Windows currently uses the demand based executable allocator. Using the demand based allocator can result in executable memory in various parts of the address space. Currently, the JSC JITs expect that all JIT'ed addresses is within a 32 bit offset of each other. The demand executable allocator cannot provide such a guarantee, therefore Windows X86-64 should use the fixed allocator like the rest of the X86-64 platforms. <rdar://problem/19804738>
Created attachment 248750 [details] Patch
Looks like the Windows implementation of the fixed allocator is not complete. More work to do.
Created attachment 248780 [details] Updated patch
Comment on attachment 248780 [details] Updated patch Clearing flags on attachment: 248780 Committed r181628: <http://trac.webkit.org/changeset/181628>
All reviewed patches have been landed. Closing bug.