Merge pull request #7716 from felipepiovezan/felipe/swift_ldv_customizations_stable

[LiveDebugValues] Remove swift customizations introducing entry values

Author: felipepiovezan

llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp

@@ -1420,7 +1420,6 @@ bool InstrRefBasedLDV::transferDebugValue(const MachineInstr &MI) {
 
   // MLocTracker needs to know that this register is read, even if it's only
   // read by a debug inst.
-  bool convertToSwiftAsyncEntryValue = false;
   for (const MachineOperand &MO : MI.debug_operands())
     if (MO.isReg() && MO.getReg() != 0) {
       ValueIDNum RegId = MTracker->readReg(MO.getReg());
@@ -1438,17 +1437,9 @@ bool InstrRefBasedLDV::transferDebugValue(const MachineInstr &MI) {
         if (!Expr || !Expr->isEntryValue()) {
           if (TTracker)
             TTracker->recoverAsEntryValue(V, Properties, RegId);
-          else
-            convertToSwiftAsyncEntryValue = true;
         }
       }
     }
-
-  if (convertToSwiftAsyncEntryValue && Expr && !MI.isDebugValueList()) {
-    const_cast<MachineInstr *>(&MI)->getOperand(3).setMetadata(
-        DIExpression::prepend(Expr, DIExpression::EntryValue));
-    Properties.DIExpr = MI.getDebugExpression();
-  }
   // END SWIFT
 
   // If we're preparing for the second analysis (variables), the machine value

llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp

@@ -2293,40 +2293,11 @@ bool VarLocBasedLDV::ExtendRanges(MachineFunction &MF,
 
   // Only in the case of entry MBB collect DBG_VALUEs representing
   // function parameters in order to generate debug entry values for them.
-  SmallVector<MachineInstr *, 8> AsyncDbgValues;
   MachineBasicBlock &First_MBB = *(MF.begin());
-  // Use a cache so that we only hoist the first swift async context debug inst
-  // for a specific DBG_VALUE. Otherwise, we may hoist inappropriately over a
-  // llvm.dbg.value.
-  SmallDenseSet<DebugVariable, 8> SeenDebugVars;
   for (auto &MI : First_MBB) {
     collectRegDefs(MI, DefinedRegs, TRI);
-    if (MI.isDebugValue()) {
-      // In Swift async functions entry values are preferred, since they
-      // can be evaluated in both live frames and virtual backtraces.
-      if (SeenDebugVars
-              .insert(DebugVariable(MI.getDebugVariable(),
-                                    MI.getDebugExpression(),
-                                    MI.getDebugLoc()->getInlinedAt()))
-              .second &&
-          isSwiftAsyncContext(MI) && !MI.isDebugValueList()) {
-        // If our instruction is not an entry value yet, make it an entry value.
-        if (!MI.getDebugExpression()->isEntryValue()) {
-          MI.getOperand(3).setMetadata(DIExpression::prepend(
-              MI.getDebugExpression(), DIExpression::EntryValue));
-        }
-        AsyncDbgValues.push_back(&MI);
-      } else {
-        recordEntryValue(MI, DefinedRegs, OpenRanges, VarLocIDs);
-      }
-    }
-  }
-
-  if (AsyncDbgValues.size()) {
-    // Make sure the async entry values are at the very start.
-    auto InsertPt = First_MBB.getFirstNonDebugInstr();
-    for (auto *MI : llvm::reverse(AsyncDbgValues))
-      MI->moveBefore(&*InsertPt);
+    if (MI.isDebugValue())
+      recordEntryValue(MI, DefinedRegs, OpenRanges, VarLocIDs);
   }
 
   // Initialize per-block structures and scan for fragment overlaps.