Teach ScalarEvolution to sharpen range information.

If x is known to have the range [a, b), in a loop predicated by (icmp
ne x, a) its range can be sharpened to [a + 1, b).  Get
ScalarEvolution and hence IndVars to exploit this fact.

This change triggers an optimization to widen-loop-comp.ll, so it had
to be edited to get it to pass.

This change was originally landed in r219834 but had a bug and broke
ASan. It was reverted in r219878, and is now being re-landed after
fixing the original bug.

phabricator: http://reviews.llvm.org/D5639
reviewed by: atrick



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221839 91177308-0d34-0410-b5e6-96231b3b80d8
[Bitcode] AtEndOfStream should only check against the size if it's known.

This avoids an issue where AtEndOfStream mistakenly returns true at the /start/ of
a stream.

(In the rare case that the size is known and actually 0, the slow path will still
handle it correctly.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221840 91177308-0d34-0410-b5e6-96231b3b80d8
Improve long path name support on Windows.

Windows normally limits the length of an absolute path name to 260
characters; directories can have lower limits.  These limits increase
to about 32K if you use absolute paths with the special '\\?\'
prefix. Teach Support\Windows\Path.inc to use that prefix as needed.

TODO: Other parts of Support could also learn to use this prefix.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221841 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "[dwarfdump] Add support for dumping accelerator tables."

This reverts commit r221836.

The tests are asserting on some buildbots. This also reverts the
test part of r221837 as it relies on dwarfdump dumping the
accelerator tables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221842 91177308-0d34-0410-b5e6-96231b3b80d8
Drop a few unneeded ctor calls (missed code review comment).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221845 91177308-0d34-0410-b5e6-96231b3b80d8
[FastISel][AArch64] Extend 'select' lowering to support also i1 to i16.

Related to rdar://problem/18960150.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221846 91177308-0d34-0410-b5e6-96231b3b80d8
[FastISel][AArch64] Fold the cmp into the select when possible.

This folds the compare emission into the select emission when possible, so we
can directly use the flags and don't have to emit a separate compare.

Related to rdar://problem/18960150.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221847 91177308-0d34-0410-b5e6-96231b3b80d8
[FastISel][AArch64] Optimize select when one of the operands is a 'true' or 'false' value.

Optimize selects of i1 in the presence of 'true' and 'false' operands to simple
logic operations.

This fixes rdar://problem/18960150.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221848 91177308-0d34-0410-b5e6-96231b3b80d8
CMake: stop setting (well, #undef'ing) HOST_LINK_VERSION; it's used in Clang, not LLVM

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221849 91177308-0d34-0410-b5e6-96231b3b80d8