VectorICs: keyed element loads were kicking out non-smi keys unnecessarily

src/arm64/code-stubs-arm64.cc

 // Copyright 2013 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_ARM64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 1449 matching lines @@
   StringCharAtGenerator char_at_generator(receiver, index, scratch, result,
                                           &miss,  // When not a string.
                                           &miss,  // When not a number.
                                           &miss,  // When index out of range.
                                           STRING_INDEX_IS_ARRAY_INDEX,
                                           RECEIVER_IS_STRING);
   char_at_generator.GenerateFast(masm);
   __ Ret();
 
   StubRuntimeCallHelper call_helper;
-  char_at_generator.GenerateSlow(masm, call_helper);
+  char_at_generator.GenerateSlow(masm, PART_OF_IC_HANDLER, call_helper);
 
   __ Bind(&miss);
   PropertyAccessCompiler::TailCallBuiltin(
       masm, PropertyAccessCompiler::MissBuiltin(Code::KEYED_LOAD_IC));
 }
 
 
 void InstanceofStub::Generate(MacroAssembler* masm) {
   // Stack on entry:
   // jssp[0]: function.
@@ skipping 1814 matching lines @@
                                     object_,
                                     index_.W(),
                                     result_,
                                     &call_runtime_);
   __ SmiTag(result_);
   __ Bind(&exit_);
 }
 
 
 void StringCharCodeAtGenerator::GenerateSlow(
-    MacroAssembler* masm,
+    MacroAssembler* masm, EmbedMode embed_mode,
     const RuntimeCallHelper& call_helper) {
   __ Abort(kUnexpectedFallthroughToCharCodeAtSlowCase);
 
   __ Bind(&index_not_smi_);
   // If index is a heap number, try converting it to an integer.
   __ JumpIfNotHeapNumber(index_, index_not_number_);
   call_helper.BeforeCall(masm);
+  if (FLAG_vector_ics && embed_mode == PART_OF_IC_HANDLER) {
+    __ Push(VectorLoadICDescriptor::VectorRegister(),
+            VectorLoadICDescriptor::SlotRegister());
+  }
   // Save object_ on the stack and pass index_ as argument for runtime call.
   __ Push(object_, index_);
   if (index_flags_ == STRING_INDEX_IS_NUMBER) {
     __ CallRuntime(Runtime::kNumberToIntegerMapMinusZero, 1);
   } else {
     DCHECK(index_flags_ == STRING_INDEX_IS_ARRAY_INDEX);
     // NumberToSmi discards numbers that are not exact integers.
     __ CallRuntime(Runtime::kNumberToSmi, 1);
   }
   // Save the conversion result before the pop instructions below
   // have a chance to overwrite it.
   __ Mov(index_, x0);
   __ Pop(object_);
+  if (FLAG_vector_ics && embed_mode == PART_OF_IC_HANDLER) {
+    __ Pop(VectorLoadICDescriptor::SlotRegister());

[Yang, 2015/03/23 14:23:59]

Can we use the equivalent Pop with two registers?

[mvstanton, 2015/03/23 15:54:44]

Done. There is some hilarity here, because arm and arm64 have a different
convention for the Pop() instruction (left-to-right, versus right-to-left).

+    __ Pop(VectorLoadICDescriptor::VectorRegister());
+  }
   // Reload the instance type.
   __ Ldr(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
   __ Ldrb(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
   call_helper.AfterCall(masm);
 
   // If index is still not a smi, it must be out of range.
   __ JumpIfNotSmi(index_, index_out_of_range_);
   // Otherwise, return to the fast path.
   __ B(&got_smi_index_);
 
@@ skipping 1317 matching lines @@
   Register scratch1 = x5;
 
   __ Add(feedback, vector, Operand::UntagSmiAndScale(slot, kPointerSizeLog2));
   __ Ldr(feedback, FieldMemOperand(feedback, FixedArray::kHeaderSize));
 
   // Is it a weak cell?
   Label try_array;
   Label not_array, smi_key, key_okay, miss;
   __ Ldr(scratch1, FieldMemOperand(feedback, HeapObject::kMapOffset));
   __ JumpIfNotRoot(scratch1, Heap::kWeakCellMapRootIndex, &try_array);
-  __ JumpIfNotSmi(key, &miss);
   HandleMonomorphicCase(masm, receiver, key, vector, slot, feedback, scratch1,
                         &miss);
 
   __ Bind(&try_array);
   // Is it a fixed array?
   __ JumpIfNotRoot(scratch1, Heap::kFixedArrayMapRootIndex, &not_array);
+
   // We have a polymorphic element handler.
-  __ JumpIfNotSmi(key, &miss);
-
   Label polymorphic, try_poly_name;
   __ Bind(&polymorphic);
   HandleArrayCases(masm, receiver, key, vector, slot, feedback, scratch1, x6,
                    x7, true, &miss);
 
   __ Bind(&not_array);
   // Is it generic?
   __ JumpIfNotRoot(feedback, Heap::kmegamorphic_symbolRootIndex,
                    &try_poly_name);
   Handle<Code> megamorphic_stub =
@@ skipping 1054 matching lines @@
                            kStackUnwindSpace, NULL, spill_offset,
                            MemOperand(fp, 6 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64