kvisc/pc/instrs/logic.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 "instrs.h"
#include "arch_i.h"

IMPL_COND(not);
IMPL_COND(and);
IMPL_COND(or);
IMPL_COND(xor);
IMPL_COND(shl);
IMPL_COND(shr);

//
// Comparison instructions
//

IMPL_START_2(test)
{
    ulong v = v1 & v2;

    if (v == 0) ctx->r[FLG].val |= ZF;
    else ctx->r[FLG].val &= ~ZF;
}
IMPL_END;

IMPL_START_2(cmp)
{
    if (v1 == v2) {
        ctx->r[FLG].val |= ZF;
        ctx->r[FLG].val &= ~CF;
    }

    else if (v1 < v2) {
        ctx->r[FLG].val &= ~ZF;
        ctx->r[FLG].val |= CF;
    }

    else {
        ctx->r[FLG].val &= ~ZF;
        ctx->r[FLG].val &= ~CF;
    }
}
IMPL_END;

//
// Logical instructions
//

IMPL_START_2(and)
{
    v1 &= v2;
}
IMPL_OUT;

IMPL_START_2(or)
{
    v1 |= v2;
}
IMPL_OUT;

IMPL_START_2(xor)
{
    v1 ^= v2;
}
IMPL_OUT;

IMPL_START_2(shl)
{
    v1 <<= v2;
}
IMPL_OUT;

IMPL_START_2(shr)
{
    v1 >>= v2;
}
IMPL_OUT;

IMPL_START_1(not)
{
    v1 = ~v1;
}
IMPL_OUT;