Re: [incremental] Patch: FYI: initial threading in gcc

[Paolo Bonzini <bonzini@gnu.org>]

> There are some limitations in the current patch.  First, it assumes
> pthreads and the existence of __thread.  Fixing this is just some
> boring configury, or perhaps figuring out how to re-use gthr* on the
> host.  (If __thread is not available, I plan to have the server fall
> back to single-threaded mode.)  Second, I haven't implemented PCH
> support for thread-locals.

Is there a way to do so, other than:

1) moving all globals to the heap or to GGC memory, so that they are at 
least in a shared address space

2) having each thread store a pointer to its heap-allocated data both in 
a thread-local variable, and in a global variable indexed by thread id.

3) having PCH look at the latter, and GCC using the former.


I fear that the above might also mean implementing pointer-swizzling on 
PCH load, because you might need the same PCH in different threads.

Great job!

Paolo