370 Commits

Author SHA1 Message Date
Adam Nemet
c956f416cc [SLP] Visualize SLP trees with -view-slp-tree
Analyzing larger trees is extremely difficult with the current debug output so
this adds GraphTraits and DOTGraphTraits on top of the VectorizableTree data
structure.  We can now display the SLP trees with Graphviz as in
https://reviews.llvm.org/F3132765.

I decorated the graph where a value needs to be gathered for one reason or
another.  These are the red nodes.

There are other improvement I am planning to make as I work through my case
here.  For example, I would also like to mark nodes that need to be extracted.

Differential Revision: https://reviews.llvm.org/D30731

llvm-svn: 297303
2017-03-08 18:47:50 +00:00
Michael Kuperstein
ecb8f70721 [SLP] Revert r296863 due to miscompiles.
Details and reproducer are on the email thread for r296863.

llvm-svn: 297103
2017-03-06 23:54:51 +00:00
Mohammad Shahid
d8acf02cf1 [SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.It also needs to recompute the proper Lane for
external use of vectorizable scalars based on shuffle mask.

Reviewers: mkuper

Differential Revision: https://reviews.llvm.org/D30159

Change-Id: Ide8773ce0ad3562f3cf4d1a0ad0f487e2f60ce5d
llvm-svn: 296863
2017-03-03 10:02:47 +00:00
Hans Wennborg
358597d3c9 Revert r296575 "[SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available"
It caused miscompiles, e.g. in Chromium (PR32109).

llvm-svn: 296654
2017-03-01 18:57:16 +00:00
Alexey Bataev
d9b0bf33dd [SLP] Preserve IR flags when vectorizing horizontal reductions.
Summary:
The SLP vectorizer should propagate IR-level optimization hints/flags
(nsw, nuw, exact, fast-math) when converting scalar horizontal
reductions instructions into vectors, just like for other vectorized
instructions.
It doe not include IR propagation for extra arguments, we need to handle
original scalar operations for extra args to propagate correct flags.

Reviewers: mkuper, mzolotukhin, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30418

llvm-svn: 296614
2017-03-01 12:43:39 +00:00
Alexey Bataev
28bee685c1 [SLP] Preserve IR flags for extra args.
Summary:
We should preserve IR flags for extra args. These IR flags should be
taken from original scalar operations, not from the reduction
operations.

Reviewers: mkuper, mzolotukhin, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30447

llvm-svn: 296613
2017-03-01 12:22:33 +00:00
Alexey Bataev
f077ffe566 [SLP] Fix for PR32038: extra add of PHI node when it is not required.
Summary:
If horizontal reduction tree starts from the binary operation that is
used in PHI node, but this PHI is not used in horizontal reduction, we
may end up with extra addition of this PHI node after vectorization.
Here is an example:
```
%phi = phi i32 [ %tmp, %end], ...
...
%tmp = add i32 %tmp1, %tmp2
end:
```
after vectorization we always have something like:

```
%phi = phi i32 [ %tmp, %end], ...
...
%red = extractelement <8 x 32> %vec.red, 0
%tmp = add i32 %red, %phi
end:
```
even if `%phi` is not used in reduction tree. Patch considers these PHI
nodes as extra arguments and considers them in the final result iff they
really used in reduction.

Reviewers: mkuper, hfinkel, mzolotukhin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30409

llvm-svn: 296606
2017-03-01 10:50:44 +00:00
Mohammad Shahid
8ddc0dd2a4 [SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.

Reviewers: mkuper

Differential Revision: https://reviews.llvm.org/D30159

Change-Id: Id1e287f073fa4959713ba545fa4254db5da8b40d
llvm-svn: 296575
2017-03-01 03:51:54 +00:00
Alexey Bataev
437d10997b [SLP] Fix for PR32036: Vectorized horizontal reduction returning wrong
result

Summary:
If the same value is used several times as an extra value, SLP
vectorizer takes it into account only once instead of actual number of
using.
For example:
```
int val = 1;
for (int y = 0; y < 8; y++) {
  for (int x = 0; x < 8; x++) {
    val = val + input[y * 8 + x] + 3;
  }
}
```
We have 2 extra rguments: `1` - initial value of horizontal reduction
and `3`, which is added 8*8 times to the reduction. Before the patch we
added `1` to the reduction value and added once `3`, though it must be
added 64 times.

Reviewers: mkuper, mzolotukhin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30262

llvm-svn: 295972
2017-02-23 13:37:09 +00:00
Alexey Bataev
04f7dbe68e Revert "[SLP] Fix for PR32036: Vectorized horizontal reduction returning wrong"
This reverts commit 7c5141e577d9efd1c8e3087566a38ce6b3a41a84.

llvm-svn: 295957
2017-02-23 11:09:35 +00:00
Alexey Bataev
f86b9bd592 [SLP] Fix for PR32036: Vectorized horizontal reduction returning wrong
result

Summary:
If the same value is used several times as an extra value, SLP
vectorizer takes it into account only once instead of actual number of
using.
For example:
```
int val = 1;
for (int y = 0; y < 8; y++) {
  for (int x = 0; x < 8; x++) {
    val = val + input[y * 8 + x] + 3;
  }
}
```
We have 2 extra rguments: `1` - initial value of horizontal reduction
and `3`, which is added 8*8 times to the reduction. Before the patch we
added `1` to the reduction value and added once `3`, though it must be
added 64 times.

Reviewers: mkuper, mzolotukhin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30262

llvm-svn: 295956
2017-02-23 10:57:15 +00:00
Alexey Bataev
165908b766 Revert "[SLP] Fix for PR32036: Vectorized horizontal reduction returning wrong"
This reverts commit d83c81ee6a8dea662808ac22b396d1bb0595c89d.

llvm-svn: 295951
2017-02-23 09:59:29 +00:00
Alexey Bataev
06a8650a4b [SLP] Fix for PR32036: Vectorized horizontal reduction returning wrong
result

Summary:
If the same value is used several times as an extra value, SLP
vectorizer takes it into account only once instead of actual number of
using.
For example:
```
int val = 1;
for (int y = 0; y < 8; y++) {
  for (int x = 0; x < 8; x++) {
    val = val + input[y * 8 + x] + 3;
  }
}
```
We have 2 extra rguments: `1` - initial value of horizontal reduction
and `3`, which is added 8*8 times to the reduction. Before the patch we
added `1` to the reduction value and added once `3`, though it must be
added 64 times.

Reviewers: mkuper, mzolotukhin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30262

llvm-svn: 295949
2017-02-23 09:40:38 +00:00
Michael Kuperstein
bb42bf14f7 Revert r295868 because it breaks a different SLP lit test.
llvm-svn: 295906
2017-02-22 23:35:13 +00:00
Alexey Bataev
59c0b46177 [SLP] Fix for PR32036: Vectorized horizontal reduction returning wrong result
Summary:
If the same value is used several times as an extra value, SLP
vectorizer takes it into account only once instead of actual number of
using.
For example:
```
int val = 1;
for (int y = 0; y < 8; y++) {
  for (int x = 0; x < 8; x++) {
    val = val + input[y * 8 + x] + 3;
  }
}
```
We have 2 extra rguments: `1` - initial value of horizontal reduction
and `3`, which is added 8*8 times to the reduction. Before the patch we
added `1` to the reduction value and added once `3`, though it must be
added 64 times.

Reviewers: mkuper, mzolotukhin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30262

llvm-svn: 295868
2017-02-22 20:06:40 +00:00
Alexey Bataev
da1fd33d4e [SLP] Remove unused initial value from the variable, NFC.
llvm-svn: 295826
2017-02-22 12:57:58 +00:00
Alexey Bataev
195cd24304 [SLP] nullptr'ize initial value in findBuildAggregate(), NFC.
Initial value of V is sett nullptr, as it is not used.

llvm-svn: 295642
2017-02-20 08:04:11 +00:00
Alexey Bataev
97eecd7096 [SLP] Rework findBuildAggregate() from ercursive form to iterative, NFC.
Reviewers: mkuper

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D30103

llvm-svn: 295641
2017-02-20 07:49:39 +00:00
Alexey Bataev
eab1c078e4 [SLP] Fix for PR31879: vectorize repeated scalar ops that don't get put
back into a vector

Previously the cost of the existing ExtractElement/ExtractValue
instructions was considered as a dead cost only if it was detected that
they have only one use. But these instructions may be considered
dead also if users of the instructions are also going to be vectorized,
like:
```
%x0 = extractelement <2 x float> %x, i32 0
%x1 = extractelement <2 x float> %x, i32 1
%x0x0 = fmul float %x0, %x0
%x1x1 = fmul float %x1, %x1
%add = fadd float %x0x0, %x1x1
```
This can be transformed to
```
%1 = fmul <2 x float> %x, %x
%2 = extractelement <2 x float> %1, i32 0
%3 = extractelement <2 x float> %1, i32 1
%add = fadd float %2, %3
```
because though `%x0` and `%x1` have 2 users each other, these users are
part of the vectorized tree and we can consider these `extractelement`
instructions as dead.

Differential Revision: https://reviews.llvm.org/D29900

llvm-svn: 295056
2017-02-14 15:20:48 +00:00
Alexey Bataev
89acda24b8 [SLP] Fix for PR31690: Allow using of extra values in horizontal
reductions.

Currently, LLVM supports vectorization of horizontal reduction
instructions with initial value set to 0. Patch supports vectorization
of reduction with non-zero initial values. Also, it supports a
vectorization of instructions with some extra arguments, like:
```
float f(float x[], int a, int b) {
  float p = a % b;
  p += x[0] + 3;
  for (int i = 1; i < 32; i++)
    p += x[i];
  return p;
}
```
Patch allows vectorization of this kind of horizontal reductions.

Differential Revision: https://reviews.llvm.org/D29727

llvm-svn: 294934
2017-02-13 08:01:26 +00:00
Michael Kuperstein
5951cf494c [SLP] Revert "Allow using of extra values in horizontal reductions."
This breaks when one of the extra values is also a scalar that
participates in the same vectorization tree which we'll end up
reducing.

llvm-svn: 294245
2017-02-06 21:50:59 +00:00
Michael Kuperstein
f2f8127335 [SLP] Make sortMemAccesses explicitly return an error. NFC.
llvm-svn: 294029
2017-02-03 19:32:50 +00:00
Alexey Bataev
dde66d4ab8 [SLP] Fix for PR31690: Allow using of extra values in horizontal reductions.
Currently LLVM supports vectorization of horizontal reduction
instructions with initial value set to 0. Patch supports vectorization
of reduction with non-zero initial values. Also it supports a
vectorization of instructions with some extra arguments, like:

float f(float x[], int a, int b) {
  float p = a % b;
  p += x[0] + 3;
  for (int i = 1; i < 32; i++)
    p += x[i];
  return p;
}

Patch allows vectorization of this kind of horizontal reductions.

Differential Revision: https://reviews.llvm.org/D28961

llvm-svn: 293994
2017-02-03 08:08:50 +00:00
Mohammad Shahid
a2646e67e7 [SLP] Vectorize loads of consecutive memory accesses, accessed in non-consecutive (jumbled) way.
The jumbled scalar loads will be sorted while building the tree and these accesses will be marked to generate shufflevector after the vectorized load with proper mask.

Reviewers: hfinkel, mssimpso, mkuper

Differential Revision: https://reviews.llvm.org/D26905

Change-Id: I9c0c8e6f91a00076a7ee1465440a3f6ae092f7ad
llvm-svn: 293386
2017-01-28 17:59:44 +00:00
Alexey Bataev
76d6416ffb [SLP] Refactoring of horizontal reduction analysis, NFC.
Some checks in SLP horizontal reduction analysis function are performed
several times, though it is enough to perform these checks only once
during an initial attempt at adding candidate for the reduction
instruction/reduced value.

Differential Revision: https://reviews.llvm.org/D29175

llvm-svn: 293274
2017-01-27 10:54:04 +00:00
Alexey Bataev
cb8becd477 [SLP] Improve horizontal vectorization for non-power-of-2 number of
instructions.

If number of instructions in horizontal reduction list is not power of 2
then only PowerOf2Floor(NumberOfInstructions) last elements are actually
vectorized, other instructions remain scalar. Patch tries to vectorize
the remaining elements either.

Differential Revision: https://reviews.llvm.org/D28959

llvm-svn: 293042
2017-01-25 09:54:38 +00:00
Alexey Bataev
5239450fd0 [SLP] Refactoring of HorizontalReduction class, NFC.
Removed data members ReduxWidth and MinVecRegSize + some C++11 stylish
improvements.

Differential Revision: https://reviews.llvm.org/D29010

llvm-svn: 292899
2017-01-24 08:57:17 +00:00
Michael Kuperstein
fe5c6f1abe [SLP] Make ReductionOpcode have the right (enum) type. NFC.
llvm-svn: 292703
2017-01-21 02:03:03 +00:00
Michael Kuperstein
88e863dd60 [SLP] Delete useless helper. NFC.
The helper contained a branch for a special case that is unnecessary,
and a cast.

llvm-svn: 292698
2017-01-21 01:33:25 +00:00
Chandler Carruth
531a8d8a72 [PM] Introduce an analysis set used to preserve all analyses over
a function's CFG when that CFG is unchanged.

This allows transformation passes to simply claim they preserve the CFG
and analysis passes to check for the CFG being preserved to remove the
fanout of all analyses being listed in all passes.

I've gone through and removed or cleaned up as many of the comments
reminding us to do this as I could.

Differential Revision: https://reviews.llvm.org/D28627

llvm-svn: 292054
2017-01-15 06:32:49 +00:00
Eric Fiselier
8117e6a0a9 Give comparator const call operator
llvm-svn: 292043
2017-01-15 02:06:44 +00:00
Michael Kuperstein
172556c384 [SLP] Remove bogus assert.
The removed assert seems bogus - it's perfectly legal for the roots of the
vectorized subtrees to be equal even if the original scalar values aren't,
if the original scalars happen to be equivalent.

This fixes PR31599.

Differential Revision: https://reviews.llvm.org/D28539

llvm-svn: 291692
2017-01-11 19:23:57 +00:00
Daniel Jasper
162ffcacd6 Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086
2016-12-19 08:22:17 +00:00
Hal Finkel
f224db75d2 Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756
2016-12-15 03:02:15 +00:00
Matthew Simpson
1d43cda909 [SLP] Fix sign-extends for type-shrinking
This patch ensures the correct minimum bit width during type-shrinking.
Previously when type-shrinking, we always sign-extended values back to their
original width. However, if we are going to sign-extend, and the sign bit is
unknown, we have to increase the minimum bit width by one bit so the
sign-extend will fill the upper bits correctly. If the sign bit is known to be
zero, we can perform a zero-extend instead. This should fix PR31243.

Reference: https://llvm.org/bugs/show_bug.cgi?id=31243
Differential Revision: https://reviews.llvm.org/D27466

llvm-svn: 289470
2016-12-12 21:11:04 +00:00
Alexey Bataev
3aadace193 [SLP] Fix for PR6246: vectorization for scalar ops on vector elements.
When trying to vectorize trees that start at insertelement instructions
function tryToVectorizeList() uses vectorization factor calculated as
MinVecRegSize/ScalarTypeSize. But sometimes it does not work as tree
cost for this fixed vectorization factor is too high.
Patch tries to improve the situation. It tries different vectorization
factors from max(PowerOf2Floor(NumberOfVectorizedValues),
MinVecRegSize/ScalarTypeSize) to MinVecRegSize/ScalarTypeSize and tries
to choose the best one.

Differential Revision: https://reviews.llvm.org/D27215

llvm-svn: 289043
2016-12-08 11:57:51 +00:00
Renato Golin
78b2b93486 Revert "[SLP] Fix for PR6246: vectorization for scalar ops on vector elements."
This reverts commit r288497, as it broke the AArch64 build of Compiler-RT's
builtins (twice: once in r288412 and once in r288497). We should investigate
this offline.

llvm-svn: 288508
2016-12-02 16:56:26 +00:00
Alexey Bataev
b767847ade [SLP] Fix for PR6246: vectorization for scalar ops on vector elements.
When trying to vectorize trees that start at insertelement instructions
function tryToVectorizeList() uses vectorization factor calculated as
MinVecRegSize/ScalarTypeSize. But sometimes it does not work as tree
cost for this fixed vectorization factor is too high.
Patch tries to improve the situation. It tries different vectorization
factors from max(PowerOf2Floor(NumberOfVectorizedValues),
MinVecRegSize/ScalarTypeSize) to MinVecRegSize/ScalarTypeSize and tries
to choose the best one.

Differential Revision: https://reviews.llvm.org/D27215

llvm-svn: 288497
2016-12-02 12:20:22 +00:00
Artem Belevich
18e8ce875f Revert "[SLP] Fix for PR6246: vectorization for scalar ops on vector elements."
This reverts r288412 which causes severe compile-time regression.

llvm-svn: 288431
2016-12-01 22:52:15 +00:00
Alexey Bataev
ec86a0f4e9 [SLP] Fix for PR6246: vectorization for scalar ops on vector elements.
When trying to vectorize trees that start at insertelement instructions
function tryToVectorizeList() uses vectorization factor calculated as
MinVecRegSize/ScalarTypeSize. But sometimes it does not work as tree
cost for this fixed vectorization factor is too high.
Patch tries to improve the situation. It tries different vectorization
factors from max(PowerOf2Floor(NumberOfVectorizedValues),
MinVecRegSize/ScalarTypeSize) to MinVecRegSize/ScalarTypeSize and tries
to choose the best one.

Differential Revision: https://reviews.llvm.org/D27215

llvm-svn: 288412
2016-12-01 20:06:53 +00:00
Alexey Bataev
7135b5ad24 [SLP] Fixed cost model for horizontal reduction.
Currently when cost of scalar operations is evaluated the vector type is
used for scalar operations. Patch fixes this issue and fixes evaluation
of the vector operations cost.
Several test showed that vector cost model is too optimistic. It
allowed vectorization of 8 or less add/fadd operations, though scalar
code is faster. Actually, only for 16 or more operations vector code
provides better performance.

Differential Revision: https://reviews.llvm.org/D26277

llvm-svn: 288398
2016-12-01 18:42:42 +00:00
Alexey Bataev
62124599cb [SLPVectorizer] Improved support of partial tree vectorization.
Currently SLP vectorizer tries to vectorize a binary operation and dies
immediately after unsuccessful the first unsuccessfull attempt. Patch
tries to improve the situation, trying to vectorize all binary
operations of all children nodes in the binop tree.

Differential Revision: https://reviews.llvm.org/D25517

llvm-svn: 288115
2016-11-29 08:21:14 +00:00
Simon Pilgrim
e116136251 Fix spelling mistakes in Transforms comments. NFC.
Identified by Pedro Giffuni in PR27636.

llvm-svn: 287488
2016-11-20 13:19:49 +00:00
Vyacheslav Klochkov
90d5b65bd8 Fixed the lost FastMathFlags for CALL operations in SLPVectorizer.
Reviewer: Michael Zolotukhin.
Differential Revision: https://reviews.llvm.org/D26575

llvm-svn: 287064
2016-11-16 00:55:50 +00:00
Vyacheslav Klochkov
6d9c315fe7 Fixed the lost FastMathFlags for FCmp operations in SLPVectorizer.
Reviewer: Michael Zolotukhin.
Differential Revision: https://reviews.llvm.org/D26543

llvm-svn: 286626
2016-11-11 19:55:29 +00:00
Alexey Bataev
b6c0260e86 [SLP] Fix for PR30626: Compiler crash inside SLP Vectorizer.
After successfull horizontal reduction vectorization attempt for PHI node
vectorizer tries to update root binary op by combining vectorized tree
and the ReductionPHI node. But during vectorization this ReductionPHI
can be vectorized itself and replaced by the `undef` value, while the
instruction itself is marked for deletion. This 'marked for deletion'
PHI node then can be used in new binary operation, causing "Use still
stuck around after Def is destroyed" crash upon PHI node deletion.

Also the test is fixed to make it perform actual testing.

Differential Revision: https://reviews.llvm.org/D25671

llvm-svn: 285286
2016-10-27 12:02:28 +00:00
Alexey Bataev
0a23402e2a [SLPVectorizer] Fix for PR25748: reduction vectorization after loop
unrolling.

The next code is not vectorized by the SLPVectorizer:
```
 int test(unsigned int *p) {
  int sum = 0;
  for (int i = 0; i < 8; i++)
    sum += p[i];
  return sum;
 }
```
During optimization this loop is fully unrolled and SLPVectorizer is
unable to vectorize it. Patch tries to fix this problem.

Differential Revision: https://reviews.llvm.org/D24796

llvm-svn: 283535
2016-10-07 09:39:22 +00:00
Duncan P. N. Exon Smith
3dccc3d478 ADT: Do not inherit from std::iterator in ilist_iterator
Inheriting from std::iterator uses more boiler-plate than manual
typedefs.  Avoid that in both ilist_iterator and
MachineInstrBundleIterator.

This has the side effect of removing ilist_iterator from certain ADL
lookups in namespace std; calls to std::next need to be qualified by
"std::" that didn't have to before.  The one case of this in-tree was
operating on a temporary, so I used the more compact operator++.

llvm-svn: 280570
2016-09-03 02:27:35 +00:00
Chad Rosier
ac5b082a70 [SLP] Don't pass a global CL option as an argument. NFC.
Differential Revision: https://reviews.llvm.org/D24199

llvm-svn: 280527
2016-09-02 19:09:50 +00:00
Chad Rosier
ce78968521 [SLP] Update the debug based on Michael's suggestion.
Passing the types/opcode check still doesn't guarantee we'll actually vectorize.
Therefore, just make it clear we're attempting to vectorize.

llvm-svn: 280263
2016-08-31 17:41:12 +00:00