Currently when tail predicating loops, vpt blocks need to be created
with the vctp predicate in case we need to revert to non-tail predicated
form. This has the unfortunate side effect of severely hampering post-ra
scheduling at times as the instructions are already stuck in vpt blocks,
not allowed to be independently ordered.
This patch addresses that by just moving the creation of VPT blocks
later in the pipeline, after post-ra scheduling has been performed. This
allows more optimal scheduling post-ra before the vpt blocks are
created, leading to more optimal tail predicated loops.
Differential Revision: https://reviews.llvm.org/D113094
This adds a pattern to recognize VIDUP from BUILD_VECTOR of incrementing
adds. This can come up from either geps or adds, and came up recently in
D100550. We are just looking for a BUILD_VECTOR where each lane is an
add of the first lane with N*i, where i is the lane and N is one of 1,
2, 4, or 8, supported by the VIDUP instruction.
Differential Revision: https://reviews.llvm.org/D101263
CGP can move instructions like a ptrtoint into a loop, but the
MVETailPredication when converting them will currently assume invariant
trip counts. This tries to ensure the operands are loop invariant, and
bails if not.
Differential Revision: https://reviews.llvm.org/D100550
David Green