When we have the remaining unique scalar, that should be inserted into
non-poison vector and into non-zero position:
```
%vec1 = insertelement %vec, %v, pos1
%res = shuffle %vec1, poison, <0, 1, 2,..., pos1, pos1 + 1, ..., pos1,
...>
```
better to estimate if it is profitable to model it as is or model it as:
```
%bv = insertelement poison, %v, 0
%splat = shuffle %bv, poison, <poison, ..., 0, ..., 0, ...>
%res = shuffle %vec, %splat, <0, 1, 2,..., pos1 + VF, pos1 + 1, ...>
```
Reviewers: preames, hiraditya, RKSimon
Reviewed By: preames
Pull Request: https://github.com/llvm/llvm-project/pull/136590
This PR removes tests with `br i1 undef` under
`llvm/tests/Transforms/ObjCARC, Reassociate, SCCP, SLPVectorizer...`.
After this PR, I'll continue to fix tests under `llvm/tests/CodeGen`,
which has more UB tests than `llvm/tests/Transforms`.
With this patch an undefined mask in a shufflevector will be printed as poison.
This change is done to support the new shufflevector semantics
for undefined mask elements.
Differential Revision: https://reviews.llvm.org/D149210
Currently compiler does not support mixing of shuffled nodes
+ gather/buildvector of the remaining scalar values. It may reduce total
number of instructions and improve performance of the
gather/buildvector sequences.
Part of D110978
Differential Revision: https://reviews.llvm.org/D146167
This is the first patch in a series intended for removing flag
-enable-new-pm=0 from lit tests. This is part of a bigger
effort of completely removing legacy code related to legacy
pass manager in favor of currently default new pass manager.
In this patch flag has been removed only from tests where no significant
change has been required because checks has been duplicated for
both PMs.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D134150
We can try to vectorize number of stores less than MinVecRegSize
/ scalar_value_size, if it is allowed by target. Gives an extra
opportunity for the vectorization.
Fixes PR54985.
Differential Revision: https://reviews.llvm.org/D124284
If we vectorize a e.g. store, we leave around a bunch of getelementptrs for the individual scalar stores which we removed. We can go ahead and delete them as well.
This is purely for test output quality and readability. It should have no effect in any sane pipeline.
Differential Revision: https://reviews.llvm.org/D122493
Revived D101297 in its original form + added some changes in X86
legalization cehcking for masked gathers.
This solution is the most stable and the most correct one. We have to
check the legality before trying to build the masked gather in SLP.
Without this check we have incorrect cost (for SLP) in case if the masked gather
is not legal/slower than the gather. And we're missing some
vectorization opportunities.
This can be fixed in the cost model, but in this case we need to add
special checks for the cost of GEPs for ScatterVectorize node, add
special check for small trees, etc., i.e. there are a lot of corner
cases here and there, which insrease code base and make it harder to
maintain the code.
> Can't we rely on cost model to deal with this? This can be profitable for futher vectorization, when we can start from such gather loads as seed.
The question from D101297. Actually, no, it can't. Actually, simple
gather may give us better result, especially after we started
vectorization of insertelements. Plus, like I said before, the cost for
non-legal masked gathers leads to missed vectorization opportunities.
Differential Revision: https://reviews.llvm.org/D105042
