For large constants (e.g. arrays and structs with many elements) just
creating the keys and doing comparisons to index into 'Map' takes a lot
of time.  For these large constants, keep an inverse map so that 'remove'
and move operations are much faster.

This speeds up a release build of the bc reader on Eric's nasty python
bytecode file from 1:39 to 1:00s.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23624 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed