[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, 19 insertions, 22 deletions

diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 6654e1d6..fe2f9cc 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -1302,10 +1302,10 @@ static bool MemOperandsHaveAlias(const MachineFrameInfo &MFI, AAResults *AA,
   int64_t OffsetB = MMOb->getOffset();
   int64_t MinOffset = std::min(OffsetA, OffsetB);
 
-  uint64_t WidthA = MMOa->getSize();
-  uint64_t WidthB = MMOb->getSize();
-  bool KnownWidthA = WidthA != MemoryLocation::UnknownSize;
-  bool KnownWidthB = WidthB != MemoryLocation::UnknownSize;
+  LocationSize WidthA = MMOa->getSize();
+  LocationSize WidthB = MMOb->getSize();
+  bool KnownWidthA = WidthA.hasValue();
+  bool KnownWidthB = WidthB.hasValue();
 
   const Value *ValA = MMOa->getValue();
   const Value *ValB = MMOb->getValue();
@@ -1325,8 +1325,8 @@ static bool MemOperandsHaveAlias(const MachineFrameInfo &MFI, AAResults *AA,
     if (!KnownWidthA || !KnownWidthB)
       return true;
     int64_t MaxOffset = std::max(OffsetA, OffsetB);
-    int64_t LowWidth = (MinOffset == OffsetA) ? WidthA : WidthB;
-    return (MinOffset + LowWidth > MaxOffset);
+    LocationSize LowWidth = (MinOffset == OffsetA) ? WidthA : WidthB;
+    return (MinOffset + (int)LowWidth.getValue() > MaxOffset);
   }
 
   if (!AA)
@@ -1338,10 +1338,10 @@ static bool MemOperandsHaveAlias(const MachineFrameInfo &MFI, AAResults *AA,
   assert((OffsetA >= 0) && "Negative MachineMemOperand offset");
   assert((OffsetB >= 0) && "Negative MachineMemOperand offset");
 
-  int64_t OverlapA =
-      KnownWidthA ? WidthA + OffsetA - MinOffset : MemoryLocation::UnknownSize;
-  int64_t OverlapB =
-      KnownWidthB ? WidthB + OffsetB - MinOffset : MemoryLocation::UnknownSize;
+  int64_t OverlapA = KnownWidthA ? WidthA.getValue() + OffsetA - MinOffset
+                                 : MemoryLocation::UnknownSize;
+  int64_t OverlapB = KnownWidthB ? WidthB.getValue() + OffsetB - MinOffset
+                                 : MemoryLocation::UnknownSize;
 
   return !AA->isNoAlias(
       MemoryLocation(ValA, OverlapA, UseTBAA ? MMOa->getAAInfo() : AAMDNodes()),
@@ -2357,15 +2357,16 @@ using MMOList = SmallVector<const MachineMemOperand *, 2>;
 static LocationSize getSpillSlotSize(const MMOList &Accesses,
                                      const MachineFrameInfo &MFI) {
   uint64_t Size = 0;
-  for (const auto *A : Accesses)
+  for (const auto *A : Accesses) {
     if (MFI.isSpillSlotObjectIndex(
             cast<FixedStackPseudoSourceValue>(A->getPseudoValue())
                 ->getFrameIndex())) {
-      uint64_t S = A->getSize();
-      if (S == ~UINT64_C(0))
+      LocationSize S = A->getSize();
+      if (!S.hasValue())
         return LocationSize::beforeOrAfterPointer();
-      Size += S;
+      Size += S.getValue();
     }
+  }
   return Size;
 }
 
@@ -2374,10 +2375,8 @@ MachineInstr::getSpillSize(const TargetInstrInfo *TII) const {
   int FI;
   if (TII->isStoreToStackSlotPostFE(*this, FI)) {
     const MachineFrameInfo &MFI = getMF()->getFrameInfo();
-    if (MFI.isSpillSlotObjectIndex(FI)) {
-      uint64_t Size = (*memoperands_begin())->getSize();
-      return Size == ~UINT64_C(0) ? LocationSize::beforeOrAfterPointer() : Size;
-    }
+    if (MFI.isSpillSlotObjectIndex(FI))
+      return (*memoperands_begin())->getSize();
   }
   return std::nullopt;
 }
@@ -2395,10 +2394,8 @@ MachineInstr::getRestoreSize(const TargetInstrInfo *TII) const {
   int FI;
   if (TII->isLoadFromStackSlotPostFE(*this, FI)) {
     const MachineFrameInfo &MFI = getMF()->getFrameInfo();
-    if (MFI.isSpillSlotObjectIndex(FI)) {
-      uint64_t Size = (*memoperands_begin())->getSize();
-      return Size == ~UINT64_C(0) ? LocationSize::beforeOrAfterPointer() : Size;
-    }
+    if (MFI.isSpillSlotObjectIndex(FI))
+      return (*memoperands_begin())->getSize();
   }
   return std::nullopt;
 }