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
Based off D148215, when expanding a min/max reduction we should be creating min/max intrinsics directly instead of relying on instcombine to fold them back together.
This patch handles integer min/max cases. Hopefully we can add floating point support soon (at least for fastmath/nnan cases) - but we're missing some of the plumbing to pass the correct FMF to the intrinsic at the moment.
Differential Revision: https://reviews.llvm.org/D148221
Two lit tests were found running something like this:
opt -O<n> -pass-locked-to-legacy-PM ...
The expand-atomicrmw-xchg-fp.ll seem to have used -O1 just to ensure
that the -atomic-expand pass were thinking that it wasn't running at
O0 level. Same thing can be ensured by using the -codegen-opt-level=1
option, making it possible to avoid using O1 in that test case.
In the vector-reductions-expanded.ll test case it was possible to
split the RUN line into using two opt invocations. First running
"opt -O2" using the new PM, and then running "opt -expand-reductions"
using the legacy PM.
I think that given this patch we get closer to removing code related
to 'AddOptimizationPasses' in opt.cpp.
Differential Revision: https://reviews.llvm.org/D137626
This pattern is visible in unrolled and vectorized loops.
Although the backend seems to be able to reassociate to
ideal form in the examples I looked at, we might as well
do that in IR for efficiency.
Since d6de1e1a71406c75a4ea4d5a2fe84289f07ea3a1, no attributes is quivalent to
setting attribute to false.
This is a preliminary commit for https://reviews.llvm.org/D99080
This doesn't change anything currently, but as discussed in
D98981 and D98152, some tests may fail to vectorize because
the cost model becomes more accurate as we switch over to
using min/max intrinsics.
The upstream callers (the vectorizers) were fixed with:
bbed5f2f8a04 ( D95690 )
77adbe6a8c71
We should remove this pass entirely now that reduction
legalization/lowering is expected to work just as well,
but we need to confirm that the shuffle ops do not
regress (for x86 in particular).
This should be the last step needed to close:
https://llvm.org/PR23116
After much refactoring over the last 2 weeks to the reduction
matching code, I think this change is finally ready.
We effectively broke fmax/fmin vector reduction optimization
when we started canonicalizing to intrinsics in instcombine,
so this should restore that functionality for SLP.
There are still FMF problems here as noted in the code comments,
but we should be avoiding miscompiles on those for fmax/fmin by
restricting to full 'fast' ops (negative tests are included).
Fixing FMF propagation is a planned follow-up.
Differential Revision: https://reviews.llvm.org/D94913
As mentioned in D93793, there are quite a few places where unary `IRBuilder::CreateShuffleVector(X, Mask)` can be used
instead of `IRBuilder::CreateShuffleVector(X, Undef, Mask)`.
Let's update them.
Actually, it would have been more natural if the patches were made in this order:
(1) let them use unary CreateShuffleVector first
(2) update IRBuilder::CreateShuffleVector to use poison as a placeholder value (D93793)
The order is swapped, but in terms of correctness it is still fine.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D93923
Use -0.0 instead of 0.0 as the start value. The previous use of 0.0
was fine for all existing uses of this function though, as it is
always generated with fast flags right now, and thus nsz.
If the constant operand is the opposite of the min/max value,
then the result must be the other value.
This is based on the similar codegen transform proposed in:
D87571
Motivating examples are seen in the PhaseOrdering tests based on:
https://bugs.llvm.org/show_bug.cgi?id=43953#c2 - if we have
intrinsics there, some pass can fold them.
The intrinsics are still named "experimental" at this point, but
if there is no fallout from this patch, that will be a good
indicator that it is safe to finalize them.
Differential Revision: https://reviews.llvm.org/D80867
