Fix secondary stub cache and add a test for the stub cache lookups.

src/ia32/stub-cache-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 26 matching lines @@
 namespace internal {
 
 #define __ ACCESS_MASM(masm)
 
 
 static void ProbeTable(Isolate* isolate,
                        MacroAssembler* masm,
                        Code::Flags flags,
                        StubCache::Table table,
                        Register name,
+                       Register receiver,
                        Register offset,
                        Register extra) {
   ExternalReference key_offset(isolate->stub_cache()->key_reference(table));
   ExternalReference value_offset(isolate->stub_cache()->value_reference(table));
+  ExternalReference map_offset(isolate->stub_cache()->map_reference(table));
 
   Label miss;
 
+  // Multiply by 3.
+  __ lea(offset, Operand(offset, offset, times_2, 0));
+
   if (extra.is_valid()) {
     // Get the code entry from the cache.
-    __ mov(extra, Operand::StaticArray(offset, times_2, value_offset));
+    __ mov(extra, Operand::StaticArray(offset, times_1, value_offset));
 
     // Check that the key in the entry matches the name.
-    __ cmp(name, Operand::StaticArray(offset, times_2, key_offset));
+    __ cmp(name, Operand::StaticArray(offset, times_1, key_offset));
+    __ j(not_equal, &miss);
+
+    // Check the map matches.
+    __ mov(offset, Operand::StaticArray(offset, times_1, map_offset));
+    __ cmp(offset, FieldOperand(receiver, HeapObject::kMapOffset));
     __ j(not_equal, &miss);
 
     // Check that the flags match what we're looking for.
     __ mov(offset, FieldOperand(extra, Code::kFlagsOffset));
     __ and_(offset, ~Code::kFlagsNotUsedInLookup);
     __ cmp(offset, flags);
     __ j(not_equal, &miss);
 
+#ifdef DEBUG
+    if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
+      __ jmp(&miss);
+    } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
+      __ jmp(&miss);
+    }
+#endif
+
     // Jump to the first instruction in the code stub.
     __ add(extra, Immediate(Code::kHeaderSize - kHeapObjectTag));
     __ jmp(extra);
 
     __ bind(&miss);
   } else {
     // Save the offset on the stack.
     __ push(offset);
 
     // Check that the key in the entry matches the name.
-    __ cmp(name, Operand::StaticArray(offset, times_2, key_offset));
+    __ cmp(name, Operand::StaticArray(offset, times_1, key_offset));
     __ j(not_equal, &miss);
 
+    // Check the map matches.
+    __ mov(offset, Operand::StaticArray(offset, times_1, map_offset));
+    __ cmp(offset, FieldOperand(receiver, HeapObject::kMapOffset));
+    __ j(not_equal, &miss);
+
+    // Restore offset register.
+    __ mov(offset, Operand(esp, 0));
+
     // Get the code entry from the cache.
-    __ mov(offset, Operand::StaticArray(offset, times_2, value_offset));
+    __ mov(offset, Operand::StaticArray(offset, times_1, value_offset));
 
     // Check that the flags match what we're looking for.
     __ mov(offset, FieldOperand(offset, Code::kFlagsOffset));
     __ and_(offset, ~Code::kFlagsNotUsedInLookup);
     __ cmp(offset, flags);
     __ j(not_equal, &miss);
 
+#ifdef DEBUG
+    if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
+      __ jmp(&miss);
+    } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
+      __ jmp(&miss);
+    }
+#endif
+
     // Restore offset and re-load code entry from cache.
     __ pop(offset);
-    __ mov(offset, Operand::StaticArray(offset, times_2, value_offset));
+    __ mov(offset, Operand::StaticArray(offset, times_1, value_offset));
 
     // Jump to the first instruction in the code stub.
     __ add(offset, Immediate(Code::kHeaderSize - kHeapObjectTag));
     __ jmp(offset);
 
     // Pop at miss.
     __ bind(&miss);
     __ pop(offset);
   }
 }
@@ skipping 49 matching lines @@
   __ DecrementCounter(counters->negative_lookups_miss(), 1);
 }
 
 
 void StubCache::GenerateProbe(MacroAssembler* masm,
                               Code::Flags flags,
                               Register receiver,
                               Register name,
                               Register scratch,
                               Register extra,
-                              Register extra2) {
+                              Register extra2,
+                              Register extra3) {
   Label miss;
 
-  // Assert that code is valid.  The shifting code relies on the entry size
-  // being 8.
-  ASSERT(sizeof(Entry) == 8);
+  // Assert that code is valid.  The multiplying code relies on the entry size
+  // being 12.
+  ASSERT(sizeof(Entry) == 12);
 
   // Assert the flags do not name a specific type.
   ASSERT(Code::ExtractTypeFromFlags(flags) == 0);
 
   // Assert that there are no register conflicts.
   ASSERT(!scratch.is(receiver));
   ASSERT(!scratch.is(name));
   ASSERT(!extra.is(receiver));
   ASSERT(!extra.is(name));
   ASSERT(!extra.is(scratch));
 
-  // Assert scratch and extra registers are valid, and extra2 is unused.
+  // Assert scratch and extra registers are valid, and extra2/3 are unused.
   ASSERT(!scratch.is(no_reg));
   ASSERT(extra2.is(no_reg));
+  ASSERT(extra3.is(no_reg));
+
+  Counters* counters = masm->isolate()->counters();
+  __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1);
 
   // Check that the receiver isn't a smi.
   __ JumpIfSmi(receiver, &miss);
 
   // Get the map of the receiver and compute the hash.
   __ mov(scratch, FieldOperand(name, String::kHashFieldOffset));
   __ add(scratch, FieldOperand(receiver, HeapObject::kMapOffset));
   __ xor_(scratch, flags);
   __ and_(scratch, (kPrimaryTableSize - 1) << kHeapObjectTagSize);
 
   // Probe the primary table.
-  ProbeTable(isolate(), masm, flags, kPrimary, name, scratch, extra);
+  ProbeTable(isolate(), masm, flags, kPrimary, name, receiver, scratch, extra);
 
   // Primary miss: Compute hash for secondary probe.
   __ mov(scratch, FieldOperand(name, String::kHashFieldOffset));
   __ add(scratch, FieldOperand(receiver, HeapObject::kMapOffset));
   __ xor_(scratch, flags);
   __ and_(scratch, (kPrimaryTableSize - 1) << kHeapObjectTagSize);
   __ sub(scratch, name);
   __ add(scratch, Immediate(flags));
   __ and_(scratch, (kSecondaryTableSize - 1) << kHeapObjectTagSize);
 
   // Probe the secondary table.
-  ProbeTable(isolate(), masm, flags, kSecondary, name, scratch, extra);
+  ProbeTable(
+      isolate(), masm, flags, kSecondary, name, receiver, scratch, extra);
 
   // Cache miss: Fall-through and let caller handle the miss by
   // entering the runtime system.
   __ bind(&miss);
+  __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1);
 }
 
 
 void StubCompiler::GenerateLoadGlobalFunctionPrototype(MacroAssembler* masm,
                                                        int index,
                                                        Register prototype) {
   __ LoadGlobalFunction(index, prototype);
   __ LoadGlobalFunctionInitialMap(prototype, prototype);
   // Load the prototype from the initial map.
   __ mov(prototype, FieldOperand(prototype, Map::kPrototypeOffset));
@@ skipping 3777 matching lines @@
     __ jmp(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32