Commit Graph

250 Commits

Author SHA1 Message Date
Arnold Schwaighofer
ac2cc0170f LoopVectorizer: Pass OperandValueKind information to the cost model
Pass down the fact that an operand is going to be a vector of constants.

This should bring the performance of MultiSource/Benchmarks/PAQ8p/paq8p on x86
back. It had degraded to scalar performance due to my pervious shift cost change
that made all shifts expensive on x86.

radar://13576547

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178809 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-04 23:26:27 +00:00
Arnold Schwaighofer
d517da33b7 LoopVectorize: Invert case when we use a vector cmp value to query select cost
We generate a select with a vectorized condition argument when the condition is
NOT loop invariant. Not the other way around.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177098 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-14 18:54:36 +00:00
Hal Finkel
76a05c93b1 BBVectorize: Fixup debugging statements
After the recent data-structure improvements, a couple of debugging statements
were broken (printing pointer values).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176791 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-10 20:57:42 +00:00
Benjamin Kramer
0d932717d8 Remove a source of nondeterminism from the LoopVectorizer.
This made us emit runtime checks in a random order. Hopefully bootstrap
miscompares will go away now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176775 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-09 19:22:40 +00:00
Arnold Schwaighofer
738295e457 LoopVectorizer: Ignore all dbg intrinisic
Ignore all DbgIntriniscInfo instructions instead of just DbgValueInst.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176769 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-09 16:27:27 +00:00
Arnold Schwaighofer
56ee544a3a LoopVectorizer: Ignore dbg.value instructions
We want vectorization to happen at -g. Ignore calls to the dbg.value intrinsic
and don't transfer them to the vectorized code.

radar://13378964

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176768 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-09 15:56:34 +00:00
Benjamin Kramer
f22d9cfa6d Insert the reduction start value into the first bypass block to preserve domination.
Fixes PR15344.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176701 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-08 16:58:37 +00:00
Nadav Rotem
5290baacb8 PR14448 - prevent the loop vectorizer from vectorizing the same loop twice.
The LoopVectorizer often runs multiple times on the same function due to inlining.
When this happens the loop vectorizer often vectorizes the same loops multiple times, increasing code size and adding unneeded branches.
With this patch, the vectorizer during vectorization puts metadata on scalar loops and marks them as 'already vectorized' so that it knows to ignore them when it sees them a second time.

PR14448.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176399 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-02 01:33:49 +00:00
Benjamin Kramer
5d79bb8770 LoopVectorize: Don't hang forever if a PHI only has skipped PHI uses.
Fixes PR15384.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-01 19:07:31 +00:00
Benjamin Kramer
2fe71f8f7e LoopVectorize: Vectorize math builtin calls.
This properly asks TargetLibraryInfo if a call is available and if it is, it
can be translated into the corresponding LLVM builtin. We don't vectorize sqrt()
yet because I'm not sure about the semantics for negative numbers. The other
intrinsic should be exact equivalents to the libm functions.

Differential Revision: http://llvm-reviews.chandlerc.com/D465

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176188 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-27 15:24:19 +00:00
Renato Golin
e18bce5317 Allow GlobalValues to vectorize with AliasAnalysis
Storing the load/store instructions with the values
and inspect them using Alias Analysis to make sure
they don't alias, since the GEP pointer operand doesn't
take the offset into account.

Trying hard to not add any extra cost to loads and stores
that don't overlap on global values, AA is *only* calculated
if all of the previous attempts failed.

Using biggest vector register size as the stride for the
vectorization access, as we're being conservative and
the cost model (which calculates the real vectorization
factor) is only run after the legalization phase.

We might re-think this relationship in the future, but
for now, I'd rather be safe than sorry.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175818 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-21 22:39:03 +00:00
Hal Finkel
f79f136cc6 BBVectorize: Fix an invalid reference bug
This fixes PR15289. This bug was introduced (recently) in r175215; collecting
all std::vector references for candidate pairs to delete at once is invalid
because subsequent lookups in the owning DenseMap could invalidate the
references.

bugpoint was able to reduce a useful test case. Unfortunately, because whether
or not this asserts depends on memory layout, this test case will sometimes
appear to produce valid output. Nevertheless, running under valgrind will
reveal the error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175397 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-17 15:59:26 +00:00
Hal Finkel
f64a7a83be BBVectorize: Call a DAG and DAG instead of a tree
Several functions and variable names used the term 'tree' to refer
to what is actually a DAG. Correcting this mistake will, hopefully,
prevent confusion in the future.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175278 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-15 17:20:54 +00:00
Hal Finkel
ab90084bca BBVectorize: Cap the number of candidate pairs in each instruction group
For some basic blocks, it is possible to generate many candidate pairs for
relatively few pairable instructions. When many (tens of thousands) of these pairs
are generated for a single instruction group, the time taken to generate and
rank the different vectorization plans can become quite large. As a result, we now
cap the number of candidate pairs within each instruction group. This is done by
closing out the group once the threshold is reached (set now at 3000 pairs).

Although this will limit the overall compile-time impact, this may not be the best
way to achieve this result. It might be better, for example, to prune excessive
candidate pairs after the fact the prevent the generation of short, but highly-connected
groups. We can experiment with this in the future.

This change reduces the overall compile-time slowdown of the csa.ll test case in
PR15222 to ~5x. If 5x is still considered too large, a lower limit can be
used as the default.

This represents a functionality change, but only for very large inputs
(thus, there is no regression test).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175251 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-15 04:28:42 +00:00
Hal Finkel
97a241b173 BBVectorize: Remove the remaining instances of std::multimap
All instances of std::multimap have now been replaced by
DenseMap<K, std::vector<V> >, and this yields a speedup of 5% on the
csa.ll test case from PR15222.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175216 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-14 22:38:04 +00:00
Hal Finkel
6ca6d3b1ea BBVectorize: Don't store candidate pairs in a std::multimap
This is another commit on the road to removing std::multimap from
BBVectorize. This gives an ~1% speedup on the csa.ll test case
in PR15222.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175215 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-14 22:37:09 +00:00
Benjamin Kramer
c0a6e070fc LoopVectorize: Simplify code for clarity.
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175076 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-13 21:12:29 +00:00
Pekka Jaaskelainen
5d0ce79e26 Metadata for annotating loops as parallel. The first consumer for this
metadata is the loop vectorizer.

See the documentation update for more info.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175060 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-13 18:08:57 +00:00
Hal Finkel
c951003faf BBVectorize: Don't over-search when building the dependency map
When building the pairable-instruction dependency map, don't search
past the last pairable instruction. For large blocks that have been
divided into multiple instruction groups, searching past the last
instruction in each group is very wasteful. This gives a 32% speedup
on the csa.ll test case from PR15222 (when using 50 instructions
in each group).

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174915 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-11 23:02:17 +00:00
Hal Finkel
8f3359a4b3 BBVectorize: Omit unnecessary entries in PairableInstUsers
This map is queried only for instructions in pairs of pairable
instructions; so make sure that only pairs of pairable
instructions are added to the map. This gives a 3.5% speedup
on the csa.ll test case from PR15222.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174914 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-11 23:02:09 +00:00
Hal Finkel
b1a8258933 BBVectorize: Eliminate one more restricted linear search
This eliminates one more linear search over a range of
std::multimap entries. This gives a 22% speedup on the
csa.ll test case from PR15222.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174893 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-11 17:19:34 +00:00
Hal Finkel
00f63b1b84 BBVectorize: Remove the linear searches from pair connection searching
This removes the last of the linear searches over ranges of std::multimap
iterators, giving a 7% speedup on the doduc.bc input from PR15222.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174859 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-11 05:29:51 +00:00
Hal Finkel
2f0e63cc16 BBVectorize: Avoid linear searches within the load-move set
This is another cleanup aimed at eliminating linear searches
in ranges of std::multimap.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174858 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-11 05:29:49 +00:00
Hal Finkel
3fc1e4aa15 BBVectorize: isa/cast cleanup in getInstructionTypes
Profiling suggests that getInstructionTypes is performance-sensitive,
this cleans up some double-casting in that function in favor of
using dyn_cast.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174857 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-11 05:29:48 +00:00
Hal Finkel
da20ea696d BBVectorize: Make the bookkeeping to support full cycle checking less expensive
By itself, this does not have much of an effect, but only because in the default
configuration the full cycle checks are used only for small problem sizes.
This is part of a general cleanup of uses of iteration over std::multimap
ranges only for the purpose of checking membership.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174856 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-11 05:29:41 +00:00
Hal Finkel
0cf5d396c1 BBVectorize: Use TTI->getAddressComputationCost
This is a follow-up to the cost-model change in r174713 which splits
the cost of a memory operation between the address computation and the
actual memory access. In r174713, this cost is always added to the
memory operation cost, and so BBVectorize will do the same.

Currently, this new cost function is used only by ARM, and I don't
have any ARM test cases for BBVectorize. Assistance in generating some
good ARM test cases for BBVectorize would be greatly appreciated!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174743 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-08 21:13:39 +00:00
Jakob Stoklund Olesen
9de31bd829 Typos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174723 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-08 17:43:32 +00:00
Arnold Schwaighofer
fb55a8fd7c ARM cost model: Address computation in vector mem ops not free
Adds a function to target transform info to query for the cost of address
computation. The cost model analysis pass now also queries this interface.
The code in LoopVectorize adds the cost of address computation as part of the
memory instruction cost calculation. Only there, we know whether the instruction
will be scalarized or not.
Increase the penality for inserting in to D registers on swift. This becomes
necessary because we now always assume that address computation has a cost and
three is a closer value to the architecture.

radar://13097204

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174713 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-08 14:50:48 +00:00
Michael Kuperstein
bcf60de5eb Test Commit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174709 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-08 12:58:29 +00:00
Nadav Rotem
4fae15e664 fix 80-col violation and fix the docs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174671 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-07 22:34:07 +00:00
Arnold Schwaighofer
96a6555b57 Loop Vectorizer: Refactor Memory Cost Computation
We don't want too many classes in a pass and the classes obscure the details. I
was going a little overboard with object modeling here. Replace classes by
generic code that handles both loads and stores.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174646 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-07 19:05:21 +00:00
Arnold Schwaighofer
7d80dad407 Loop Vectorizer: Refactor code to compute vectorized memory instruction cost
Introduce a helper class that computes the cost of memory access instructions.
No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174422 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-05 18:46:41 +00:00
Arnold Schwaighofer
935645b765 Loop Vectorizer: Handle pointer stores/loads in getWidestType()
In the loop vectorizer cost model, we used to ignore stores/loads of a pointer
type when computing the widest type within a loop. This meant that if we had
only stores/loads of pointers in a loop we would return a widest type of 8bits
(instead of 32 or 64 bit) and therefore a vector factor that was too big.

Now, if we see a consecutive store/load of pointers we use the size of a pointer
(from data layout).

This problem occured in SingleSource/Benchmarks/Shootout-C++/hash.cpp (reduced
test case is the first test in vector_ptr_load_store.ll).

radar://13139343

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174377 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-05 15:08:02 +00:00
Pekka Jaaskelainen
d855049576 LoopVectorize: convert TinyTripCountVectorThreshold constant
to a command line switch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173837 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-29 21:42:08 +00:00
Benjamin Kramer
8c3a411cd6 LoopVectorize: Clean up ValueMap a bit and avoid double lookups.
No intended functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173809 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-29 17:31:33 +00:00
Renato Golin
237f09db09 Vectorization Factor clarification
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173691 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-28 16:02:45 +00:00
Hal Finkel
245b657ab6 BBVectorize: Better use of TTI->getShuffleCost
When flipping the pair of subvectors that form a vector, if the
vector length is 2, we can use the SK_Reverse shuffle kind to get
more-accurate cost information. Also we can use the SK_ExtractSubvector
shuffle kind to get accurate subvector extraction costs.

The current cost model implementations don't yet seem complex enough
for this to make a difference (thus, there are no test cases with this
commit), but it should help in future.

Depending on how the various targets optimize and combine shuffles in
practice, we might be able to get more-accurate costs by combining the
costs of multiple shuffle kinds. For example, the cost of flipping the
subvector pairs could be modeled as two extractions and two subvector
insertions. These changes, however, should probably be motivated
by specific test cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173621 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-27 20:07:01 +00:00
Hal Finkel
ec5c3c2bd3 BBVectorize: Add a additional comment about the cost computation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173580 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-26 16:49:04 +00:00
Hal Finkel
7a8aba9064 BBVectorize: Fix anomalous capital letter in comment
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173579 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-26 16:49:03 +00:00
Nadav Rotem
c655c43ba5 LoopVectorize: Refactor the code that vectorizes loads/stores to remove duplication.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173500 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25 21:47:42 +00:00
Benjamin Kramer
5ac70a3804 LoopVectorize: Simplify code. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173475 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25 19:43:15 +00:00
Nadav Rotem
1275708f29 LoopVectorizer: Refactor more code to use the IRBuilder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173471 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25 19:26:23 +00:00
Nadav Rotem
f8c2f90bb3 Refactor some code to use the IRBuilder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173467 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25 18:34:09 +00:00
Nadav Rotem
f148c66ce4 Add support for reverse pointer induction variables. These are loops that contain pointers that count backwards.
For example, this is the hot loop in BZIP:

  do {
    m = *--p;
    *p = ( ... );
  } while (--n);



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173219 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-23 01:35:00 +00:00
Nadav Rotem
dc0a5fd226 Fix a comment. Induction vars dont need to start at zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173061 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-21 17:59:18 +00:00
Benjamin Kramer
5ff7a3f947 LoopVectorize: Fix a C++11 incompatibility.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172990 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-20 20:29:52 +00:00
Nadav Rotem
e6e7606118 Fix a build error.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172971 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-20 09:39:17 +00:00
Nadav Rotem
0bbbc52dc8 LoopVectorizer: Implement a new heuristics for selecting the unroll factor.
We ignore the cpu frontend and focus on pipeline utilization. We do this because we
don't have a good way to estimate the loop body size at the IR level.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172964 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-20 05:24:29 +00:00
Benjamin Kramer
1af132dcf3 LoopVectorizer: Emit memory checks into their own basic block.
This separates the check for "too few elements to run the vector loop" from the
"memory overlap" check, giving a lot nicer code and allowing to skip the memory
checks when we're not going to execute the vector code anyways. We still leave
the decision of whether to emit the memory checks as branches or setccs, but it
seems to be doing a good job. If ugly code pops up we may want to emit them as
separate blocks too. Small speedup on MultiSource/Benchmarks/MallocBench/espresso.

Most of this is legwork to allow multiple bypass blocks while updating PHIs,
dominators and loop info.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172902 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-19 13:57:58 +00:00
Nadav Rotem
6a459e65c8 LoopVectorizer cost model. Honor the user command line flag that selects the vectorization factor even if the target machine does not have any vector registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172544 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-15 18:25:16 +00:00