/***************************
 * D programming language http://www.digitalmars.com/d/
 * Runtime support for double array operations.
 * Placed in public domain.
 */

import std.cpuid;

version (unittest)
{
    /* This is so unit tests will test every CPU variant
     */
    int cpuid;
    const int CPUID_MAX = 1;
    bool mmx()      { return cpuid == 1 && std.cpuid.mmx(); }
    bool sse()      { return cpuid == 2 && std.cpuid.sse(); }
    bool sse2()     { return cpuid == 3 && std.cpuid.sse2(); }
    bool amd3dnow() { return cpuid == 4 && std.cpuid.amd3dnow(); }
}
else
{
    import std.cpuid;
    alias std.cpuid.mmx mmx;
    alias std.cpuid.sse sse;
    alias std.cpuid.sse2 sse2;
    alias std.cpuid.amd3dnow amd3dnow;
}

//version = log;

bool disjoint(T)(T[] a, T[] b)
{
    return (a.ptr + a.length <= b.ptr || b.ptr + b.length <= a.ptr);
}

alias real T;

extern (C):

/* ======================================================================== */

/***********************
 * Computes:
 *	a[] = b[] + c[]
 */

T[] _arraySliceSliceAddSliceAssign_r(T[] a, T[] c, T[] b)
in
{
	assert(a.length == b.length && b.length == c.length);
	assert(disjoint(a, b));
	assert(disjoint(a, c));
	assert(disjoint(b, c));
}
body
{
    for (int i = 0; i < a.length; i++)
	a[i] = b[i] + c[i];
    return a;
}

unittest
{
    printf("_arraySliceSliceAddSliceAssign_r unittest\n");
    for (cpuid = 0; cpuid < CPUID_MAX; cpuid++)
    {
	version (log) printf("    cpuid %d\n", cpuid);

	for (int j = 0; j < 2; j++)
	{
	    const int dim = 67;
	    T[] a = new T[dim + j];	// aligned on 16 byte boundary
	    a = a[j .. dim + j];	// misalign for second iteration
	    T[] b = new T[dim + j];
	    b = b[j .. dim + j];
	    T[] c = new T[dim + j];
	    c = c[j .. dim + j];

	    for (int i = 0; i < dim; i++)
	    {   a[i] = cast(T)i;
		b[i] = cast(T)(i + 7);
		c[i] = cast(T)(i * 2);
	    }

	    c[] = a[] + b[];

	    for (int i = 0; i < dim; i++)
	    {
		if (c[i] != cast(T)(a[i] + b[i]))
		{
		    printf("[%d]: %Lg != %Lg + %Lg\n", i, c[i], a[i], b[i]);
		    assert(0);
		}
	    }
	}
    }
}

/* ======================================================================== */

/***********************
 * Computes:
 *	a[] = b[] - c[]
 */

T[] _arraySliceSliceMinSliceAssign_r(T[] a, T[] c, T[] b)
in
{
	assert(a.length == b.length && b.length == c.length);
	assert(disjoint(a, b));
	assert(disjoint(a, c));
	assert(disjoint(b, c));
}
body
{
    for (int i = 0; i < a.length; i++)
	a[i] = b[i] - c[i];
    return a;
}


unittest
{
    printf("_arraySliceSliceMinSliceAssign_r unittest\n");
    for (cpuid = 0; cpuid < CPUID_MAX; cpuid++)
    {
	version (log) printf("    cpuid %d\n", cpuid);

	for (int j = 0; j < 2; j++)
	{
	    const int dim = 67;
	    T[] a = new T[dim + j];	// aligned on 16 byte boundary
	    a = a[j .. dim + j];	// misalign for second iteration
	    T[] b = new T[dim + j];
	    b = b[j .. dim + j];
	    T[] c = new T[dim + j];
	    c = c[j .. dim + j];

	    for (int i = 0; i < dim; i++)
	    {   a[i] = cast(T)i;
		b[i] = cast(T)(i + 7);
		c[i] = cast(T)(i * 2);
	    }

	    c[] = a[] - b[];

	    for (int i = 0; i < dim; i++)
	    {
		if (c[i] != cast(T)(a[i] - b[i]))
		{
		    printf("[%d]: %Lg != %Lg - %Lg\n", i, c[i], a[i], b[i]);
		    assert(0);
		}
	    }
	}
    }
}

/* ======================================================================== */

/***********************
 * Computes:
 *	a[] -= b[] * value
 */

T[] _arraySliceExpMulSliceMinass_r(T[] a, T value, T[] b)
{
    return _arraySliceExpMulSliceAddass_r(a, -value, b);
}

/***********************
 * Computes:
 *	a[] += b[] * value
 */

T[] _arraySliceExpMulSliceAddass_r(T[] a, T value, T[] b)
in
{
	assert(a.length == b.length);
	assert(disjoint(a, b));
}
body
{
    auto aptr = a.ptr;
    auto aend = aptr + a.length;
    auto bptr = b.ptr;

    // Handle remainder
    while (aptr < aend)
	*aptr++ += *bptr++ * value;

    return a;
}

unittest
{
    printf("_arraySliceExpMulSliceAddass_r unittest\n");

    cpuid = 1;
    {
	version (log) printf("    cpuid %d\n", cpuid);

	for (int j = 0; j < 1; j++)
	{
	    const int dim = 67;
	    T[] a = new T[dim + j];	// aligned on 16 byte boundary
	    a = a[j .. dim + j];	// misalign for second iteration
	    T[] b = new T[dim + j];
	    b = b[j .. dim + j];
	    T[] c = new T[dim + j];
	    c = c[j .. dim + j];

	    for (int i = 0; i < dim; i++)
	    {   a[i] = cast(T)i;
		b[i] = cast(T)(i + 7);
		c[i] = cast(T)(i * 2);
	    }

	    b[] = c[];
	    c[] += a[] * 6;

	    for (int i = 0; i < dim; i++)
	    {
		//printf("[%d]: %Lg ?= %Lg + %Lg * 6\n", i, c[i], b[i], a[i]);
		if (c[i] != cast(T)(b[i] + a[i] * 6))
		{
		    printf("[%d]: %Lg ?= %Lg + %Lg * 6\n", i, c[i], b[i], a[i]);
		    assert(0);
		}
	    }
	}
    }
}