Changeset 286856 in webkit

Timestamp:

Dec 10, 2021, 9:25:22 AM (5 years ago)

Author:

Tadeu Zagallo

Message:

Remove Mac-specific ARM64EHash implementation
​https://bugs.webkit.org/show_bug.cgi?id=234150

Reviewed by Saam Barati.

Currently we have a weaker implementation of ARM64EHash on mac, but we measured it and it's not
any faster than the stricter version we use on iOS. We are removing the mac-specific version and
switching it to use the stricter version.

• assembler/AssemblerBuffer.h:

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• assembler/AssemblerBuffer.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2021-12-10  Tadeu Zagallo  <tzagallo@apple.com>
+
+        Remove Mac-specific ARM64EHash implementation
+        https://bugs.webkit.org/show_bug.cgi?id=234150
+
+        Reviewed by Saam Barati.
+
+        Currently we have a weaker implementation of ARM64EHash on mac, but we measured it and it's not
+        any faster than the stricter version we use on iOS. We are removing the mac-specific version and
+        switching it to use the stricter version.
+
+        * assembler/AssemblerBuffer.h:
+
 2021-12-10  Adrian Perez de Castro  <aperez@igalia.com>
 

trunk/Source/JavaScriptCore/assembler/AssemblerBuffer.h

@@ -204 +204 @@
 
 #if CPU(ARM64E)
-#if PLATFORM(MAC)
-    class ARM64EHash {
-    public:
-        ARM64EHash(void* initialHash)
-            : m_hash(static_cast<uint32_t>(bitwise_cast<uintptr_t>(initialHash)))
-        {
-        }
-
-        ALWAYS_INLINE uint32_t update(uint32_t value, uint32_t, void*)
-        {
-            uint64_t input = value ^ m_hash;
-            uint64_t a = static_cast<uint32_t>(tagInt(input, static_cast<PtrTag>(0)) >> 39);
-            uint64_t b = tagInt(input, static_cast<PtrTag>(0xb7e151628aed2a6a)) >> 23;
-            m_hash = a ^ b;
-            return m_hash;
-        }
-
-    private:
-        uint32_t m_hash;
-    };
-#else
     class ARM64EHash {
     public:
@@ -281 +260 @@
         uint64_t m_hash;
     };
-#endif // PLATFORM(MAC)
 #endif // CPU(ARM64E)