We currently canonicalize shuffles in the architecture specific
instruction selector. This has the drawback that if we want to pattern
match on nodes that have a shuffle as input, they need to individually
canonicalize the shuffle. There can also be a subtle bug if we
canonicalize the same shuffle node twice (see bug for details).
This moves the canonicalization to "construction time", in
wasm-compiler, when building the graph. As such, any pattern matches in
instruction-selector will only need to deal with canonicalized shuffles.
We introduce a new kind of parameter for shuffle nodes,
ShuffleParameter, to store the 16 bytes plus a bool indicating if this
is a swizzle. A swizzle essentially: inputs to the shuffle are the same
or all indices only touch 1 input. We calculate this when
canonicalizing, so store this bit of information inside of the node's
parameter.
We update the tests in x64 to handle special cases where, even though
the node's inputs are not swapped (due to canonicalization), they need
to be swapped for the specific instruction selected (e.g. palignr). The
test data also contains canonicalized shuffles, so we have to manually
canonicalize them.
Bug: v8:11542
Change-Id: I4e78082267bd03d6caedf43d68d81ef3f5f364a8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2762420
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73495}
d16eefe0f2