The default legalization of unsupported vector types is to promote the integers
in each lane, which leads to extra sign or zero extending and masking when
moving data into and out of vectors. Switch our preferred type legalization from
the default to vector widening, which keeps the data in the low lanes of the
vector rather than in the low bits of each lane. The unused high lanes can be
ignored.
Half-wide vectors are now loaded from memory into the low 64 bits of the v128
rather than spread out among the lanes. As a result, v128.load64_splat is a much
more common operation, so add new patterns to support it.
Differential Revision: https://reviews.llvm.org/D107502
The data layout strings do not have any effect on llc tests and will become
misleadingly out of date as we continue to update the canonical data layout, so
remove them from the tests.
Differential Revision: https://reviews.llvm.org/D105842
When lowering a BUILD_VECTOR SDNode, we choose among various possible vector
creation instructions in an attempt to minimize the total number of instructions
used. We previously considered using swizzles, consts, and splats, and this
patch adds shuffles as well. A common pattern that now lowers to shuffles is
when two 64-bit vectors are concatenated. Previously, concatenations generally
lowered to sequences of extract_lane and replace_lane instructions when they
could have been a single shuffle.
Differential Revision: https://reviews.llvm.org/D100018
Thomas Lively