Various improvements:

* rename many functions to do with shadow memory handling, to
  more clearly differentiate reads and writes directly of the
  shadow state from client reads and writes, each of which
  generate both a read and a write of the client state.  It was
  getting confusing (== hard to verify) in there.

* use idempotency of memory state machine transition rules to
  speed up long sequential sections, speedups in range 0% to 28%

* remove 4-way Pord (EQ, LT, GT, UN) and associated machinery,
  and replace it with something that merely computes LEQ in the
  partial ordering, since that's all that is necessary, and
  this simplifies some fast-case paths.

* add optional approx history mechanism a la DRD (start/end stack
  of conflicting segment), much faster if you don't need exact
  conflicting-access details

* libhb_so_recv: tick the VTS in the receiving thread; don't just
  join with the VC in the SO.  It's probably correct without this
  modification, but that correctness is fragile and depends on
  complex properties of how SOs are used/created.  Much better to
  be completely safe.  (Needs cache-isation).

* get rid of unnecessary shadow memory state "SVal_NOACCESS"
  and simplify associated fast-case paths in msmc{read,write}



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10589 a5019735-40e9-0310-863c-91ae7b9d1cf9
7 files changed