[llvm] Call *Map::erase directly (NFC) (llvm#135545)

Author: kazutakahirata

llvm/include/llvm/DebugInfo/LogicalView/Readers/LVDWARFReader.h

@@ -102,11 +102,7 @@ class LVDWARFReader final : public LVBinaryReader {
   }
 
   // Remove offset from global map.
-  void removeGlobalOffset(LVOffset Offset) {
-    LVOffsetElementMap::iterator Iter = GlobalOffsets.find(Offset);
-    if (Iter != GlobalOffsets.end())
-      GlobalOffsets.erase(Iter);
-  }
+  void removeGlobalOffset(LVOffset Offset) { GlobalOffsets.erase(Offset); }
 
   // Get the location information for DW_AT_data_member_location.
   void processLocationMember(dwarf::Attribute Attr,

llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp

@@ -2849,12 +2849,10 @@ ARMPreAllocLoadStoreOpt::RescheduleLoadStoreInstrs(MachineBasicBlock *MBB) {
         //  Erase the entry into the DbgValueSinkCandidates for the DBG_VALUE
         //  that was moved.
         auto DbgVar = createDebugVariableFromMachineInstr(DbgInstr);
-        auto DbgIt = DbgValueSinkCandidates.find(DbgVar);
-        // If the instruction is a DBG_VALUE_LIST, it may have already been
-        // erased from the DbgValueSinkCandidates. Only erase if it exists in
-        // the DbgValueSinkCandidates.
-        if (DbgIt != DbgValueSinkCandidates.end())
-          DbgValueSinkCandidates.erase(DbgIt);
+        // Erase DbgVar from DbgValueSinkCandidates if still present.  If the
+        // instruction is a DBG_VALUE_LIST, it may have already been erased from
+        // DbgValueSinkCandidates.
+        DbgValueSinkCandidates.erase(DbgVar);
         // Zero out original dbg instr
         forEachDbgRegOperand(DbgInstr,
                              [&](MachineOperand &Op) { Op.setReg(0); });

llvm/lib/Target/Hexagon/HexagonTfrCleanup.cpp

@@ -160,11 +160,8 @@ bool HexagonTfrCleanup::updateImmMap(MachineInstr *MI, ImmediateMap &IMap) {
     if (!Mo->isReg() || !Mo->isDef())
       continue;
     unsigned R = Mo->getReg();
-    for (MCRegAliasIterator AR(R, TRI, true); AR.isValid(); ++AR) {
-      ImmediateMap::iterator F = IMap.find(*AR);
-      if (F != IMap.end())
-        IMap.erase(F);
-    }
+    for (MCRegAliasIterator AR(R, TRI, true); AR.isValid(); ++AR)
+      IMap.erase(*AR);
   }
   return true;
 }

llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp

@@ -754,9 +754,7 @@ class LowerMatrixIntrinsics {
   /// Erase \p Inst from both ShapeMap (if an entry exists) and erase \p Inst
   /// itself.
   void eraseFromParentAndRemoveFromShapeMap(Instruction *Inst) {
-    auto Iter = ShapeMap.find(Inst);
-    if (Iter != ShapeMap.end())
-      ShapeMap.erase(Iter);
+    ShapeMap.erase(Inst);
     Inst->eraseFromParent();
   }