Changeset 261050 in webkit

Timestamp:

May 2, 2020, 10:03:42 AM (5 years ago)

Author:

mark.lam@apple.com

Message:

Allow Bitmap to use up to a UCPURegister word size for internal bit storage.
​https://bugs.webkit.org/show_bug.cgi?id=211328
<rdar://problem/62755865>

Reviewed by Yusuke Suzuki.

Source/JavaScriptCore:

• assembler/CPU.h:

Source/WTF:

1. Moved the definition of CPURegister and UCPURegister down into WTF.
2. Updated Bitmap so that it will automatically choose the minimal required word size for the number of bits it needs to store. This means the Bitmap can automatically choose a WordType from uint8_t up to UCPURegister. Previously, the WordType is always uint32_t by default.

This should improve perf with use of Bitmap on 64-bit platforms. The size
optimization is necessary to prevent bloat on 64-bit platforms which would have
resulted if we simply set the default to always be UCPURegister.

• WTF.xcodeproj/project.pbxproj:
• wtf/Bitmap.h:
• wtf/CMakeLists.txt:
• wtf/StdIntExtras.h: Added.

Location:

trunk/Source

Files:

• JavaScriptCore/ChangeLog (modified) (1 diff)
• JavaScriptCore/assembler/CPU.h (modified) (2 diffs)
• WTF/ChangeLog (modified) (1 diff)
• WTF/WTF.xcodeproj/project.pbxproj (modified) (2 diffs)
• WTF/wtf/Bitmap.h (modified) (2 diffs)
• WTF/wtf/CMakeLists.txt (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2020-05-01  Mark Lam  <mark.lam@apple.com>
+
+        Allow Bitmap to use up to a UCPURegister word size for internal bit storage.
+        https://bugs.webkit.org/show_bug.cgi?id=211328
+        <rdar://problem/62755865>
+
+        Reviewed by Yusuke Suzuki.
+
+        * assembler/CPU.h:
+
 2020-05-01  Saam Barati  <sbarati@apple.com>
 

trunk/Source/JavaScriptCore/assembler/CPU.h

@@ -1 +1 @@
 /*
- * Copyright (C) 2008-2019 Apple Inc. All rights reserved.
+ * Copyright (C) 2008-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -28 +28 @@
 #include "Options.h"
 #include <wtf/NumberOfCores.h>
+#include <wtf/StdIntExtras.h>
 
 namespace JSC {
-
-#if USE(JSVALUE64)
-using CPURegister = int64_t;
-using UCPURegister = uint64_t;
-#else
-using CPURegister = int32_t;
-using UCPURegister = uint32_t;
-#endif
 
 using UCPUStrictInt32 = UCPURegister;

trunk/Source/WTF/ChangeLog

@@ +1 @@
+2020-05-01  Mark Lam  <mark.lam@apple.com>
+
+        Allow Bitmap to use up to a UCPURegister word size for internal bit storage.
+        https://bugs.webkit.org/show_bug.cgi?id=211328
+        <rdar://problem/62755865>
+
+        Reviewed by Yusuke Suzuki.
+
+        1. Moved the definition of CPURegister and UCPURegister down into WTF.
+        2. Updated Bitmap so that it will automatically choose the minimal required
+           word size for the number of bits it needs to store.  This means the Bitmap
+           can automatically choose a WordType from uint8_t up to UCPURegister.
+           Previously, the WordType is always uint32_t by default.
+
+        This should improve perf with use of Bitmap on 64-bit platforms.  The size
+        optimization is necessary to prevent bloat on 64-bit platforms which would have
+        resulted if we simply set the default to always be UCPURegister.
+
+        * WTF.xcodeproj/project.pbxproj:
+        * wtf/Bitmap.h:
+        * wtf/CMakeLists.txt:
+        * wtf/StdIntExtras.h: Added.
+
 2020-05-01  Saam Barati  <sbarati@apple.com>
 

trunk/Source/WTF/WTF.xcodeproj/project.pbxproj

@@ -752 +752 @@
                 FE86A8741E59440200111BBF /* ForbidHeapAllocation.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ForbidHeapAllocation.h; sourceTree = "<group>"; };
                 FE8925AF1D00DAEC0046907E /* Indenter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = Indenter.h; sourceTree = "<group>"; };
+                FE97F6A8245CE5DD00C63FC6 /* StdIntExtras.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = StdIntExtras.h; sourceTree = "<group>"; };
                 FEB6B035201BE0B600B958C1 /* PointerPreparations.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = PointerPreparations.h; sourceTree = "<group>"; };
                 FEDACD3B1630F83F00C69634 /* StackStats.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = StackStats.cpp; sourceTree = "<group>"; };
@@ -1235 +1236 @@
                                 313EDEC9778E49C9BEA91CFC /* StackTrace.cpp */,
                                 EF7D6CD59D8642A8A0DA86AD /* StackTrace.h */,
+                                FE97F6A8245CE5DD00C63FC6 /* StdIntExtras.h */,
                                 A8A47311151A825B004123FF /* StdLibExtras.h */,
                                 FF0A436588954F3CB07DBECA /* StdList.h */,

trunk/Source/WTF/wtf/Bitmap.h

@@ -1 +1 @@
 /*
- *  Copyright (C) 2010-2019 Apple Inc. All rights reserved.
+ *  Copyright (C) 2010-2020 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
@@ -23 +23 @@
 #include <wtf/Atomics.h>
 #include <wtf/HashFunctions.h>
+#include <wtf/StdIntExtras.h>
 #include <wtf/StdLibExtras.h>
-#include <stdint.h>
 #include <string.h>
+#include <type_traits>
 
 namespace WTF {
 
-template<size_t bitmapSize, typename WordType = uint32_t>
+template<size_t size>
+using BitmapWordType = std::conditional_t<(size <= 32 && sizeof(UCPURegister) > sizeof(uint32_t)), uint32_t, UCPURegister>;
+
+template<size_t bitmapSize, typename WordType = BitmapWordType<bitmapSize>>
 class Bitmap final {
     WTF_MAKE_FAST_ALLOCATED;
     
-    static_assert(sizeof(WordType) <= sizeof(unsigned), "WordType must not be bigger than unsigned");
+    static_assert(sizeof(WordType) <= sizeof(UCPURegister), "WordType must not be bigger than the CPU atomic word size");
 public:
     constexpr Bitmap();

trunk/Source/WTF/wtf/CMakeLists.txt

@@ -239 +239 @@
     StackStats.h
     StackTrace.h
+    StdIntExtras.h
     StdLibExtras.h
     StdList.h