Revision: 12035
Author: [email protected]
Date: Tue Jul 10 06:33:19 2012
Log: Port r11344 (Try aligning unboxed double array backing store in
allocation or
scavenge promotion.) to ARM.
BUG=none
TEST=none
Review URL: https://chromiumcodereview.appspot.com/10696097
Patch from Rodolph Perfetta <[email protected]>.
http://code.google.com/p/v8/source/detail?r=12035
Modified:
/branches/bleeding_edge/src/arm/codegen-arm.cc
=======================================
--- /branches/bleeding_edge/src/arm/codegen-arm.cc Wed May 23 07:24:29 2012
+++ /branches/bleeding_edge/src/arm/codegen-arm.cc Tue Jul 10 06:33:19 2012
@@ -121,15 +121,34 @@
// r5: number of elements (smi-tagged)
// Allocate new FixedDoubleArray.
- __ mov(lr, Operand(FixedDoubleArray::kHeaderSize));
- __ add(lr, lr, Operand(r5, LSL, 2));
+ // Use lr as a temporary register.
+ __ mov(lr, Operand(r5, LSL, 2));
+ __ add(lr, lr, Operand(FixedDoubleArray::kHeaderSize + kPointerSize));
__ AllocateInNewSpace(lr, r6, r7, r9, &gc_required, NO_ALLOCATION_FLAGS);
- // r6: destination FixedDoubleArray, not tagged as heap object
+ // r6: destination FixedDoubleArray, not tagged as heap object.
+
+ // Align the array conveniently for doubles.
+ // Store a filler value in the unused memory.
+ Label aligned, aligned_done;
+ __ tst(r6, Operand(kDoubleAlignmentMask));
+ __ mov(ip,
Operand(masm->isolate()->factory()->one_pointer_filler_map()));
+ __ b(eq, &aligned);
+ // Store at the beginning of the allocated memory and update the base
pointer.
+ __ str(ip, MemOperand(r6, kPointerSize, PostIndex));
+ __ b(&aligned_done);
+
+ __ bind(&aligned);
+ // Store the filler at the end of the allocated memory.
+ __ sub(lr, lr, Operand(kPointerSize));
+ __ str(ip, MemOperand(r6, lr));
+
+ __ bind(&aligned_done);
+
// Set destination FixedDoubleArray's length and map.
__ LoadRoot(r9, Heap::kFixedDoubleArrayMapRootIndex);
__ str(r5, MemOperand(r6, FixedDoubleArray::kLengthOffset));
- __ str(r9, MemOperand(r6, HeapObject::kMapOffset));
// Update receiver's map.
+ __ str(r9, MemOperand(r6, HeapObject::kMapOffset));
__ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
__ RecordWriteField(r2,
--
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