[RISCV] Enable store clustering by default (#73796)

Builds on #73789, enabling store clustering by default using the same
heuristic.

[RISCV] Enable load clustering by default (#73789)

We believe this is neutral or slightly better in the majority of cases.

[CodeGen] Convert tests to opaque pointers (NFC)

[MachineScheduler] Add option to control reordering for store/load clustering (#75338)

Reordering based on the sort order of the MemOpInfo array was disabled
in <https://reviews.llvm.org/D72706>. H

[MachineScheduler] Add option to control reordering for store/load clustering (#75338)

Reordering based on the sort order of the MemOpInfo array was disabled
in <https://reviews.llvm.org/D72706>. However, it's not clear this is
desirable for al targets. It also makes it more difficult to compare the
incremental benefit of enabling load clustering in the selectiondag
scheduler as well was the machinescheduler, as the sdag scheduler does
seem to allow this reordering.

This patch adds a parameter that can control the behaviour on a
per-target basis.

Split out from #73789.

show more ...

[RISCV] Support load clustering in the MachineScheduler (off by default) (#73754)

This adds minimal support for load clustering, but disables it by
default. The intent is to iterate on the precise

[RISCV] Support load clustering in the MachineScheduler (off by default) (#73754)

This adds minimal support for load clustering, but disables it by
default. The intent is to iterate on the precise heuristic and the
question of turning this on by default in a separate PR. Although
previous discussion indicates hope that the MachineScheduler would
replace most uses of the SelectionDAG scheduler, it does seem most
targets aren't using MachineScheduler load clustering right now:
PPC+AArch64 seem to just use it to help with paired load/store formation
and although AMDGPU uses it for general clustering it also implements
ShouldScheduleLoadsNear for the SelectionDAG scheduler's clustering.

show more ...