Experimental Physics and
Industrial Control System

[email protected] (Nick Rees) · Fri, 10 Mar 95 15:47:59 HST

OK, OK, all you users of CA on VMS ;-). Have you fixed this one before I
embark on a fault finding exercise?

Reserved operand fault at PC=0000AB55, PSL=03C00000
Symbolic stack dump follows
module name     routine name                     line       rel PC    abs PC

CONVERT         ntohd                           10008      00000005  0000AB55
CONVERT         cvrt_double                      8898      00000037  00009B0B
SERVICE         cacMsg                           8926      0000025B  0000B367
SERVICE         post_msg                         8730      000001B0  0000B0EC
IOCINF          ca_process_tcp                   9465      000000B8  00007D3C
IOCINF          ca_process_input_queue           9353      0000002D  00007AF9
VMS_DEPEN       cac_block_for_io_completion      9419      00000045  00006DB9
ACCESS          ca_pend                         11275      000001AD  00005EA5
THI_CA          thi_wait                         5192      00000012  00003E36
FAST_MAIN       FAST_MAIN                         153      00000075  00003875

The relevant bit of code (which has a comment about a similar problem) is:

 9996 /*
 9997  * sign must be forced to zero if the exponent is zero to prevent reserved
 9998  * operand fault- joh 9-13-90
 9999  */
10000 void ntohd(double *pNet, double *pHost)
10001 {
10002     double          copyin;
10003     struct mitdbl   *pMIT;
10004     struct ieeedbl  *pIEEE;
10005     ca_uint32_t     *ptmp;
10006     ca_uint32_t     tmp;
10007
10008     copyin = *pNet;
10009     pMIT = (struct mitdbl *)pHost;
10010     pIEEE = (struct ieeedbl *)&copyin;
10011 
10012 /*
10013  * Byte swap from net order to host order
10014  */
10015     ptmp = (ca_uint32_t *) pIEEE;
.
.
.

Nick

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System