A name that is not resolved in the local scope gets looked up
in the global scope of the library to which the code being compiled
belongs. The local name dictionary gets searched first, then the
dictionary of each imported library (and and their re-exported
libraries.) Each dictionary lookup includes the lookup of the
mangled getter and setter names, which means that we concatenate
the same name many times.
This change introduces a cache that stores the result of a previous
name lookup, including negative lookup results. The latter is important
to speed up the resolution of names that are not in the global name
space, e.g. class members like .length in lists.
Experiments running dart2js (with VM option --compile_all) show
that this reduces the number of name mangling calls by a factor of 10
and speeds up compiling dart2js by 15%.
R=asiva@google.com
Review URL: https://codereview.chromium.org//135123011
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@32385 260f80e4-7a28-3924-810f-c04153c831b5
On standalone dartium which has about 50000 tokens in the libraries (core, coreimpl, builtin, io etc.) this reduces the heap size by about 180kb. The size of the standalone snapshot buffer reduces by about 72kb.
Also moved the keyword symbol table to the object store so that it does not have to repopulated on every script compilation. Should benefit regular user script load times.
Review URL: https://chromiumcodereview.appspot.com//9462003
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@4734 260f80e4-7a28-3924-810f-c04153c831b5
iposva@google.com