[TypeFeedbackVector] Root feedback vectors at function literal site.

src/builtins/mips/builtins-mips.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_MIPS
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 1000 matching lines @@
   __ bind(&bytecode_array_loaded);
 
   // Check whether we should continue to use the interpreter.
   Label switch_to_different_code_kind;
   __ lw(a0, FieldMemOperand(a0, SharedFunctionInfo::kCodeOffset));
   __ Branch(&switch_to_different_code_kind, ne, a0,
             Operand(masm->CodeObject()));  // Self-reference to this code.
 
   // Increment invocation count for the function.
   __ lw(a0, FieldMemOperand(a1, JSFunction::kFeedbackVectorOffset));
+  __ lw(a0, FieldMemOperand(a0, Cell::kValueOffset));
   __ lw(t0, FieldMemOperand(
                 a0, TypeFeedbackVector::kInvocationCountIndex * kPointerSize +
                         TypeFeedbackVector::kHeaderSize));
   __ Addu(t0, t0, Operand(Smi::FromInt(1)));
   __ sw(t0, FieldMemOperand(
                 a0, TypeFeedbackVector::kInvocationCountIndex * kPointerSize +
                         TypeFeedbackVector::kHeaderSize));
 
   // Check function data field is actually a BytecodeArray object.
   if (FLAG_debug_code) {
@@ skipping 314 matching lines @@
   //  -- a1 : target function (preserved for callee)
   // -----------------------------------
   // First lookup code, maybe we don't need to compile!
   Label gotta_call_runtime, gotta_call_runtime_no_stack;
   Label try_shared;
   Label loop_top, loop_bottom;
 
   Register argument_count = a0;
   Register closure = a1;
   Register new_target = a3;
+  Register map = a0;
+  Register index = a2;
+
+  // Do we have a valid feedback vector?
+  __ lw(index, FieldMemOperand(closure, JSFunction::kFeedbackVectorOffset));
+  __ lw(index, FieldMemOperand(index, Cell::kValueOffset));
+  __ JumpIfRoot(index, Heap::kUndefinedValueRootIndex,
+                &gotta_call_runtime_no_stack);
+
   __ push(argument_count);
   __ push(new_target);
   __ push(closure);
 
-  Register map = a0;
-  Register index = a2;
   __ lw(map, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ lw(map, FieldMemOperand(map, SharedFunctionInfo::kOptimizedCodeMapOffset));
   __ lw(index, FieldMemOperand(map, FixedArray::kLengthOffset));
-  __ Branch(&gotta_call_runtime, lt, index, Operand(Smi::FromInt(2)));
+  __ Branch(&try_shared, lt, index, Operand(Smi::FromInt(2)));
 
-  // Find literals.
   // a3  : native context
   // a2  : length / index
   // a0  : optimized code map
   // stack[0] : new target
   // stack[4] : closure
   Register native_context = a3;
   __ lw(native_context, NativeContextMemOperand());
 
   __ bind(&loop_top);
   Register temp = a1;
   Register array_pointer = t1;
 
   // Does the native context match?
   __ sll(at, index, kPointerSizeLog2 - kSmiTagSize);
   __ Addu(array_pointer, map, Operand(at));
   __ lw(temp, FieldMemOperand(array_pointer,
                               SharedFunctionInfo::kOffsetToPreviousContext));
   __ lw(temp, FieldMemOperand(temp, WeakCell::kValueOffset));
   __ Branch(&loop_bottom, ne, temp, Operand(native_context));
-  // Feedback vector available?
-  __ lw(temp, FieldMemOperand(array_pointer,
-                              SharedFunctionInfo::kOffsetToPreviousLiterals));
-  __ lw(temp, FieldMemOperand(temp, WeakCell::kValueOffset));
-  __ JumpIfSmi(temp, &gotta_call_runtime);
-
-  // Save the feedback vector in the closure.
-  __ lw(t0, MemOperand(sp, 0));
-  __ sw(temp, FieldMemOperand(t0, JSFunction::kFeedbackVectorOffset));
-  __ push(index);
-  __ RecordWriteField(t0, JSFunction::kFeedbackVectorOffset, temp, index,
-                      kRAHasNotBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
-                      OMIT_SMI_CHECK);
-  __ pop(index);
 
   // Code available?
   Register entry = t0;
   __ lw(entry,
         FieldMemOperand(array_pointer,
                         SharedFunctionInfo::kOffsetToPreviousCachedCode));
   __ lw(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
   __ JumpIfSmi(entry, &try_shared);
 
-  // Found literals and code. Get them into the closure and return.
+  // Found code. Get it into the closure and return.
   __ pop(closure);
   // Store code entry in the closure.
   __ Addu(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
   __ sw(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset));
   __ RecordWriteCodeEntryField(closure, entry, t1);
 
   // Link the closure into the optimized function list.
   // t0 : code entry
   // a3 : native context
   // a1 : closure
@@ skipping 14 matching lines @@
   __ mov(closure, t1);
   __ pop(new_target);
   __ pop(argument_count);
   __ Jump(entry);
 
   __ bind(&loop_bottom);
   __ Subu(index, index,
           Operand(Smi::FromInt(SharedFunctionInfo::kEntryLength)));
   __ Branch(&loop_top, gt, index, Operand(Smi::FromInt(1)));
 
-  // We found neither literals nor code.
-  __ jmp(&gotta_call_runtime);
-
+  // We found no code.
   __ bind(&try_shared);
   __ pop(closure);
   __ pop(new_target);
   __ pop(argument_count);
   __ lw(entry, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   // Is the shared function marked for tier up?
   __ lbu(t1, FieldMemOperand(entry,
                              SharedFunctionInfo::kMarkedForTierUpByteOffset));
   __ And(t1, t1,
          Operand(1 << SharedFunctionInfo::kMarkedForTierUpBitWithinByte));
@@ skipping 1737 matching lines @@
     __ break_(0xCC);
   }
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS