building with GCC-4.2 on amd64

[Kelly O'Hair]

This kind of change concerns me a little.
Are we punishing the jdk performance of everybody because of a problem building
with GCC 4.2?

I know this is always a difficult situation, effectively we have a workaround
for an unknown problem. Whether it's a bug in GCC 4.2 or a bug in the jdk source
due to some code constructs that violate some C or C++ compiler assumptions.

My tendency is to file a bug against something, GCC or jdk, and then in the
makefiles, refer to this bug number, explaining that the opt level had to be
downgraded for this reason. That gives people like ma a fighting chance when
I decide to try and crank up the opt level 2 or 3 years from now. ;^)

Do other people have different ways of handling this?

In the hotspot Makefiles, they usually try and isolate the particular source file
that triggers the failure, and then only downgrade the opt level for that one
source file.

-kto

Matthias Klose wrote:
> When building with GCC 4.2 from the 4.2 branch, all the demos in demos/jfc and
> the gcjwebplugin crash. Lowering the optimization for the jdk to -O2 results in
> working demos and plugin. The build with GCC 4.1 does fail for me on amd64, GCC
> 4.3 from trunk works fine with -O2 and -O3. Appended is a patch to lower the
> optimization.
> 
>   Matthias
>