Changeset 172853 in webkit for trunk/Source/JavaScriptCore/bytecode

Timestamp:

Aug 21, 2014, 10:30:02 PM (11 years ago)

Author:

[email protected]

Message:

r171362 accidentally increased the size of InlineCallFrame.
<​https://webkit.org/b/136141>

Reviewed by Filip Pizlo.

r171362 increased the size of InlineCallFrame::kind to 2 bits. This increased
the size of InlineCallFrame from 72 to 80 though not intentionally. The fix
is to reduce the size of InlineCallFrame::stackOffset to 29 bits.

Also added an assert to ensure that we never set a value that exceeds the size
of InlineCallFrame::stackOffset.

• bytecode/CodeOrigin.h:

(JSC::InlineCallFrame::setStackOffset):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::InlineStackEntry::InlineStackEntry):

File:

• trunk/Source/JavaScriptCore/bytecode/CodeOrigin.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/bytecode/CodeOrigin.h

@@ -160 +160 @@
     CodeOrigin caller;
     BitVector capturedVars; // Indexed by the machine call frame's variable numbering.
-    signed stackOffset : 30;
+
+    signed stackOffset : 29;
     unsigned kind : 2; // real type is Kind
     bool isClosureCall : 1; // If false then we know that callee/scope are constants and the DFG won't treat them as variables, i.e. they have to be recovered manually.
@@ -198 +199 @@
     CodeBlock* baselineCodeBlock() const;
     
+    void setStackOffset(signed offset)
+    {
+        stackOffset = offset;
+        RELEASE_ASSERT(static_cast<signed>(stackOffset) == offset);
+    }
+
     ptrdiff_t callerFrameOffset() const { return stackOffset * sizeof(Register) + CallFrame::callerFrameOffset(); }
     ptrdiff_t returnPCOffset() const { return stackOffset * sizeof(Register) + CallFrame::returnPCOffset(); }