fis-gtm/sr_port/op_fnzbitget.c

45 lines
1.2 KiB
C

/****************************************************************
* *
* Copyright 2001, 2005 Fidelity Information Services, Inc *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
#include "mdef.h"
#include "op.h"
#include "mvalconv.h"
void op_fnzbitget(mval *dst, mval *bitstr, int pos)
{
int str_len;
unsigned char *byte_1, byte_n;
int mp, np, bn;
error_def(ERR_INVBITSTR);
error_def(ERR_INVBITPOS);
MV_FORCE_STR(bitstr);
if (!bitstr->str.len)
rts_error(VARLSTCNT(1) ERR_INVBITSTR);
byte_1 = (unsigned char *)bitstr->str.addr;
str_len = (bitstr->str.len -1) * 8;
if (7 < *byte_1)
rts_error(VARLSTCNT(1) ERR_INVBITSTR);
if ((1 > pos) || (pos > str_len - *byte_1))
rts_error(VARLSTCNT(1) ERR_INVBITPOS);
np = ((pos + 7) / 8) - 1;
mp = pos % 8;
if (0 == mp)
mp = 8;
byte_n = *(byte_1 + np + 1);
byte_n = byte_n << (mp - 1);
byte_n = byte_n >> 7;
bn = byte_n;
MV_FORCE_MVAL(dst, bn);
}