On 2020-05-26 00:48, fo...@univ-mlv.fr wrote:
Not sure in which sense you mean inlining? Few of the methods in the
bootstrap code are likely hot enough to see inlining by a JIT - and the
resulting MHs should be identical, just not constructed over and over
again.
I'm wondering if the code without the null tests was not simple enough to be
inlined by c1,
the MH creations tends to do a lot of checks that can be removed even by c1.
Time spent in prepender() does not seem to be a significant contributor
to bootstrap overhead - time spent in MHs.insertArguments is, though.
One thing that falls out naturally from this is that prefix can only be
non-null on the first prepender: "foo" + a + "bar" + b ... will bind
both "foo" and "bar" to the a-prepender, then b and subsequent
prependers will never see a prefix constant since it will be bound in
as a suffix of the preceding argument. Thus it makes sense to either
provide a caching mechanism for prependers whose prefix arguments are
pre-bound to null:
http://cr.openjdk.java.net/~redestad/8245756/open.01
We might be able to special-case the first prepender so that we can
remove the prefix argument from prependers in general, which might make
the final MH a bit smaller and easier for the JIT to optimize.
Testing: tier1+2
/Claes
