Fix 2346: Generic KeyedStoreIC doesn't change length and element_kind atomically

src/ia32/ic-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 729 matching lines @@
   __ mov(unmapped_location, eax);
   __ lea(edi, unmapped_location);
   __ mov(edx, eax);
   __ RecordWrite(ebx, edi, edx, kDontSaveFPRegs);
   __ Ret();
   __ bind(&slow);
   GenerateMiss(masm, false);
 }
 
 
+static void KeyedStoreGeneratGenericHelper(MacroAssembler* masm,

[Erik Corry, 2012/09/25 09:26:26]

Ken Thompson was once asked what he would do differently if he were redesigning
the UNIX system. His reply: "I'd spell creat with an e."

+                                           Label* fast_object,
+                                           Label* fast_double,
+                                           Label* slow,
+                                           bool check_map,
+                                           bool increment_length) {
+  Label transition_smi_elements;
+  Label finish_object_store, non_double_value, transition_double_elements;
+  Label fast_double_without_map_check;
+  // eax: value
+  // ecx: key (a smi)
+  // edx: receiver
+  // ebx: FixedArray receiver->elements
+  // edi: receiver map
+  // Fast case: Do the store, could either Object or double.
+  __ bind(fast_object);
+  if (check_map) {
+    __ mov(edi, FieldOperand(ebx, HeapObject::kMapOffset));
+    __ cmp(edi, masm->isolate()->factory()->fixed_array_map());
+    __ j(not_equal, fast_double);
+  }
+  // Smi stores don't require further checks.
+  Label non_smi_value;
+  __ JumpIfNotSmi(eax, &non_smi_value);
+  if (increment_length) {
+    // Add 1 to receiver->length, and go to common element store code for
+    // doubles.
+    __ add(FieldOperand(edx, JSArray::kLengthOffset),
+           Immediate(Smi::FromInt(1)));
+  }
+  // It's irrelevant whether array is smi-only or not when writing a smi.
+  __ mov(CodeGenerator::FixedArrayElementOperand(ebx, ecx), eax);
+  __ ret(0);
+
+  __ bind(&non_smi_value);
+  // Escape to elements kind transition case.
+  __ mov(edi, FieldOperand(edx, HeapObject::kMapOffset));
+  __ CheckFastObjectElements(edi, &transition_smi_elements);
+
+  // Fast elements array, store the value to the elements backing store.
+  __ bind(&finish_object_store);
+  if (increment_length) {
+    // Add 1 to receiver->length, and go to common element store code for
+    // doubles.
+    __ add(FieldOperand(edx, JSArray::kLengthOffset),
+           Immediate(Smi::FromInt(1)));
+  }
+  __ mov(CodeGenerator::FixedArrayElementOperand(ebx, ecx), eax);
+  // Update write barrier for the elements array address.
+  __ mov(edx, eax);  // Preserve the value which is returned.
+  __ RecordWriteArray(
+      ebx, edx, ecx, kDontSaveFPRegs, EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+  __ ret(0);
+
+  __ bind(fast_double);
+  if (check_map) {
+    // Check for fast double array case. If this fails, call through to the
+    // runtime.
+    __ cmp(edi, masm->isolate()->factory()->fixed_double_array_map());
+    __ j(not_equal, slow);
+    // If the value is a number, store it as a double in the FastDoubleElements
+    // array.
+  }
+  __ bind(&fast_double_without_map_check);
+  __ StoreNumberToDoubleElements(eax, ebx, ecx, edi, xmm0,
+                                 &transition_double_elements, false);
+  if (increment_length) {
+    // Add 1 to receiver->length, and go to common element store code for

[Erik Corry, 2012/09/25 09:26:26]

Comment out of date.

+    // doubles.
+    __ add(FieldOperand(edx, JSArray::kLengthOffset),
+           Immediate(Smi::FromInt(1)));
+  }
+  __ ret(0);
+
+  __ bind(&transition_smi_elements);
+  __ mov(ebx, FieldOperand(edx, HeapObject::kMapOffset));
+
+  // Transition the array appropriately depending on the value type.
+  __ CheckMap(eax,
+              masm->isolate()->factory()->heap_number_map(),
+              &non_double_value,
+              DONT_DO_SMI_CHECK);
+
+  // Value is a double. Transition FAST_SMI_ELEMENTS -> FAST_DOUBLE_ELEMENTS
+  // and complete the store.
+  __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
+                                         FAST_DOUBLE_ELEMENTS,
+                                         ebx,
+                                         edi,
+                                         slow);
+  ElementsTransitionGenerator::GenerateSmiToDouble(masm, slow);
+  __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
+  __ jmp(&fast_double_without_map_check);
+
+  __ bind(&non_double_value);
+  // Value is not a double, FAST_SMI_ELEMENTS -> FAST_ELEMENTS
+  __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
+                                         FAST_ELEMENTS,
+                                         ebx,
+                                         edi,
+                                         slow);
+  ElementsTransitionGenerator::GenerateMapChangeElementsTransition(masm);
+  __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
+  __ jmp(&finish_object_store);
+
+  __ bind(&transition_double_elements);
+  // Elements are FAST_DOUBLE_ELEMENTS, but value is an Object that's not a
+  // HeapNumber. Make sure that the receiver is a Array with FAST_ELEMENTS and
+  // transition array from FAST_DOUBLE_ELEMENTS to FAST_ELEMENTS
+  __ mov(ebx, FieldOperand(edx, HeapObject::kMapOffset));
+  __ LoadTransitionedArrayMapConditional(FAST_DOUBLE_ELEMENTS,
+                                         FAST_ELEMENTS,
+                                         ebx,
+                                         edi,
+                                         slow);
+  ElementsTransitionGenerator::GenerateDoubleToObject(masm, slow);
+  __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
+  __ jmp(&finish_object_store);
+}
+

[Erik Corry, 2012/09/25 09:26:26]

Missing blank line.

 void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm,
                                    StrictModeFlag strict_mode) {
   // ----------- S t a t e -------------
   //  -- eax    : value
   //  -- ecx    : key
   //  -- edx    : receiver
   //  -- esp[0] : return address
   // -----------------------------------
-  Label slow, fast_object_with_map_check, fast_object_without_map_check;
-  Label fast_double_with_map_check, fast_double_without_map_check;
-  Label check_if_double_array, array, extra, transition_smi_elements;
-  Label finish_object_store, non_double_value, transition_double_elements;
+  Label slow, fast_object, fast_object_grow;
+  Label fast_double, fast_double_grow;
+  Label array, extra, check_if_double_array;
 
   // Check that the object isn't a smi.
   __ JumpIfSmi(edx, &slow);
   // Get the map from the receiver.
   __ mov(edi, FieldOperand(edx, HeapObject::kMapOffset));
   // Check that the receiver does not require access checks.  We need
   // to do this because this generic stub does not perform map checks.
   __ test_b(FieldOperand(edi, Map::kBitFieldOffset),
             1 << Map::kIsAccessCheckNeeded);
   __ j(not_zero, &slow);
   // Check that the key is a smi.
   __ JumpIfNotSmi(ecx, &slow);
   __ CmpInstanceType(edi, JS_ARRAY_TYPE);
   __ j(equal, &array);
   // Check that the object is some kind of JSObject.
   __ CmpInstanceType(edi, FIRST_JS_OBJECT_TYPE);
   __ j(below, &slow);
 
   // Object case: Check key against length in the elements array.
   // eax: value
   // edx: JSObject
   // ecx: key (a smi)
   // edi: receiver map
   __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
   // Check array bounds. Both the key and the length of FixedArray are smis.
   __ cmp(ecx, FieldOperand(ebx, FixedArray::kLengthOffset));
-  __ j(below, &fast_object_with_map_check);
+  __ j(below, &fast_object);
 
   // Slow case: call runtime.
   __ bind(&slow);
   GenerateRuntimeSetProperty(masm, strict_mode);
 
   // Extra capacity case: Check if there is extra capacity to
   // perform the store and update the length. Used for adding one
   // element to the array by writing to array[array.length].
   __ bind(&extra);
   // eax: value
   // edx: receiver, a JSArray
   // ecx: key, a smi.
   // ebx: receiver->elements, a FixedArray
   // edi: receiver map
   // flags: compare (ecx, edx.length())
   // do not leave holes in the array:
   __ j(not_equal, &slow);
   __ cmp(ecx, FieldOperand(ebx, FixedArray::kLengthOffset));
   __ j(above_equal, &slow);
   __ mov(edi, FieldOperand(ebx, HeapObject::kMapOffset));
   __ cmp(edi, masm->isolate()->factory()->fixed_array_map());
   __ j(not_equal, &check_if_double_array);
-  // Add 1 to receiver->length, and go to common element store code for Objects.
-  __ add(FieldOperand(edx, JSArray::kLengthOffset),
-         Immediate(Smi::FromInt(1)));
-  __ jmp(&fast_object_without_map_check);
+  __ jmp(&fast_object_grow);
 
   __ bind(&check_if_double_array);
   __ cmp(edi, masm->isolate()->factory()->fixed_double_array_map());
   __ j(not_equal, &slow);
-  // Add 1 to receiver->length, and go to common element store code for doubles.
-  __ add(FieldOperand(edx, JSArray::kLengthOffset),
-         Immediate(Smi::FromInt(1)));
-  __ jmp(&fast_double_without_map_check);
+  __ jmp(&fast_double_grow);
 
   // Array case: Get the length and the elements array from the JS
   // array. Check that the array is in fast mode (and writable); if it
   // is the length is always a smi.
   __ bind(&array);
   // eax: value
   // edx: receiver, a JSArray
   // ecx: key, a smi.
   // edi: receiver map
   __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
 
   // Check the key against the length in the array and fall through to the
   // common store code.
   __ cmp(ecx, FieldOperand(edx, JSArray::kLengthOffset));  // Compare smis.
   __ j(above_equal, &extra);
 
-  // Fast case: Do the store, could either Object or double.
-  __ bind(&fast_object_with_map_check);
-  // eax: value
-  // ecx: key (a smi)
-  // edx: receiver
-  // ebx: FixedArray receiver->elements
-  // edi: receiver map
-  __ mov(edi, FieldOperand(ebx, HeapObject::kMapOffset));
-  __ cmp(edi, masm->isolate()->factory()->fixed_array_map());
-  __ j(not_equal, &fast_double_with_map_check);
-  __ bind(&fast_object_without_map_check);
-  // Smi stores don't require further checks.
-  Label non_smi_value;
-  __ JumpIfNotSmi(eax, &non_smi_value);
-  // It's irrelevant whether array is smi-only or not when writing a smi.
-  __ mov(CodeGenerator::FixedArrayElementOperand(ebx, ecx), eax);
-  __ ret(0);
-
-  __ bind(&non_smi_value);
-  // Escape to elements kind transition case.
-  __ mov(edi, FieldOperand(edx, HeapObject::kMapOffset));
-  __ CheckFastObjectElements(edi, &transition_smi_elements);
-
-  // Fast elements array, store the value to the elements backing store.
-  __ bind(&finish_object_store);
-  __ mov(CodeGenerator::FixedArrayElementOperand(ebx, ecx), eax);
-  // Update write barrier for the elements array address.
-  __ mov(edx, eax);  // Preserve the value which is returned.
-  __ RecordWriteArray(
-      ebx, edx, ecx, kDontSaveFPRegs, EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
-  __ ret(0);
-
-  __ bind(&fast_double_with_map_check);
-  // Check for fast double array case. If this fails, call through to the
-  // runtime.
-  __ cmp(edi, masm->isolate()->factory()->fixed_double_array_map());
-  __ j(not_equal, &slow);
-  __ bind(&fast_double_without_map_check);
-  // If the value is a number, store it as a double in the FastDoubleElements
-  // array.
-  __ StoreNumberToDoubleElements(eax, ebx, ecx, edx, xmm0,
-                                 &transition_double_elements, false);
-  __ ret(0);
-
-  __ bind(&transition_smi_elements);
-  __ mov(ebx, FieldOperand(edx, HeapObject::kMapOffset));
-
-  // Transition the array appropriately depending on the value type.
-  __ CheckMap(eax,
-              masm->isolate()->factory()->heap_number_map(),
-              &non_double_value,
-              DONT_DO_SMI_CHECK);
-
-  // Value is a double. Transition FAST_SMI_ELEMENTS -> FAST_DOUBLE_ELEMENTS
-  // and complete the store.
-  __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
-                                         FAST_DOUBLE_ELEMENTS,
-                                         ebx,
-                                         edi,
-                                         &slow);
-  ElementsTransitionGenerator::GenerateSmiToDouble(masm, &slow);
-  __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
-  __ jmp(&fast_double_without_map_check);
-
-  __ bind(&non_double_value);
-  // Value is not a double, FAST_SMI_ELEMENTS -> FAST_ELEMENTS
-  __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
-                                         FAST_ELEMENTS,
-                                         ebx,
-                                         edi,
-                                         &slow);
-  ElementsTransitionGenerator::GenerateMapChangeElementsTransition(masm);
-  __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
-  __ jmp(&finish_object_store);
-
-  __ bind(&transition_double_elements);
-  // Elements are FAST_DOUBLE_ELEMENTS, but value is an Object that's not a
-  // HeapNumber. Make sure that the receiver is a Array with FAST_ELEMENTS and
-  // transition array from FAST_DOUBLE_ELEMENTS to FAST_ELEMENTS
-  __ mov(ebx, FieldOperand(edx, HeapObject::kMapOffset));
-  __ LoadTransitionedArrayMapConditional(FAST_DOUBLE_ELEMENTS,
-                                         FAST_ELEMENTS,
-                                         ebx,
-                                         edi,
-                                         &slow);
-  ElementsTransitionGenerator::GenerateDoubleToObject(masm, &slow);
-  __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
-  __ jmp(&finish_object_store);
+  KeyedStoreGeneratGenericHelper(masm, &fast_object, &fast_double, &slow,
+                                 true, false);
+  KeyedStoreGeneratGenericHelper(masm, &fast_object_grow, &fast_double_grow,
+                                 &slow, false, true);
 }
 
 
 // The generated code does not accept smi keys.
 // The generated code falls through if both probes miss.
 void CallICBase::GenerateMonomorphicCacheProbe(MacroAssembler* masm,
                                                int argc,
                                                Code::Kind kind,
                                                Code::ExtraICState extra_state) {
   // ----------- S t a t e -------------
@@ skipping 828 matching lines @@
   Condition cc = (check == ENABLE_INLINED_SMI_CHECK)
       ? (*jmp_address == Assembler::kJncShortOpcode ? not_zero : zero)
       : (*jmp_address == Assembler::kJnzShortOpcode ? not_carry : carry);
   *jmp_address = static_cast<byte>(Assembler::kJccShortPrefix | cc);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32