Optimize AOT's switchable calls for the monomorphic case.

runtime/vm/stub_code_mips.cc

Index: runtime/vm/stub_code_mips.cc
diff --git a/runtime/vm/stub_code_mips.cc b/runtime/vm/stub_code_mips.cc
index f40dd22009dbceabcbe0842aa547a9253d6512e2..dc5788bb928be504734e2f5c39495f044c027064 100644
--- a/runtime/vm/stub_code_mips.cc
+++ b/runtime/vm/stub_code_mips.cc
@@ -2150,10 +2150,10 @@ void StubCode::GenerateOptimizedIdenticalWithNumberCheckStub(
 //  T0: receiver
 //  S5: MegamorphicCache (preserved)
 // Result:
-//  T1: target entry point
-//  CODE_REG: target Code
 //  S4: arguments descriptor
 void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
+  __ NoMonomorphicCheckedEntry();
+
   __ LoadTaggedClassIdMayBeSmi(T0, T0);
   // T0: class ID of the receiver (smi).
   __ lw(S4, FieldAddress(S5, MegamorphicCache::arguments_descriptor_offset()));
@@ -2194,7 +2194,7 @@ void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
 
   __ lw(T1, FieldAddress(T0, Function::entry_point_offset()));
   __ lw(CODE_REG, FieldAddress(T0, Function::code_offset()));
-  __ Ret();
+  __ jr(T1);
 }
 
 
@@ -2202,10 +2202,11 @@ void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
 //  T0: receiver
 //  S5: ICData (preserved)
 // Result:
-//  T1: target entry point
 //  CODE_REG: target Code object
 //  S4: arguments descriptor
 void StubCode::GenerateICLookupThroughFunctionStub(Assembler* assembler) {
+  __ NoMonomorphicCheckedEntry();
+
   Label loop, found, miss;
   __ lw(T6, FieldAddress(S5, ICData::ic_data_offset()));
   __ lw(S4, FieldAddress(S5, ICData::arguments_descriptor_offset()));
@@ -2229,17 +2230,19 @@ void StubCode::GenerateICLookupThroughFunctionStub(Assembler* assembler) {
   __ lw(T0, Address(T6, target_offset));
   __ lw(T1, FieldAddress(T0, Function::entry_point_offset()));
   __ lw(CODE_REG, FieldAddress(T0, Function::code_offset()));
-  __ Ret();
+  __ jr(T1);
 
   __ Bind(&miss);
   __ LoadIsolate(T2);
   __ lw(CODE_REG, Address(T2, Isolate::ic_miss_code_offset()));
   __ lw(T1, FieldAddress(CODE_REG, Code::entry_point_offset()));
-  __ Ret();
+  __ jr(T1);
 }
 
 
 void StubCode::GenerateICLookupThroughCodeStub(Assembler* assembler) {
+  __ NoMonomorphicCheckedEntry();
+
   Label loop, found, miss;
   __ lw(T6, FieldAddress(S5, ICData::ic_data_offset()));
   __ lw(S4, FieldAddress(S5, ICData::arguments_descriptor_offset()));
@@ -2263,13 +2266,34 @@ void StubCode::GenerateICLookupThroughCodeStub(Assembler* assembler) {
   const intptr_t entry_offset = ICData::EntryPointIndexFor(1) * kWordSize;
   __ lw(T1, Address(T6, entry_offset));
   __ lw(CODE_REG, Address(T6, code_offset));
-  __ Ret();
+  __ jr(T1);
 
   __ Bind(&miss);
   __ LoadIsolate(T2);
   __ lw(CODE_REG, Address(T2, Isolate::ic_miss_code_offset()));
   __ lw(T1, FieldAddress(CODE_REG, Code::entry_point_offset()));
-  __ Ret();
+  __ jr(T1);
+}
+
+
+// Called from the monomorphic checked entry.
+//  T0: receiver
+void StubCode::GenerateMonomorphicMissStub(Assembler* assembler) {
+  __ EnterStubFrame();
+  __ Push(T0);  // Preserve receiver.
+
+  __ PushObject(Object::null_object());  // Result.
+  __ Push(T0);                           // Arg0: Receiver
+  __ CallRuntime(kMonomorphicMissRuntimeEntry, 1);
+  __ Drop(1);
+  __ Pop(S5);  // result = IC
+
+  __ Pop(T0);  // Restore receiver.
+  __ LeaveStubFrame();
+
+  __ lw(CODE_REG, Address(THR, Thread::ic_lookup_through_code_stub_offset()));
+  __ lw(T1, FieldAddress(CODE_REG, Code::checked_entry_point_offset()));
+  __ jr(T1);
 }