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...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289756 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The "getVectorizablePrefix" method would give up if it found an aliasing load for a store chain.
In practice, the aliasing load can be treated as a memory barrier and all stores that precede it
are a valid vectorizable prefix.
Issue found by volkan in D26962. Testcase is a pruned version of the one in the original patch.
Reviewers: jlebar, arsenm, tstellarAMD
Subscribers: mzolotukhin, wdng, nhaehnle, anna, volkan, llvm-commits
Differential Revision: https://reviews.llvm.org/D27008
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287781 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Added 6 new target hooks for the vectorizer in order to filter types, handle size constraints and decide how to split chains.
Reviewers: tstellarAMD, arsenm
Subscribers: arsenm, mzolotukhin, wdng, llvm-commits, nhaehnle
Differential Revision: https://reviews.llvm.org/D24727
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283099 91177308-0d34-0410-b5e6-96231b3b80d8
If the unaligned access has a dynamic offset, it may be odd which
would make the adjusted alignment incorrect to use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281110 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
LSV replaces multiple adjacent loads with one vectorized load and a
bunch of extractelement instructions. This patch makes the
extractelement instructions' names match those of the original loads,
for (hopefully) improved readability.
Reviewers: asbirlea, tstellarAMD
Subscribers: arsenm, mzolotukhin
Differential Revision: https://reviews.llvm.org/D23748
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280818 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
LSV was using two vector sets (heads and tails) to track pairs of adjiacent position to vectorize.
A recent optimization is trying to obtain the longest chain to vectorize and assumes the positions
in heads(H) and tails(T) match, which is not the case is there are multiple tails for the same head.
e.g.:
i1: store a[0]
i2: store a[1]
i3: store a[1]
Leads to:
H: i1
T: i2 i3
Instead of:
H: i1 i1
T: i2 i3
So the positions for instructions that follow i3 will have different indexes in H/T.
This patch resolves PR29148.
This issue also surfaced the fact that if the chain is too long, and TLI
returns a "not-fast" answer, the whole chain will be abandoned for
vectorization, even though a smaller one would be beneficial.
Added a testcase and FIXME for this.
Reviewers: tstellarAMD, arsenm, jlebar
Subscribers: mzolotukhin, wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D24057
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280179 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In getVectorizablePrefix, this is less efficient (because we have to
iterate over the BB twice), but boy is it simpler. Given how much
trouble we've had here, I think the simplicity gain is worthwhile.
In reorder(), this is actually more efficient, as
DominatorTree::dominates iterates over the BB from the beginning when
the two instructions are in the same BB.
Reviewers: asbirlea
Subscribers: arsenm, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D23472
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278580 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
TargetBaseAlign is no longer required since LSV checks if target allows misaligned accesses.
A constant defining a base alignment is still needed for stack accesses where alignment can be adjusted.
Previous patch (D22936) was reverted because tests were failing. This patch also fixes the cause of those failures:
- x86 failing tests either did not have the right target, or the right alignment.
- NVPTX failing tests did not have the right alignment.
- AMDGPU failing test (merge-stores) should allow vectorization with the given alignment but the target info
considers <3xi32> a non-standard type and gives up early. This patch removes the condition and only checks
for a maximum size allowed and relies on the next condition checking for %4 for correctness.
This should be revisited to include 3xi32 as a MVT type (on arsenm's non-immediate todo list).
Note that checking the sizeInBits for a MVT is undefined (leads to an assertion failure),
so we need to create an EVT, hence the interface change in allowsMisaligned to include the Context.
Reviewers: arsenm, jlebar, tstellarAMD
Subscribers: jholewinski, arsenm, mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D23068
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277735 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
TargetBaseAlign is no longer required since LSV checks if target allows misaligned accesses.
A constant defining a base alignment is still needed for stack accesses where alignment can be adjusted.
Reviewers: llvm-commits, jlebar
Subscribers: mzolotukhin, arsenm
Differential Revision: https://reviews.llvm.org/D22936
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277038 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Given the crash in D22878, this patch converts the load/store vectorizer
to use explicit Instruction*s wherever possible. This is an overall
simplification and should be an improvement in safety, as we have fewer
naked cast<>s, and now where we use Value*, we really mean something
different from Instruction*.
This patch also gets rid of some cast<>s around Value*s returned by
Builder. Given that Builder constant-folds everything, we can't assume
much about what we get out of it.
One downside of this patch is that we have to copy our chain before
calling propagateMetadata. But I don't think this is a big deal, as our
chains are very small (usually 2 or 4 elems).
Reviewers: asbirlea
Subscribers: mzolotukhin, llvm-commits, arsenm
Differential Revision: https://reviews.llvm.org/D22887
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276938 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When we ask the builder to create a bitcast on a constant, we get back a
constant, not an instruction.
Reviewers: asbirlea
Subscribers: jholewinski, mzolotukhin, llvm-commits, arsenm
Differential Revision: https://reviews.llvm.org/D22878
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276922 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Previously we wouldn't move loads/stores across instructions that had
side-effects, where that was defined as may-write or may-throw. But
this is not sufficiently restrictive: Stores can't safely be moved
across instructions that may load.
This patch also adds a DEBUG check that all instructions in our chain
are either loads or stores.
Reviewers: asbirlea
Subscribers: llvm-commits, jholewinski, arsenm, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22547
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276171 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Previously if we had a chain that contained a side-effecting
instruction, we wouldn't vectorize it at all. Now we'll vectorize
everything that comes before the side-effecting instruction.
Reviewers: asbirlea
Subscribers: arsenm, jholewinski, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22536
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276170 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
getVectorizablePrefix previously didn't work properly in the face of
aliasing loads/stores. It unwittingly assumed that the loads/stores
appeared in the BB in address order. If they didn't, it would do the
wrong thing.
Reviewers: asbirlea, tstellarAMD
Subscribers: arsenm, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22535
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276072 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Previously, the insertion point for stores was the last instruction in
Chain *before calling getVectorizablePrefixEndIdx*. Thus if
getVectorizablePrefixEndIdx didn't return Chain.size(), we still would
insert at the last instruction in Chain.
This patch changes our internal API a bit in an attempt to make it less
prone to this sort of error. As a result, we end up recalculating the
Chain's boundary instructions, but I think worrying about the speed hit
of this is a premature optimization right now.
Reviewers: asbirlea, tstellarAMD
Subscribers: mzolotukhin, arsenm, llvm-commits
Differential Revision: https://reviews.llvm.org/D22534
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276056 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The DEBUG message was hard to read because two Values were being printed
on the same line with only the delimiter "aliases". This change makes
us print each Value on its own line.
Reviewers: asbirlea
Subscribers: llvm-commits, arsenm, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22533
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276055 91177308-0d34-0410-b5e6-96231b3b80d8
Malcolm Parsons
Daniel Jasper
Hal Finkel
Alina Sbirlea
Volkan Keles
Mehdi Amini
Matt Arsenault
Justin Lebar
David Majnemer
Benjamin Kramer