5121 Commits

Author SHA1 Message Date
David Majnemer
f51bbb84ed Specify a more specific triple for constant-pool-remat-0.ll
Instead of specifying 32-bit x86, specify 32-bit x86 linux.

This test is testing a very specific behavior which changed with
WinCOFF's constant pools.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213041 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-15 03:00:39 +00:00
David Majnemer
2067d91b1e Relax tests expecting to see CPI symbols
WinCOFF doesn't use CPI symbols, it has a different scheme for naming
constant pool entries.  Update tests to handle either appearing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213039 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-15 02:44:49 +00:00
David Majnemer
cdc1044944 CodeGen: Handle ConstantVector and undef in WinCOFF constant pools
The constant pool entry code for WinCOFF assumed that vector constants
would be formed using ConstantDataVector, it did not expect to see a
ConstantVector.  Furthermore, it did not expect undef as one of the
elements of the vector.

ConstantVectors should be handled like ConstantDataVectors, treat Undef
as zero.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213038 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-15 02:34:12 +00:00
Andrea Di Biagio
e3c3920258 Improve test 'CodeGen/X86/combine-vec-shuffle-3.ll'.
Now functions 'test4', 'test9', 'test14' and 'test19' correctly perform
a move of two packed values from the high quadword of vector %b to the low
quadword of vector %a (movhlps idiom).

No functional change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213029 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-15 01:29:27 +00:00
Andrea Di Biagio
217cd18656 [DAGCombiner] Avoid calling method 'isShuffleMaskLegal' on illegal vector types.
This patch fixes a crasher in method 'DAGCombiner::visitOR' due to an invalid
call to method 'isShuffleMaskLegal'. On x86, method 'isShuffleMaskLegal'
always expects a legal vector value type in input.

With this patch, we immediately check if the input OR dag node has a legal
vector type; we only try to fold a OR dag node into a single shufflevector
if we know that the resulting shuffle will have a legal type.
This is to avoid calling method 'isShuffleMaskLegal' on a potentially
illegal vector value type.

Added a new test-case to file 'CodeGen/X86/combine-or.ll' to verify that
DAGCombiner doesn't crash in the attempt to check/combine an OR between shuffles
with illegal types.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213020 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-15 00:02:32 +00:00
David Majnemer
38d8be1ad8 CodeGen: Stick constant pool entries in COMDAT sections for WinCOFF
COFF lacks a feature that other object file formats support: mergeable
sections.

To work around this, MSVC sticks constant pool entries in special COMDAT
sections so that each constant is in it's own section.  This permits
unused constants to be dropped and it also allows duplicate constants in
different translation units to get merged together.

This fixes PR20262.

Differential Revision: http://reviews.llvm.org/D4482

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213006 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-14 22:57:27 +00:00
Andrea Di Biagio
7847229c31 [DAGCombiner] Add more rules to combine shuffle vector dag nodes.
This patch teaches the DAGCombiner how to fold a pair of shuffles
according to rules:
  1.  shuffle(shuffle A, B, M0), B, M1) -> shuffle(A, B, M2)
  2.  shuffle(shuffle A, B, M0), A, M1) -> shuffle(A, B, M3)

The new rules would only trigger if the resulting shuffle has legal type and
legal mask.

Added test 'combine-vec-shuffle-3.ll' to verify that DAGCombiner correctly
folds shuffles on x86 when the resulting mask is legal. Also added some negative
cases to verify that we avoid introducing illegal shuffles.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213001 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-14 22:46:26 +00:00
Saleem Abdulrasool
5335b49f96 X86: correct 64-bit atomics on 32-bit
We would emit a libcall for a 64-bit atomic on x86 after SVN r212119.  This was
due to the misuse of hasCmpxchg16 to indicate if cmpxchg8b was supported on a
32-bit target.  They were added at different times and would result in the
border condition being mishandled.

This fixes the border case to emit the cmpxchg8b instruction for 64-bit atomic
operations on x86 at the cost of restoring a long-standing bug in the codegen.
We emit a cmpxchg8b on all x86 targets even where the CPU does not support this
instruction (pre-Pentium CPUs).  Although this bug should be fixed, this was
present prior to SVN r212119 and this change, so this is not really introducing
a regression.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212956 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-14 16:28:13 +00:00
Tim Northover
9e251d6d41 X86: remove temporary atomicrmw used during lowering.
We construct a temporary "atomicrmw xchg" instruction when lowering atomic
stores for widths that aren't supported natively. This isn't on the top-level
worklist though, so it won't be removed automatically and we have to do it
ourselves once that itself has been lowered.

Thanks Saleem for pointing this out!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212948 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-14 15:31:13 +00:00
Andrea Di Biagio
124ce3ab36 [DAGCombiner] Fix a crash caused by a missing check for legal type when trying to fold shuffles.
Verify that DAGCombiner does not crash when trying to fold a pair of shuffles
according to rule (added at r212539):
  (shuffle (shuffle A, Undef, M0), Undef, M1) -> (shuffle A, Undef, M2)

The DAGCombiner avoids folding shuffles if the resulting shuffle dag node
is not legal for the target. That means, the resulting shuffle must have
legal type and legal mask.

Before, the DAGCombiner only called method
'TargetLowering::isShuffleMaskLegal' to check if it was "safe" to fold according
to the above-mentioned rule. However, this caused a crash in the x86 backend
since method 'isShuffleMaskLegal' always expects to be called on a
legal vector type.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212915 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-13 21:02:14 +00:00
Quentin Colombet
52c50f5ec5 [X86] Fix the inversion of low and high bits for the lowering of MUL_LOHI.
Also add a few comments.

<rdar://problem/17581756>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212808 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-11 12:08:23 +00:00
Andrea Di Biagio
4d3b6131c7 Extend the test coverage in combine-vec-shuffle-2.ll adding some negative tests.
Add test cases where we don't expect to trigger the combine optimizations
introduced at revision 212748.

No functional change intended.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212756 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 18:59:41 +00:00
Matt Arsenault
b730c3d28d Revert "Revert r212640, "Add trunc (select c, a, b) -> select c (trunc a), (trunc b) combine.""
Don't try to convert the select condition type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212750 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 18:21:04 +00:00
Andrea Di Biagio
3996e5290a [DAG] Further improve the logic in DAGCombiner that folds a pair of shuffles into a single shuffle if the resulting mask is legal.
This patch teaches the DAGCombiner how to fold shuffles according to the
following new rules:
  1. shuffle(shuffle(x, y), undef) -> x
  2. shuffle(shuffle(x, y), undef) -> y
  3. shuffle(shuffle(x, y), undef) -> shuffle(x, undef)
  4. shuffle(shuffle(x, y), undef) -> shuffle(y, undef)

The backend avoids to combine shuffles according to rules 3. and 4. if
the resulting shuffle does not have a legal mask. This is to avoid introducing
illegal shuffles that are potentially expanded into a sub-optimal sequence of
target specific dag nodes during vector legalization.

Added test case combine-vec-shuffle-2.ll to verify that we correctly triggers
the new rules when combining shuffles.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212748 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 18:04:55 +00:00
Akira Hatanaka
60079c18bc [X86] Mark pseudo instruction TEST8ri_NOEREX as hasSIdeEffects=0.
Also, add a case clause in X86InstrInfo::shouldScheduleAdjacent to enable
macro-fusion.

<rdar://problem/15680770>



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212747 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 18:00:53 +00:00
Chandler Carruth
cdbdfa28d1 [x86,SDAG] Introduce any- and sign-extend-vector-inreg nodes analogous
to the zero-extend-vector-inreg node introduced previously for the same
purpose: manage the type legalization of widened extend operations,
especially to support the experimental widening mode for x86.

I'm adding both because sign-extend is expanded in terms of any-extend
with shifts to propagate the sign bit. This removes the last
fundamental scalarization from vec_cast2.ll (a test case that hit many
really bad edge cases for widening legalization), although the trunc
tests in that file still appear scalarized because the the shuffle
legalization is scalarizing. Funny thing, I've been working on that.

Some initial experiments with this and SSE2 scenarios is showing
moderately good behavior already for sign extension. Still some work to
do on the shuffle combining on X86 before we're generating optimal
sequences, but avoiding scalarization is a huge step forward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212714 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 12:32:32 +00:00
NAKAMURA Takumi
e93de7fb73 llvm/test/CodeGen/X86/shift-parts.ll: FileCheck-ize. (from r212640)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212709 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 11:37:39 +00:00
NAKAMURA Takumi
5290734b8f Revert r212640, "Add trunc (select c, a, b) -> select c (trunc a), (trunc b) combine."
This caused miscompilation on, at least, x86-64. SExt(i1 cond) confused other optimizations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212708 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 11:37:28 +00:00
Chandler Carruth
a4e7f05a28 [x86] Add another combine that is particularly useful for the new vector
shuffle lowering: match shuffle patterns equivalent to an unpcklwd or
unpckhwd instruction.

This allows us to use generic lowering code for v8i16 shuffles and match
the unpack pattern late.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212705 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 11:09:29 +00:00
Chandler Carruth
977aab501d [x86] Expand the target DAG combining for PSHUFD nodes to be able to
combine into half-shuffles through unpack instructions that expand the
half to a whole vector without messing with the dword lanes.

This fixes some redundant instructions in splat-like lowerings for
v16i8, which are now getting to be *really* nice.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212695 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 09:57:36 +00:00
Chandler Carruth
dc90a3ab8f [x86] Tweak the v16i8 single input special case lowering for shuffles
that splat i8s into i16s.

Previously, we would try much too hard to arrange a sequence of i8s in
one half of the input such that we could unpack them into i16s and
shuffle those into place. This isn't always going to be a cheaper i8
shuffle than our other strategies. The case where it is always going to
be cheaper is when we can arrange all the necessary inputs into one half
using just i16 shuffles. It happens that viewing the problem this way
also makes it much easier to produce an efficient set of shuffles to
move the inputs into one half and then unpack them.

With this, our splat code gets one step closer to being not terrible
with the new experimental lowering strategy. It also exposes two
combines missing which I will add next.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212692 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 09:16:40 +00:00
Chandler Carruth
95b14b00da [x86] Initial improvements to the new shuffle lowering for v16i8
shuffles specifically for cases where a small subset of the elements in
the input vector are actually used.

This is specifically targetted at improving the shuffles generated for
trunc operations, but also helps out splat-like operations.

There is still some really low-hanging fruit here that I want to address
but this is a huge step in the right direction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212680 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 04:34:06 +00:00
David Blaikie
eff0c67b6a Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information.
Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson
reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped
provide a reduced reproduction, though the failure wasn't too hard to
guess, and even easier with the example to confirm.

The assertion that the subprogram metadata associated with an
llvm::Function matches the scope data referenced by the DbgLocs on the
instructions in that function is not valid under LTO. In LTO, a C++
inline function might exist in multiple CUs and the subprogram metadata
nodes will refer to the same llvm::Function. In this case, depending on
the order of the CUs, the first intance of the subprogram metadata may
not be the one referenced by the instructions in that function and the
assertion will fail.

A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the
assertion removed and a comment added to explain this situation.

Original commit message:

If a function isn't actually in a CU's subprogram list in the debug info
metadata, ignore all the DebugLocs and don't try to build scopes, track
variables, etc.

While this is possibly a minor optimization, it's also a correctness fix
for an incoming patch that will add assertions to LexicalScopes and the
debug info verifier to ensure that all scope chains lead to debug info
for the current function.

Fix up a few test cases that had broken/incomplete debug info that could
violate this constraint.

Add a test case where this occurs by design (inlining a
debug-info-having function in an attribute nodebug function - we want
this to work because /if/ the nodebug function is then inlined into a
debug-info-having function, it should be fine (and will work fine - we
just stitch the scopes up as usual), but should the inlining not happen
we need to not assert fail either).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212649 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-09 21:02:41 +00:00
Matt Arsenault
3e8ed89484 Add trunc (select c, a, b) -> select c (trunc a), (trunc b) combine.
Do this if the truncate is free and the select is legal.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212640 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-09 19:12:07 +00:00
Chandler Carruth
4c27c85cde [x86] Fix a bug in my new zext-vector-inreg DAG trickery where we were
not widening the input type to the node sufficiently to let the ext take
place in a register.

This would in turn result in a mysterious bitcast assertion failure
downstream. First change here is to add back the helpful assert I had in
an earlier version of the code to catch this immediately.

Next change is to add support to the type legalization to detect when we
have widened the operand either too little or too much (for whatever
reason) and find a size-matched legal vector type to convert it to
first. This can also fail so we get a new fallback path, but that seems
OK.

With this, we no longer crash on vec_cast2.ll when using widening. I've
also added the CHECK lines for the zero-extend cases here. We still need
to support sign-extend and trunc (or something) to get plausible code
for the other two thirds of this test which is one of the regression
tests that showed the most scalarization when widening was
force-enabled. Slowly closing in on widening being a viable legalization
strategy without it resorting to scalarization at every turn. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212614 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-09 12:36:54 +00:00
Benjamin Kramer
4afbd3e941 X86: When lowering v8i32 himuls use the correct shuffle masks for AVX2.
Turns out my trick of using the same masks for SSE4.1 and AVX2 didn't work out
as we have to blend two vectors. While there remove unecessary cross-lane moves
from the shuffles so the backend can lower it to palignr instead of vperm.

Fixes PR20118, a miscompilation of vector sdiv by constant on AVX2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212611 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-09 11:12:39 +00:00
Chandler Carruth
ce184e95f9 [x86] Add a ZERO_EXTEND_VECTOR_INREG DAG node and use it when widening
vector types to be legal and a ZERO_EXTEND node is encountered.

When we use widening to legalize vector types, extend nodes are a real
challenge. Either the input or output is likely to be legal, but in many
cases not both. As a consequence, we don't really have any way to
represent this situation and the prior code in the widening legalization
framework would just scalarize the extend operation completely.

This patch introduces a new DAG node to represent doing a zero extend of
a vector "in register". The core of the idea is to allow legal but
different vector types in the input and output. The output vector must
have fewer lanes but wider elements. The operation is defined to zero
extend the low elements of the input to the size of the output elements,
and drop all of the high elements which don't have a corresponding lane
in the output vector.

It also includes generic expansion of this node in terms of blending
a zero vector into the high elements of the vector and bitcasting
across. This in turn yields extremely nice code for x86 SSE2 when we use
the new widening legalization logic in conjunction with the new shuffle
lowering logic.

There is still more to do here. We need to support sign extension, any
extension, and potentially int-to-float conversions. My current plan is
to continue using similar synthetic nodes to model each of these
transitions with generic lowering code for each one.

However, with this patch LLVM already reaches performance parity with
GCC for the core C loops of the x264 code (assuming you disable the
hand-written assembly versions) when compiling for SSE2 and SSE3
architectures and enabling the new widening and lowering logic for
vectors.

Differential Revision: http://reviews.llvm.org/D4405

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212610 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-09 10:58:18 +00:00
Chandler Carruth
98eac0a244 [x86] Re-apply a variant of the x86 side of r212324 now that the rest
has settled without incident, removing the x86-specific and overly
strict 'isVectorSplat' routine in favor of generic and more powerful
splat detection.

The primary motivation and result of this is that the x86 backend can
now see through splats which contain undef elements. This is essential
if we are using a widening form of legalization and I've updated a test
case to also run in that mode as before this change the generated code
for the test case was completely scalarized.

This version of the patch much more carefully handles the undef lanes.
- We aren't overly conservative about them in the shift lowering
  (where we will never use the splat itself).
- One place where the splat would have been re-used by the existing code
  now explicitly constructs a new constant splat that will be safe.
- The broadcast lowering is much more reasonable with undefs by doing
  a correct check of whether the splat is the only user of a loaded
  value, checking that the splat actually crosses multiple lanes before
  using a broadcast, and handling broadcasts of non-constant splats.

As a consequence of the last bullet, the weird usage of vpshufd instead
of vbroadcast is gone, and we actually can lower an AVX splat with
vbroadcastss where before we emitted a really strange pattern of
a vector load and a manual splat across the vector.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212602 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-09 10:06:58 +00:00
Andrea Di Biagio
b8245a4599 [DAG] Teach how to combine a pair of shuffles into a single shuffle if the resulting mask is legal.
This patch teaches how to fold a shuffle according to rule:
  shuffle (shuffle (x, undef, M0), undef, M1) -> shuffle(x, undef, M2)

We do this only if the resulting mask M2 is legal; this is to avoid introducing
illegal shuffles that are potentially expanded into a sub-optimal sequence
of target specific dag nodes.

This patch has the advantage of being target independent, since it works on ISD
nodes. Therefore, all targets (not only x86) can take advantage of this rule.
The idea behind this patch is that most shuffle pairs can be safely combined
before we run the legalizer on vector operations. This allows us to
combine/simplify dag nodes earlier in the process and not only immediately
before instruction selection stage.

That said. This patch is not meant to replace any existing target specific
combine rules; backends might still introduce new shuffles during legalization
stage. Also, this rule is very simple and avoids to aggressively optimize
shuffles.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212539 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-08 15:22:29 +00:00
Chandler Carruth
25b7d54e7f [x86,SDAG] Sink the logic for folding shuffles of splats more
aggressively from the x86 shuffle lowering to the generic SDAG vector
shuffle formation code.

This code already tried to fold away shuffles of splats! It just had
lots of bugs and couldn't handle the case my new x86 shuffle lowering
needed.

First, it failed to correctly compute whether N2 was undef because it
pre-computed this, then did transformations which could *make* N2 undef,
then failed to ever re-consider the precomputed state.

Second, it didn't look through bitcasts at all, even in the safe cases
where they are just element-type bitcasts with no change to the number
of elements.

Third, it didn't handle all-zero bit casts nicely the way my code in the
x86 side of things did, which is essential to getting good zext-shuffle
lowerings.

But all of these are generic. I just ported the code down to this layer
and fixed the surrounding bugs. Tests exercising this in the x86 backend
still pass and some silly code in widen_cast-6.ll gets better. I updated
that test to be a bit more precise but it's still pretty unclear what
the value of the test is in this day and age.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212517 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-08 08:45:38 +00:00
Andrea Di Biagio
cfb83b7bac [x86] Fix assertion failure caused by a wrong combine of PSHUFD nodes with different types.
When combining a sequence of two PSHUFD dag nodes into a single PSHUFD,
make sure that we assign the correct type to the resulting PSHUFD.
X86ISD::PSHUFD dag nodes can be either MVT::v4i32 or MVT::v4f32.

Before this change, an assertion failure was triggered in method
'DAGCombinerInfo::CombineTo' when trying to combine the shuffles from the test
below into a single PSHUFD.

define <4 x float> @test1(<4 x float> %V) {
  %1 = shufflevector <4 x float> %V, <4 x float> undef, <4 x i32> <i32 3, i32 0, i32 2, i32 1>
  %2 = shufflevector <4 x float> %1, <4 x float> undef, <4 x i32> <i32 3, i32 0, i32 2, i32 1>
  ret <4 x float> %2
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212498 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-07 23:25:23 +00:00
Juergen Ributzka
1154be8198 [FastISel][X86] Fix smul.with.overflow.i8 lowering.
Add custom lowering code for signed multiply instruction selection, because the
default FastISel instruction selection for ISD::MUL will use unsigned multiply
for the i8 type and signed multiply for all other types. This would set the
incorrect flags for the overflow check.

This fixes <rdar://problem/17549300>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212493 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-07 21:52:21 +00:00
Chandler Carruth
7fcb422bb2 [x86] Revert r212324 which was too aggressive w.r.t. allowing undef
lanes in vector splats.

The core problem here is that undef lanes can't *unilaterally* be
considered to contribute to splats. Their handling needs to be more
cautious. There is also a reported failure of the nightly testers
(thanks Tobias!) that may well stem from the same core issue. I'm going
to fix this theoretical issue, factor the APIs a bit better, and then
verify that I don't see anything bad with Tobias's reduction from the
test suite before recommitting.

Original commit message for r212324:
  [x86] Generalize BuildVectorSDNode::getConstantSplatValue to work for
  any constant, constant FP, or undef splat and to tolerate any undef
  lanes in a splat, then replace all uses of isSplatVector in X86's
  lowering with it.

  This fixes issues where undef lanes in an otherwise splat vector would
  prevent the splat logic from firing. It is a touch more awkward to use
  this interface, but it is much more accurate. Suggestions for better
  interface structuring welcome.

  With this fix, the code generated with the widening legalization
  strategy for widen_cast-4.ll is *dramatically* improved as the special
  lowering strategies for a v16i8 SRA kick in even though the high lanes
  are undef.

  We also get a slightly different choice for broadcasting an aligned
  memory location, and use vpshufd instead of vbroadcastss. This looks
  like a minor win for pipelining and domain crossing, but a minor loss
  for the number of micro-ops. I suspect its a wash, but folks can
  easily tweak the lowering if they want.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212475 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-07 19:03:32 +00:00
Chandler Carruth
36ad61f4ea [x86] Teach the new vector shuffle lowering code to handle what is
essentially a DAG combine that never gets a chance to run.

We might typically expect DAG combining to remove shuffles-of-splats and
other similar patterns, but we don't get a chance to run the DAG
combiner when we recursively form sub-shuffles during the lowering of
a shuffle. So instead hand-roll a really important combine directly into
the lowering code to detect shuffles-of-splats, especially shuffles of
an all-zero splat which needn't even have the same element width, etc.

This lets the new vector shuffle lowering handle shuffles which
implement things like zero-extension really nicely. This will become
even more important when I wire the legalization of zero-extension to
vector shuffles with the new widening legalization strategy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212444 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-07 09:06:58 +00:00
NAKAMURA Takumi
4a183c6b87 llvm/test/CodeGen/X86/vector-gep.ll: Appease to add -mtriple=i686-linux.
This doesn't pass if stack alignment is not 16, like cygming, *bsd.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-04 11:55:40 +00:00
Chandler Carruth
f9749edd61 [x86] Relax the line in this check to pacify build bots.
I still don't love testing the comments, but its the only sane way to
check shuffle instructions...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212326 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-04 08:39:30 +00:00
Chandler Carruth
b2a3131c88 [x86] Move some check lines to be slightly easier for me to find.
(meant to put this cleanup in the previous patch, sorry)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212325 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-04 08:19:37 +00:00
Chandler Carruth
a46e60eb2e [x86] Generalize BuildVectorSDNode::getConstantSplatValue to work for
any constant, constant FP, or undef splat and to tolerate any undef
lanes in a splat, then replace all uses of isSplatVector in X86's
lowering with it.

This fixes issues where undef lanes in an otherwise splat vector would
prevent the splat logic from firing. It is a touch more awkward to use
this interface, but it is much more accurate. Suggestions for better
interface structuring welcome.

With this fix, the code generated with the widening legalization
strategy for widen_cast-4.ll is *dramatically* improved as the special
lowering strategies for a v16i8 SRA kick in even though the high lanes
are undef.

We also get a slightly different choice for broadcasting an aligned
memory location, and use vpshufd instead of vbroadcastss. This looks
like a minor win for pipelining and domain crossing, but a minor loss
for the number of micro-ops. I suspect its a wash, but folks can easily
tweak the lowering if they want.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212324 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-04 08:11:49 +00:00
Eric Christopher
3a3941576d Temporarily revert "Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information." as it appears to be breaking some LTO constructs.
This reverts commit r212203.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212298 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-03 22:24:54 +00:00
Andrea Di Biagio
d4167d0b29 [X86] Add ISel patterns to select 'f32_to_f16' and 'f16_to_f32' dag nodes.
This patch adds tablegen patterns to select F16C float-to-half-float
conversion instructions from 'f32_to_f16' and 'f16_to_f32' dag nodes.

If the target doesn't have F16C, then 'f32_to_f16' and 'f16_to_f32'
are expanded into library calls.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212293 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-03 21:51:06 +00:00
Sanjay Patel
1a699b6833 bug fix for PR20020: anti-dependency-breaker causes miscompilation
This patch sets the 'KeepReg' bit for any tied and live registers during the PrescanInstruction() phase of the dependency breaking algorithm. It then checks those 'KeepReg' bits during the ScanInstruction() phase to avoid changing any tied registers. For more details, please see comments in:
http://llvm.org/bugs/show_bug.cgi?id=20020

I added two FIXME comments for code that I think can be removed by using register iterators that include self. I don't want to include those code changes with this patch, however, to keep things as small as possible.

The test case is larger than I'd like, but I don't know how to reduce it further and still produce the failing asm.

Differential Revision: http://reviews.llvm.org/D4351



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212275 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-03 15:19:40 +00:00
Ulrich Weigand
1ef2cec146 Fix ppcf128 component access on little-endian systems
The PowerPC 128-bit long double data type (ppcf128 in LLVM) is in fact a
pair of two doubles, where one is considered the "high" or
more-significant part, and the other is considered the "low" or
less-significant part.  When a ppcf128 value is stored in memory or a
register pair, the high part always comes first, i.e. at the lower
memory address or in the lower-numbered register, and the low part
always comes second.  This is true both on big-endian and little-endian
PowerPC systems.  (Similar to how with a complex number, the real part
always comes first and the imaginary part second, no matter the byte
order of the system.)

This was implemented incorrectly for little-endian systems in LLVM.
This commit fixes three related issues:

- When printing an immediate ppcf128 constant to assembler output
  in emitGlobalConstantFP, emit the high part first on both big-
  and little-endian systems.

- When lowering a ppcf128 type to a pair of f64 types in SelectionDAG
  (which is used e.g. when generating code to load an argument into a
  register pair), use correct low/high part ordering on little-endian
  systems.

- In a related issue, because lowering ppcf128 into a pair of f64 must
  operate differently from lowering an int128 into a pair of i64,
  bitcasts between ppcf128 and int128 must not be optimized away by the
  DAG combiner on little-endian systems, but must effect a word-swap.

Reviewed by Hal Finkel.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212274 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-03 15:06:47 +00:00
NAKAMURA Takumi
693b9ee16f Let llvm/test/CodeGen/X86/lower-bitcast.ll tolerant of win32 calling convention.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212258 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-03 07:25:00 +00:00
Chandler Carruth
90ac572331 [x86] Fix the completely broken vector widening legalization of bswap.
This operation was classified as a binary operation in the widening
logic for some reason (clearly, untested). It is in fact a unary
operation. Add a RUN line to a test to exercise this for x86.

Note that again the vector widening strategy doesn't regress anything
and in one case removes a totally unecessary instruction that we
couldn't avoid when promoting the element type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212257 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-03 07:04:38 +00:00
Chandler Carruth
7e924a68b5 [x86] Fix crashes in lowering bitcast instructions with the widening
mode.

This also runs the test in that mode which would reproduce the crash.
What I love is that *every single FIXME* in the test is addressed by
switching to widening.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212254 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-03 03:43:47 +00:00
Adam Nemet
998743e185 [X86] AVX512: Allow writemask argument in vpermt* intrinsics
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212223 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-02 21:26:01 +00:00
Adam Nemet
df5d431084 [X86] AVX512: Add writemask variants for vperm*2*
This includes assembler and codegen support (see the new tests in
avx512-encodings.s and avx512-shuffle.ll).

<rdar://problem/17492620>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212221 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-02 21:25:54 +00:00
David Blaikie
f9b6d0373a Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information.
If a function isn't actually in a CU's subprogram list in the debug info
metadata, ignore all the DebugLocs and don't try to build scopes, track
variables, etc.

While this is possibly a minor optimization, it's also a correctness fix
for an incoming patch that will add assertions to LexicalScopes and the
debug info verifier to ensure that all scope chains lead to debug info
for the current function.

Fix up a few test cases that had broken/incomplete debug info that could
violate this constraint.

Add a test case where this occurs by design (inlining a
debug-info-having function in an attribute nodebug function - we want
this to work because /if/ the nodebug function is then inlined into a
debug-info-having function, it should be fine (and will work fine - we
just stitch the scopes up as usual), but should the inlining not happen
we need to not assert fail either).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212203 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-02 18:31:35 +00:00
Benjamin Kramer
11be760757 X86: When combining shuffles just remove shuffles that are completely redundant.
CombineTo doesn't allow replacing a node with itself so this would crash if the
combined shuffle is the same as the input shuffle.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212181 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-02 15:09:44 +00:00
Elena Demikhovsky
0780b6db5d AVX-512: dec/inc instructions are slow on KNL
After Alexey Volkov, I'm adding the same property for KNL, that prefers ADD/SUB instead of INC/DEC.
Added a test.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212178 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-02 14:11:05 +00:00