PPC: v8:3539 - hold constructor feedback in weak cells

src/ppc/code-stubs-ppc.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_PPC
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 2508 matching lines @@
   // (9) Sliced string.  Replace subject with parent.  Go to (4).
   // Load offset into r11 and replace subject string with parent.
   __ LoadP(r11, FieldMemOperand(subject, SlicedString::kOffsetOffset));
   __ SmiUntag(r11);
   __ LoadP(subject, FieldMemOperand(subject, SlicedString::kParentOffset));
   __ b(&check_underlying);  // Go to (4).
 #endif  // V8_INTERPRETED_REGEXP
 }
 
 
+static void CallStubInRecordCallTarget(MacroAssembler* masm, CodeStub* stub) {
+  // r3 : number of arguments to the construct function
+  // r5 : Feedback vector
+  // r6 : slot in feedback vector (Smi)
+  // r4 : the function to call
+  FrameScope scope(masm, StackFrame::INTERNAL);
+
+  // Arguments register must be smi-tagged to call out.
+  __ SmiTag(r3);
+  __ Push(r6, r5, r4, r3);
+
+  __ CallStub(stub);
+
+  __ Pop(r6, r5, r4, r3);
+  __ SmiUntag(r3);
+}
+
+
 static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // Cache the called function in a feedback vector slot.  Cache states
   // are uninitialized, monomorphic (indicated by a JSFunction), and
   // megamorphic.
   // r3 : number of arguments to the construct function
   // r4 : the function to call
   // r5 : Feedback vector
   // r6 : slot in feedback vector (Smi)
   Label initialize, done, miss, megamorphic, not_array_function;
 
   DCHECK_EQ(*TypeFeedbackVector::MegamorphicSentinel(masm->isolate()),
             masm->isolate()->heap()->megamorphic_symbol());
   DCHECK_EQ(*TypeFeedbackVector::UninitializedSentinel(masm->isolate()),
             masm->isolate()->heap()->uninitialized_symbol());
 
   // Load the cache state into r7.
   __ SmiToPtrArrayOffset(r7, r6);
   __ add(r7, r5, r7);
   __ LoadP(r7, FieldMemOperand(r7, FixedArray::kHeaderSize));
 
   // A monomorphic cache hit or an already megamorphic state: invoke the
   // function without changing the state.
-  __ cmp(r7, r4);
-  __ b(eq, &done);
+  Label check_allocation_site;
+  Register feedback_map = r8;
+  Register weak_value = r9;
+  __ LoadP(weak_value, FieldMemOperand(r7, WeakCell::kValueOffset));
+  __ cmp(r4, weak_value);
+  __ beq(&done);
+  __ CompareRoot(r7, Heap::kmegamorphic_symbolRootIndex);
+  __ beq(&done);
+  __ LoadP(feedback_map, FieldMemOperand(r7, 0));
+  __ CompareRoot(feedback_map, Heap::kWeakCellMapRootIndex);
+  __ bne(FLAG_pretenuring_call_new ? &miss : &check_allocation_site);
+
+  // If r4 is not equal to the weak cell value, and the weak cell value is
+  // cleared, we have a new chance to become monomorphic.
+  __ JumpIfSmi(weak_value, &initialize);
+  __ b(&megamorphic);
 
   if (!FLAG_pretenuring_call_new) {
+    __ bind(&check_allocation_site);
     // If we came here, we need to see if we are the array function.
     // If we didn't have a matching function, and we didn't find the megamorph
     // sentinel, then we have in the slot either some other function or an
     // AllocationSite. Do a map check on the object in ecx.
-    __ LoadP(r8, FieldMemOperand(r7, 0));
-    __ CompareRoot(r8, Heap::kAllocationSiteMapRootIndex);
+    __ CompareRoot(feedback_map, Heap::kAllocationSiteMapRootIndex);
     __ bne(&miss);
 
     // Make sure the function is the Array() function
     __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, r7);
     __ cmp(r4, r7);
     __ bne(&megamorphic);
     __ b(&done);
   }
 
   __ bind(&miss);
@@ skipping 16 matching lines @@
 
   if (!FLAG_pretenuring_call_new) {
     // Make sure the function is the Array() function.
     __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, r7);
     __ cmp(r4, r7);
     __ bne(&not_array_function);
 
     // The target function is the Array constructor,
     // Create an AllocationSite if we don't already have it, store it in the
     // slot.
-    {
-      FrameScope scope(masm, StackFrame::INTERNAL);
-
-      // Arguments register must be smi-tagged to call out.
-      __ SmiTag(r3);
-      __ Push(r6, r5, r4, r3);
-
-      CreateAllocationSiteStub create_stub(masm->isolate());
-      __ CallStub(&create_stub);
-
-      __ Pop(r6, r5, r4, r3);
-      __ SmiUntag(r3);
-    }
+    CreateAllocationSiteStub create_stub(masm->isolate());
+    CallStubInRecordCallTarget(masm, &create_stub);
     __ b(&done);
 
     __ bind(&not_array_function);
   }
 
-  __ SmiToPtrArrayOffset(r7, r6);
-  __ add(r7, r5, r7);
-  __ addi(r7, r7, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  __ StoreP(r4, MemOperand(r7, 0));
-
-  __ Push(r7, r5, r4);
-  __ RecordWrite(r5, r7, r4, kLRHasNotBeenSaved, kDontSaveFPRegs,
-                 EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
-  __ Pop(r7, r5, r4);
-
+  CreateWeakCellStub create_stub(masm->isolate());
+  CallStubInRecordCallTarget(masm, &create_stub);
   __ bind(&done);
 }
 
 
 static void EmitContinueIfStrictOrNative(MacroAssembler* masm, Label* cont) {
   // Do not transform the receiver for strict mode functions and natives.
   __ LoadP(r6, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
   __ lwz(r7, FieldMemOperand(r6, SharedFunctionInfo::kCompilerHintsOffset));
   __ TestBit(r7,
 #if V8_TARGET_ARCH_PPC64
@@ skipping 2952 matching lines @@
                            kStackUnwindSpace, NULL,
                            MemOperand(fp, 6 * kPointerSize), NULL);
 }
 
 
 #undef __
 }
 }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_PPC