Reviewers: Yang, danno,
Message:
Hi Yang - Your changes r9747 and r9751, as 2 patches in one issue, since
they
overlapped a bit.
Description:
MIPS: port Refactor and clean up array allocation across platforms.
Port r9747 (dc33375)
BUG=
TEST=
Please review this at http://codereview.chromium.org/8395030/
Affected files:
M src/mips/builtins-mips.cc
Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index
16b6a202ad117d103fbc32f00e6e3a86a8dd60d3..32ac36150d00ce72b7d481502bf7fe138c40c039
100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -88,12 +88,6 @@ static void GenerateLoadArrayFunction(MacroAssembler*
masm, Register result) {
}
-// This constant has the same value as JSArray::kPreallocatedArrayElements
and
-// if JSArray::kPreallocatedArrayElements is changed handling of loop
unfolding
-// below should be reconsidered.
-static const int kLoopUnfoldLimit = 4;
-
-
// Allocate an empty JSArray. The allocated array is put into the result
// register. An elements backing store is allocated with size
initial_capacity
// and filled with the hole values.
@@ -103,9 +97,9 @@ static void AllocateEmptyJSArray(MacroAssembler* masm,
Register scratch1,
Register scratch2,
Register scratch3,
- int initial_capacity,
Label* gc_required) {
- ASSERT(initial_capacity > 0);
+ const int initial_capacity = JSArray::kPreallocatedArrayElements;
+ STATIC_ASSERT(initial_capacity >= 0);
// Load the initial map from the array function.
__ lw(scratch1, FieldMemOperand(array_function,
JSFunction::kPrototypeOrInitialMapOffset));
@@ -155,13 +149,24 @@ static void AllocateEmptyJSArray(MacroAssembler* masm,
__ sw(scratch3, MemOperand(scratch1));
__ Addu(scratch1, scratch1, kPointerSize);
- // Fill the FixedArray with the hole value.
+ // Fill the FixedArray with the hole value. Inline the code if short.
+ if (initial_capacity == 0) return;
ASSERT_EQ(2 * kPointerSize, FixedArray::kHeaderSize);
- ASSERT(initial_capacity <= kLoopUnfoldLimit);
__ LoadRoot(scratch3, Heap::kTheHoleValueRootIndex);
- for (int i = 0; i < initial_capacity; i++) {
+ static const int kLoopUnfoldLimit = 4;
+ if (initial_capacity <= kLoopUnfoldLimit) {
+ for (int i = 0; i < initial_capacity; i++) {
+ __ sw(scratch3, MemOperand(scratch1, i * kPointerSize));
+ }
+ } else {
+ Label loop, entry;
+ __ Addu(scratch2, scratch1, Operand(initial_capacity * kPointerSize));
+ __ Branch(&entry);
+ __ bind(&loop);
__ sw(scratch3, MemOperand(scratch1));
__ Addu(scratch1, scratch1, kPointerSize);
+ __ bind(&entry);
+ __ Branch(&loop, lt, scratch1, Operand(scratch2));
}
}
@@ -177,7 +182,7 @@ static void AllocateEmptyJSArray(MacroAssembler* masm,
// register elements_array_storage is scratched.
static void AllocateJSArray(MacroAssembler* masm,
Register array_function, // Array function.
- Register array_size, // As a smi.
+ Register array_size, // As a smi, cannot be 0.
Register result,
Register elements_array_storage,
Register elements_array_end,
@@ -185,31 +190,17 @@ static void AllocateJSArray(MacroAssembler* masm,
Register scratch2,
bool fill_with_hole,
Label* gc_required) {
- Label not_empty, allocated;
-
// Load the initial map from the array function.
__ lw(elements_array_storage,
FieldMemOperand(array_function,
JSFunction::kPrototypeOrInitialMapOffset));
- // Check whether an empty sized array is requested.
- __ Branch(¬_empty, ne, array_size, Operand(zero_reg));
-
- // If an empty array is requested allocate a small elements array
anyway. This
- // keeps the code below free of special casing for the empty array.
- int size = JSArray::kSize +
- FixedArray::SizeFor(JSArray::kPreallocatedArrayElements);
- __ AllocateInNewSpace(size,
- result,
- elements_array_end,
- scratch1,
- gc_required,
- TAG_OBJECT);
- __ Branch(&allocated);
+ if (FLAG_debug_code) { // Assert that array size is not zero.
+ __ Assert(ne, "array size is unexpectedly 0", array_size,
Operand(zero_reg));
+ }
// Allocate the JSArray object together with space for a FixedArray with
the
// requested number of elements.
- __ bind(¬_empty);
STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
__ li(elements_array_end,
(JSArray::kSize + FixedArray::kHeaderSize) / kPointerSize);
@@ -228,7 +219,6 @@ static void AllocateJSArray(MacroAssembler* masm,
// result: JSObject
// elements_array_storage: initial map
// array_size: size of array (smi)
- __ bind(&allocated);
__ sw(elements_array_storage, FieldMemOperand(result,
JSObject::kMapOffset));
__ LoadRoot(elements_array_storage, Heap::kEmptyFixedArrayRootIndex);
__ sw(elements_array_storage,
@@ -262,8 +252,6 @@ static void AllocateJSArray(MacroAssembler* masm,
// the actual JSArray has length 0 and the size of the JSArray for
non-empty
// JSArrays. The length of a FixedArray is stored as a smi.
STATIC_ASSERT(kSmiTag == 0);
- __ li(at, Operand(Smi::FromInt(JSArray::kPreallocatedArrayElements)));
- __ movz(array_size, at, array_size);
ASSERT_EQ(1 * kPointerSize, FixedArray::kLengthOffset);
__ sw(array_size, MemOperand(elements_array_storage));
@@ -312,18 +300,18 @@ static void AllocateJSArray(MacroAssembler* masm,
static void ArrayNativeCode(MacroAssembler* masm,
Label* call_generic_code) {
Counters* counters = masm->isolate()->counters();
- Label argc_one_or_more, argc_two_or_more;
+ Label argc_one_or_more, argc_two_or_more, not_empty_array, empty_array;
// Check for array construction with zero arguments or one.
__ Branch(&argc_one_or_more, ne, a0, Operand(zero_reg));
// Handle construction of an empty array.
+ __ bind(&empty_array);
AllocateEmptyJSArray(masm,
a1,
a2,
a3,
t0,
t1,
- JSArray::kPreallocatedArrayElements,
call_generic_code);
__ IncrementCounter(counters->array_function_native(), 1, a3, t0);
// Setup return value, remove receiver from stack and return.
@@ -338,6 +326,12 @@ static void ArrayNativeCode(MacroAssembler* masm,
STATIC_ASSERT(kSmiTag == 0);
__ lw(a2, MemOperand(sp)); // Get the argument from the stack.
+ __ Branch(¬_empty_array, ne, a2, Operand(zero_reg));
+ __ Drop(1); // Adjust stack.
+ __ mov(a0, zero_reg); // Treat this as a call with argc of zero.
+ __ Branch(&empty_array);
+
+ __ bind(¬_empty_array);
__ And(a3, a2, Operand(kIntptrSignBit | kSmiTagMask));
__ Branch(call_generic_code, eq, a3, Operand(zero_reg));
--
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