Fix ValueTracking to conclude that debug intrinsics are safe to
speculate. Without this, loop rotate (among many other places) would
suddenly stop working in the presence of debug info. I found this
looking at loop rotate, and have augmented its tests with a reduction
out of a very hot loop in yacr2 where failing to do this rotation costs
sometimes more than 10% in runtime performance, perturbing numerous
downstream optimizations.

This should have no impact on performance without debug info, but the
change in performance when debug info is enabled can be extreme. As
a consequence (and this how I got to this yak) any profiling of
performance problems should be treated with deep suspicion -- they may
have been wildly innacurate of debug info was enabled for profiling. =/
Just a heads up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154263 91177308-0d34-0410-b5e6-96231b3b80d8
Perform partial SROA on the helper hashing structure. I really wish the
optimizers could do this for us, but expecting partial SROA of classes
with template methods through cloning is probably expecting too much
heroics. With this change, the begin/end pointer pairs which indicate
the status of each loop iteration are actually passed directly into each
layer of the combine_data calls, and the inliner has a chance to see
when most of the combine_data function could be deleted by inlining.
Similarly for 'length'.

We have to be careful to limit the places where in/out reference
parameters are used as those will also defeat the inliner / optimizers
from properly propagating constants.

With this change, LLVM is able to fully inline and unroll the hash
computation of small sets of values, such as two or three pointers.
These now decompose into essentially straight-line code with no loops or
function calls.

There is still one code quality problem to be solved with the hashing --
LLVM is failing to nuke the alloca. It removes all loads from the
alloca, leaving only lifetime intrinsics and dead(!!) stores to the
alloca. =/ Very unfortunate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154264 91177308-0d34-0410-b5e6-96231b3b80d8
Convert floating point division by a constant into multiplication by the
reciprocal if converting to the reciprocal is exact.  Do it even if inexact
if -ffast-math.  This substantially speeds up ac.f90 from the polyhedron
benchmarks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154265 91177308-0d34-0410-b5e6-96231b3b80d8
1. Remove the part of r153848 which optimizes shuffle-of-shuffle into a new
   shuffle node because it could introduce new shuffle nodes that were not
   supported efficiently by the target.

2. Add a more restrictive shuffle-of-shuffle optimization for cases where the
   second shuffle reverses the transformation of the first shuffle.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154266 91177308-0d34-0410-b5e6-96231b3b80d8
Remove 'else' after 'if' that ends in return.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154267 91177308-0d34-0410-b5e6-96231b3b80d8
Move vinsertf128 patterns near the instruction definitions. Add AddedComplexity to AVX2 vextracti128 patterns to give them priority over the integer versions of vextractf128 patterns.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154268 91177308-0d34-0410-b5e6-96231b3b80d8
Turn avx2 vinserti128 intrinsic calls into INSERT_SUBVECTOR DAG nodes and remove patterns for selecting the intrinsic. Similar was already done for avx1.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154272 91177308-0d34-0410-b5e6-96231b3b80d8
Allow subclasses of the ValueHandleBase to store information as part of the
value pointer by making the value pointer into a pointer-int pair with 2 bits
available for flags.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154279 91177308-0d34-0410-b5e6-96231b3b80d8
Remove the 'Parent' pointer from the MDNodeOperand class.

An MDNode has a list of MDNodeOperands allocated directly after it as part of
its allocation. Therefore, the Parent of the MDNodeOperands can be found by
walking back through the operands to the beginning of that list. Mark the first
operand's value pointer as being the 'first' operand so that we know where the
beginning of said list is.

This saves a *lot* of space during LTO with -O0 -g flags.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154280 91177308-0d34-0410-b5e6-96231b3b80d8
FileCheckize these testcases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154281 91177308-0d34-0410-b5e6-96231b3b80d8
Formatting changes. Don't put spaces in front of some code, which only makes it look 'off'.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154282 91177308-0d34-0410-b5e6-96231b3b80d8
Remove old 'grep' lines.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154283 91177308-0d34-0410-b5e6-96231b3b80d8
AVX2: Build splat vectors by broadcasting a scalar from the constant pool.
Previously we used three instructions to broadcast an immediate value into a
vector register.
On Sandybridge we continue to load the broadcasted value from the constant pool.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154284 91177308-0d34-0410-b5e6-96231b3b80d8
Teach InstCombine to nuke a common alloca pattern -- an alloca which has
GEPs, bit casts, and stores reaching it but no other instructions. These
often show up during the iterative processing of the inliner, SROA, and
DCE. Once we hit this point, we can completely remove the alloca. These
were actually showing up in the final, fully optimized code in a bunch
of inliner tests I've been working on, and notably they show up after
LLVM finishes optimizing away all function calls involved in
hash_combine(a, b).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154285 91177308-0d34-0410-b5e6-96231b3b80d8
Add a debug-only 'dump' method to the BlockChain structure to ease
debugging.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154286 91177308-0d34-0410-b5e6-96231b3b80d8
Remove an over zealous assert. The assert was trying to catch places
where a chain outside of the loop block-set ended up in the worklist for
scheduling as part of the contiguous loop. However, asserting the first
block in the chain is in the loop-set isn't a valid check -- we may be
forced to drag a chain into the worklist due to one block in the chain
being part of the loop even though the first block is *not* in the loop.
This occurs when we have been forced to form a chain early due to
un-analyzable branches.

No test case here as I have no idea how to even begin reducing one, and
it will be hopelessly fragile. We have to somehow end up with a loop
header of an inner loop which is a successor of a basic block with an
unanalyzable pair of branch instructions. Ow. Self-host triggers it so
it is unlikely it will regress.

This at least gets block placement back to passing selfhost and the test
suite. There are still a lot of slowdown that I don't like coming out of
block placement, although there are now also a lot of speedups. =[ I'm
seeing swings in both directions up to 10%. I'm going to try to find
time to dig into this and see if we can turn this on for 3.1 as it does
a really good job of cleaning up after some loops that degraded with the
inliner changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154287 91177308-0d34-0410-b5e6-96231b3b80d8
EngineBuilder::create is expected to take ownership of the TargetMachine passed to it. Delete it on error or when we create an interpreter that doesn't need it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154288 91177308-0d34-0410-b5e6-96231b3b80d8
Move the TLSModel information into the TargetMachine rather than hiding
in TargetLowering. There was already a FIXME about this location being
odd. The interface is simplified as a consequence. This will also make
it easier to change TLS models when compiling with PIE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154292 91177308-0d34-0410-b5e6-96231b3b80d8
Teach LLVM about a PIE option which, when enabled on top of PIC, makes
optimizations which are valid for position independent code being linked
into a single executable, but not for such code being linked into
a shared library.

I discussed the design of this with Eric Christopher, and the decision
was to support an optional bit rather than a completely separate
relocation model. Fundamentally, this is still PIC relocation, its just
that certain optimizations are only valid under a PIC relocation model
when the resulting code won't be in a shared library. The simplest path
to here is to expose a single bit option in the TargetOptions. If folks
have different/better designs, I'm all ears. =]

I've included the first optimization based upon this: changing TLS
models to the *Exec models when PIE is enabled. This is the LLVM
component of PR12380 and is all of the hard work.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154294 91177308-0d34-0410-b5e6-96231b3b80d8
Simplify code that tries to do vector extracts for shuffles when the mask width and the input vector widths don't match. No need to check the min and max are in range before calculating the start index. The range check after having the start index is sufficient. Also no need to check for an extract from the beginning differently.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154295 91177308-0d34-0410-b5e6-96231b3b80d8