SimplifyCFG: Use parallel-and and parallel-or mode to consolidate branch conditions

Merge consecutive if-regions if they contain identical statements.
Both transformations reduce number of branches.  The transformation
is guarded by a target-hook, and is currently enabled only for +R600,
but the correctness has been tested on X86 target using a variety of
CPU benchmarks.

Patch by: Mei Ye

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187278 91177308-0d34-0410-b5e6-96231b3b80d8
Re-enabling some more MSVC warnings; all of these compile cleanly with no further changes required.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187279 91177308-0d34-0410-b5e6-96231b3b80d8
Reimplement isPotentiallyReachable to make nocapture deduction much stronger.
Adds unit tests for it too.

Split BasicBlockUtils into an analysis-half and a transforms-half, and put the
analysis bits into a new Analysis/CFG.{h,cpp}. Promote isPotentiallyReachable
into llvm::isPotentiallyReachable and move it into Analysis/CFG.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187283 91177308-0d34-0410-b5e6-96231b3b80d8
Also update CMakeLists.txt for r187283.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187284 91177308-0d34-0410-b5e6-96231b3b80d8
Debug Info Verifier: verify SPs in llvm.dbg.sp.

Also always add DIType, DISubprogram and DIGlobalVariable to the list
in DebugInfoFinder without checking them, so we can verify them later
on.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187285 91177308-0d34-0410-b5e6-96231b3b80d8
Update this CMakeLists.txt for r187283 too.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187286 91177308-0d34-0410-b5e6-96231b3b80d8
SimplifyCFG: Add missing tests from r187278

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187291 91177308-0d34-0410-b5e6-96231b3b80d8
Re-enabling a warning in MSVC mode now that r187292 fixed the only instance of the warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187293 91177308-0d34-0410-b5e6-96231b3b80d8
Merge the removal of dead instructions and lifetime markers with the
analysis of the alloca. We don't need to visit all the users twice for
this. We build up a kill list during the analysis and then just process
it afterward. This recovers the tiny bit of performance lost by moving
to the visitor based analysis system as it removes one entire use-list
walk from mem2reg. In some cases, this is now faster than mem2reg was
previously.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187296 91177308-0d34-0410-b5e6-96231b3b80d8
Don't use all the #ifdefs to hide the stats counters and instead rely on
their being optimized out in debug mode. Realistically, this just isn't
going to be the slow part anyways. This also fixes unused variable
warnings that are breaking LLD build bots. =/ I didn't see these at
first, and kept losing track of the fact that they were broken.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187297 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a memory leak in the hexagon scheduler. We call initialize here more
than once, and the second time through we leaked memory. Found thanks to
the vg-leak bot, but I can't locally reproduce it with valgrind. The
debugger confirms that it is in fact leaking here.

This whole code is totally gross. Why is initialize being called on each
runOnFunction??? Why aren't these OwningPtr<>s, and why aren't their
lifetimes better defined? Anyways, this is just a surgical change to
help out the leak checking bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187299 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a memory leak in the debug emission by simply not allocating memory.
There doesn't appear to be any reason to put this variable on the heap.
I'm suspicious of the LexicalScope above that we stuff in a map and then
delete afterward, but I'm just trying to get the valgrind bot clean.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187301 91177308-0d34-0410-b5e6-96231b3b80d8
Fix yet another memory leak found by the vg-leak bot. Folks (including
me) should start watching this bot more as its catching lots of bugs.

The fix here is to not construct the global if we aren't going to need
it. That's cheaper anyways, and globals have highly predictable types in
practice. I've added an assert to catch skew between our manual testing
of the type and the actual type just for paranoia's sake.

Note that this pattern is actually fine in most globals because when you
build a global with a module it automatically is moved to be owned by
that module. But here, we're in isel and don't really want to do that.
The solution of not creating a global is simpler anyways.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187302 91177308-0d34-0410-b5e6-96231b3b80d8
Create a constant pool symbol for the GOT in the ARMCGBR the same way we
do in the SDag when lowering references to the GOT: use
ARMConstantPoolSymbol rather than creating a dummy global variable. The
computation of the alignment still feels weird (it uses IR types and
datalayout) but it preserves the exact previous behavior. This change
fixes the memory leak of the global variable detected on the valgrind
leak checking bot.

Thanks to Benjamin Kramer for pointing me at ARMConstantPoolSymbol to
handle this use case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187303 91177308-0d34-0410-b5e6-96231b3b80d8
DwarfDebug: MD5 is always little endian, bswap on big endian platforms.

This makes LLVM emit the same signature regardless of host and target endianess.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187304 91177308-0d34-0410-b5e6-96231b3b80d8
Minor code simplification suggested by Duncan

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187309 91177308-0d34-0410-b5e6-96231b3b80d8
Re-enabling some more MSVC warnings; all of these compile cleanly with no further changes required.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187310 91177308-0d34-0410-b5e6-96231b3b80d8