RE: R3.14.8 testing

["Jeff Hill" <johill@lanl.gov>]

Ø     I don't see this as an argument for making 'long' a 64-bit type. It's an argument for 64-bit pointers, yes,

Ø     but I think that making 'sizeof(long)==8' is a separate issue.

 

There may be compiler switches that provide sizeof(long)==4, but I expect that the defacto standard compiler default will eventually be sizeof(long)==8.

 

I can think of some reasons why that default might become ubiquitous, but my opinion doesn’t matter. You can take that issue up with the compiler vendors.

 

IMHO the important issue for EPICS developers is instead this: should we define an EPICS base default which requires EPICS applications to compile with a non-standard sizeof(long) default. The downside is that if the users inadvertently take the compiler default an incomprehensible crash will occur.

 

Jeff

 

-----Original Message-----
From: Eric Norum [mailto:norume@aps.anl.gov]
Sent: Wednesday, November 02, 2005 2:24 PM
To: Ernest L. Williams Jr.
Cc: Marty Kraimer; Andrew Johnson; Janet Anderson; Jeff Hill
Subject: Re: R3.14.8 testing

 

On Nov 2, 2005, at 2:59 PM, Ernest L. Williams Jr. wrote:

 

We are moving to the use of linux-x86_64 and want to run native 64-bit

apps.  

We want to take advantage of not only the AMD64 hardware but also the

larger address space which will be very useful for database applications

and systems which have a lot of RAM e.g. our ChannelArchiver. 

 

There is a very small performance penalty within the OS for translating

32-bit app to use the AMD64. Probably not much.

 

I don't see this as an argument for making 'long' a 64-bit type. It's an argument for 64-bit pointers, yes, but I think that making 'sizeof(long)==8' is a separate issue.

 

I seem to recall some earlier discussions where we had decided that EPICS would use 'long long' where 64-bit integers were needed.

 

-- 

Eric Norum <norume@aps.anl.gov>

Advanced Photon Source

Argonne National Laboratory

(630) 252-4793