Commit Graph

751 Commits

Author SHA1 Message Date
Ivan Krasin c2124e185c Revert r298620: [LV] Vectorize GEPs
Reason: breaks linking Chromium with LLD + ThinLTO (a pass crashes)
LLVM bug: https://bugs.llvm.org//show_bug.cgi?id=32413

Original change description:

[LV] Vectorize GEPs

This patch adds support for vectorizing GEPs. Previously, we only generated
vector GEPs on-demand when creating gather or scatter operations. All GEPs from
the original loop were scalarized by default, and if a pointer was to be stored
to memory, we would have to build up the pointer vector with insertelement
instructions.

With this patch, we will vectorize all GEPs that haven't already been marked
for scalarization.

The patch refines collectLoopScalars to more exactly identify the scalar GEPs.
The function now more closely resembles collectLoopUniforms. And the patch
moves vector GEP creation out of vectorizeMemoryInstruction and into the main
vectorization loop. The vector GEPs needed for gather and scatter operations
will have already been generated before vectoring the memory accesses.

Original Differential Revision: https://reviews.llvm.org/D30710

llvm-svn: 298735
2017-03-24 20:49:43 +00:00
Matthew Simpson 4e7b71bc86 [LV] Vectorize GEPs
This patch adds support for vectorizing GEPs. Previously, we only generated
vector GEPs on-demand when creating gather or scatter operations. All GEPs from
the original loop were scalarized by default, and if a pointer was to be stored
to memory, we would have to build up the pointer vector with insertelement
instructions.

With this patch, we will vectorize all GEPs that haven't already been marked
for scalarization.

The patch refines collectLoopScalars to more exactly identify the scalar GEPs.
The function now more closely resembles collectLoopUniforms. And the patch
moves vector GEP creation out of vectorizeMemoryInstruction and into the main
vectorization loop. The vector GEPs needed for gather and scatter operations
will have already been generated before vectoring the memory accesses.

Differential Revision: https://reviews.llvm.org/D30710

llvm-svn: 298620
2017-03-23 16:29:58 +00:00
Matthew Simpson 1fb4064531 [LV] Delete unneeded scalar GEP creation code
The code for generating scalar base pointers in vectorizeMemoryInstruction is
not needed. We currently scalarize all GEPs and maintain the scalarized values
in VectorLoopValueMap. The GEP cloning in this unneeded code is the same as
that in scalarizeInstruction. The test cases that changed as a result of this
patch changed because we were able to reuse the scalarized GEP that we
previously generated instead of cloning a new one.

Differential Revision: https://reviews.llvm.org/D30587

llvm-svn: 298615
2017-03-23 16:07:21 +00:00
Gil Rapaport 28d0f8ddf7 [LV] Refactor cross-iteration phi's back-patching; NFC
This patch refactors the PHisToFix loop as follows:

- The loop itself now resides in its own method.
- The new method iterates on scalar-loop's header; the PHIsToFix map formerly
  propagated as an output parameter and filled during phi widening is removed.
- The code handling reductions is moved into its own method, similar to the
  existing fixFirstOrderRecurrence().

Differential Revision: https://reviews.llvm.org/D30755

llvm-svn: 297740
2017-03-14 13:50:47 +00:00
Ayal Zaks 928ec40584 [LV] Refactor Cost Model's selectVectorizationFactor(); NFC
Refactoring Cost Model's selectVectorizationFactor() so that it handles only the
selection of the best VF from a pre-computed range of candidate VF's, extracting
early-exit criteria and the computation of a MaxVF upper-bound to other methods,
all driven by a newly introduced LoopVectorizationPlanner.

Differential Revision: https://reviews.llvm.org/D30653

llvm-svn: 297737
2017-03-14 13:07:04 +00:00
Jonas Paulsson a48ea231c0 [TargetTransformInfo] getIntrinsicInstrCost() scalarization estimation improved
getIntrinsicInstrCost() used to only compute scalarization cost based on types.
This patch improves this so that the actual arguments are checked when they are
available, in order to handle only unique non-constant operands.

Tests updates:

Analysis/CostModel/X86/arith-fp.ll
Transforms/LoopVectorize/AArch64/interleaved_cost.ll
Transforms/LoopVectorize/ARM/interleaved_cost.ll

The improvement in getOperandsScalarizationOverhead() to differentiate on
constants made it necessary to update the interleaved_cost.ll tests even
though they do not relate to intrinsics.

Review: Hal Finkel
https://reviews.llvm.org/D29540

llvm-svn: 297705
2017-03-14 06:35:36 +00:00
Gil Rapaport 00cb43908c [LV] Set memcheck metadata also for VF==1
This commit is a follow-up on r297580. It fixes the FIXME added temporarily
by that commit to keep the removal of Unroller's specialized version of
scalarizeInstruction() an NFC. See https://reviews.llvm.org/D30715 for details.

llvm-svn: 297610
2017-03-13 10:23:46 +00:00
Gil Rapaport a1e5a37d3f [LV] A unified scalarizeInstruction() for Vectorizer and Unroller; NFC
Unroller's specialized scalarizeInstruction() is mostly duplicating Vectorizer's
variant. OTOH Vectorizer's scalarizeInstruction() already supports the special
case of VF==1 except for avoiding mask-bit extraction in that case. This patch
removes Unroller's specialized version in favor of a unified method.

The only functional difference between the two variants seems to be setting
memcheck metadata for loads and stores only in Vectorizer's variant, which is a
bug in Unroller. To keep this patch an NFC the unified method doesn't set
memcheck metadata for VF==1.

Differential Revision: https://reviews.llvm.org/D30715

llvm-svn: 297580
2017-03-12 12:31:38 +00:00
Ayal Zaks 09cf3121d8 Test commit.
llvm-svn: 297579
2017-03-12 09:48:06 +00:00
Daniel Berlin 04d9e746f1 Add support for DenseMap/DenseSet count and find using const pointers
Summary:
Similar to SmallPtrSet, this makes find and count work with both const
referneces and const pointers.

Reviewers: dblaikie

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D30713

llvm-svn: 297424
2017-03-10 00:25:26 +00:00
Matthew Simpson 3388de1349 [LV] Select legal insert point when fixing first-order recurrences
Because IRBuilder performs constant-folding, it's not guaranteed that an
instruction in the original loop map to an instruction in the vector loop. It
could map to a constant vector instead. The handling of first-order recurrences
was incorrectly making this assumption when setting the IRBuilder's insert
point.

llvm-svn: 297302
2017-03-08 18:18:20 +00:00
Matthew Simpson c86b2134c7 [LV] Consider users that are memory accesses in uniforms expansion step
When expanding the set of uniform instructions beyond the seed instructions
(e.g., consecutive pointers), we mark a new instruction uniform if all its
loop-varying users are uniform. We should also allow users that are consecutive
or interleaved memory accesses. This fixes cases where we have an instruction
that is used as the pointer operand of a consecutive access but also used by a
non-memory instruction that later becomes uniform as part of the expansion.

llvm-svn: 297179
2017-03-07 18:47:30 +00:00
Matthew Simpson 455c2ee394 [LV] Considier non-consecutive but vectorizable accesses for VF selection
When computing the smallest and largest types for selecting the maximum
vectorization factor, we currently ignore loads and stores of pointer types if
the memory access is non-consecutive. We do this because such accesses must be
scalarized regardless of vectorization factor, and thus shouldn't be considered
when determining the factor. This patch makes this check less aggressive by
also considering non-consecutive accesses that may be vectorized, such as
interleaved accesses. Because we don't know at the time of the check if an
accesses will certainly be vectorized (this is a cost model decision given a
particular VF), we consider all accesses that can potentially be vectorized.

Differential Revision: https://reviews.llvm.org/D30305

llvm-svn: 296747
2017-03-02 13:55:05 +00:00
Adam Nemet 15032a0455 [LV] These remark should have been missed remarks
The practice in LV is that we emit analysis remarks and then finally report
either a missed or applied remark on the final decision whether vectorization
is taking place.  On this code path, we were closing with an analysis remark.

llvm-svn: 296578
2017-03-01 04:31:15 +00:00
Adam Nemet abe46080d4 Revert "(HEAD, origin/master, origin/HEAD, master) [LV] These should missed remarks"
This reverts commit r296544.

This got committed by accident.

llvm-svn: 296546
2017-02-28 23:54:27 +00:00
Adam Nemet e193da191d [LV] These should missed remarks
llvm-svn: 296544
2017-02-28 23:48:58 +00:00
Matthew Simpson bdc9c78880 [LV] Merge floating-point and integer induction widening code
This patch merges the existing floating-point induction variable widening code
into the integer induction variable widening code, creating a single set of
functions for both kinds of inductions. The primary motivation for doing this
is to enable vector phi node creation for floating-point induction variables.

Differential Revision: https://reviews.llvm.org/D30211

llvm-svn: 296145
2017-02-24 18:20:12 +00:00
Adam Nemet 41b019a39c [LAA] Remove unused LoopAccessReport
The need for this removed when I converted everything to use the opt-remark
classes directly with the streaming interface.

llvm-svn: 296017
2017-02-23 21:17:36 +00:00
Adam Nemet bf0e69532c [LV] Remove unused VectorizationReport
The need for this removed when I converted everything to use the opt-remark
classes directly with the streaming interface.

llvm-svn: 296016
2017-02-23 21:17:31 +00:00
Karl-Johan Karlsson 6eaed7aceb [LoopVectorize] Added address space check when analysing interleaved accesses
Prevent memory objects of different address spaces to be part of
the same load/store groups when analysing interleaved accesses.

This is fixing pr31900.

Reviewers: HaoLiu, mssimpso, mkuper

Reviewed By: mssimpso, mkuper

Subscribers: llvm-commits, efriedma, mzolotukhin

Differential Revision: https://reviews.llvm.org/D29717

This reverts r295042 (re-applies r295038) with an additional fix for the
buildbot problem.

llvm-svn: 295858
2017-02-22 18:37:36 +00:00
Matthew Simpson f68e183f91 [LV] Remove constant restriction for vector phi creation
We previously only created a vector phi node for an induction variable if its
step had a constant integer type. However, the step actually only needs to be
loop-invariant. We only handle inductions having loop-invariant steps, so this
patch should enable vector phi node creation for all integer induction
variables that will be vectorized.

Differential Revision: https://reviews.llvm.org/D29956

llvm-svn: 295456
2017-02-17 16:09:07 +00:00
Michael Kuperstein 569162fefe [LV] Rename Induction to PrimaryInduction. NFC.
llvm-svn: 295111
2017-02-14 22:14:01 +00:00
Matthew Simpson f09d13e5cc Reapply "[LV] Extend trunc optimization to all IVs with constant integer steps"
This reapplies commit r294967 with a fix for the execution time regressions
caught by the clang-cmake-aarch64-quick bot. We now extend the truncate
optimization to non-primary induction variables only if the truncate isn't
already free.

Differential Revision: https://reviews.llvm.org/D29847

llvm-svn: 295063
2017-02-14 16:28:32 +00:00
Karl-Johan Karlsson ec21b769ec Revert "[LoopVectorize] Added address space check when analysing interleaved accesses"
This reverts r295038. The buildbot clang-with-thin-lto-ubuntu failed.
I'm reverting to investigate.

llvm-svn: 295042
2017-02-14 10:06:16 +00:00
Karl-Johan Karlsson 2ec409cca2 [LoopVectorize] Added address space check when analysing interleaved accesses
Prevent memory objects of different address spaces to be part of
the same load/store groups when analysing interleaved accesses.

This is fixing pr31900.

Reviewers: HaoLiu, mssimpso, mkuper

Reviewed By: mssimpso, mkuper

Subscribers: llvm-commits, efriedma, mzolotukhin

Differential Revision: https://reviews.llvm.org/D29717

llvm-svn: 295038
2017-02-14 08:14:06 +00:00