Summary:
If the load/extractelement/extractvalue instructions are not originally
consecutive, the SLP vectorizer is unable to vectorize them. Patch
allows reordering of such instructions.
Patch does not support reordering of the repeated instruction, this must
be handled in the separate patch.
Reviewers: RKSimon, spatel, hfinkel, mkuper, Ayal, ashahid
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43776
llvm-svn: 329085
We use two approaches for determining the minimum bitwidth.
* Demanded bits
* Value tracking
If demanded bits doesn't result in a narrower type, we then try value tracking.
We need this if we want to root SLP trees with the indices of getelementptr
instructions since all the bits of the indices are demanded.
But there is a missing piece though. We need to be able to distinguish "demanded
and shrinkable" from "demanded and not shrinkable". For example, the bits of %i
in
%i = sext i32 %e1 to i64
%gep = getelementptr inbounds i64, i64* %p, i64 %i
are demanded, but we can shrink %i's type to i32 because it won't change the
result of the getelementptr. On the other hand, in
%tmp15 = sext i32 %tmp14 to i64
%tmp16 = insertvalue { i64, i64 } undef, i64 %tmp15, 0
it doesn't make sense to shrink %tmp15 and we can skip the value tracking.
Ideas are from Matthew Simpson!
Differential Revision: https://reviews.llvm.org/D44868
llvm-svn: 329035
Summary:
If the load/extractelement/extractvalue instructions are not originally
consecutive, the SLP vectorizer is unable to vectorize them. Patch
allows reordering of such instructions.
Reviewers: RKSimon, spatel, hfinkel, mkuper, Ayal, ashahid
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43776
llvm-svn: 328980
When building the SLP tree, we look for reuse among the vectorized tree
entries. However, each gather sequence is represented by a unique tree entry,
even though the sequence may be identical to another one. This means, for
example, that a gather sequence with two uses will be counted twice when
computing the cost of the tree. We should only count the cost of the definition
of a gather sequence rather than its uses. During code generation, the
redundant gather sequences are emitted, but we optimize them away with CSE. So
it looks like this problem just affects the cost model.
Differential Revision: https://reviews.llvm.org/D44742
llvm-svn: 328316
This patch provides an implementation of getArithmeticReductionCost for
AArch64. We can specialize the cost of add reductions since they are computed
using the 'addv' instruction.
Differential Revision: https://reviews.llvm.org/D44490
llvm-svn: 327702
This is a slight reduction of one of the benchmarks
that suffered with D43079. Cost model changes should
not cause this test to remain scalarized.
llvm-svn: 326217
Agner's tables indicate that for SSE42+ targets (Core2 and later) we can reduce the FADD/FSUB/FMUL costs down to 1, which should fix the Himeno benchmark.
Note: the AVX512 FDIV costs look rather dodgy, but this isn't part of this patch.
Differential Revision: https://reviews.llvm.org/D43733
llvm-svn: 326133
This is a slight reduction of one of the benchmarks
that suffered with D43079. Cost model changes should
not cause this test to remain scalarized.
llvm-svn: 325717
There are too many perf regressions resulting from this, so we need to
investigate (and add tests for) targets like ARM and AArch64 before
trying to reinstate.
llvm-svn: 325658
This change was mentioned at least as far back as:
https://bugs.llvm.org/show_bug.cgi?id=26837#c26
...and I found a real program that is harmed by this:
Himeno running on AMD Jaguar gets 6% slower with SLP vectorization:
https://bugs.llvm.org/show_bug.cgi?id=36280
...but the change here appears to solve that bug only accidentally.
The div/rem costs for x86 look very wrong in some cases, but that's already true,
so we can fix those in follow-up patches. There's also evidence that more cost model
changes are needed to solve SLP problems as shown in D42981, but that's an independent
problem (though the solution may be adjusted after this change is made).
Differential Revision: https://reviews.llvm.org/D43079
llvm-svn: 325515
Summary:
Reversed loads are handled as gathering. But we can just reshuffle
these values. Patch adds support for vectorization of reversed loads.
Reviewers: RKSimon, spatel, mkuper, hfinkel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43022
llvm-svn: 325134
Summary:
For better vectorization result we should take into consideration the
cost of the user insertelement instructions when we try to
vectorize sequences that build the whole vector. I.e. if we have the
following scalar code:
```
<Scalar code>
insertelement <ScalarCode>, ...
```
we should consider the cost of the last `insertelement ` instructions as
the cost of the scalar code.
Reviewers: RKSimon, spatel, hfinkel, mkuper
Subscribers: javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D42657
llvm-svn: 324893
Summary:
If the same value is going to be vectorized several times in the same
tree entry, this entry is considered to be a gather entry and cost of
this gather is counter as cost of InsertElementInstrs for each gathered
value. But we can consider these elements as ShuffleInstr with
SK_PermuteSingle shuffle kind.
Reviewers: spatel, RKSimon, mkuper, hfinkel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38697
llvm-svn: 323662
Summary:
If the same value is going to be vectorized several times in the same
tree entry, this entry is considered to be a gather entry and cost of
this gather is counter as cost of InsertElementInstrs for each gathered
value. But we can consider these elements as ShuffleInstr with
SK_PermuteSingle shuffle kind.
Reviewers: spatel, RKSimon, mkuper, hfinkel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38697
llvm-svn: 323530
Summary:
If the same value is going to be vectorized several times in the same
tree entry, this entry is considered to be a gather entry and cost of
this gather is counter as cost of InsertElementInstrs for each gathered
value. But we can consider these elements as ShuffleInstr with
SK_PermuteSingle shuffle kind.
Reviewers: spatel, RKSimon, mkuper, hfinkel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38697
llvm-svn: 323441
Summary:
If the same value is going to be vectorized several times in the same
tree entry, this entry is considered to be a gather entry and cost of
this gather is counter as cost of InsertElementInstrs for each gathered
value. But we can consider these elements as ShuffleInstr with
SK_PermuteSingle shuffle kind.
Reviewers: spatel, RKSimon, mkuper, hfinkel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38697
llvm-svn: 323430
Summary:
If the same value is going to be vectorized several times in the same
tree entry, this entry is considered to be a gather entry and cost of
this gather is counter as cost of InsertElementInstrs for each gathered
value. But we can consider these elements as ShuffleInstr with
SK_PermuteSingle shuffle kind.
Reviewers: spatel, RKSimon, mkuper, hfinkel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38697
llvm-svn: 323348
This was probably fixed long ago, but I don't see a test
that lines up with the example and target in the bug report:
https://bugs.llvm.org/show_bug.cgi?id=13837
...so adding it here.
llvm-svn: 323269
Summary:
If the same value is going to be vectorized several times in the same
tree entry, this entry is considered to be a gather entry and cost of
this gather is counter as cost of InsertElementInstrs for each gathered
value. But we can consider these elements as ShuffleInstr with
SK_PermuteSingle shuffle kind.
Reviewers: spatel, RKSimon, mkuper, hfinkel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38697
llvm-svn: 323246
Summary:
If the vectorized tree has truncate to minimum required bit width and
the vector type of the cast operation after the truncation is the same
as the vector type of the cast operands, count cost of the vector cast
operation as 0, because this cast will be later removed.
Also, if the vectorization tree root operations are integer cast operations, do not consider them as candidates for truncation. It will just create extra number of the same vector/scalar operations, which will be removed by instcombiner.
Reviewers: RKSimon, spatel, mkuper, hfinkel, mssimpso
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41948
llvm-svn: 322946
Simon Pilgrim