Precompilation: Have instances calls load the entry point and Code object from the ic data array in…

runtime/vm/stub_code_arm.cc

Index: runtime/vm/stub_code_arm.cc
diff --git a/runtime/vm/stub_code_arm.cc b/runtime/vm/stub_code_arm.cc
index 6b8812e3a5b57e1c069d318cbddab02c2faa9481..9a31d4271410429dfb1b5ec7eeed4ee288ef55bd 100644
--- a/runtime/vm/stub_code_arm.cc
+++ b/runtime/vm/stub_code_arm.cc
@@ -2110,7 +2110,7 @@ void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
 //  R1: target entry point
 //  CODE_REG: target Code object
 //  R4: arguments descriptor
-void StubCode::GenerateICLookupStub(Assembler* assembler) {
+void StubCode::GenerateICLookupThroughFunctionStub(Assembler* assembler) {

[srdjan, 2016/03/15 19:15:48]

Is anybody using this stub at all?

[rmacnak, 2016/03/16 18:21:32]

Instance calls are initially compiled with this stub. The new stub does not
handle lazy compilation, which we need to bring up the service isolate for
loading, etc.

   Label loop, found, miss;
   __ ldr(R4, FieldAddress(R9, ICData::arguments_descriptor_offset()));
   __ ldr(R8, FieldAddress(R9, ICData::ic_data_offset()));
@@ -2144,6 +2144,41 @@ void StubCode::GenerateICLookupStub(Assembler* assembler) {
   __ Ret();
 }
 
+
+void StubCode::GenerateICLookupThroughCodeStub(Assembler* assembler) {
+  Label loop, found, miss;
+  __ ldr(R4, FieldAddress(R9, ICData::arguments_descriptor_offset()));
+  __ ldr(R8, FieldAddress(R9, ICData::ic_data_offset()));
+  __ AddImmediate(R8, R8, Array::data_offset() - kHeapObjectTag);
+  // R8: first IC entry
+  __ LoadTaggedClassIdMayBeSmi(R1, R0);
+  // R1: receiver cid as Smi
+
+  __ Bind(&loop);
+  __ ldr(R2, Address(R8, 0));
+  __ cmp(R1, Operand(R2));
+  __ b(&found, EQ);
+  __ CompareImmediate(R2, Smi::RawValue(kIllegalCid));
+  __ b(&miss, EQ);
+
+  const intptr_t entry_length = ICData::TestEntryLengthFor(1) * kWordSize;
+  __ AddImmediate(R8, entry_length);  // Next entry.
+  __ b(&loop);
+
+  __ Bind(&found);
+  const intptr_t code_offset = ICData::CodeIndexFor(1) * kWordSize;
+  const intptr_t entry_offset = ICData::EntryPointIndexFor(1) * kWordSize;
+  __ ldr(R1, Address(R8, entry_offset));
+  __ ldr(CODE_REG, Address(R8, code_offset));
+  __ Ret();
+
+  __ Bind(&miss);
+  __ LoadIsolate(R2);
+  __ ldr(CODE_REG, Address(R2, Isolate::ic_miss_code_offset()));
+  __ ldr(R1, FieldAddress(CODE_REG, Code::entry_point_offset()));
+  __ Ret();
+}
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM