rename "SkipToWord" to "SkipToFourByteBoundary" since a word is not always 4 bytes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173062 91177308-0d34-0410-b5e6-96231b3b80d8
wean Blob handling logic off of banging on NextChar directly.  Instead, make
it reason about the current bit position, which is always independent of the
underlying cursors word size.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173063 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce a new data structure, the SparseMultiSet, and changes to the MI scheduler to use it.

A SparseMultiSet adds multiset behavior to SparseSet, while retaining SparseSet's desirable properties. Essentially, SparseMultiSet provides multiset behavior by storing its dense data in doubly linked lists that are inlined into the dense vector. This allows it to provide good data locality as well as vector-like constant-time clear() and fast constant time find(), insert(), and erase(). It also allows SparseMultiSet to have a builtin recycler rather than keeping SparseSet's behavior of always swapping upon removal, which allows it to preserve more iterators. It's often a better alternative to a SparseSet of a growable container or vector-of-vector.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173064 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a heinous inefficiency introduced in r149918, wherein reading each byte of a
BLOB (i.e., large, performance intensive data) in a bitcode file was switched to
invoking one virtual method call per byte read.  Now we do one virtual call per
BLOB.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173065 91177308-0d34-0410-b5e6-96231b3b80d8
rework the Bitstream reader to actually work a machine word at a time, instead of 32-bits at a time.
This cuts in half the number of virtual methods called to refill that word when compiling on a 64-bit
host, and will make 64-bit read operations faster.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173072 91177308-0d34-0410-b5e6-96231b3b80d8