2349 Commits

Author SHA1 Message Date
Arnold Schwaighofer
3610139ac5 LoopVectorizer: Improve reduction variable identification
The two nested loops were confusing and also conservative in identifying
reduction variables. This patch replaces them by a worklist based approach.

llvm-svn: 181369
2013-05-07 21:55:37 +00:00
Arnold Schwaighofer
e78b76fbed LoopVectorize: getConsecutiveVector must respect signed arithmetic
We were passing an i32 to ConstantInt::get where an i64 was needed and we must
also pass the sign if we pass negatives numbers. The start index passed to
getConsecutiveVector must also be signed.

Should fix PR15882.

llvm-svn: 181286
2013-05-07 04:37:05 +00:00
Nadav Rotem
632b25b743 Update the comment to mention that we use TTI.
llvm-svn: 181178
2013-05-06 03:06:36 +00:00
Benjamin Kramer
3e3f2a4b8d LoopVectorize: Print values instead of pointers in debug output.
llvm-svn: 181157
2013-05-05 14:54:52 +00:00
Arnold Schwaighofer
d96e427eac LoopVectorize: Add support for floating point min/max reductions
Add support for min/max reductions when "no-nans-float-math" is enabled. This
allows us to assume we have ordered floating point math and treat ordered and
unordered predicates equally.

radar://13723044

llvm-svn: 181144
2013-05-05 01:54:48 +00:00
Arnold Schwaighofer
f5183729db LoopVectorizer: Cleanup of miminimum/maximum pattern match code
No need for setting the operands. The pointers are going to be bound by the
matcher.

radar://13723044

llvm-svn: 181142
2013-05-05 01:54:44 +00:00
Arnold Schwaighofer
a670a0a3aa LoopVectorize: We don't need an identity element for min/max reductions
We can just use the initial element that feeds the reduction.

  max(max(x, y), z) == max(max(x,y), max(x,z))

radar://13723044

llvm-svn: 181141
2013-05-05 01:54:42 +00:00
Dmitri Gribenko
3238fb7595 Add ArrayRef constructor from None, and do the cleanups that this constructor enables
Patch by Robert Wilhelm.

llvm-svn: 181138
2013-05-05 00:40:33 +00:00
Nadav Rotem
4ce060b3da LoopVectorizer: Add support for if-conversion of PHINodes with 3+ incoming values.
By supporting the vectorization of PHINodes with more than two incoming values we can increase the complexity of nested if statements.

We can now vectorize this loop:

int foo(int *A, int *B, int n) {
  for (int i=0; i < n; i++) {
    int x = 9;
    if (A[i] > B[i]) {
      if (A[i] > 19) {
        x = 3;
      } else if (B[i] < 4 ) {
        x = 4;
      } else {
        x = 5;
      }
    }
    A[i] = x;
  }
}

llvm-svn: 181037
2013-05-03 17:42:55 +00:00
Filip Pizlo
dec20e43c0 This patch breaks up Wrap.h so that it does not have to include all of
the things, and renames it to CBindingWrapping.h.  I also moved 
CBindingWrapping.h into Support/.

This new file just contains the macros for defining different wrap/unwrap 
methods.

The calls to those macros, as well as any custom wrap/unwrap definitions 
(like for array of Values for example), are put into corresponding C++ 
headers.

Doing this required some #include surgery, since some .cpp files relied 
on the fact that including Wrap.h implicitly caused the inclusion of a 
bunch of other things.

This also now means that the C++ headers will include their corresponding 
C API headers; for example Value.h must include llvm-c/Core.h.  I think 
this is harmless, since the C API headers contain just external function 
declarations and some C types, so I don't believe there should be any 
nasty dependency issues here.

llvm-svn: 180881
2013-05-01 20:59:00 +00:00
Nadav Rotem
9feda6071a Fix a typo
llvm-svn: 180806
2013-04-30 21:04:51 +00:00
Nadav Rotem
13306816fc LoopVectorizer: Calculate the number of pointers to disambiguate at runtime based on the numbers of reads and writes.
llvm-svn: 180593
2013-04-26 05:08:59 +00:00
Nadav Rotem
f43cbeee15 LoopVectorizer: No need to generate pointer disambiguation checks between readonly pointers.
llvm-svn: 180570
2013-04-25 19:55:03 +00:00
Arnold Schwaighofer
3fa801fbc2 LoopVectorizer: Change variable name Stride to ConsecutiveStride
This makes it easier to read the code.

No functionality change.

llvm-svn: 180197
2013-04-24 16:16:03 +00:00
Arnold Schwaighofer
a6578f7056 LoopVectorize: Scalarize padded types
This patch disables memory-instruction vectorization for types that need padding
bytes, e.g., x86_fp80 has 10 bytes store size with 6 bytes padding in darwin on
x86_64. Because the load/store vectorization is performed by the bit casting to
a packed vector, which has incompatible memory layout due to the lack of padding
bytes, the present vectorizer produces inconsistent result for memory
instructions of those types.
This patch checks an equality of the AllocSize of a scalar type and allocated
size for each vector element, to ensure that there is no padding bytes and the
array can be read/written using vector operations.

Patch by Daisuke Takahashi!

Fixes PR15758.

llvm-svn: 180196
2013-04-24 16:16:01 +00:00
Arnold Schwaighofer
23a0589bce LoopVectorizer: Bail out if we don't have datalayout we need it
llvm-svn: 180195
2013-04-24 16:15:58 +00:00
Nadav Rotem
71c9d6d333 LoopVectorizer: Fix 15830. When scalarizing and unrolling stores make sure that the order in which the elements are scalarized is the same as the original order.
This fixes a miscompilation in FreeBSD's regex library.

llvm-svn: 180121
2013-04-23 17:12:42 +00:00
Pekka Jaaskelainen
d3c90e132a Call the potentially costly isAnnotatedParallel() only once.
Made the uniform write test's checks a bit stricter.

llvm-svn: 180119
2013-04-23 16:44:43 +00:00
Pekka Jaaskelainen
6f2f66b63f Refuse to (even try to) vectorize loops which have uniform writes,
even if erroneously annotated with the parallel loop metadata.

Fixes Bug 15794: 
"Loop Vectorizer: Crashes with the use of llvm.loop.parallel metadata"

llvm-svn: 180081
2013-04-23 08:08:51 +00:00
Eric Christopher
04d4e9312c Move C++ code out of the C headers and into either C++ headers
or the C++ files themselves. This enables people to use
just a C compiler to interoperate with LLVM.

llvm-svn: 180063
2013-04-22 22:47:22 +00:00
Nadav Rotem
c57af326a4 SLPVectorize: Add support for vectorization of casts.
llvm-svn: 179975
2013-04-21 08:05:59 +00:00
Nadav Rotem
98ad5f0f4c SLPVectorizer: Fix a bug in the code that scans the tree in search of nodes with multiple users.
We did not terminate the switch case and we executed the search routine twice.

llvm-svn: 179974
2013-04-21 07:37:56 +00:00
Nadav Rotem
8aca44a623 Fix PR15800. Do not try to vectorize vectors and structs.
llvm-svn: 179960
2013-04-20 22:29:43 +00:00
Benjamin Kramer
519b2e3087 VecUtils: Clean up uses of dyn_cast.
llvm-svn: 179936
2013-04-20 10:36:17 +00:00
Benjamin Kramer
4600bcc337 SLPVectorizer: Strength reduce SmallVectors to ArrayRefs.
Avoids a couple of copies and allows more flexibility in the clients.

llvm-svn: 179935
2013-04-20 09:49:10 +00:00
Nadav Rotem
ce2660d639 SLPVectorizer: Reduce the compile time by eliminating the search for some of the more expensive patterns. After this change will only check basic arithmetic trees that start at cmpinstr.
llvm-svn: 179933
2013-04-20 07:29:34 +00:00
Nadav Rotem
998e035cae refactor tryToVectorizePair to a new method that supports vectorization of lists.
llvm-svn: 179932
2013-04-20 07:22:58 +00:00
Nadav Rotem
890387289e Fix an unused variable warning.
llvm-svn: 179931
2013-04-20 06:40:28 +00:00
Nadav Rotem
83c7c41bc2 SLPVectorizer: Improve the cost model for loop invariant broadcast values.
llvm-svn: 179930
2013-04-20 06:13:47 +00:00
Nadav Rotem
dfe1c93ca4 Report the number of stores that were found in the debug message.
llvm-svn: 179929
2013-04-20 05:23:11 +00:00
Nadav Rotem
dfd8fcbb00 Fix the header comment.
llvm-svn: 179928
2013-04-20 05:18:51 +00:00
Nadav Rotem
5ed99674e9 Use 64bit arithmetic for calculating distance between pointers.
llvm-svn: 179927
2013-04-20 05:17:47 +00:00
Arnold Schwaighofer
5146940316 LoopVectorizer: Use matcher from PatternMatch.h for the min/max patterns
Also make some static function class functions to avoid having to mention the
class namespace for enums all the time.

No functionality change intended.

llvm-svn: 179886
2013-04-19 21:03:36 +00:00
Dmitri Gribenko
d29ea04446 Fix a -Wdocumentation warning
llvm-svn: 179789
2013-04-18 20:13:04 +00:00
Arnold Schwaighofer
4cd6aa110c 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

llvm-svn: 179773
2013-04-18 17:22:34 +00:00
Benjamin Kramer
8df2cfb858 LoopVectorize: Use a set to avoid longer cycles in the reduction chain too.
Fixes PR15748.

llvm-svn: 179757
2013-04-18 14:29:13 +00:00
Nadav Rotem
b9116e6966 SLPVectorizer: Make it a function pass and add code for hoisting the vector-gather sequence out of loops.
llvm-svn: 179562
2013-04-15 22:00:26 +00:00
Nadav Rotem
5d393c416f SLPVectorizer: Add support for vectorizing trees that start at compare instructions.
llvm-svn: 179504
2013-04-15 04:25:27 +00:00
Benjamin Kramer
7d62ea86e5 Miscellaneous cleanups for VecUtils.h
llvm-svn: 179483
2013-04-14 09:33:08 +00:00
Nadav Rotem
3403c11529 SLP: Document the scalarization cost method.
llvm-svn: 179479
2013-04-14 07:22:22 +00:00
Nadav Rotem
54b413d157 SLPVectorizer: Add support for trees that don't start at binary operators, and add the cost of extracting values from the roots of the tree.
llvm-svn: 179475
2013-04-14 05:15:53 +00:00
Nadav Rotem
0b9cf8567b SLPVectorizer: add initial support for reduction variable vectorization.
llvm-svn: 179470
2013-04-14 03:22:20 +00:00
Nadav Rotem
8543ba3e52 SLPVectorizer: add support for vectorization of diamond shaped trees. We now perform a preliminary traversal of the graph to collect values with multiple users and check where the users came from.
llvm-svn: 179414
2013-04-12 21:16:54 +00:00
Nadav Rotem
4da0ab1d68 Add debug prints.
llvm-svn: 179412
2013-04-12 21:11:14 +00:00
Arnold Schwaighofer
f9cea17f75 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

llvm-svn: 179381
2013-04-12 15:15:19 +00:00
Benjamin Kramer
c86fdf12e8 Rename the C function to create a SLPVectorizerPass to something sane and expose it in the header file.
llvm-svn: 179272
2013-04-11 11:36:36 +00:00
Nadav Rotem
73dffa4184 Make the SLP store-merger less paranoid about function calls. We check for function calls when we check if it is safe to sink instructions.
llvm-svn: 179207
2013-04-10 19:41:36 +00:00
Nadav Rotem
88dd5f7a38 We require DataLayout for analyzing the size of stores.
llvm-svn: 179206
2013-04-10 18:57:27 +00:00
Nadav Rotem
2d9dec322e Add support for bottom-up SLP vectorization infrastructure.
This commit adds the infrastructure for performing bottom-up SLP vectorization (and other optimizations) on parallel computations.
The infrastructure has three potential users:

  1. The loop vectorizer needs to be able to vectorize AOS data structures such as (sum += A[i] + A[i+1]).

  2. The BB-vectorizer needs this infrastructure for bottom-up SLP vectorization, because bottom-up vectorization is faster to compute.

  3. A loop-roller needs to be able to analyze consecutive chains and roll them into a loop, in order to reduce code size. A loop roller does not need to create vector instructions, and this infrastructure separates the chain analysis from the vectorization.

This patch also includes a simple (100 LOC) bottom up SLP vectorizer that uses the infrastructure, and can vectorize this code:

void SAXPY(int *x, int *y, int a, int i) {
  x[i]   = a * x[i]   + y[i];
  x[i+1] = a * x[i+1] + y[i+1];
  x[i+2] = a * x[i+2] + y[i+2];
  x[i+3] = a * x[i+3] + y[i+3];
}

llvm-svn: 179117
2013-04-09 19:44:35 +00:00
Arnold Schwaighofer
df6f67ed87 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

llvm-svn: 178809
2013-04-04 23:26:27 +00:00