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Re: [PATCH] Use lwsync in PowerPC sync_* builtins
David Edelsohn wrote:
On Thu, Sep 4, 2008 at 8:31 AM, Joel Sherrill <joel.sherrill@oarcorp.com> wrote:
Another related issue is that psim in gdb does not currently
support the lwsync instruction so any code generated using it
would fail there. Since this is used as the test platform for
the embedded gcc targets (at least powerpc-elf and powerpc-rtems)
if gcc is going to generate this instruction, the simulator
needs to support it or there will be lots of failures.
Joel,
That is unfortunate, but it is a long-term, known problem with PSIM. Someone
maintaining PSIM needs to update it. At worst, just make lwsync an alias
for sync.
Honestly the psim code is very cryptic in this area. I would
add it if I could figure out how. :(
It does not make sense to delay improving performance because
a simulator is far out of date.
No I would never say that it did either.
You also can make a private change to GCC
rs6000 port sources to set TARGET_NO_LWSYNC so that sync is generated
instead of lwsync.
That's what we do now but I would like to not have to do
that.
David
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