Commit Graph

51 Commits

Author SHA1 Message Date
Craig Topper
62eaac6087 [X86] Use vmovss to handle inserting an element into index 0 of a v8f32 vector of zeros.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231354 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 06:38:42 +00:00
David Blaikie
7c9c6ed761 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230794 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 21:17:42 +00:00
Chandler Carruth
07ef8904ad [x86] Now that the new vector shuffle legality is enabled and everything
is going well, remove the flag and the code for the old legality tests.

This is the first step toward removing the entire old vector shuffle
lowering. *Much* more code to delete coming up next.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229963 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 03:59:35 +00:00
Simon Pilgrim
cbc2ca5ec9 [X86][SSE] Generalised unpckl/unpckh shuffle matching
Added commuted unpckl/unpckh shuffle matching patterns as many cases containing undefined lanes fail to commute by themselves.

Differential Revision: http://reviews.llvm.org/D7564

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229571 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-17 22:24:32 +00:00
Craig Topper
74b9ad3485 [X86] Add support for lowering shuffles to 256-bit PALIGNR instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229359 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-16 06:29:06 +00:00
Craig Topper
abdf58f7f9 [X86] Remove some hard tab characters from tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229358 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-16 06:29:02 +00:00
Simon Pilgrim
f4e056ac2a Added (still inefficient) shuffle test case for PR21138
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229321 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 18:21:39 +00:00
Simon Pilgrim
afcb895fe1 Added some test cases of missed opportunities to use unpckl/unpckh shuffles
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229313 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 15:07:45 +00:00
Simon Pilgrim
28f299b62d [X86][AVX2] vpslldq/vpsrldq byte shifts for AVX2
This patch refactors the existing lowerVectorShuffleAsByteShift function to add support for 256-bit vectors on AVX2 targets.

It also fixes a tablegen issue that prevented the lowering of vpslldq/vpsrldq vec256 instructions.

Differential Revision: http://reviews.llvm.org/D7596

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229311 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 13:19:52 +00:00
Chandler Carruth
fbde8bffba [x86] Teach the decomposed shuffle/blend lowering to use an early blend
when that will allow it to lower with a single permute instead of
multiple permutes.

It tries to detect when it will only have to do a single permute in
either case to maximize folding of loads and such.

This cuts a *lot* of the avx2 shuffle permute counts in half. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229309 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 12:42:15 +00:00
Chandler Carruth
72753f87f2 [SDAG] Teach the SelectionDAG to canonicalize vector shuffles of splats
directly into blends of the splats.

These patterns show up even very late in the vector shuffle lowering
where we don't have any chance for DAG combining to kick in, and
blending is a tremendously simpler operation to model. By coercing the
shuffle into a blend we can much more easily match and lower shuffles of
splats.

Immediately with this change there are significantly more blends being
matched in the x86 vector shuffle lowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229308 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 12:18:12 +00:00
Chandler Carruth
46d3e580ed [x86] When splitting 256-bit vectors into 128-bit vectors, don't extract
subvectors from buildvectors. That doesn't really make any sense and it
breaks all of the down-stream matching of buildvectors to cleverly lower
shuffles.

With this, we now get the shift-based lowering of 256-bit vector
shuffles with AVX1 when we split them into 128-bit vectors. We also do
much better on the zero-extension patterns, although there remains quite
a bit of room for improvement here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229299 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 10:12:02 +00:00
Chandler Carruth
62ba2b29d8 [x86] Add a slight variation on some of the other generic shuffle
lowerings -- one which decomposes into an initial blend followed by
a permute.

Particularly on newer chips, blends are handled independently of
shuffles and so this is much less bottlenecked on the single port that
floating point shuffles are executed with on Intel.

I'll be adding this lowering to a bunch of other code paths in
subsequent commits to handle still more places where we can effectively
leverage blends when they're available in the ISA.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229292 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 08:26:30 +00:00
Chandler Carruth
9bb943b185 [x86] Switch a collection of tests explicitly to the new vector shuffle
legality test (essentially, everything is legal).

I'm planning to make this the default shortly, but I'd like to fix
a collection of the bugs it exposes first, and this will let me easily
test them. It also showcases both the improvements and a few of the
regressions triggered by the change. The biggest improvements by far are
the significantly reduced shuffling and domain crossing in the combining
test case. The biggest regressions are missing some clever blending
patterns.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229284 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 06:37:21 +00:00
Chandler Carruth
0294b517ac [x86] Remove the now-default-on flag for the new vector shuffle lowering
strategy from a bunch of tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229283 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 06:20:51 +00:00
Chandler Carruth
424a198c30 [x86] Mechanically update a bunch of tests' check lines using the latest
version of the script.

Changes include:
- Using the VEX prefix
- Skipping more detail when we have useful shuffle comments to match
- Matching more shuffle comments that have been added to the printer
  (yay!)
- Matching the destination registers of some AVX instructions
- Stripping trailing whitespace that crept in
- Fixing indentation issues

Nothing interesting going on here. I'm just trying really hard to ensure
these changes don't show up in the diffs with actual changes to the
backend.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228132 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-04 10:46:53 +00:00
Simon Pilgrim
3d04e48cb6 [X86][SSE] psrl(w/d/q) and psll(w/d/q) bit shifts for SSE2
Patch to match cases where shuffle masks can be reduced to bit shifts. Similar to byte shift shuffle matching from D5699.

Differential Revision: http://reviews.llvm.org/D6649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228047 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-03 21:58:29 +00:00
Simon Pilgrim
71a4e9522e [X86][AVX2] Enabled shuffle matching for the AVX2 zero extension (128bit -> 256bit) vpmovzx* instructions.
Differential Revision: http://reviews.llvm.org/D7251

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228014 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-03 19:34:09 +00:00
Simon Pilgrim
982005c23e [X86][SSE] Shuffle mask decode support for zero extend, scalar float/double moves and integer load instructions
This patch adds shuffle mask decodes for integer zero extends (pmovzx** and movq xmm,xmm) and scalar float/double loads/moves (movss/movsd).

Also adds shuffle mask decodes for integer loads (movd/movq).

Differential Revision: http://reviews.llvm.org/D7228

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227688 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-31 14:09:36 +00:00
Simon Pilgrim
38c35f3e2c Line endings fix. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227138 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 21:28:32 +00:00
Simon Pilgrim
4269590166 [X86][SSE] Added support for SSE3 lane duplication shuffle instructions
This patch adds shuffle matching for the SSE3 MOVDDUP, MOVSLDUP and MOVSHDUP instructions. The big use of these being that they avoid many single source shuffles from needing to use (pre-AVX) dual source instructions such as SHUFPD/SHUFPS: causing extra moves and preventing load folds.

Adding these instructions uncovered an issue in XFormVExtractWithShuffleIntoLoad which crashed on single operand shuffle instructions (now fixed). It also involved fixing getTargetShuffleMask to correctly identify theses instructions as unary shuffles.

Also adds a missing tablegen pattern for MOVDDUP.

Differential Revision: http://reviews.llvm.org/D7042



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226716 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 22:44:35 +00:00
Mehdi Amini
5eed637b34 Improve DAG combine pass on certain IR vector patterns
Loading 2 2x32-bit float vectors into the bottom half of a 256-bit vector
produced suboptimal code in AVX2 mode with certain IR combinations.

In particular, the IR optimizer folded 2f32 + 2f32 -> 4f32, 4f32 + 4f32
(undef) -> 8f32 into a 2f32 + 2f32 -> 8f32, which seems more canonical,
but then mysteriously generated rather bad code; the movq/movhpd combination
didn't match.

The problem lay in the BUILD_VECTOR optimization path. The 2f32 inputs
would get promoted to 4f32 by the type legalizer, eventually resulting
in a BUILD_VECTOR on two 4f32 into an 8f32. The BUILD_VECTOR then, recognizing
these were both half the output size, concatted them and then produced
a shuffle. However, the resulting concat + shuffle was more complex than
it should be; in the case where the upper half of the output is undef, we
probably want to generate shuffle + concat instead.

This enhancement causes the vector_shuffle combine step to recognize this
suboptimal pattern and correct it. I included it there instead of in BUILD_VECTOR
in case the same suboptimal pattern occurs for other reasons.

This results in the optimizer correctly producing the optimal movq + movhpd
sequence for all three variations on this IR, even with AVX2.

I've included a test case.

Radar link: rdar://problem/19287012
Fix for PR 21943.

From: Fiona Glaser <fglaser@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226360 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-17 01:35:56 +00:00
Chandler Carruth
0889d65fd5 [x86] Make the previous logic significantly less conservative and get
a bunch more improvements.

Non-lane-crossing is fine, the key is that lane merging only makes sense
for single-input shuffles. Not sure why I got so turned around here. The
code all works, I was just using the wrong model for it.

This only updates v4 and v8 lowering. The v16 and v32 lowering requires
restructuring the entire check sequence.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222537 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-21 14:33:24 +00:00
Chandler Carruth
bd357588a1 [x86] Teach the x86 vector shuffle lowering to detect mergable 128-bit
lanes.

By special casing these we can often either reduce the total number of
shuffles significantly or reduce the number of (high latency on Haswell)
AVX2 shuffles that potentially cross 128-bit lanes. Even when these
don't actually cross lanes, they have much higher latency to support
that. Doing two of them and a blend is worse than doing a single insert
across the 128-bit lanes to blend and then doing a single interleaved
shuffle.

While this seems like a narrow case, it kept cropping up on me and the
difference is *huge* as you can see in many of the test cases. I first
hit this trying to perfectly fix the interleaving shuffle patterns used
by Halide for AVX2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222533 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-21 13:56:05 +00:00
Chandler Carruth
a5408b9c7c [x86] Add some tests for specific patterns of lane-flips combined with
in-lane shuffles that aren't always handled well by the current vector
shuffle lowering.

No functionality change yet, that will follow in a subsequent commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221938 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 22:49:44 +00:00
Chandler Carruth
4ea3097d08 [x86] Teach the vector shuffle lowering to make a more nuanced decision
between splitting a vector into 128-bit lanes and recombining them vs.
decomposing things into single-input shuffles and a final blend.

This handles a large number of cases in AVX1 where the cross-lane
shuffles would be much more expensive to represent even though we end up
with a fast blend at the root. Instead, we can do a better job of
shuffling in a single lane and then inserting it into the other lanes.

This fixes the remaining bits of Halide's regression captured in PR21281
for AVX1. However, the bug persists in AVX2 because I've made this
change reasonably conservative. The cases where it makes sense in AVX2
to split into 128-bit lanes are much more rare because we can often do
full permutations across all elements of the 256-bit vector. However,
the particular test case in PR21281 is an example of one of the rare
cases where it is *always* better to work in a single 128-bit lane. I'm
going to try to teach the logic to detect and form the good code even in
AVX2 next, but it will need to use a separate heuristic.

Finally, there is one pesky regression here where we previously would
craftily use vpermilps in AVX1 to shuffle both high and low halves at
the same time. We no longer pull that off, and not for any really good
reason. Ultimately, I think this is just another missing nuance to the
selection heuristic that I'll try to add in afterward, but this change
already seems strictly worth doing considering the magnitude of the
improvements in common matrix math shuffle patterns.

As always, please let me know if this causes a surprising regression for
you.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221861 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 04:06:10 +00:00
Filipe Cabecinhas
40251eb0b0 Fix a broadcast related regression on the vector shuffle lowering.
Summary: Test by Robert Lougher!

Reviewers: chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5745

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219617 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-13 16:16:16 +00:00
Chandler Carruth
bf21d40070 [x86] Teach the new vector shuffle lowering to widen floating point
elements as well as integer elements in order to form simpler shuffle
patterns.

This is the primary reason why we were failing to match some of the
2-and-2 floating point shuffles such as PR21140. Even after fixing this
we need to support some extra patterns in the backend in order to match
the resulting X86ISD::UNPCKL nodes into the correct instructions. This
commit should fix PR21140 and includes more comprehensive testing of
insertion patterns in v4 shuffles.

Not all of the added tests are beautiful. For example, we don't have
clever instructions to insert-via-load in the integer domain. There are
also some places where we aren't sufficiently cunning with our use of
movq and movd, but that's future work.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218911 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-02 21:37:14 +00:00
Chandler Carruth
afe75172b1 [x86] Teach the new vector shuffle lowering about VBROADCAST and
VPBROADCAST.

This has the somewhat expected pervasive impact. I don't know why
I forgot about this. Everything seems good with lots of significant
improvements in the tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218724 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-01 00:41:21 +00:00
Chandler Carruth
3a926b9b5c [x86] Update the exact FileCheck syntax of the 256-bit and 512-bit
shuffle tests to match that used in the script I posted and now used
consistently in 128-bit tests.

Nothing interesting changing here, just using the label name as the
FileCheck label and a slightly more general comment marker consumption
strategy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218709 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 22:04:45 +00:00
Chandler Carruth
7929a210d5 [x86] In the new vector shuffle lowering, when trying to do another
layer of tie-breaking sorting, it really helps to check that you're in
a tie first. =] Otherwise the whole thing cycles infinitely. Test case
added, another one found through fuzz testing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218523 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-26 17:24:26 +00:00
Chandler Carruth
7164a4ae0a [x86] Fix a large collection of bugs that crept in as I fleshed out the
AVX support.

New test cases included. Note that none of the existing test cases
covered these buggy code paths. =/ Also, it is clear from this that
SHUFPS and SHUFPD are the most bug prone shuffle instructions in x86. =[

These were all detected by fuzz-testing. (I <3 fuzz testing.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218522 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-26 17:11:02 +00:00
Chandler Carruth
4b667ee436 [x86] Teach the new vector shuffle lowering to use AVX2 instructions for
v4f64 and v8f32 shuffles when they are lane-crossing. We have fully
general lane-crossing permutation functions in AVX2 that make this easy.

Part of this also changes exactly when and how these vectors are split
up when we don't have AVX2. This isn't always a win but it usually is
a win, so on the balance I think its better. The primary regressions are
all things that just need to be fixed anyways such as modeling when
a blend can be completely accomplished via VINSERTF128, etc.

Also, this highlights one of the few remaining big features: we do
a really poor job of inserting elements into AVX registers efficiently.

This completes almost all of the big tricks I have in mind for AVX2. The
only things left that I plan to add:

1) element insertion smarts
2) palignr and other fairly specialized lowerings when they happen to
   apply

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218449 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-25 11:03:55 +00:00
Chandler Carruth
05901d80ba [x86] Teach the new vector shuffle lowering a fancier way to lower
256-bit vectors with lane-crossing.

Rather than immediately decomposing to 128-bit vectors, try flipping the
256-bit vector lanes, shuffling them and blending them together. This
reduces our worst case shuffle by a pretty significant margin across the
board.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218446 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-25 10:21:15 +00:00
Chandler Carruth
2e8d2c727c [x86] Fix an oversight in the v8i32 path of the new vector shuffle
lowering where it only used the mask of the low 128-bit lane rather than
the entire mask.

This allows the new lowering to correctly match the unpack patterns for
v8i32 vectors.

For reference, the reason that we check for the the entire mask rather
than checking the repeated mask is because the repeated masks don't
abide by all of the invariants of normal masks. As a consequence, it is
safer to use the full mask with functions like the generic equivalence
test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218442 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-25 04:10:27 +00:00
Chandler Carruth
10cd8098a7 [x86] Teach the instruction lowering to add comments describing constant
pool data being loaded into a vector register.

The comments take the form of:

  # ymm0 = [a,b,c,d,...]
  # xmm1 = <x,y,z...>

The []s are used for generic sequential data and the <>s are used for
specifically ConstantVector loads. Undef elements are printed as the
letter 'u', integers in decimal, and floating point values as floating
point values. Suggestions on improving the formatting or other aspects
of the display are very welcome.

My primary use case for this is to be able to FileCheck test masks
passed to vector shuffle instructions in-register. It isn't fantastic
for that (no decoding special zeroing semantics or other tricks), but it
at least puts the mask onto an instruction line that could reasonably be
checked. I've updated many of the new vector shuffle lowering tests to
leverage this in their test cases so that we're actually checking the
shuffle masks remain as expected.

Before implementing this, I tried a *bunch* of different approaches.
I looked into teaching the MCInstLower code to scan up the basic block
and find a definition of a register used in a shuffle instruction and
then decode that, but this seems incredibly brittle and complex.
I talked to Hal a lot about the "right" way to do this: attach the raw
shuffle mask to the instruction itself in some form of unencoded
operands, and then use that to emit the comments. I still think that's
the optimal solution here, but it proved to be beyond what I'm up for
here. In particular, it seems likely best done by completing the
plumbing of metadata through these layers and attaching the shuffle mask
in metadata which could have fully automatic dropping when encoding an
actual instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218377 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-24 09:39:41 +00:00
Chandler Carruth
6717f9d907 [x86] Teach the new vector shuffle lowering to lower v8i32 shuffles with
the native AVX2 instructions.

Note that the test case is really frustrating here because VPERMD
requires the mask to be in the register input and we don't produce
a comment looking through that to the constant pool. I'm going to
attempt to improve this in a subsequent commit, but not sure if I will
succeed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218347 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-24 01:24:44 +00:00
Chandler Carruth
30ce74b5e3 [x86] Teach the new vector shuffle lowering to lower v4i64 vector
shuffles using the AVX2 instructions. This is the first step of cutting
in real AVX2 support.

Note that I have spotted at least one bug in the test cases already, but
I suspect it was already present and just is getting surfaced. Will
investigate next.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218338 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-23 22:39:02 +00:00
Chandler Carruth
4850be49a3 [x86] Teach the vector comment parsing and printing to correctly handle
undef in the shuffle mask. This shows up when we're printing comments
during lowering and we still have an IR-level constant hanging around
that models undef.

A nice consequence of this is *much* prettier test cases where the undef
lanes actually show up as undef rather than as a particular set of
values. This also allows us to print shuffle comments in cases that use
undef such as the recently added variable VPERMILPS lowering. Now those
test cases have nice shuffle comments attached with their details.

The shuffle lowering for PSHUFB has been augmented to use undef, and the
shuffle combining has been augmented to comprehend it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218301 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-23 11:15:19 +00:00
Chandler Carruth
8f637786d8 [x86] Teach the AVX1 path of the new vector shuffle lowering one more
trick that I missed.

VPERMILPS has a non-immediate memory operand mode that allows it to do
asymetric shuffles in the two 128-bit lanes. Use this rather than two
shuffles and a blend.

However, it turns out the variable shuffle path to VPERMILPS (and
VPERMILPD, although that one offers no functional differenc from the
immediate operand other than variability) wasn't even plumbed through
codegen. Do such plumbing so that we can reasonably emit
a variable-masked VPERMILP instruction. Also plumb basic comment parsing
and printing through so that the tests are reasonable.

There are still a few tests which don't show the shuffle pattern. These
are tests with undef lanes. I'll teach the shuffle decoding and printing
to handle undef mask entries in a follow-up. I've looked at the masks
and they seem reasonable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218300 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-23 10:08:29 +00:00
Chandler Carruth
56c7cfe41f [x86] Introduce tests covering the gamut of 256-bit vector shuffling.
These are just test cases, no actual code yet. This establishes the
baseline fallback strategy we're starting from on AVX2 and the expected
lowering we use on AVX1.

Also, these test cases are very much generated. I've manually crafted
the specific pattern set that I'm hoping will be useful at exercising
the lowering code, but I've not (and could not) manually verify *all* of
these. I've spot checked and they seem legit to me.

As with the rest of vector shuffling, at a certain point the only really
useful way to check the correctness of this stuff is through fuzz
testing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218267 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-22 20:25:08 +00:00
Chandler Carruth
37bb4b0365 [x86] Teach the new vector shuffle lowering how to cleverly lower single
input v8f32 shuffles which are not 128-bit lane crossing but have
different shuffle patterns in the low and high lanes. This removes most
of the extract/insert traffic that was unnecessary and is particularly
good at lowering cases where only one of the two lanes is shuffled at
all.

I've also added a collection of test cases with undef lanes because this
lowering is somewhat more sensitive to undef lanes than others.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218226 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 23:46:13 +00:00
Chandler Carruth
7da57cf5b4 [x86] Add a bunch of test cases where we have different shuffle patterns
in the high and low 128-bit lanes of a v8f32 vector.

No functionality change yet, but wanted to set up the baseline for my
next patch which will make these quite a bit better. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218224 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 23:32:42 +00:00
Chandler Carruth
974542d7d8 [x86] Teach the new vector shuffle lowering to re-use the SHUFPS
lowering when it can use a symmetric SHUFPS across both 128-bit lanes.

This required making the SHUFPS lowering tolerant of other vector types,
and adjusting our canonicalization to canonicalize harder.

This is the last of the clever uses of symmetry I've thought of for
v8f32. The rest of the tricks I'm aware of here are to work around
assymetry in the mask.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218216 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 13:35:14 +00:00
Chandler Carruth
6ef31b0079 [x86] Teach the new vector shuffle lowering how to lower to UNPCKLPS and
UNPCKHPS with AVX vectors by recognizing those patterns when they are
repeated for both 128-bit lanes.

With this, we now generate the exact same (really nice) code for
Quentin's avx_test_case.ll which was the most significant regression
reported for the new shuffle lowering. In fact, I'm out of specific test
cases for AVX lowering, the rest were AVX2 I think. However, there are
a bunch of pretty obvious remaining things to improve with AVX...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218213 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 12:20:44 +00:00
Chandler Carruth
7a94357b04 [x86] Add test cases for UNPCK instructions with v8f32 AVX vectors in
preparation for enhancing their support in the new vector shuffle
lowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218212 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 12:13:11 +00:00
Chandler Carruth
7922d3e39a [x86] Begin teaching the new vector shuffle lowering among the most
important bits of cleverness: to detect and lower repeated shuffle
patterns between the two 128-bit lanes with a single instruction.

This patch just teaches it how to lower single-input shuffles that fit
this model using VPERMILPS. =] There is more that needs to happen here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218211 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 12:01:19 +00:00
Chandler Carruth
e4cb9d5f25 [x86] Regenerate this test case now that I've improved my script for
generating the test cases to format things more consistently and
actually catch all the operand sequences that should be elided in favor
of the asm comments. No actual changes here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218210 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 11:51:33 +00:00
Chandler Carruth
291140b112 [x86] Teach the new vector shuffle lowering the first step toward more
actual support for complex AVX shuffling tricks. We can do independent
blends of the low and high 128-bit lanes of an avx vector, so shuffle
the inputs into place and then do the blend at 256 bits. This will in
many cases remove one blend instruction.

The next step is to permute the low and high halves in-place rather than
extracting them and re-inserting them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218202 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 09:35:22 +00:00
Chandler Carruth
1ca1e33c3a [x86] Add some more test cases covering specific blend patterns.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218200 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 09:01:26 +00:00