Speeding up parallel compilation

[Stefan Monnier]

The recent change I installed which macro-expands Elisp code eagerly
upon load does not speed up sequential compilation very much, but it
seems to help parallel compilation significantly: on a 12-core
24-threads machine, "make -j24 bootstrap" went down from 2:20 to 1:50,
and the CPU utilization went up (from 800% to 1000%).

In other words, this mostly sped up a part of the compilation which does
not parallelize well.  I guess that would be either the construction of
loaddefs, or the compilation of the compiler.

So, lucky those with manycore systems.


        Stefan