Add a cache to SourceManager to accellerate line # lookup. This is a

bottleneck for -E computation, because every token that starts a line needs
to determine *which* line it is on (so -E mode can insert the appropriate 
vertical whitespace).  This optimization improves this common case where
it is striding through the line # table.

This speeds up -E on xalancbmk by 3.2%


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40459 91177308-0d34-0410-b5e6-96231b3b80d8

0 files changed, 0 insertions, 0 deletions