[CodeGen] Use LocationSize for MMO getSize (#84751)

This is part of #70452 that changes the type used for the external
interface of MMO to LocationSize as opposed to uint64_t. This means the
constructors take LocationSize, and convert ~UINT64_C(0) to
LocationSize::beforeOrAfter(). The getSize methods return a
LocationSize.

This allows us to be more precise with unknown sizes, not accidentally
treating them as unsigned values, and in the future should allow us to
add proper scalable vector support but none of that is included in this
patch. It should mostly be an NFC.

Global ISel is still expected to use the underlying LLT as it needs, and
are not expected to see unknown sizes for generic operations. Most of
the changes are hopefully fairly mechanical, adding a lot of getValue()
calls and protecting them with hasValue() where needed.

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp b/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp
index cfc8c28..481d9e3 100644
--- a/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp
+++ b/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp
@@ -1356,10 +1356,11 @@ InstrRefBasedLDV::findLocationForMemOperand(const MachineInstr &MI) {
   // from the stack at some point. Happily the memory operand will tell us
   // the size written to the stack.
   auto *MemOperand = *MI.memoperands_begin();
-  unsigned SizeInBits = MemOperand->getSizeInBits();
+  LocationSize SizeInBits = MemOperand->getSizeInBits();
+  assert(SizeInBits.hasValue() && "Expected to find a valid size!");
 
   // Find that position in the stack indexes we're tracking.
-  auto IdxIt = MTracker->StackSlotIdxes.find({SizeInBits, 0});
+  auto IdxIt = MTracker->StackSlotIdxes.find({SizeInBits.getValue(), 0});
   if (IdxIt == MTracker->StackSlotIdxes.end())
     // That index is not tracked. This is suprising, and unlikely to ever
     // occur, but the safe action is to indicate the variable is optimised out.