bits_image_fetch_pixel_bilinear (bits_image_t   *image,
				 pixman_fixed_t  x,
				 pixman_fixed_t  y,
				 get_pixel_t	 get_pixel)
{
    pixman_repeat_t repeat_mode = image->common.repeat;
    int width = image->width;
    int height = image->height;
    int x1, y1, x2, y2;
    uint32_t tl, tr, bl, br;
    int32_t distx, disty;

    x1 = x - pixman_fixed_1 / 2;
    y1 = y - pixman_fixed_1 / 2;

    distx = pixman_fixed_to_bilinear_weight (x1);
    disty = pixman_fixed_to_bilinear_weight (y1);

    x1 = pixman_fixed_to_int (x1);
    y1 = pixman_fixed_to_int (y1);
    x2 = x1 + 1;
    y2 = y1 + 1;

    if (repeat_mode != PIXMAN_REPEAT_NONE)
    {
	repeat (repeat_mode, &x1, width);
	repeat (repeat_mode, &y1, height);
	repeat (repeat_mode, &x2, width);
	repeat (repeat_mode, &y2, height);

	tl = get_pixel (image, x1, y1, FALSE);
	bl = get_pixel (image, x1, y2, FALSE);
	tr = get_pixel (image, x2, y1, FALSE);
	br = get_pixel (image, x2, y2, FALSE);
    }
    else
    {
	tl = get_pixel (image, x1, y1, TRUE);
	tr = get_pixel (image, x2, y1, TRUE);
	bl = get_pixel (image, x1, y2, TRUE);
	br = get_pixel (image, x2, y2, TRUE);
    }

    return bilinear_interpolation (tl, tr, bl, br, distx, disty);
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.