \t"
  		"shr $2, %0
  \t"
  		"rep movsl
  \t"
  		"mov %3, (%4)
  \t"
  		"jmp 11f
  \t"
  		/*
  		 * Handle data backward by movs.
  		 */
  		".p2align 4
  \t"
  		"6:
  \t"
  		"mov (%1), %3
  \t"
  		"mov %2, %4
  \t"
  		"lea -4(%1, %0), %1
  \t"
  		"lea -4(%2, %0), %2
  \t"
  		"shr $2, %0
  \t"
  		"std
  \t"
  		"rep movsl
  \t"
  		"mov %3,(%4)
  \t"
  		"cld
  \t"
  		"jmp 11f
  \t"
  
  		/*
  		 * Start to prepare for backward copy.
  		 */
  		".p2align 4
  \t"
  		"2:
  \t"
  		"cmp  $680, %0
  \t"
  		"jb 5f
  \t"
  		"mov %1, %3
  \t"
  		"xor %2, %3
  \t"
  		"and $0xff, %3
  \t"
  		"jz 6b
  \t"
  
  		/*
  		 * Calculate copy position to tail.
  		 */
  		"5:
  \t"
  		"add %0, %1
  \t"
  		"add %0, %2
  \t"
  		"sub $0x10, %0
  \t"
  
  		/*
  		 * We gobble 16 bytes backward in each loop.
  		 */
  		"7:
  \t"
  		"sub $0x10, %0
  \t"
  
  		"mov -1*4(%1), %3
  \t"
  		"mov -2*4(%1), %4
  \t"
  		"mov  %3, -1*4(%2)
  \t"
  		"mov  %4, -2*4(%2)
  \t"
  		"mov -3*4(%1), %3
  \t"
  		"mov -4*4(%1), %4
  \t"
  		"mov  %3, -3*4(%2)
  \t"
  		"mov  %4, -4*4(%2)
  \t"
  		"lea  -0x10(%1), %1
  \t"
  		"lea  -0x10(%2), %2
  \t"
  		"jae 7b
  \t"
  		/*
  		 * Calculate copy position to head.
  		 */
  		"add $0x10, %0
  \t"
  		"sub %0, %1
  \t"
  		"sub %0, %2
  \t"
  
  		/*
  		 * Move data from 8 bytes to 15 bytes.
  		 */
  		".p2align 4
  \t"
  		"1:
  \t"
  		"cmp $8, %0
  \t"
  		"jb 8f
  \t"
  		"mov 0*4(%1), %3
  \t"
  		"mov 1*4(%1), %4
  \t"
  		"mov -2*4(%1, %0), %5
  \t"
  		"mov -1*4(%1, %0), %1
  \t"
  
  		"mov  %3, 0*4(%2)
  \t"
  		"mov  %4, 1*4(%2)
  \t"
  		"mov  %5, -2*4(%2, %0)
  \t"
  		"mov  %1, -1*4(%2, %0)
  \t"
  		"jmp 11f
  \t"
  
  		/*
  		 * Move data from 4 bytes to 7 bytes.
  		 */
  		".p2align 4
  \t"
  		"8:
  \t"
  		"cmp $4, %0
  \t"
  		"jb 9f
  \t"
  		"mov 0*4(%1), %3
  \t"
  		"mov -1*4(%1, %0), %4
  \t"
  		"mov  %3, 0*4(%2)
  \t"
  		"mov  %4, -1*4(%2, %0)
  \t"
  		"jmp 11f
  \t"
  
  		/*
  		 * Move data from 2 bytes to 3 bytes.
  		 */
  		".p2align 4
  \t"
  		"9:
  \t"
  		"cmp $2, %0
  \t"
  		"jb 10f
  \t"
  		"movw 0*2(%1), %%dx
  \t"
  		"movw -1*2(%1, %0), %%bx
  \t"
  		"movw %%dx, 0*2(%2)
  \t"
  		"movw %%bx, -1*2(%2, %0)
  \t"
  		"jmp 11f
  \t"
  
  		/*
  		 * Move data for 1 byte.
  		 */
  		".p2align 4
  \t"
  		"10:
  \t"
  		"cmp $1, %0
  \t"
  		"jb 11f
  \t"
  		"movb (%1), %%cl
  \t"
  		"movb %%cl, (%2)
  \t"
  		".p2align 4
  \t"
  		"11:"
  		: "=&c" (d0), "=&S" (d1), "=&D" (d2),
  		  "=r" (d3),"=r" (d4), "=r"(d5)
  		:"0" (n),
  		 "1" (src),
  		 "2" (dest)
  		:"memory");
  
  	return ret;
  
  }
  EXPORT_SYMBOL(memmove);