/*
 * Copyright 2002-2019 Intel Corporation.
 * 
 * This software is provided to you as Sample Source Code as defined in the accompanying
 * End User License Agreement for the Intel(R) Software Development Products ("Agreement")
 * section 1.L.
 * 
 * This software and the related documents are provided as is, with no express or implied
 * warranties, other than those that are expressly stated in the License.
 */

#include <unistd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

intptr_t target_space;
intptr_t swizzle_space;
intptr_t page_mask;

int Swizzled(void *ptr)
{
    return ((intptr_t)ptr & page_mask) == swizzle_space;
}

void MyFree(void * p)
{
	if (Swizzled(p)) {
		fprintf (stderr, "Error MyFree got swizzled %p\n", p);
        fflush (stderr);
	}
}

void * MyAlloc(void *ptr)
{
    return ptr; // returned value will be swizzled
}

void * mmemcpy(void * to, const void * from, size_t n, void ** toout, void **fromout)
{
void * d0, *d1, *d2;
__asm__ __volatile__(
	"cld; rep ; movsl; testb $2,%b4; je 1f; movsw;"
	"1:testb $1,%b4;je 2f;"
	"movsb;"
	"2:"
	: "=&c" (d0), "=&D" (d1), "=&S" (d2):"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from) : "memory");
  *toout = d1;
  *fromout = d2;

return (to);
}

void memindex(void * ad)
{
    void * ptr = 0;
    __asm__ __volatile__("movl $0,(%0,%1,1)" :: "r"(ptr),"r"(ad));
}

int n = 8;

int main()
{
    char buffer2[20];
    char buffer3[20];
    void * al;
    void *toout,*fromout;
    int page_size = getpagesize();
    page_mask = ~((intptr_t)page_size-1);
    // Get some page aligned memory
    void * x = malloc(page_size * 2);
    target_space = ((intptr_t)x + page_size - 1) & page_mask;
    void * mm = (void*)target_space;

    al = MyAlloc(mm); // cause the swizzle
    swizzle_space = (intptr_t)al & page_mask;
    
    if (swizzle_space == target_space)
    {
        fprintf (stderr,"Error al not swizzled\n");
    }

    ((char*)al)[0] = 1;
    
    buffer2[0] = 2;
    buffer3[0] = 3;

    mmemcpy(buffer2, al, n, &toout, &fromout);
    
    fprintf(stderr, "al[0] %d buffer2[0] %d  toout - to %lx fromout - from %lx\n",
           ((char*)al)[0], buffer2[0], 
           (unsigned long)toout - (unsigned long)buffer2, (unsigned long)fromout- (unsigned long)al);
    if (!Swizzled (al)) {
        fprintf (stderr,"Error1 al not swizzled\n");
    }
    if (!Swizzled (fromout)) {
        fprintf (stderr,"Error2 fromout not swizzled\n");
    }

    mmemcpy(al, buffer3, n, &toout, &fromout);
    if (!Swizzled (al)) {
        fprintf (stderr,"Error3 al not swizzled\n");
        fflush (stderr);
    }
    if (!Swizzled (toout)) {
        fprintf (stderr,"Error4 toout not swizzled\n");
        fflush (stderr);
    }
    fprintf(stderr, "al[0] %d  buffer3[0] %d  toout - to %lx fromout - from %lx\n",((char*)al)[0],
            buffer3[0], (unsigned long)toout-(unsigned long)al, (unsigned long)fromout - (unsigned long)buffer3);
    fflush (stderr);
    
    memindex(al);
    
    MyFree(al);
    
    return 0;
}