Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Sat, 5 Sep 1998 9:38:36 -0500

Folks,

As was pointed out the other day, there is a problem with channel access 
reading short integers on Intel platforms. Until Jeff Hill has a chance to 
check in his patch for the problem here is a fix I have come up with.  The
source of the problem is that the ">>" operator is doing sign extension on
Intel systems, while it does not on other little-endian architectures like DEC
Alpha.  The problem is in base/src/ca/net_convert.h

corvette> diff net_convert.h net_convert.h_orig
23d22
<  *      mlr     09-03-98        Fixed problems with short ints
111c110
<       ((((SHORT) & (dbr_short_t) 0xff00) >> 8) & (dbr_short_t) 0x00ff) ) )
---
>       ((SHORT) & (dbr_short_t) 0xff00) >> 8) )
117c116
<       ((((SHORT) & (dbr_short_t) 0xff00) >> 8) & (dbr_short_t) 0x00ff) ) )
---
>       ((SHORT) & (dbr_short_t) 0xff00) >> 8) )
133c132
<               ( ((((dbr_ulong_t)LONG) & 0xff000000 ) >> 24u) & (dbr_short_t)
0x00ff) |\
---
>               ( ((dbr_ulong_t)LONG) & 0xff000000 ) >> 24u |\
143c142
<               ( ((((dbr_ulong_t)LONG) & 0xff000000 ) >> 24u) & (dbr_short_t)
0x00ff) |\
---
>               ( ((dbr_ulong_t)(LONG)) & 0xff000000 ) >> 24u |\

                                   Mark Rivers

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System