[DebugInfo][NFC] Fixup the UserValue methods to use FragmentInfo

Fixup the UserValue methods to use FragmentInfo instead of DIExpression because
the DIExpression is only ever used to get the to get the FragmentInfo. The
DIExpression is meaningless in the UserValue class because each definition point
added to a UserValue may have a unique DIExpression.

Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D74057

1 files changed, 19 insertions, 18 deletions

diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp
index 4ce0529..2b3e98f 100644
--- a/llvm/lib/CodeGen/LiveDebugVariables.cpp
+++ b/llvm/lib/CodeGen/LiveDebugVariables.cpp
@@ -159,9 +159,8 @@ class LDVImpl;
 /// closure of that relation.
 class UserValue {
   const DILocalVariable *Variable; ///< The debug info variable we are part of.
-  // FIXME: This is only used to get the FragmentInfo that describes the part
-  // of the variable we are a part of. We should just store the FragmentInfo.
-  const DIExpression *Expression; ///< Any complex address expression.
+  /// The part of the variable we describe.
+  const Optional<DIExpression::FragmentInfo> Fragment;
   DebugLoc dl;            ///< The debug location for the variable. This is
                           ///< used by dwarf writer to find lexical scope.
   UserValue *leader;      ///< Equivalence class leader.
@@ -191,9 +190,10 @@ class UserValue {
 
 public:
   /// Create a new UserValue.
-  UserValue(const DILocalVariable *var, const DIExpression *expr, DebugLoc L,
+  UserValue(const DILocalVariable *var,
+            Optional<DIExpression::FragmentInfo> Fragment, DebugLoc L,
             LocMap::Allocator &alloc)
-      : Variable(var), Expression(expr), dl(std::move(L)), leader(this),
+      : Variable(var), Fragment(Fragment), dl(std::move(L)), leader(this),
         locInts(alloc) {}
 
   /// Get the leader of this value's equivalence class.
@@ -208,20 +208,20 @@ public:
   UserValue *getNext() const { return next; }
 
   /// Does this UserValue match the parameters?
-  bool match(const DILocalVariable *Var, const DIExpression *Expr,
+  bool matches(const DILocalVariable *Var,
+             Optional<DIExpression::FragmentInfo> OtherFragment,
              const DILocation *IA) const {
     // FIXME: Handle partially overlapping fragments.
     // A DBG_VALUE with a fragment which overlaps a previous DBG_VALUE fragment
     // for the same variable terminates the interval opened by the first.
-    // getUserValue() uses match() to filter DBG_VALUEs into interval maps to
+    // getUserValue() uses matches() to filter DBG_VALUEs into interval maps to
     // represent these intervals.
-    // Given two _partially_ overlapping fragments match() will always return
+    // Given two _partially_ overlapping fragments matches() will always return
     // false. The DBG_VALUEs will be filtered into separate interval maps and
     // therefore we do not faithfully represent the original intervals.
     // See D70121#1849741 for a more detailed explanation and further
     // discussion.
-    return Var == Variable &&
-           Expr->getFragmentInfo() == Expression->getFragmentInfo() &&
+    return Var == Variable && OtherFragment == Fragment &&
            dl->getInlinedAt() == IA;
   }
 
@@ -391,7 +391,7 @@ public:
       : Label(label), dl(std::move(L)), loc(Idx) {}
 
   /// Does this UserLabel match the parameters?
-  bool match(const DILabel *L, const DILocation *IA,
+  bool matches(const DILabel *L, const DILocation *IA,
              const SlotIndex Index) const {
     return Label == L && dl->getInlinedAt() == IA && loc == Index;
   }
@@ -434,7 +434,8 @@ class LDVImpl {
   UVMap userVarMap;
 
   /// Find or create a UserValue.
-  UserValue *getUserValue(const DILocalVariable *Var, const DIExpression *Expr,
+  UserValue *getUserValue(const DILocalVariable *Var,
+                          Optional<DIExpression::FragmentInfo> Fragment,
                           const DebugLoc &DL);
 
   /// Find the EC leader for VirtReg or null.
@@ -597,18 +598,19 @@ void UserValue::mapVirtRegs(LDVImpl *LDV) {
 }
 
 UserValue *LDVImpl::getUserValue(const DILocalVariable *Var,
-                                 const DIExpression *Expr, const DebugLoc &DL) {
+                                 Optional<DIExpression::FragmentInfo> Fragment,
+                                 const DebugLoc &DL) {
   UserValue *&Leader = userVarMap[Var];
   if (Leader) {
     UserValue *UV = Leader->getLeader();
     Leader = UV;
     for (; UV; UV = UV->getNext())
-      if (UV->match(Var, Expr, DL->getInlinedAt()))
+      if (UV->matches(Var, Fragment, DL->getInlinedAt()))
         return UV;
   }
 
   userValues.push_back(
-      std::make_unique<UserValue>(Var, Expr, DL, allocator));
+      std::make_unique<UserValue>(Var, Fragment, DL, allocator));
   UserValue *UV = userValues.back().get();
   Leader = UserValue::merge(Leader, UV);
   return UV;
@@ -674,8 +676,7 @@ bool LDVImpl::handleDebugValue(MachineInstr &MI, SlotIndex Idx) {
     assert(MI.getOperand(1).getImm() == 0 && "DBG_VALUE with nonzero offset");
   const DILocalVariable *Var = MI.getDebugVariable();
   const DIExpression *Expr = MI.getDebugExpression();
-  UserValue *UV =
-      getUserValue(Var, Expr, MI.getDebugLoc());
+  UserValue *UV = getUserValue(Var, Expr->getFragmentInfo(), MI.getDebugLoc());
   if (!Discard)
     UV->addDef(Idx, MI.getOperand(0), IsIndirect, *Expr);
   else {
@@ -698,7 +699,7 @@ bool LDVImpl::handleDebugLabel(MachineInstr &MI, SlotIndex Idx) {
   const DebugLoc &DL = MI.getDebugLoc();
   bool Found = false;
   for (auto const &L : userLabels) {
-    if (L->match(Label, DL->getInlinedAt(), Idx)) {
+    if (L->matches(Label, DL->getInlinedAt(), Idx)) {
       Found = true;
       break;
     }