[RegAllocGreedy] Provide a flag to disable the local reassignment heuristic.
By default, no functionality change.

Before evicting a local variable, this heuristic tries to find another (set of)
local(s) that can be reassigned to a free color.

In some extreme cases (large basic blocks with tons of local variables), the
compilation time is dominated by the local interference checks that this
heuristic must perform, with no code gen gain.
E.g., the motivating example takes 4 minutes to compile with this heuristic, 12
seconds without.

Improving the situation will likely require to make drastic changes to the
register allocator and/or the interference check framework.

For now, provide this flag to better understand the impact of that heuristic.

<rdar://problem/17444599>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212099 91177308-0d34-0410-b5e6-96231b3b80d8
[PeepholeOptimizer] Advanced rewriting of copies to avoid cross register banks
copies.

This patch extends the peephole optimization introduced in r190713 to produce
register-coalescer friendly copies when possible.

This extension taught the existing cross-bank copy optimization how to deal
with the instructions that generate cross-bank copies, i.e., insert_subreg,
extract_subreg, reg_sequence, and subreg_to_reg.
E.g.
b = insert_subreg e, A, sub0 <-- cross-bank copy
...
C = copy b.sub0 <-- cross-bank copy

Would produce the following code:
b = insert_subreg e, A, sub0 <-- cross-bank copy
...
C = copy A <-- same-bank copy

This patch also introduces a new helper class for that: ValueTracker.
This class implements the logic to look through the copy related instructions
and get the related source.

For now, the advanced rewriting is disabled by default as we are lacking the
semantic on target specific instructions to catch the motivating examples.

Related to <rdar://problem/12702965>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212100 91177308-0d34-0410-b5e6-96231b3b80d8
Avoid revocations when possible.

This is a small targeted fix for pr20119. The code needs quiet a bit of
refactoring and I added some FIXMEs about it, but I want to get the testcase
passing first.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212101 91177308-0d34-0410-b5e6-96231b3b80d8
Rephrase loop so it doesn't leave unused bools around in Release mode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212102 91177308-0d34-0410-b5e6-96231b3b80d8
GlobalOpt: FileCheck-ize test

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212103 91177308-0d34-0410-b5e6-96231b3b80d8
GlobalOpt: Don't swap private for internal linkage

There were transforms whose *intent* was to downgrade the linkage of
external objects to have internal linkage.

However, it fired on things with private linkage as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212104 91177308-0d34-0410-b5e6-96231b3b80d8
Remove unused typedef. GCC warns about this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212105 91177308-0d34-0410-b5e6-96231b3b80d8
[PeepholeOptimzer] Fix a typo in a comment.
Spotted by Amara Emerson.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212106 91177308-0d34-0410-b5e6-96231b3b80d8
Add the -arch flag support to llvm-size like what was done to llvm-nm
to select the slice out of a Mach-O universal file.  This also includes
support for -arch all, selecting the host architecture by default from
a universal file and checking if -arch is used with a standard Mach-O
it matches that architecture.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212108 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "MachineScheduler: better book-keeping for asserts."

This reverts commit r212088, which is causing a number of spec
failures.  Will provide reduced test cases shortly.
PR20057

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212109 91177308-0d34-0410-b5e6-96231b3b80d8
[X86] AVX512: Factor generating the AsmString into avx512_icmp_cc

Adding a writemask variant would require a third asm string to be passed to
the template.  Generate the AsmString in the template instead.

No change in X86.td.expanded.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212113 91177308-0d34-0410-b5e6-96231b3b80d8
[X86] AVX512: Allow writemasks with vpcmp

For now I only updated the _alt variants.  The main variants are used by
codegen and that will need a bit more work to trigger.

<rdar://problem/17492620>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212114 91177308-0d34-0410-b5e6-96231b3b80d8
[docs] Remove stray HTML tag.

Fixes PR20167

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212115 91177308-0d34-0410-b5e6-96231b3b80d8
[docs] Fix a mangled sentence.

Fixes PR20169

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212116 91177308-0d34-0410-b5e6-96231b3b80d8
X86: expand atomics in IR instead of as MachineInstrs.

The logic for expanding atomics that aren't natively supported in
terms of cmpxchg loops is much simpler to express at the IR level. It
also allows the normal optimisations and CodeGen improvements to help
out with atomics, instead of using a limited set of possible
instructions..

rdar://problem/13496295

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212119 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64: fix comment typo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212120 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Provide a utility for building a mapping from llvm::Function*s to llvm::DISubprograms

Update DeadArgumentElimintation to use this, with the intent of reusing
the functionality for ArgumentPromotion as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212122 91177308-0d34-0410-b5e6-96231b3b80d8
Remove the use and initialization of the target machine and subtarget
from SystemZFrameLowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212123 91177308-0d34-0410-b5e6-96231b3b80d8
Move the subtarget dependent features from SystemZTargetMachine
down to the subtarget. Add an initialization routine to assist.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212124 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Keep track of subprograms who's arguments have been promoted.

Matching behavior with DeadArgumentElimination (and leveraging some
now-common infrastructure), keep track of the function from debug info
metadata if arguments are promoted.

This may produce interesting debug info - since the arguments may be
missing or of different types... but at least backtraces, inlining, etc,
will be correct.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212128 91177308-0d34-0410-b5e6-96231b3b80d8