[Codegen] Change getSpillSize/getReloadSize to LocationSize. NFC (#82636)

This is a small part of #70452, attempting to take a small simpler part
of it in isolation to simplify what remains. It changes the getSpillSize,
getFoldedSpillSize, getRestoreSize and getFoldedRestoreSize methods to return
optional<LocationSize> instead of unsigned. The code is intended to be the
same, keeping the optional<> to specify when there was no size found, with some
minor adjustments to make sure that unknown (~UINT64_C(0)) sizes are handled
sensibly.  Hopefully as more unsigned's are converted to LocationSize's the use
of ~UINT64_C(0) can be cleaned up too.

1 files changed, 21 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index efbcc83..6654e1d6 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -2354,29 +2354,35 @@ void MachineInstr::changeDebugValuesDefReg(Register Reg) {
 
 using MMOList = SmallVector<const MachineMemOperand *, 2>;
 
-static unsigned getSpillSlotSize(const MMOList &Accesses,
-                                 const MachineFrameInfo &MFI) {
-  unsigned Size = 0;
+static LocationSize getSpillSlotSize(const MMOList &Accesses,
+                                     const MachineFrameInfo &MFI) {
+  uint64_t Size = 0;
   for (const auto *A : Accesses)
     if (MFI.isSpillSlotObjectIndex(
             cast<FixedStackPseudoSourceValue>(A->getPseudoValue())
-                ->getFrameIndex()))
-      Size += A->getSize();
+                ->getFrameIndex())) {
+      uint64_t S = A->getSize();
+      if (S == ~UINT64_C(0))
+        return LocationSize::beforeOrAfterPointer();
+      Size += S;
+    }
   return Size;
 }
 
-std::optional<unsigned>
+std::optional<LocationSize>
 MachineInstr::getSpillSize(const TargetInstrInfo *TII) const {
   int FI;
   if (TII->isStoreToStackSlotPostFE(*this, FI)) {
     const MachineFrameInfo &MFI = getMF()->getFrameInfo();
-    if (MFI.isSpillSlotObjectIndex(FI))
-      return (*memoperands_begin())->getSize();
+    if (MFI.isSpillSlotObjectIndex(FI)) {
+      uint64_t Size = (*memoperands_begin())->getSize();
+      return Size == ~UINT64_C(0) ? LocationSize::beforeOrAfterPointer() : Size;
+    }
   }
   return std::nullopt;
 }
 
-std::optional<unsigned>
+std::optional<LocationSize>
 MachineInstr::getFoldedSpillSize(const TargetInstrInfo *TII) const {
   MMOList Accesses;
   if (TII->hasStoreToStackSlot(*this, Accesses))
@@ -2384,18 +2390,20 @@ MachineInstr::getFoldedSpillSize(const TargetInstrInfo *TII) const {
   return std::nullopt;
 }
 
-std::optional<unsigned>
+std::optional<LocationSize>
 MachineInstr::getRestoreSize(const TargetInstrInfo *TII) const {
   int FI;
   if (TII->isLoadFromStackSlotPostFE(*this, FI)) {
     const MachineFrameInfo &MFI = getMF()->getFrameInfo();
-    if (MFI.isSpillSlotObjectIndex(FI))
-      return (*memoperands_begin())->getSize();
+    if (MFI.isSpillSlotObjectIndex(FI)) {
+      uint64_t Size = (*memoperands_begin())->getSize();
+      return Size == ~UINT64_C(0) ? LocationSize::beforeOrAfterPointer() : Size;
+    }
   }
   return std::nullopt;
 }
 
-std::optional<unsigned>
+std::optional<LocationSize>
 MachineInstr::getFoldedRestoreSize(const TargetInstrInfo *TII) const {
   MMOList Accesses;
   if (TII->hasLoadFromStackSlot(*this, Accesses))