Revision: 5445
Author: [email protected]
Date: Sun Sep 12 23:13:20 2010
Log: Implement for-in cache validity checking in the full codegen on IA-32.
Review URL: http://codereview.chromium.org/3376003
http://code.google.com/p/v8/source/detail?r=5445
Modified:
/branches/bleeding_edge/src/arm/full-codegen-arm.cc
/branches/bleeding_edge/src/ia32/full-codegen-ia32.cc
/branches/bleeding_edge/src/x64/full-codegen-x64.cc
=======================================
--- /branches/bleeding_edge/src/arm/full-codegen-arm.cc Fri Sep 10 03:57:07
2010
+++ /branches/bleeding_edge/src/arm/full-codegen-arm.cc Sun Sep 12 23:13:20
2010
@@ -744,11 +744,10 @@
__ bind(&done_convert);
__ push(r0);
- // TODO(kasperl): Check cache validity in generated code. This is a
- // fast case for the JSObject::IsSimpleEnum cache validity
- // checks. If we cannot guarantee cache validity, call the runtime
- // system to check cache validity or get the property names in a
- // fixed array.
+ // BUG(867): Check cache validity in generated code. This is a fast
+ // case for the JSObject::IsSimpleEnum cache validity checks. If we
+ // cannot guarantee cache validity, call the runtime system to check
+ // cache validity or get the property names in a fixed array.
// Get the set of properties to enumerate.
__ push(r0); // Duplicate the enumerable object on the stack.
=======================================
--- /branches/bleeding_edge/src/ia32/full-codegen-ia32.cc Fri Sep 10
03:57:07 2010
+++ /branches/bleeding_edge/src/ia32/full-codegen-ia32.cc Sun Sep 12
23:13:20 2010
@@ -756,13 +756,57 @@
__ bind(&done_convert);
__ push(eax);
- // TODO(kasperl): Check cache validity in generated code. This is a
- // fast case for the JSObject::IsSimpleEnum cache validity
- // checks. If we cannot guarantee cache validity, call the runtime
- // system to check cache validity or get the property names in a
- // fixed array.
+ // Check cache validity in generated code. This is a fast case for
+ // the JSObject::IsSimpleEnum cache validity checks. If we cannot
+ // guarantee cache validity, call the runtime system to check cache
+ // validity or get the property names in a fixed array.
+ Label next, call_runtime;
+ __ mov(ecx, eax);
+ __ bind(&next);
+
+ // Check that there are no elements. Register ecx contains the
+ // current JS object we've reached through the prototype chain.
+ __ cmp(FieldOperand(ecx, JSObject::kElementsOffset),
+ Factory::empty_fixed_array());
+ __ j(not_equal, &call_runtime);
+
+ // Check that instance descriptors are not empty so that we can
+ // check for an enum cache. Leave the map in ebx for the subsequent
+ // prototype load.
+ __ mov(ebx, FieldOperand(ecx, HeapObject::kMapOffset));
+ __ mov(edx, FieldOperand(ebx, Map::kInstanceDescriptorsOffset));
+ __ cmp(edx, Factory::empty_descriptor_array());
+ __ j(equal, &call_runtime);
+
+ // Check that there in an enum cache in the non-empty instance
+ // descriptors (edx). This is the case if the next enumeration
+ // index field does not contain a smi.
+ __ mov(edx, FieldOperand(edx, DescriptorArray::kEnumerationIndexOffset));
+ __ test(edx, Immediate(kSmiTagMask));
+ __ j(zero, &call_runtime);
+
+ // For all objects but the receiver, check that the cache is empty.
+ Label check_prototype;
+ __ cmp(ecx, Operand(eax));
+ __ j(equal, &check_prototype);
+ __ mov(edx, FieldOperand(edx,
DescriptorArray::kEnumCacheBridgeCacheOffset));
+ __ cmp(edx, Factory::empty_fixed_array());
+ __ j(not_equal, &call_runtime);
+
+ // Load the prototype from the map and loop if non-null.
+ __ bind(&check_prototype);
+ __ mov(ecx, FieldOperand(ebx, Map::kPrototypeOffset));
+ __ cmp(ecx, Factory::null_value());
+ __ j(not_equal, &next);
+
+ // The enum cache is valid. Load the map of the object being
+ // iterated over and use the cache for the iteration.
+ Label use_cache;
+ __ mov(eax, FieldOperand(eax, HeapObject::kMapOffset));
+ __ jmp(&use_cache);
// Get the set of properties to enumerate.
+ __ bind(&call_runtime);
__ push(eax); // Duplicate the enumerable object on the stack.
__ CallRuntime(Runtime::kGetPropertyNamesFast, 1);
@@ -774,6 +818,7 @@
__ j(not_equal, &fixed_array);
// We got a map in register eax. Get the enumeration cache from it.
+ __ bind(&use_cache);
__ mov(ecx, FieldOperand(eax, Map::kInstanceDescriptorsOffset));
__ mov(ecx, FieldOperand(ecx, DescriptorArray::kEnumerationIndexOffset));
__ mov(edx, FieldOperand(ecx,
DescriptorArray::kEnumCacheBridgeCacheOffset));
=======================================
--- /branches/bleeding_edge/src/x64/full-codegen-x64.cc Fri Sep 10 03:57:07
2010
+++ /branches/bleeding_edge/src/x64/full-codegen-x64.cc Sun Sep 12 23:13:20
2010
@@ -746,11 +746,10 @@
__ bind(&done_convert);
__ push(rax);
- // TODO(kasperl): Check cache validity in generated code. This is a
- // fast case for the JSObject::IsSimpleEnum cache validity
- // checks. If we cannot guarantee cache validity, call the runtime
- // system to check cache validity or get the property names in a
- // fixed array.
+ // BUG(867): Check cache validity in generated code. This is a fast
+ // case for the JSObject::IsSimpleEnum cache validity checks. If we
+ // cannot guarantee cache validity, call the runtime system to check
+ // cache validity or get the property names in a fixed array.
// Get the set of properties to enumerate.
__ push(rax); // Duplicate the enumerable object on the stack.
--
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