Changeset 267221 in webkit

Timestamp:

Sep 17, 2020, 7:06:41 PM (5 years ago)

Author:

mark.lam@apple.com

Message:

Use OS_CONSTANT(EFFECTIVE_ADDRESS_WIDTH) in speculationFromCell()'s isSanePointer().
​https://bugs.webkit.org/show_bug.cgi?id=216638

Reviewed by Saam Barati.

We should be using OS_CONSTANT(EFFECTIVE_ADDRESS_WIDTH) instead of assuming the
width of the pointer address bits.

• bytecode/SpeculatedType.cpp:

(JSC::isSanePointer):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• bytecode/SpeculatedType.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2020-09-17  Mark Lam  <mark.lam@apple.com>
+
+        Use OS_CONSTANT(EFFECTIVE_ADDRESS_WIDTH) in speculationFromCell()'s isSanePointer().
+        https://bugs.webkit.org/show_bug.cgi?id=216638
+
+        Reviewed by Saam Barati.
+
+        We should be using OS_CONSTANT(EFFECTIVE_ADDRESS_WIDTH) instead of assuming the
+        width of the pointer address bits.
+
+        * bytecode/SpeculatedType.cpp:
+        (JSC::isSanePointer):
+
 2020-09-17  Devin Rousso  <drousso@apple.com>
 

trunk/Source/JavaScriptCore/bytecode/SpeculatedType.cpp

@@ -554 +554 @@
 #if CPU(ADDRESS64)
     uintptr_t pointerAsInt = bitwise_cast<uintptr_t>(pointer);
-    uintptr_t canonicalPointerBits = pointerAsInt << 16;
-    uintptr_t nonCanonicalPointerBits = pointerAsInt >> 48;
+    uintptr_t canonicalPointerBits = pointerAsInt << (64 - OS_CONSTANT(EFFECTIVE_ADDRESS_WIDTH));
+    uintptr_t nonCanonicalPointerBits = pointerAsInt >> OS_CONSTANT(EFFECTIVE_ADDRESS_WIDTH);
     return !nonCanonicalPointerBits && canonicalPointerBits;
 #else