Experimental Physics and
Industrial Control System

 

All,

 

There is a bug in Red Hat Linux g++ 3.2.3 when -O3 is specified that causes CA R3.14.9 to fail. The bug is known not to occur with several other g++ versions, but many versions have not been tested. I also don’t know what versions of Linux g++ are most commonly used at the various EPICS sites.

 

So I am curious if this is a substantial issue for the EPICS community or if it can be safely ignored? If defective compilers are still in widespread use I could look for a workaround in the EPICS source code.

 

Jeff

During testing of R3.14.9 I see a bug showing up only in optimized builds on Linux using g++ 3.2.3 that I don't see with other compilers. This bug appears to be related to failure of this particular compiler to follow the strict alias rules specified in the standard when optimizing the byte swapping templates installed for R3.14.9.

Problems

Red hat Linux g++ 3.2.3 when -O3 is specified

No problems

mingw g++ 3.4.2 -O3

Tornado 2.02 g++ -O2

Microsoft C++ 2005 full optimization builds

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Jeffrey O. Hill           Internet     [email protected]
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