Implement tracking and optimizations of packed arrays

src/arm/stub-cache-arm.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 1563 matching lines @@
       __ bind(&with_write_barrier);
 
       __ ldr(r3, FieldMemOperand(receiver, HeapObject::kMapOffset));
 
       if (FLAG_smi_only_arrays  && !FLAG_trace_elements_transitions) {
         Label fast_object, not_fast_object;
         __ CheckFastObjectElements(r3, r7, &not_fast_object);
         __ jmp(&fast_object);
         // In case of fast smi-only, convert to fast object, otherwise bail out.
         __ bind(&not_fast_object);
-        __ CheckFastSmiOnlyElements(r3, r7, &call_builtin);
+        __ CheckFastSmiElements(r3, r7, &call_builtin);
         // edx: receiver
         // r3: map
-        __ LoadTransitionedArrayMapConditional(FAST_SMI_ONLY_ELEMENTS,
+        Label try_holey_map;
+        __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                                FAST_ELEMENTS,
                                                r3,
                                                r7,
+                                               &try_holey_map);
+        __ mov(r2, receiver);
+        ElementsTransitionGenerator::GenerateMapChangeElementTransition(masm());
+        __ jmp(&fast_object);
+
+        __ bind(&try_holey_map);
+        __ LoadTransitionedArrayMapConditional(FAST_HOLEY_SMI_ELEMENTS,
+                                               FAST_HOLEY_ELEMENTS,
+                                               r3,
+                                               r7,
                                                &call_builtin);
         __ mov(r2, receiver);
-        ElementsTransitionGenerator::GenerateSmiOnlyToObject(masm());
+        ElementsTransitionGenerator::GenerateMapChangeElementTransition(masm());
         __ bind(&fast_object);
       } else {
         __ CheckFastObjectElements(r3, r3, &call_builtin);
       }
 
       // Save new length.
       __ str(r0, FieldMemOperand(receiver, JSArray::kLengthOffset));
 
       // Store the value.
       // We may need a register containing the address end_elements below,
@@ skipping 1761 matching lines @@
 
     case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
     case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
     case EXTERNAL_UNSIGNED_INT_ELEMENTS:
     case EXTERNAL_PIXEL_ELEMENTS:
       return false;
 
     case EXTERNAL_FLOAT_ELEMENTS:
     case EXTERNAL_DOUBLE_ELEMENTS:
     case FAST_ELEMENTS:
-    case FAST_SMI_ONLY_ELEMENTS:
+    case FAST_SMI_ELEMENTS:
     case FAST_DOUBLE_ELEMENTS:
+    case FAST_HOLEY_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS:
+    case FAST_HOLEY_DOUBLE_ELEMENTS:
     case DICTIONARY_ELEMENTS:
     case NON_STRICT_ARGUMENTS_ELEMENTS:
       UNREACHABLE();
       return false;
   }
   return false;
 }
 
 
 static void GenerateSmiKeyCheck(MacroAssembler* masm,
@@ skipping 103 matching lines @@
         __ add(r2, r3, Operand(key, LSL, 2));
         __ vldr(d0, r2, 0);
       } else {
         __ add(r4, r3, Operand(key, LSL, 2));
         // r4: pointer to the beginning of the double we want to load.
         __ ldr(r2, MemOperand(r4, 0));
         __ ldr(r3, MemOperand(r4, Register::kSizeInBytes));
       }
       break;
     case FAST_ELEMENTS:
-    case FAST_SMI_ONLY_ELEMENTS:
+    case FAST_SMI_ELEMENTS:
     case FAST_DOUBLE_ELEMENTS:
+    case FAST_HOLEY_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS:
+    case FAST_HOLEY_DOUBLE_ELEMENTS:
     case DICTIONARY_ELEMENTS:
     case NON_STRICT_ARGUMENTS_ELEMENTS:
       UNREACHABLE();
       break;
   }
 
   // For integer array types:
   // r2: value
   // For float array type:
   // s0: value (if VFP3 is supported)
@@ skipping 319 matching lines @@
           r4, s2);  // These are: scratch2, single_scratch.
       if (destination == FloatingPointHelper::kVFPRegisters) {
         CpuFeatures::Scope scope(VFP3);
         __ vstr(d0, r3, 0);
       } else {
         __ str(r6, MemOperand(r3, 0));
         __ str(r7, MemOperand(r3, Register::kSizeInBytes));
       }
       break;
     case FAST_ELEMENTS:
-    case FAST_SMI_ONLY_ELEMENTS:
+    case FAST_SMI_ELEMENTS:
     case FAST_DOUBLE_ELEMENTS:
+    case FAST_HOLEY_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS:
+    case FAST_HOLEY_DOUBLE_ELEMENTS:
     case DICTIONARY_ELEMENTS:
     case NON_STRICT_ARGUMENTS_ELEMENTS:
       UNREACHABLE();
       break;
   }
 
   // Entry registers are intact, r0 holds the value which is the return value.
   __ Ret();
 
   if (elements_kind != EXTERNAL_PIXEL_ELEMENTS) {
@@ skipping 42 matching lines @@
             __ strh(r5, MemOperand(r3, key, LSL, 0));
             break;
           case EXTERNAL_INT_ELEMENTS:
           case EXTERNAL_UNSIGNED_INT_ELEMENTS:
             __ str(r5, MemOperand(r3, key, LSL, 1));
             break;
           case EXTERNAL_PIXEL_ELEMENTS:
           case EXTERNAL_FLOAT_ELEMENTS:
           case EXTERNAL_DOUBLE_ELEMENTS:
           case FAST_ELEMENTS:
-          case FAST_SMI_ONLY_ELEMENTS:
+          case FAST_SMI_ELEMENTS:
           case FAST_DOUBLE_ELEMENTS:
+          case FAST_HOLEY_ELEMENTS:
+          case FAST_HOLEY_SMI_ELEMENTS:
+          case FAST_HOLEY_DOUBLE_ELEMENTS:
           case DICTIONARY_ELEMENTS:
           case NON_STRICT_ARGUMENTS_ELEMENTS:
             UNREACHABLE();
             break;
         }
       }
 
       // Entry registers are intact, r0 holds the value which is the return
       // value.
       __ Ret();
@@ skipping 118 matching lines @@
             __ strh(r5, MemOperand(r3, key, LSL, 0));
             break;
           case EXTERNAL_INT_ELEMENTS:
           case EXTERNAL_UNSIGNED_INT_ELEMENTS:
             __ str(r5, MemOperand(r3, key, LSL, 1));
             break;
           case EXTERNAL_PIXEL_ELEMENTS:
           case EXTERNAL_FLOAT_ELEMENTS:
           case EXTERNAL_DOUBLE_ELEMENTS:
           case FAST_ELEMENTS:
-          case FAST_SMI_ONLY_ELEMENTS:
+          case FAST_SMI_ELEMENTS:
           case FAST_DOUBLE_ELEMENTS:
+          case FAST_HOLEY_ELEMENTS:
+          case FAST_HOLEY_SMI_ELEMENTS:
+          case FAST_HOLEY_DOUBLE_ELEMENTS:
           case DICTIONARY_ELEMENTS:
           case NON_STRICT_ARGUMENTS_ELEMENTS:
             UNREACHABLE();
             break;
         }
       }
     }
   }
 
   // Slow case, key and receiver still in r0 and r1.
@@ skipping 161 matching lines @@
   Register elements_reg = r3;
   Register length_reg = r5;
   Register scratch2 = r6;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
   // Check that the key is a smi or a heap number convertible to a smi.
   GenerateSmiKeyCheck(masm, key_reg, r4, r5, d1, &miss_force_generic);
 
-  if (elements_kind == FAST_SMI_ONLY_ELEMENTS) {
+  if (IsFastSmiElementsKind(elements_kind)) {
     __ JumpIfNotSmi(value_reg, &transition_elements_kind);
   }
 
   // Check that the key is within bounds.
   __ ldr(elements_reg,
          FieldMemOperand(receiver_reg, JSObject::kElementsOffset));
   if (is_js_array) {
     __ ldr(scratch, FieldMemOperand(receiver_reg, JSArray::kLengthOffset));
   } else {
     __ ldr(scratch, FieldMemOperand(elements_reg, FixedArray::kLengthOffset));
   }
   // Compare smis.
   __ cmp(key_reg, scratch);
   if (is_js_array && grow_mode == ALLOW_JSARRAY_GROWTH) {
     __ b(hs, &grow);
   } else {
     __ b(hs, &miss_force_generic);
   }
 
   // Make sure elements is a fast element array, not 'cow'.
   __ CheckMap(elements_reg,
               scratch,
               Heap::kFixedArrayMapRootIndex,
               &miss_force_generic,
               DONT_DO_SMI_CHECK);
 
   __ bind(&finish_store);
-  if (elements_kind == FAST_SMI_ONLY_ELEMENTS) {
+  if (IsFastSmiElementsKind(elements_kind)) {
     __ add(scratch,
            elements_reg,
            Operand(FixedArray::kHeaderSize - kHeapObjectTag));
     STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kPointerSizeLog2);
     __ add(scratch,
            scratch,
            Operand(key_reg, LSL, kPointerSizeLog2 - kSmiTagSize));
     __ str(value_reg, MemOperand(scratch));
   } else {
-    ASSERT(elements_kind == FAST_ELEMENTS);
+    ASSERT(IsFastObjectElementsKind(elements_kind));
     __ add(scratch,
            elements_reg,
            Operand(FixedArray::kHeaderSize - kHeapObjectTag));
     STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kPointerSizeLog2);
     __ add(scratch,
            scratch,
            Operand(key_reg, LSL, kPointerSizeLog2 - kSmiTagSize));
     __ str(value_reg, MemOperand(scratch));
     __ mov(receiver_reg, value_reg);
     __ RecordWrite(elements_reg,  // Object.
@@ skipping 226 matching lines @@
     __ Jump(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM