Summary:
This is a follow up to r288303, where I have introduced TrigramIndex
to speed up SpecialCaseList for the cases when all rules are
simple wildcards, like *hello*wor.d*.
Here, I add support for escaping, so that it's possible to
specify rules like *c\+\+abi*.
Reviewers: pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27318
llvm-svn: 288553
Summary:
it's often the case when the rules in the SpecialCaseList
are of the form hel.o*bar. That gives us a chance to build
trigram index to quickly discard 99% of inputs without
running a full regex. A similar idea was used in Google Code Search
as described in the blog post:
https://swtch.com/~rsc/regexp/regexp4.html
The check is defeated, if there's at least one regex
more complicated than that. In this case, all inputs
will go through the regex. That said, the real-world
rules are often simple or can be simplied. That considerably
speeds up compiling Chromium with CFI and UBSan.
As measured on Chromium's content_message_generator.cc:
before, CFI: 44 s
after, CFI: 23 s
after, CFI, no blacklist: 23 s (~1% slower, but 3 runs were unable to show the difference)
after, regular compilation to bitcode: 23 s
Reviewers: pcc
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D27188
llvm-svn: 288303
