Changeset 165362 in webkit for trunk/Source/JavaScriptCore/jit/GPRInfo.h

Timestamp:

Mar 9, 2014, 11:57:13 PM (11 years ago)

Author:

[email protected]

Message:

GPRInfo::toIndex should return InvalidIndex for non-temp registers on ARM64
​https://bugs.webkit.org/show_bug.cgi?id=129998

Reviewed by Geoffrey Garen.

Not only is that the established contract, but this is used to signal to
ScratchRegisterAllocator that the register doesn't need locking since it isn't a register
that this allocator would use. In the FTL, we may have an inline cache where LLVM had used
some non-temp register (i.e. a register that JSC itself wouldn't have used). This is totally
fine but previously it would have led to either an assertion failure, or data corruption, in
the ScratchRegisterAllocator.

• jit/GPRInfo.h:

(JSC::GPRInfo::toIndex):

File:

• trunk/Source/JavaScriptCore/jit/GPRInfo.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/jit/GPRInfo.h

@@ -1 +1 @@
 /*
- * Copyright (C) 2011, 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2011, 2013, 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -602 +602 @@
     static unsigned toIndex(GPRReg reg)
     {
+        if (reg > regT15)
+            return InvalidIndex;
         return (unsigned)reg;
     }