kvisc/vm/in/arith.c

// The OS/K Team licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

#include <in/instrs.h>

//----------------------------------------------------------------------------//

IMPL_START_2(sgn)
{
    v1 = (v2 == 0 ? 0 : 
            ((long)v2 < 0 ? (ulong)-1L : 1));
}
IMPL_OUT;

IMPL_START_2(neg)
{
    v1 = ~v2 + 1;
}
IMPL_OUT;

//----------------------------------------------------------------------------//

IMPL_START_1(inc)
{
    v1++;
}
IMPL_OUT;

IMPL_START_1(dec)
{
    v1--;
}
IMPL_OUT;

//----------------------------------------------------------------------------//

IMPL_START_2(add)
{
    ALU_GET_SRCS();
    v1 = src1 + src2;
}
IMPL_OUT;

IMPL_START_2(xadd)
{
    ulong tmp = v1;
    v1 += v2;
    v2 = tmp;
}
IMPL_OUT_2;

IMPL_START_2(addf)
{
    ALU_GET_SRCS();
    COMPARE(src1, ~src2+1);
    v1 = src1 + src2;
}
IMPL_OUT_ZSF;

//----------------------------------------------------------------------------//

IMPL_START_2(sub)
{
    ALU_GET_SRCS();
    v1 = src1 - src2;
}
IMPL_OUT;

IMPL_START_2(subf)
{
    ALU_GET_SRCS();
    COMPARE(src1, src2);
    v1 = src1 - src2;
}
IMPL_OUT;

//
// i_subf but discards result
//
IMPL_START_2(cmp)
{
    COMPARE(v1, v2);
}
IMPL_END;

//----------------------------------------------------------------------------//

IMPL_START_2(adc)
{
    ALU_GET_SRCS();
    v1 = src1 + src2 + !!(rfx&CF);
}
IMPL_OUT;

IMPL_START_2(ado)
{
    ALU_GET_SRCS();
    v1 = src1 + src2 + !!(rfx&OF);
}
IMPL_OUT;

IMPL_START_2(sbb)
{
    ALU_GET_SRCS();
    v1 = src1 - src2 - !!(rfx&CF);
}
IMPL_OUT;

IMPL_START_2(sbo)
{
    ALU_GET_SRCS();
    v1 = src1 - src2 - !!(rfx&OF);
}
IMPL_OUT;

//----------------------------------------------------------------------------//

//
// www.codeproject.com/Tips/618570/UInt-Multiplication-Squaring
//
static void multiply(ulong u, ulong v, ulong *hi, ulong *lo)
{
    ulong u1 = (u & 0xffffffff);
    ulong v1 = (v & 0xffffffff);
    ulong t = (u1 * v1);
    ulong w3 = (t & 0xffffffff);
    ulong k = (t >> 32);
    
    u >>= 32;
    t = (u * v1) + k;
    k = (t & 0xffffffff);
    ulong w1 = (t >> 32);
    
    v >>= 32;
    t = (u1 * v) + k;
    k = (t >> 32);
    
    if (hi) *hi = (u * v) + w1 + k;
    if (lo) *lo = (t << 32) + w3;
}

IMPL_START_2(mul)
{
    ALU_GET_SRCS();
    multiply(src1, src2, 0, &v1);
}
IMPL_OUT;

IMPL_START_2(mulhi)
{
    ALU_GET_SRCS();
    multiply(src1, src2, &v1, &v2);
}
IMPL_OUT_2;

IMPL_START_2(mulf)
{
    ALU_GET_SRCS();
    multiply(src1, src2, &v2, &v1);

    if (v2 > 0) {
        rfx |= CF;
        rfx |= OF;
    }

    else {
        rfx &= ~CF;
        rfx &= ~OF;
    }
}
IMPL_OUT;

//----------------------------------------------------------------------------//

IMPL_START_2(div)
{
    ALU_GET_SRCS();
    v1 = src1 / src2;
}
IMPL_OUT;

IMPL_START_2(rem)
{
    ALU_GET_SRCS();
    v1 = src1 % src2;
}
IMPL_OUT;

//----------------------------------------------------------------------------//