Experimental Physics and
Industrial Control System

Michael Davidsaver <[email protected]> · Sat, 18 Jun 2011 08:59:52 -0400

Hello Andrew,

On 06/17/11 18:31, Andrew Johnson wrote:
> Hi Michael,
> 
> On 2011-06-17 Michael Davidsaver wrote:
>> I'd like to add a standard 64-bit integer type to epicsTypes.h.
>> Currently this is only available when compiling with the C99 extensions
>> enabled.
>>
>> Attached are two proposed patches.  The first adds sanity checks of the
>> existing type sizes.  The second defines epicsUInt64 and epicsInt64.
>>
>> The C primitive used (either long or long long) is chosen by testing the
>> size of LONG_MAX.  I think this should work for all toolchains which
>> actually provide a 64-bit integer type.  The question is, are there any
>> which don't and need to be supported?
> 
> There were issues with using long long on some vxWorks versions/architectures, 
> although from what I can see they were only in vxWorks 5.3.x releases and the 
> later releases apparently do provide full support.  I believe there were some 
> support routines that gcc calls implicitly which the OS relegated to an 
> external libgcc.a library rather than building them into the OS image.

Does sizeof(long)==8 in these cases?  If it does then there is no need
for long long.

> I would suggest moving your verification code into libCom/test and adding a 
> test program to the file that exercises the basic operations +-*/&|^~ with the 
> epicsInt64 and epicsUInt64 types to ensure they are all implemented.  The 
> tests in libCom/test are intended to help us confirm that the OS properly 
> implements all the facilities we need/expect.

My reason for not wanting to put these tests in libCom/test is that they
are most useful when compiled before everything else.  These checks are
the sort usually found in autoconf ./configure scripts.

I was tempted to put them into epicsTypes.h directly.

> Are you looking for this in 3.14.x or 3.15?

Certainly 3.15.

I would also like to see it added to 3.14, if this can be done without
breaking compatibility with old vxWorks versions.  It is really up to
you to decide if this can be done.

> - Andrew

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System