webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 51 insertions, 13 deletions

diff --git a/Source/JavaScriptCore/runtime/ArrayConventions.h b/Source/JavaScriptCore/runtime/ArrayConventions.h
index e5ef96336..6aacb978c 100644
--- a/Source/JavaScriptCore/runtime/ArrayConventions.h
+++ b/Source/JavaScriptCore/runtime/ArrayConventions.h
@@ -1,6 +1,6 @@
 /*
  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
- *  Copyright (C) 2003, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
+ *  Copyright (C) 2003, 2007, 2008, 2009, 2012, 2016 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
@@ -18,8 +18,7 @@
  *
  */
 
-#ifndef ArrayConventions_h
-#define ArrayConventions_h
+#pragma once
 
 #include "IndexingHeader.h"
 #include "WriteBarrier.h"
@@ -38,7 +37,7 @@ namespace JSC {
 // (specifically, this is only one property - the value 0xFFFFFFFFU as an unsigned 32-bit
 // integer) are not considered array indices and will be stored in the JSObject property map.
 //
-// All properties with a numeric identifer, representable as an unsigned integer i,
+// All properties with a numeric identifier, representable as an unsigned integer i,
 // where (i <= MAX_ARRAY_INDEX), are an array index and will be stored in either the
 // storage vector or the sparse map. An array index i will be handled in the following
 // fashion:
@@ -58,18 +57,27 @@ namespace JSC {
 
 // These values have to be macros to be used in max() and min() without introducing
 // a PIC branch in Mach-O binaries, see <rdar://problem/5971391>.
+
+// If you grow an ArrayStorage array by more than this, then the array will go sparse. Note that we
+// could probably make this smaller (it's large because it used to be conflated with
+// MIN_ARRAY_STORAGE_CONSTRUCTION_LENGTH).
 #define MIN_SPARSE_ARRAY_INDEX 100000U
+// If you try to allocate a contiguous array larger than this, then we will allocate an ArrayStorage
+// array instead. We allow for an array that occupies 1GB of VM.
+#define MIN_ARRAY_STORAGE_CONSTRUCTION_LENGTH 1024 * 1024 * 1024 / 8
 #define MAX_STORAGE_VECTOR_INDEX (MAX_STORAGE_VECTOR_LENGTH - 1)
 // 0xFFFFFFFF is a bit weird -- is not an array index even though it's an integer.
 #define MAX_ARRAY_INDEX 0xFFFFFFFEU
 
-// The value BASE_VECTOR_LEN is the maximum number of vector elements we'll allocate
+// The value BASE_XXX_VECTOR_LEN is the maximum number of vector elements we'll allocate
 // for an array that was created with a sepcified length (e.g. a = new Array(123))
-#define BASE_VECTOR_LEN 4U
-    
+#define BASE_CONTIGUOUS_VECTOR_LEN 3U
+#define BASE_CONTIGUOUS_VECTOR_LEN_EMPTY 5U
+#define BASE_ARRAY_STORAGE_VECTOR_LEN 4U
+
 // The upper bound to the size we'll grow a zero length array when the first element
 // is added.
-#define FIRST_VECTOR_GROW 4U
+#define FIRST_ARRAY_STORAGE_VECTOR_GROW 4U
 
 #define MIN_BEYOND_LENGTH_SPARSE_INDEX 1000
 
@@ -89,7 +97,7 @@ inline bool indexIsSufficientlyBeyondLengthForSparseMap(unsigned i, unsigned len
     return i >= MIN_BEYOND_LENGTH_SPARSE_INDEX && i > length;
 }
 
-inline IndexingHeader indexingHeaderForArray(unsigned length, unsigned vectorLength)
+inline IndexingHeader indexingHeaderForArrayStorage(unsigned length, unsigned vectorLength)
 {
     IndexingHeader result;
     result.setPublicLength(length);
@@ -97,12 +105,42 @@ inline IndexingHeader indexingHeaderForArray(unsigned length, unsigned vectorLen
     return result;
 }
 
-inline IndexingHeader baseIndexingHeaderForArray(unsigned length)
+inline IndexingHeader baseIndexingHeaderForArrayStorage(unsigned length)
 {
-    return indexingHeaderForArray(length, BASE_VECTOR_LEN);
+    return indexingHeaderForArrayStorage(length, BASE_ARRAY_STORAGE_VECTOR_LEN);
 }
 
-} // namespace JSC
+#if USE(JSVALUE64)
+JS_EXPORT_PRIVATE void clearArrayMemset(WriteBarrier<Unknown>* base, unsigned count);
+JS_EXPORT_PRIVATE void clearArrayMemset(double* base, unsigned count);
+#endif // USE(JSVALUE64)
+
+ALWAYS_INLINE void clearArray(WriteBarrier<Unknown>* base, unsigned count)
+{
+#if USE(JSVALUE64)
+    const unsigned minCountForMemset = 100;
+    if (count >= minCountForMemset) {
+        clearArrayMemset(base, count);
+        return;
+    }
+#endif
+    
+    for (unsigned i = count; i--;)
+        base[i].clear();
+}
 
-#endif // ArrayConventions_h
+ALWAYS_INLINE void clearArray(double* base, unsigned count)
+{
+#if USE(JSVALUE64)
+    const unsigned minCountForMemset = 100;
+    if (count >= minCountForMemset) {
+        clearArrayMemset(base, count);
+        return;
+    }
+#endif
+    
+    for (unsigned i = count; i--;)
+        base[i] = PNaN;
+}
 
+} // namespace JSC