#include "tdkpin_arithmetic.h"
#include "tdkpin_borland_runtime.h"

/* Low 32 bits of signed DX:AX * BX:CX, independent of CPU implementation path. */
int32_t borland_multiply_i32(int32_t left, int32_t right)
{
    uint32_t bits = (uint32_t)((uint64_t)(uint32_t)left * (uint32_t)right);
    return (int32_t)bits;
}

BorlandDivI32Result borland_divide_i32(int32_t dividend, int32_t divisor)
{
    if (divisor == 0) {
        borland_runtime_error(200);
    }
    if (dividend == INT32_MIN && divisor == -1) {
        if (g_borland_cpu_level >= 2) {
            win16_integer_divide_fault();
        }
        return (BorlandDivI32Result){INT32_MIN, 0};
    }

    bool quotient_negative = (dividend < 0) != (divisor < 0);
    bool remainder_negative = dividend < 0;
    uint32_t dividend_magnitude = dividend < 0
        ? (uint32_t)(0u - (uint32_t)dividend)
        : (uint32_t)dividend;
    uint32_t divisor_magnitude = divisor < 0
        ? (uint32_t)(0u - (uint32_t)divisor)
        : (uint32_t)divisor;
    uint32_t quotient_bits = dividend_magnitude / divisor_magnitude;
    uint32_t remainder_bits = dividend_magnitude % divisor_magnitude;
    if (quotient_negative) {
        quotient_bits = 0u - quotient_bits;
    }
    if (remainder_negative) {
        remainder_bits = 0u - remainder_bits;
    }
    return (BorlandDivI32Result){
        (int32_t)quotient_bits,
        (int32_t)remainder_bits,
    };
}