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Bug#520877: I do not see the need for a new port !

Hi all

> looks like this is a new port. won't fix in GCC for the powerpc port.
The e500 core is no new port, it is powerpc it just misses one "lwsync" instruction used in libstdc++6 (this seems to be a bug in the e500 powerpc core)

Some have created a new "unofficial" debian port for e500 cores (see [0]), but I think a small modification to the build system would fix the problem for the main powerpc port.

I managed to have the official port working on e500 by manually changing the lwsync opcode in the libstdc++6 binary, using the sync (or msync ?) opcode.
It's used only once.
And maybe even only in this library.
So preventing the use of this particular instruction in the gcc package and in the gcc used to build the port will not be a performance issue for the other cores.

Of course, another solution is to add a trap in the kernel for this instruction and perform a sync instead of the lwsync (see [1])

The problem is that I do not have any more e500 cores at hand, so I cannot test or spend more time for investigations.

Have fun :)

[0] http://lists.debian.org/debian-powerpc/2009/02/msg00128.html
[1] http://lists.debian.org/debian-powerpc/2009/02/msg00136.html

Nathaël PAJANI
ED3L - Etude et Développement - Linux et Logiciels Libres
Internet : http://www.ed3l.fr

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