Commit Graph

170 Commits

Author SHA1 Message Date
Arnold Schwaighofer
a3fb330d05 LoopVectorizer: Recognize min/max reductions
A min/max operation is represented by a select(cmp(lt/le/gt/ge, X, Y), X, Y)
sequence in LLVM. If we see such a sequence we can treat it just as any other
commutative binary instruction and reduce it.

This appears to help bzip2 by about 1.5% on an imac12,2.

radar://12960601

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179773 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-18 17:22:34 +00:00
Benjamin Kramer
403fc14370 LoopVectorize: Use a set to avoid longer cycles in the reduction chain too.
Fixes PR15748.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179757 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-18 14:29:13 +00:00
Arnold Schwaighofer
08a0e8f8db LoopVectorizer: integer division is not a reduction operation
Don't classify idiv/udiv as a reduction operation. Integer division is lossy.
For example : (1 / 2) * 4 != 4/2.

Example:

int a[] = { 2, 5, 2, 2}
int x = 80;

for()
  x /= a[i];

Scalar:
  x /= 2 // = 40
  x /= 5 // = 8
  x /= 2 // = 4
  x /= 2 // = 2

Vectorized:

 <80, 1> / <2,5> //= <40,0>
 <40, 0> / <2,2> //= <20,0>

 20*0 = 0

radar://13640654

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179381 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 15:15:19 +00:00
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
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
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
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
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
Nadav Rotem
b6db95f42b Fix PR14547. Handle induction variables of small sizes smaller than i32 (i8 and i16).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172348 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-13 07:56:29 +00:00
Nadav Rotem
a675c74208 ARM Cost Model: We need to detect the max bitwidth of types in the loop in order to select the max vectorization factor.
We don't have a detailed analysis on which values are vectorized and which stay scalars in the vectorized loop so we use
another method. We look at reduction variables, loads and stores, which are the only ways to get information in and out
of loop iterations. If the data types are extended and truncated then the cost model will catch the cost of the vector
zext/sext/trunc operations.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172178 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-11 07:11:59 +00:00
Nadav Rotem
c560bf638b LoopVectorizer: Fix a bug in the vectorization of BinaryOperators. The BinaryOperator can be folded to an Undef, and we don't want to set NSW flags to undef vals.
PR14878



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172079 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-10 17:34:39 +00:00
Nadav Rotem
14925e6b88 ARM Cost model: Use the size of vector registers and widest vectorizable instruction to determine the max vectorization factor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172010 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 22:29:00 +00:00
Nadav Rotem
83be7b0dd3 Cost Model: Move the 'max unroll factor' variable to the TTI and add initial Cost Model support on ARM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171928 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 01:15:42 +00:00
Nadav Rotem
8327474e4b Code cleanup: refactor the switch statements in the generation of reduction variables into an IR builder call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171871 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-08 17:37:45 +00:00
Nadav Rotem
aae3d6fb53 Rename the enum members to match the LLVM coding style.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171868 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-08 17:23:17 +00:00
Nadav Rotem
111e5fe7e0 LoopVectorizer: Add support for floating point reductions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171812 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 23:13:00 +00:00
Nadav Rotem
9a6c6a3736 LoopVectorizer: When we vectorizer and widen loops we process many elements at once. This is a good thing, except for
small loops. On small loops post-loop that handles scalars (and runs slower) can take more time to execute than the
rest of the loop. This patch disables widening of loops with a small static trip count.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171798 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 21:54:51 +00:00
Chandler Carruth
1cbeaeb194 Simplify LoopVectorize to require target transform info and rely on it
being present. Make a member of one of the helper classes a reference as
part of this.

Reformatting goodness brought to you by clang-format.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171726 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 11:12:29 +00:00
Chandler Carruth
f3252b12e0 Merge the unused header file for LoopVectorizer into the source file.
This makes the loop vectorizer match the pattern followed by roughly all
other passses. =]

Notably, this header file was braken in several regards: it contained
a using namespace directive, global #define's that aren't globaly
appropriate, and global constants defined directly in the header file.

As a side benefit, lots of the types in this file become internal, which
will cause the optimizer to chew on this pass more effectively.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171723 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 10:44:06 +00:00
Chandler Carruth
bb00800ff4 Fix the enumerator names for ShuffleKind to match tho coding standards,
and make its comments doxygen comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171688 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 03:20:02 +00:00
Chandler Carruth
be04929f7f Move TargetTransformInfo to live under the Analysis library. This no
longer would violate any dependency layering and it is in fact an
analysis. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171686 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 03:08:10 +00:00
Chandler Carruth
be73c7b903 Switch the loop vectorizer from VTTI to just use TTI directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171620 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-05 10:16:02 +00:00