Modify the tree builder to use a fixed-size binding environment rather
than one that is potentially proportional to the length of the input
BB.  This changes its complexity from quadratic to linear (in the
length of the BB) and gives a noticable increase in the overall speed
of vex.  The tradeoff is that it can no longer guarantee to build
maximal trees, but in practice in only rarely fails to do so (about 1
in 100 bbs) and so the resulting degradation in code quality is
completely insignificant (unmeasurable).



git-svn-id: svn://svn.valgrind.org/vex/trunk@1474 8f6e269a-dfd6-0310-a8e1-e2731360e62c
3 files changed