Optimize containsKey -> get pattern

compiler/backend/src/org/jetbrains/kotlin/codegen/context/CodegenContext.java

@@ -485,19 +485,19 @@ public abstract class CodegenContext<T extends DeclarationDescriptor> {
         AccessorKey key = new AccessorKey(descriptor, superCallTarget, accessorKind);
 
         // NB should check for property accessor factory first (or change property accessor tracking under propertyAccessorFactory creation)
-        if (propertyAccessorFactories.containsKey(key)) {
-            return (D) propertyAccessorFactories.get(key).getOrCreateAccessorIfNeeded(getterAccessorRequired, setterAccessorRequired);
+        AccessorForPropertyDescriptorFactory propertyAccessorFactory = propertyAccessorFactories.get(key);
+        if (propertyAccessorFactory != null) {
+            return (D) propertyAccessorFactory.getOrCreateAccessorIfNeeded(getterAccessorRequired, setterAccessorRequired);
         }
 
-        if (accessors.containsKey(key)) {
-            AccessorForCallableDescriptor<?> accessor = accessors.get(key);
+        AccessorForCallableDescriptor<?> accessor = accessors.get(key);
+        if (accessor != null) {
             assert accessorKind == AccessorKind.NORMAL ||
                    accessor instanceof AccessorForPropertyBackingField : "There is already exists accessor with isForBackingField = false in this context";
             return (D) accessor;
         }
 
         String nameSuffix = SyntheticAccessorUtilKt.getAccessorNameSuffix(descriptor, key.superCallLabelTarget, accessorKind);
-        AccessorForCallableDescriptor<?> accessor;
         if (descriptor instanceof SimpleFunctionDescriptor) {
             accessor = new AccessorForFunctionDescriptor((FunctionDescriptor) descriptor, contextDescriptor, superCallTarget, nameSuffix, accessorKind);
         }

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/RemappingClassBuilder.java

@@ -59,7 +59,8 @@ public class RemappingClassBuilder extends DelegatingClassBuilder {
             @Nullable String signature,
             @Nullable Object value
     ) {
-        if (spilledCoroutineVariables.containsKey(name)) return spilledCoroutineVariables.get(name);
+        FieldVisitor spilledCoroutineVariable = spilledCoroutineVariables.get(name);
+        if (spilledCoroutineVariable != null) return spilledCoroutineVariable;
 
         FieldRemapper field = new FieldRemapper(
                 builder.newField(origin, access, name, this.remapper.mapDesc(desc), this.remapper.mapSignature(signature, true), value),

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/TypeRemapper.kt

@@ -30,7 +30,7 @@ class TypeRemapper private constructor(
     private val typeParametersMapping = hashMapOf<String, TypeParameter>()
 
     fun addMapping(type: String, newType: String) {
-        typeMapping.put(type, newType)
+        typeMapping[type] = newType
     }
 
     fun hasNoAdditionalMapping(type: String): Boolean {

compiler/backend/src/org/jetbrains/kotlin/codegen/state/BuilderFactoryForDuplicateSignatureDiagnostics.kt

@@ -111,9 +111,10 @@ class BuilderFactoryForDuplicateSignatureDiagnostics(
         signatures: MultiMap<RawSignature, JvmDeclarationOrigin>
     ) {
         for (predefinedSignature in PREDEFINED_SIGNATURES) {
-            if (!signatures.containsKey(predefinedSignature)) continue
+            val signature = signatures[predefinedSignature]
+            if (signature.isEmpty()) continue
 
-            val origins = signatures[predefinedSignature] + JvmDeclarationOrigin.NO_ORIGIN
+            val origins = signature + JvmDeclarationOrigin.NO_ORIGIN
 
             val diagnostic = computeDiagnosticToReport(classOrigin, classInternalName, predefinedSignature, origins) ?: continue
             diagnostics.report(ErrorsJvm.CONFLICTING_INHERITED_JVM_DECLARATIONS.on(diagnostic.element, diagnostic.data))

compiler/backend/src/org/jetbrains/kotlin/codegen/when/StringSwitchCodegen.java

@@ -51,12 +51,16 @@ public class StringSwitchCodegen extends SwitchCodegen {
         assert constant instanceof StringValue : "guaranteed by usage contract";
         int hashCode = constant.hashCode();
 
+        List<StringSwitchCodegen.Entry> hashCodesToEntry;
         if (!transitionsTable.containsKey(hashCode)) {
             transitionsTable.put(hashCode, new Label());
-            hashCodesToEntries.put(hashCode, new ArrayList<>());
+            hashCodesToEntry = new ArrayList<>();
+            hashCodesToEntries.put(hashCode, hashCodesToEntry);
+        } else {
+            hashCodesToEntry = hashCodesToEntries.get(hashCode);
         }
 
-        hashCodesToEntries.get(hashCode).add(new Entry(((StringValue) constant).getValue(), entryLabel, entry));
+        hashCodesToEntry.add(new Entry(((StringValue) constant).getValue(), entryLabel, entry));
     }
 
     @Override