7 Commits

Author SHA1 Message Date
Luke Lau
8107b430ed
[VPlan] Simplify select c, x, x -> x (#133731)
As noted in 1a9358c090d0507be21c5e9b2d97a23ef1de8ab0, some
simplifications can produce a redundant select where the true and false
operands are the same, which this patch removes.

The is_fpclass test was changed so the condition wasn't made dead.
2025-04-02 10:26:48 +01:00
Florian Hahn
dfca6c0d3b
[VPlan] Remove no-op SCALAR-STEPS after unrolling. (#123655)
After unrolling, there may be additional simplifications that can be
applied. One example is removing SCALAR-STEPS for the first part where
only the first lane is demanded.

This removes redundant adds of 0 from a large number of tests (~200),
many which I am still working on updating.

In preparation for removing redundant WideIV steps added in
https://github.com/llvm/llvm-project/pull/119284.

PR: https://github.com/llvm/llvm-project/pull/123655
2025-03-25 12:57:24 +00:00
Florian Hahn
1de3dc7d23 [LV] Bail out early if BTC+1 wraps.
Currently we fail to detect the case where BTC + 1 wraps, i.e. the
vector trip count is 0, In those cases, the minimum iteration count
check will fail, and the vector code will never be executed.

Explicitly check for this condition in computeMaxVF and avoid trying to
vectorize alltogether.

Note that a number of tests needed to be updated, because the vector
loop would never be executed given the input IR.

Fixes https://github.com/llvm/llvm-project/issues/122558.
2025-01-14 22:07:38 +00:00
Florian Hahn
e584278289
[LV] Update tests to avoid loop invariant instructions.
Update some tests with loop invariant instructions so the instructions
cannot be hoisted out.

This preserves the original test intention after
https://github.com/llvm/llvm-project/pull/107894.
2024-09-19 18:50:10 +01:00
Florian Hahn
96e83d3705
[LV] Use IRBuilder to create and optimize middle-block compare.
Split off from D150398 to avoid builder-related diff changes there.
Using IRBuilder to create ICmps simplifies the result if both operands
are constants.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D158332
2023-08-29 11:42:18 +01:00
Jay Foad
593e25ffae [Vectorize] Fix vectorization, scalarization and folding of llvm.is.fpclass
llvm.is.fpclass is different from other vectorizable intrinsics in that
it is overloaded on an argument type, not on the return type.

Differential Revision: https://reviews.llvm.org/D148905
2023-04-24 13:42:08 +01:00
Jay Foad
3237497d01 [Vectorize] Pre-commit tests for D148905
Differential Revision: https://reviews.llvm.org/D149050
2023-04-24 13:42:08 +01:00