Revision: 7069
Author: [email protected]
Date: Mon Mar 7 00:35:19 2011
Log: Optimize loads from root-array in X64.
Move the value of the root-array register to offset 128 from the start of
the root array. This allows indices 16..31 to be reached using only an
8-bit displacement, saving three bytes per access.
Review URL: http://codereview.chromium.org/6594115
http://code.google.com/p/v8/source/detail?r=7069
Modified:
/branches/bleeding_edge/src/heap.h
/branches/bleeding_edge/src/x64/code-stubs-x64.cc
/branches/bleeding_edge/src/x64/codegen-x64.cc
/branches/bleeding_edge/src/x64/deoptimizer-x64.cc
/branches/bleeding_edge/src/x64/lithium-codegen-x64.cc
/branches/bleeding_edge/src/x64/macro-assembler-x64.cc
/branches/bleeding_edge/src/x64/macro-assembler-x64.h
=======================================
--- /branches/bleeding_edge/src/heap.h Tue Feb 22 02:05:30 2011
+++ /branches/bleeding_edge/src/heap.h Mon Mar 7 00:35:19 2011
@@ -49,7 +49,6 @@
V(Map, one_pointer_filler_map,
OnePointerFillerMap) \
V(Map, two_pointer_filler_map,
TwoPointerFillerMap) \
/* Cluster the most popular ones in a few cache lines here at the
top. */ \
- V(Smi, stack_limit,
StackLimit) \
V(Object, undefined_value,
UndefinedValue) \
V(Object, the_hole_value,
TheHoleValue) \
V(Object, null_value,
NullValue) \
@@ -62,21 +61,29 @@
V(Map, fixed_cow_array_map,
FixedCOWArrayMap) \
V(Object, no_interceptor_result_sentinel,
NoInterceptorResultSentinel) \
V(Map, meta_map,
MetaMap) \
- V(Object, termination_exception,
TerminationException) \
V(Map, hash_table_map,
HashTableMap) \
+ V(Smi, stack_limit,
StackLimit) \
+ V(FixedArray, number_string_cache,
NumberStringCache) \
+ V(Object, instanceof_cache_function,
InstanceofCacheFunction) \
+ V(Object, instanceof_cache_map,
InstanceofCacheMap) \
+ V(Object, instanceof_cache_answer,
InstanceofCacheAnswer) \
+ V(FixedArray, single_character_string_cache,
SingleCharacterStringCache) \
+ V(Object, termination_exception,
TerminationException) \
V(FixedArray, empty_fixed_array,
EmptyFixedArray) \
V(ByteArray, empty_byte_array,
EmptyByteArray) \
+ V(String, empty_string,
EmptyString) \
+ V(DescriptorArray, empty_descriptor_array,
EmptyDescriptorArray) \
V(Map, string_map,
StringMap) \
V(Map, ascii_string_map,
AsciiStringMap) \
V(Map, symbol_map,
SymbolMap) \
+ V(Map, cons_string_map,
ConsStringMap) \
+ V(Map, cons_ascii_string_map,
ConsAsciiStringMap) \
V(Map, ascii_symbol_map,
AsciiSymbolMap) \
V(Map, cons_symbol_map,
ConsSymbolMap) \
V(Map, cons_ascii_symbol_map,
ConsAsciiSymbolMap) \
V(Map, external_symbol_map,
ExternalSymbolMap) \
V(Map, external_symbol_with_ascii_data_map,
ExternalSymbolWithAsciiDataMap) \
V(Map, external_ascii_symbol_map,
ExternalAsciiSymbolMap) \
- V(Map, cons_string_map,
ConsStringMap) \
- V(Map, cons_ascii_string_map,
ConsAsciiStringMap) \
V(Map, external_string_map,
ExternalStringMap) \
V(Map, external_string_with_ascii_data_map,
ExternalStringWithAsciiDataMap) \
V(Map, external_ascii_string_map,
ExternalAsciiStringMap) \
@@ -100,11 +107,6 @@
V(Map, proxy_map,
ProxyMap) \
V(Object, nan_value,
NanValue) \
V(Object, minus_zero_value,
MinusZeroValue) \
- V(Object, instanceof_cache_function,
InstanceofCacheFunction) \
- V(Object, instanceof_cache_map,
InstanceofCacheMap) \
- V(Object, instanceof_cache_answer,
InstanceofCacheAnswer) \
- V(String, empty_string,
EmptyString) \
- V(DescriptorArray, empty_descriptor_array,
EmptyDescriptorArray) \
V(Map, neander_map,
NeanderMap) \
V(JSObject, message_listeners,
MessageListeners) \
V(Proxy, prototype_accessors,
PrototypeAccessors) \
@@ -113,8 +115,6 @@
V(Code, js_entry_code,
JsEntryCode) \
V(Code, js_construct_entry_code,
JsConstructEntryCode) \
V(Code, c_entry_code,
CEntryCode) \
- V(FixedArray, number_string_cache,
NumberStringCache) \
- V(FixedArray, single_character_string_cache,
SingleCharacterStringCache) \
V(FixedArray, natives_source_cache,
NativesSourceCache) \
V(Object, last_script_id,
LastScriptId) \
V(Script, empty_script,
EmptyScript) \
@@ -218,7 +218,6 @@
V(KeyedLoadExternalArray_symbol, "KeyedLoadExternalArray") \
V(KeyedStoreExternalArray_symbol, "KeyedStoreExternalArray")
-
// Forward declarations.
class GCTracer;
class HeapStats;
=======================================
--- /branches/bleeding_edge/src/x64/code-stubs-x64.cc Fri Mar 4 05:01:47
2011
+++ /branches/bleeding_edge/src/x64/code-stubs-x64.cc Mon Mar 7 00:35:19
2011
@@ -3561,8 +3561,7 @@
// Set up the roots and smi constant registers.
// Needs to be done before any further smi loads.
- ExternalReference roots_address = ExternalReference::roots_address();
- __ movq(kRootRegister, roots_address);
+ __ InitializeRootRegister();
__ InitializeSmiConstantRegister();
#ifdef ENABLE_LOGGING_AND_PROFILING
=======================================
--- /branches/bleeding_edge/src/x64/codegen-x64.cc Wed Mar 2 03:45:31 2011
+++ /branches/bleeding_edge/src/x64/codegen-x64.cc Mon Mar 7 00:35:19 2011
@@ -8217,7 +8217,8 @@
// This is the map check instruction that will be patched (so we can't
// use the double underscore macro that may insert instructions).
// Initially use an invalid map to force a failure.
- masm()->Move(kScratchRegister, Factory::null_value());
+ masm()->movq(kScratchRegister, Factory::null_value(),
+ RelocInfo::EMBEDDED_OBJECT);
masm()->cmpq(FieldOperand(receiver.reg(), HeapObject::kMapOffset),
kScratchRegister);
// This branch is always a forwards branch so it's always a fixed
@@ -8293,7 +8294,8 @@
// the __ macro for the following two instructions because it
// might introduce extra instructions.
__ bind(&patch_site);
- masm()->Move(kScratchRegister, Factory::null_value());
+ masm()->movq(kScratchRegister, Factory::null_value(),
+ RelocInfo::EMBEDDED_OBJECT);
masm()->cmpq(FieldOperand(receiver.reg(), HeapObject::kMapOffset),
kScratchRegister);
// This branch is always a forwards branch so it's always a fixed size
=======================================
--- /branches/bleeding_edge/src/x64/deoptimizer-x64.cc Fri Mar 4 04:34:05
2011
+++ /branches/bleeding_edge/src/x64/deoptimizer-x64.cc Mon Mar 7 00:35:19
2011
@@ -749,11 +749,8 @@
// Set up the roots register.
ExternalReference roots_address = ExternalReference::roots_address();
- __ movq(r13, roots_address);
-
- __ movq(kSmiConstantRegister,
-
reinterpret_cast<uint64_t>(Smi::FromInt(kSmiConstantRegisterValue)),
- RelocInfo::NONE);
+ __ InitializeRootRegister();
+ __ InitializeSmiConstantRegister();
// Return to the continuation point.
__ ret(0);
=======================================
--- /branches/bleeding_edge/src/x64/lithium-codegen-x64.cc Thu Mar 3
08:09:52 2011
+++ /branches/bleeding_edge/src/x64/lithium-codegen-x64.cc Mon Mar 7
00:35:19 2011
@@ -1432,7 +1432,7 @@
__ j(equal, &load);
__ movl(result, Immediate(Heap::kFalseValueRootIndex));
__ bind(&load);
- __ movq(result, Operand(kRootRegister, result, times_pointer_size, 0));
+ __ LoadRootIndexed(result, result, 0);
} else {
NearLabel true_value, false_value, done;
__ j(equal, &true_value);
@@ -1563,8 +1563,7 @@
}
// result is zero if input is a smi, and one otherwise.
ASSERT(Heap::kFalseValueRootIndex == Heap::kTrueValueRootIndex + 1);
- __ movq(result, Operand(kRootRegister, result, times_pointer_size,
- Heap::kTrueValueRootIndex * kPointerSize));
+ __ LoadRootIndexed(result, result, Heap::kTrueValueRootIndex);
}
=======================================
--- /branches/bleeding_edge/src/x64/macro-assembler-x64.cc Thu Mar 3
03:49:03 2011
+++ /branches/bleeding_edge/src/x64/macro-assembler-x64.cc Mon Mar 7
00:35:19 2011
@@ -49,22 +49,35 @@
void MacroAssembler::LoadRoot(Register destination, Heap::RootListIndex
index) {
- movq(destination, Operand(kRootRegister, index << kPointerSizeLog2));
+ movq(destination, Operand(kRootRegister,
+ (index << kPointerSizeLog2) -
kRootRegisterBias));
+}
+
+
+void MacroAssembler::LoadRootIndexed(Register destination,
+ Register variable_offset,
+ int fixed_offset) {
+ movq(destination,
+ Operand(kRootRegister,
+ variable_offset, times_pointer_size,
+ (fixed_offset << kPointerSizeLog2) - kRootRegisterBias));
}
void MacroAssembler::StoreRoot(Register source, Heap::RootListIndex index)
{
- movq(Operand(kRootRegister, index << kPointerSizeLog2), source);
+ movq(Operand(kRootRegister, (index << kPointerSizeLog2) -
kRootRegisterBias),
+ source);
}
void MacroAssembler::PushRoot(Heap::RootListIndex index) {
- push(Operand(kRootRegister, index << kPointerSizeLog2));
+ push(Operand(kRootRegister, (index << kPointerSizeLog2) -
kRootRegisterBias));
}
void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index)
{
- cmpq(with, Operand(kRootRegister, index << kPointerSizeLog2));
+ cmpq(with, Operand(kRootRegister,
+ (index << kPointerSizeLog2) - kRootRegisterBias));
}
=======================================
--- /branches/bleeding_edge/src/x64/macro-assembler-x64.h Fri Feb 25
05:22:38 2011
+++ /branches/bleeding_edge/src/x64/macro-assembler-x64.h Mon Mar 7
00:35:19 2011
@@ -52,6 +52,9 @@
static const Register kRootRegister = { 13 }; // r13 (callee save).
// Value of smi in kSmiConstantRegister.
static const int kSmiConstantRegisterValue = 1;
+// Actual value of root register is offset from the root array's start
+// to take advantage of negitive 8-bit displacement values.
+static const int kRootRegisterBias = 128;
// Convenience for platform-independent signatures.
typedef Operand MemOperand;
@@ -74,6 +77,12 @@
MacroAssembler(void* buffer, int size);
void LoadRoot(Register destination, Heap::RootListIndex index);
+ // Load a root value where the index (or part of it) is variable.
+ // The variable_offset register is added to the fixed_offset value
+ // to get the index into the root-array.
+ void LoadRootIndexed(Register destination,
+ Register variable_offset,
+ int fixed_offset);
void CompareRoot(Register with, Heap::RootListIndex index);
void CompareRoot(const Operand& with, Heap::RootListIndex index);
void PushRoot(Heap::RootListIndex index);
@@ -176,6 +185,12 @@
void StoreToSafepointRegisterSlot(Register dst, Register src);
void LoadFromSafepointRegisterSlot(Register dst, Register src);
+ void InitializeRootRegister() {
+ ExternalReference roots_address = ExternalReference::roots_address();
+ movq(kRootRegister, roots_address);
+ addq(kRootRegister, Immediate(kRootRegisterBias));
+ }
+
//
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// JavaScript invokes
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