Commit Graph

363 Commits

Author SHA1 Message Date
Nadav Rotem
d4a9ebc734 We preserve the CFG and some of the analysis passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185251 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-29 05:38:15 +00:00
Nadav Rotem
08e20fbea1 Update docs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185250 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-29 05:37:19 +00:00
Nadav Rotem
ac26786846 SLP Vectorizer: Add support for trees with external users.
To support this we have to insert 'extractelement' instructions to pick the right lane.
We had this functionality before but I removed it when we moved to the multi-block design because it was too complicated.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185230 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-28 22:07:09 +00:00
Nadav Rotem
4025fa5b85 LoopVectorizer: Refactor the code that checks if it is safe to predicate blocks.
In this code we keep track of pointers that we are allowed to read from, if they are accessed by non-predicated blocks.
We use this list to allow vectorization of conditional loads in predicated blocks because we know that these addresses don't segfault.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185214 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-28 20:46:27 +00:00
Arnold Schwaighofer
0ee20c9d80 LoopVectorize: Pull dyn_cast into setDebugLocFromInst
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185168 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-28 17:14:48 +00:00
Arnold Schwaighofer
b0f11e3701 LoopVectorize: Use static function instead of DebugLocSetter class
I used the class to safely reset the state of the builder's debug location.  I
think I have caught all places where we need to set the debug location to a new
one. Therefore, we can replace the class by a function that just sets the debug
location.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185165 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-28 16:26:54 +00:00
Arnold Schwaighofer
57a7da8b23 LoopVectorize: Preserve debug location info
radar://14169017

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185122 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-28 00:38:54 +00:00
Arnold Schwaighofer
0bbbf7cbb0 LoopVectorize: Cache edge masks created during if-conversion
Otherwise, we end up with an exponential IR blowup.
Fixes PR16472.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185097 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 20:31:06 +00:00
Arnold Schwaighofer
0862d589ee LoopVectorize: Use vectorized loop invariant gep index anchored in loop
Use vectorized instruction instead of original instruction anchored in the
original loop.

Fixes PR16452 and t2075.c of PR16455.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185081 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 15:11:55 +00:00
Arnold Schwaighofer
45ef457b8f LoopVectorize: Don't store a reversed value in the vectorized value map
When we store values for reversed induction stores we must not store the
reversed value in the vectorized value map. Another instruction might use this
value.

This fixes 3 test cases of PR16455.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185051 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 00:45:41 +00:00
Nadav Rotem
9367c79e62 No need to use a Set when a vector would do.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185047 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 00:14:13 +00:00
Nadav Rotem
70d695801a SLP: When searching for vectorization opportunities scan the blocks in post-order because we grow chains upwards.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185041 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-26 23:44:45 +00:00
Nadav Rotem
1e1c694dcd SLP: Dont erase instructions during vectorization because it prevents the outerloops from iterating over the instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185040 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-26 23:43:23 +00:00
Nadav Rotem
e26fa2dd73 Erase all of the instructions that we RAUWed
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184969 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-26 17:16:09 +00:00
Nadav Rotem
29acf7e03a Do not add cse-ed instructions into the visited map because we dont want to consider them as a candidate for replacement of instructions to be visited.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184966 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-26 16:54:53 +00:00
Nadav Rotem
805e8a01fe SLPVectorizer: support slp-vectorization of PHINodes between basic blocks
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184888 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-25 23:04:09 +00:00
Nadav Rotem
58bf5ea452 Fix a typo in the code that collected the costs recursively.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184827 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-25 05:30:56 +00:00
Nadav Rotem
f4b0e81085 Rename the variable to fix a warning. Thanks Andy Gibbs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184749 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 15:59:47 +00:00
Arnold Schwaighofer
bc7c58d2b1 Reapply 184685 after the SetVector iteration order fix.
This should hopefully have fixed the stage2/stage3 miscompare on the dragonegg
testers.

"LoopVectorize: Use the dependence test utility class

We now no longer need alias analysis - the cases that alias analysis would
handle are now handled as accesses with a large dependence distance.

We can now vectorize loops with simple constant dependence distances.

  for (i = 8; i < 256; ++i) {
    a[i] = a[i+4] * a[i+8];
  }

  for (i = 8; i < 256; ++i) {
    a[i] = a[i-4] * a[i-8];
  }

We would be able to vectorize about 200 more loops (in many cases the cost model
instructs us no to) in the test suite now. Results on x86-64 are a wash.

I have seen one degradation in ammp. Interestingly, the function in which we
now vectorize a loop is never executed so we probably see some instruction
cache effects. There is a 2% improvement in h264ref. There is one or the other
TSCV loop kernel that speeds up.

radar://13681598"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184724 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 12:09:15 +00:00
Arnold Schwaighofer
7e96b4dfce LoopVectorize: Use SetVector for the access set
We are creating the runtime checks using this set so we need a deterministic
iteration order.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184723 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 12:09:12 +00:00
Arnold Schwaighofer
ec677e2a64 Revert "LoopVectorize: Use the dependence test utility class"
This reverts commit cbfa1ca993.

We are seeing a stage2 and stage3 miscompare on some dragonegg bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184690 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 06:10:41 +00:00
Arnold Schwaighofer
cbfa1ca993 LoopVectorize: Use the dependence test utility class
We now no longer need alias analysis - the cases that alias analysis would
handle are now handled as accesses with a large dependence distance.

We can now vectorize loops with simple constant dependence distances.

  for (i = 8; i < 256; ++i) {
    a[i] = a[i+4] * a[i+8];
  }

  for (i = 8; i < 256; ++i) {
    a[i] = a[i-4] * a[i-8];
  }

We would be able to vectorize about 200 more loops (in many cases the cost model
instructs us no to) in the test suite now. Results on x86-64 are a wash.

I have seen one degradation in ammp. Interestingly, the function in which we
now vectorize a loop is never executed so we probably see some instruction
cache effects. There is a 2% improvement in h264ref. There is one or the other
TSCV loop kernel that speeds up.

radar://13681598

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184685 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 03:55:48 +00:00
Arnold Schwaighofer
5df684a6d1 LoopVectorize: Add utility class for checking dependency among accesses
This class checks dependences by subtracting two Scalar Evolution access
functions allowing us to catch very simple linear dependences.

The checker assumes source order in determining whether vectorization is safe.
We currently don't reorder accesses.
Positive true dependencies need to be a multiple of VF otherwise we impede
store-load forwarding.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184684 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 03:55:45 +00:00
Arnold Schwaighofer
5737d3f433 LoopVectorize: Add utility class for building sets of dependent accesses
Sets of dependent accesses are built by unioning sets based on underlying
objects. This class will be used by the upcoming dependence checker.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184683 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 03:55:44 +00:00
Nadav Rotem
25961b469a SLP Vectorizer: Add support for vectorizing parts of the tree.
Untill now we detected the vectorizable tree and evaluated the cost of the
entire tree.  With this patch we can decide to trim-out branches of the tree
that are not profitable to vectorizer.

Also, increase the max depth from 6 to 12. In the worse possible case where all
of the code is made of diamond-shaped graph this can bring the cost to 2**10,
but diamonds are not very common.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184681 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 02:52:43 +00:00
Nadav Rotem
722b0a4d29 SLP Vectorizer: Fix a bug in the code that does CSE on the generated gather sequences.
Make sure that we don't replace and RAUW two sequences if one does not dominate the other.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184674 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-23 21:57:27 +00:00
Nadav Rotem
787ad64b98 SLP Vectorizer: Erase instructions outside the vectorizeTree method.
The RAII builder location guard is saving a reference to instructions, so we can't erase instructions during vectorization.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184671 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-23 19:38:56 +00:00
Nadav Rotem
6959f08f44 SLP Vectorizer: Implement a simple CSE optimization for the gather sequences.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184660 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-23 06:15:46 +00:00
Nadav Rotem
53a0552b06 SLP Vectorizer: Implement multi-block slp-vectorization.
Rewrote the SLP-vectorization as a whole-function vectorization pass. It is now able to vectorize chains across multiple basic blocks.
It still does not vectorize PHIs, but this should be easy to do now that we scan the entire function.
I removed the support for extracting values from trees.
We are now able to vectorize more programs, but there are some serious regressions in many workloads (such as flops-6 and mandel-2).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184647 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-22 21:34:10 +00:00
Nadav Rotem
de26195f3c SLP Vectorizer: do not search for store-chains that are wider than the vector-register size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184527 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 04:18:13 +00:00
Nadav Rotem
0b827993ed Clang-format the SLP vectorizer. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184446 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-20 17:54:36 +00:00
Nadav Rotem
d69d9f20bc SLPVectorization: Add a basic support for cross-basic block slp vectorization.
We collect gather sequences when we vectorize basic blocks. Gather sequences are excellent
hints for vectorization of other basic blocks.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184444 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-20 17:41:45 +00:00
Nadav Rotem
dc4dcb6762 Change the debug type to match the debug type that is used by vecutils.cpp.
This change makes it easier to filter debug messages.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184440 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-20 16:38:05 +00:00
Nadav Rotem
80a6d6526c SLPVectorizer: handle scalars that are extracted from vectors (using ExtractElementInst).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184325 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 17:33:16 +00:00
Nadav Rotem
7d180ac7b6 SLPVectorizer: start constructing chains at stores that are not power of two.
The type <3 x i8> is a common in graphics and we want to be able to vectorize it.

This changes accelerates bullet by 12% and 471_omnetpp by 5%.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184317 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 15:57:29 +00:00
Nadav Rotem
eb30e5115e SLPVectorizer: vectorize compares and selects.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184282 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 05:49:52 +00:00
Nadav Rotem
69466952ed Document the return value and fix a typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184281 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 05:47:33 +00:00
Nadav Rotem
5cb84896bc Scan the successor blocks and use the PHI nodes as a hint for possible chain roots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184201 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-18 15:58:05 +00:00
Nadav Rotem
7a0fad9a86 Add a return value to make this function more useful.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184200 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-18 15:57:12 +00:00
Pekka Jaaskelainen
a8a04380c5 Fix for a regression caused by the LoopVectorizer when
vectorizing loops with memory accesses to non-zero address spaces. It
simply dropped the AS info. Fixes PR16306.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184103 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-17 18:49:06 +00:00
Arnold Schwaighofer
35b4cf868e LoopVectorize: Change API call to get the backedge taken count
Use ScalarEvolution's getBackedgeTakenCount API instead of getExitCount since
that is really what we want to know. Using the more specific getExitCount was
safe because we made sure that there is only one exiting block.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183047 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-31 21:48:56 +00:00
Arnold Schwaighofer
47afc19625 LoopVectorize: PHIs with only outside users should prevent vectorization
We check that instructions in the loop don't have outside users (except if
they are reduction values). Unfortunately, we skipped this check for
if-convertable PHIs.

Fixes PR16184.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183035 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-31 19:53:50 +00:00
NAKAMURA Takumi
0cf4adbcef LoopVectorize.cpp: Fix abuse of StringRef on Twine. Twine captures the pointer of StringRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182820 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-29 03:13:47 +00:00
NAKAMURA Takumi
51c292a360 Whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182819 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-29 03:13:41 +00:00
Paul Redmond
ee21b6f7b4 Add support for llvm.vectorizer metadata
- llvm.loop.parallel metadata has been renamed to llvm.loop to be more generic
  by making the root of additional loop metadata.
  - Loop::isAnnotatedParallel now looks for llvm.loop and associated
    llvm.mem.parallel_loop_access
  - document llvm.loop and update llvm.mem.parallel_loop_access
- add support for llvm.vectorizer.width and llvm.vectorizer.unroll
  - document llvm.vectorizer.* metadata
  - add utility class LoopVectorizerHints for getting/setting loop metadata
  - use llvm.vectorizer.width=1 to indicate already vectorized instead of
    already_vectorized
- update existing tests that used llvm.loop.parallel and
  llvm.vectorizer.already_vectorized

Reviewed by: Nadav Rotem


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182802 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-28 20:00:34 +00:00
Benjamin Kramer
959ecb2eec LoopVectorize: LoopSimplify can't canonicalize loops with an indirectbr in it, don't assert on those cases.
Fixes PR16139.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182656 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-24 18:05:35 +00:00
Nadav Rotem
3f75c6cfb5 SLPVectorizer: Change the order in which new instructions are added to the function.
We are not working on a DAG and I ran into a number of problems when I enabled the vectorizations of 'diamond-trees' (trees that share leafs).
* Imroved the numbering API.
* Changed the placement of new instructions to the last root.
* Fixed a bug with external tree users with non-zero lane.
* Fixed a bug in the placement of in-tree users.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182508 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-22 19:47:32 +00:00
Arnold Schwaighofer
6e4a9c14f6 LoopVectorize: Make Value pointers that could be RAUW'ed a VH
The Value pointers we store in the induction variable list can be RAUW'ed by a
call to SCEVExpander::expandCodeFor, use a TrackingVH instead. Do the same thing
in some other places where we store pointers that could potentially be RAUW'ed.

Fixes PR16073.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182485 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-22 16:54:56 +00:00
Arnold Schwaighofer
688b5103eb LoopVectorize: Handle single edge PHIs
We might encouter single edge PHIs - handle them with an identity select.

Fixes PR15990.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182199 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-18 18:38:34 +00:00
Benjamin Kramer
c53bee6eae LoopVectorize: Simplify code. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182100 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-17 14:48:17 +00:00