Recurse instead of returning on the first found optimization. Also, return early in the caller
instead of continuing because that allows another round of simplification before we might
potentially lose undef information from a shuffle mask by eliminating the shuffle.
As noted in the review, we could probably do better and be more efficient by moving all of
demanded elements into a separate pass, but this is yet another quick fix to instcombine.
Differential Revision: https://reviews.llvm.org/D37236
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312248 91177308-0d34-0410-b5e6-96231b3b80d8
This intrinsic clears the upper bits starting at a specified index. If the index is a constant we can do some simplifications.
This could be in InstSimplify, but we don't handle any target specific intrinsics there today.
Differential Revision: https://reviews.llvm.org/D36069
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309604 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds simplification support for the BEXTR/BEXTRI intrinsics to match gcc. This only supports cases that fold to 0 or can be fully constant folded. Theoretically we could support converting to AND if the shift part is unused or to only a shift if the mask doesn't modify any bits after an equivalent shl. gcc doesn't do these transformations either.
I put this in InstCombine, but it could be done in InstSimplify. It would be the first target specific intrinsic in InstSimplify.
Differential Revision: https://reviews.llvm.org/D36063
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309603 91177308-0d34-0410-b5e6-96231b3b80d8
Tests with target intrinsics are inherently target specific, so it
doesn't actually make sense to run them if we've excluded their
target.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302979 91177308-0d34-0410-b5e6-96231b3b80d8
