[Sched] Skip MemOp with unknown size when clustering (#118443)

In #83875, we changed the type of `Width` to `LocationSize`. To get
the clsuter bytes, we use `LocationSize::getValue()` to calculate
the value.

But when `Width` is an unknown size `LocationSize`, an assertion
"Getting value from an unknown LocationSize!" will be triggered.

This patch simply skips MemOp with unknown size to fix this issue
and keep the logic the same as before.

This issue was found when implementing software pipeliner for
RISC-V in #117546. The pipeliner may clone some memory operations
with `BeforeOrAfterPointer` size.

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index 23e5e4a..7da9b3a 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -1947,6 +1947,9 @@ void BaseMemOpClusterMutation::collectMemOpRecords(
     LocationSize Width = 0;
     if (TII->getMemOperandsWithOffsetWidth(MI, BaseOps, Offset,
                                            OffsetIsScalable, Width, TRI)) {
+      if (!Width.hasValue())
+        continue;
+
       MemOpRecords.push_back(
           MemOpInfo(&SU, BaseOps, Offset, OffsetIsScalable, Width));