tree add486a52520cfeed5f210203015a43c80cac730
parent 379e30038237c6db8af1cf84b1bdd3d5f31da59c
author Marc-Andre Laperle <malaperle@gmail.com> 1601182799 -0400
committer Marc-André Laperle <malaperle@gmail.com> 1601836151 -0400

Bug 565553 - Improve performance of build command parsers with large number of files

Narrow down parsers based on option string

Instead of trying to match all patterns one by one, we can check the
start of the option string to be parsed and narrow down which pattern
(parsers) should be used.

Doing so is much less elegant code-wise as we are "unrolling" the
beginning of the patterns by hand, but it gives a good speed up. Around
300ms saved with a test of LLVM code base (~50% of parseOption time) and
much larger gains on much larger projects or course.

Change-Id: I9e841e7233078d6e38ad08943d98966d0e3c661e
Signed-off-by: Marc-Andre Laperle <malaperle@gmail.com>