scala/scala — pull request #835 by paulp (2012-07-06 06:07:57+00:00)
Title: Optimization in asSeenFrom.

Eliminated about half the allocations of AsSeenFromMap by examining the
arguments more closely. The impact is not what one might conclude from
that statistic, because those were the cheap asSeenFrom calls - but now
they are cheaper. Also,

- worked in some eager vals rather than lazy ones.
- changed hot-spot comparison to use eq
- simplified annotationArgRewriter
- elimnated separate tracking of capturedPre

Statistics from compiling scala/collection/**.scala:

- 4209382 calls to asSeenFrom
- 1025945 maps created (instantiations of AsSeenFromMap)
- 1525649 maps avoided (these were instantiations before this patch)

Review by most honorable performance-san @gkossakowski .