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/* ---------------------------------------------------------------------------- */
/*                                                                              */
/* Localise op_mask then opmask_add()                                           */
/*                                                                              */
/* Just copied from Opcode.xs                                                   */
/*                                                                              */
/* ---------------------------------------------------------------------------- */


static void
opmask_addlocal(SV *   opset,
                char * op_mask_buf) 
    {
    char *orig_op_mask = op_mask;
    int i,j;
    char *bitmask;
    STRLEN len;
    int myopcode  = 0;
    int opset_len = (maxo + 7) / 8 ;

    SAVEPPTR(op_mask);
    op_mask = &op_mask_buf[0];
    if (orig_op_mask)
	Copy(orig_op_mask, op_mask, maxo, char);
    else
	Zero(op_mask, maxo, char);


    /* OPCODES ALREADY MASKED ARE NEVER UNMASKED. See opmask_addlocal()	*/

    bitmask = SvPV(opset, len);
    for (i=0; i < opset_len; i++)
        {
	U16 bits = bitmask[i];
	if (!bits)
            {	/* optimise for sparse masks */
	    myopcode += 8;
	    continue;
	    }
	for (j=0; j < 8 && myopcode < maxo; )
	    op_mask[myopcode++] |= bits & (1 << j++);
        }