commit d873b743f4ddd4c9d2156e8c34e47b682606d59f
author Clement Courbet <courbet@google.com> Tue Oct 10 15:54:22 2017 +0200
committer Paul Wankadia <junyer@google.com> Tue Oct 10 14:08:20 2017 +0000
tree 28ed0202d94d6dd7ee78d7bf10e04f7bc2814322
parent a6f63b88f24e470bb9d9401ec752a23f0ecc9535

Avoid another copy in RE2::PossibleMatchRange, and simplify the code.

Again, this improves the case when the prefix is a large proportion of
maxlen. Gains are ~20% in this case.

Before:

Benchmark                    Time(ns)        CPU(ns)     Iterations
-------------------------------------------------------------------
PossibleMatchRange_Trivial       1158           1156         513274
PossibleMatchRange_Complex       2593           2589         272939
PossibleMatchRange_Prefix          71.1           71.0      9838330
PossibleMatchRange_NoProg          71.3           71.2      9844569

After:
Benchmark                    Time(ns)        CPU(ns)     Iterations
-------------------------------------------------------------------
PossibleMatchRange_Trivial       1134           1132         617832
PossibleMatchRange_Complex       2545           2542         276152
PossibleMatchRange_Prefix          56.5           56.4     10000000
PossibleMatchRange_NoProg          57.7           57.6     10000000

Change-Id: Ie3c6c4ea0b4de3575675fbca4856734a5f5120cc
Reviewed-on: https://code-review.googlesource.com/17730
Reviewed-by: Paul Wankadia <junyer@google.com>