The only X86-64 instructions for storing to, or loading from, 64-bit absolute immediate addresses require that the source of the store (or the target of the load) is EAX. If the X86-64 assembler in JSC is asked to emit code for storing, or loading, an absolute immediate address where the register containing the value is not EAX, it will emit two additional instructions to swap values between EAX and the requested register. This is not as efficient as simply moving the 64-bit address into the assembler's scratch register, which would result in two instructions.
Created attachment 101850 [details] the patch
Comment on attachment 101850 [details] the patch Clearing flags on attachment: 101850 Committed r91678: <http://trac.webkit.org/changeset/91678>
All reviewed patches have been landed. Closing bug.