Revision: 12539
Author: [email protected]
Date: Tue Sep 18 06:40:24 2012
Log: MIPS: Do not go to slow mode and back to fast in initializer
blocks.
Port r12534 (4acfb92e)
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10905313
Patch from Akos Palfi <[email protected]>.
http://code.google.com/p/v8/source/detail?r=12539
Modified:
/branches/bleeding_edge/src/mips/full-codegen-mips.cc
/branches/bleeding_edge/src/mips/macro-assembler-mips.cc
/branches/bleeding_edge/src/mips/macro-assembler-mips.h
=======================================
--- /branches/bleeding_edge/src/mips/full-codegen-mips.cc Mon Sep 10
01:35:26 2012
+++ /branches/bleeding_edge/src/mips/full-codegen-mips.cc Tue Sep 18
06:40:24 2012
@@ -2759,27 +2759,31 @@
__ Branch(if_false, eq, a2, Operand(t0));
// Look for valueOf symbol in the descriptor array, and indicate false if
- // found. The type is not checked, so if it is a transition it is a false
- // negative.
- __ LoadInstanceDescriptors(a1, t0, a3);
- __ lw(a3, FieldMemOperand(t0, FixedArray::kLengthOffset));
- // t0: descriptor array
- // a3: length of descriptor array
- // Calculate the end of the descriptor array.
+ // found. Since we omit an enumeration index check, if it is added via a
+ // transition that shares its descriptor array, this is a false positive.
+ Label entry, loop, done;
+
+ // Skip loop if no descriptors are valid.
+ __ NumberOfOwnDescriptors(a3, a1);
+ __ Branch(&done, eq, a3, Operand(zero_reg));
+
+ __ LoadInstanceDescriptors(a1, t0, a2);
+ // t0: descriptor array.
+ // a3: valid entries in the descriptor array.
STATIC_ASSERT(kSmiTag == 0);
STATIC_ASSERT(kSmiTagSize == 1);
STATIC_ASSERT(kPointerSize == 4);
- __ Addu(a2, t0, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+ __ li(at, Operand(DescriptorArray::kDescriptorSize));
+ __ Mult(a3, at);
+ // Calculate location of the first key name.
+ __ Addu(t0, t0, Operand(DescriptorArray::kFirstOffset - kHeapObjectTag));
+ // Calculate the end of the descriptor array.
+ __ mov(a2, t0);
__ sll(t1, a3, kPointerSizeLog2 - kSmiTagSize);
__ Addu(a2, a2, t1);
- // Calculate location of the first key name.
- __ Addu(t0,
- t0,
- Operand(DescriptorArray::kFirstOffset - kHeapObjectTag));
// Loop through all the keys in the descriptor array. If one of these is
the
// symbol valueOf the result is false.
- Label entry, loop;
// The use of t2 to store the valueOf symbol asumes that it is not
otherwise
// used in the loop below.
__ LoadRoot(t2, Heap::kvalue_of_symbolRootIndex);
@@ -2791,7 +2795,8 @@
__ bind(&entry);
__ Branch(&loop, ne, t0, Operand(a2));
- // If a valueOf property is not found on the object check that it's
+ __ bind(&done);
+ // If a valueOf property is not found on the object check that its
// prototype is the un-modified String prototype. If not result is false.
__ lw(a2, FieldMemOperand(a1, Map::kPrototypeOffset));
__ JumpIfSmi(a2, if_false);
=======================================
--- /branches/bleeding_edge/src/mips/macro-assembler-mips.cc Fri Aug 31
02:50:27 2012
+++ /branches/bleeding_edge/src/mips/macro-assembler-mips.cc Tue Sep 18
06:40:24 2012
@@ -5299,18 +5299,35 @@
Register temp = descriptors;
lw(temp, FieldMemOperand(map, Map::kTransitionsOrBackPointerOffset));
- Label ok, fail;
+ Label ok, fail, load_from_back_pointer;
CheckMap(temp,
scratch,
isolate()->factory()->fixed_array_map(),
&fail,
DONT_DO_SMI_CHECK);
- lw(descriptors, FieldMemOperand(temp,
TransitionArray::kDescriptorsOffset));
+ lw(temp, FieldMemOperand(temp,
TransitionArray::kDescriptorsPointerOffset));
+ lw(descriptors, FieldMemOperand(temp,
JSGlobalPropertyCell::kValueOffset));
jmp(&ok);
+
bind(&fail);
+ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+ Branch(&load_from_back_pointer, ne, temp, Operand(scratch));
LoadRoot(descriptors, Heap::kEmptyDescriptorArrayRootIndex);
+ jmp(&ok);
+
+ bind(&load_from_back_pointer);
+ lw(temp, FieldMemOperand(temp, Map::kTransitionsOrBackPointerOffset));
+ lw(temp, FieldMemOperand(temp,
TransitionArray::kDescriptorsPointerOffset));
+ lw(descriptors, FieldMemOperand(temp,
JSGlobalPropertyCell::kValueOffset));
+
bind(&ok);
}
+
+
+void MacroAssembler::NumberOfOwnDescriptors(Register dst, Register map) {
+ lbu(dst, FieldMemOperand(map, Map::kBitFieldOffset));
+ DecodeField<Map::NumberOfOwnDescriptorsBits>(dst);
+}
void MacroAssembler::EnumLength(Register dst, Register map) {
=======================================
--- /branches/bleeding_edge/src/mips/macro-assembler-mips.h Fri Aug 31
02:50:27 2012
+++ /branches/bleeding_edge/src/mips/macro-assembler-mips.h Tue Sep 18
06:40:24 2012
@@ -1400,7 +1400,15 @@
Register descriptors,
Register scratch);
void EnumLength(Register dst, Register map);
+ void NumberOfOwnDescriptors(Register dst, Register map);
+ template<typename Field>
+ void DecodeField(Register reg) {
+ static const int shift = Field::kShift;
+ static const int mask = (Field::kMask >> shift) << kSmiTagSize;
+ srl(reg, reg, shift);
+ And(reg, reg, Operand(mask));
+ }
// Activation support.
void EnterFrame(StackFrame::Type type);
--
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