no 64 bit JIT yet ...

[Steven Parkes]

I guess there's good reason the JIT is turned off in 64 bit builds. From the latest mozilla-central branch (which does have JIT turned on for 64 bits):

smparkes@collegeterrace ~/capybara $ spec spec/driver/envjs_driver_spec.rb
.Assertion failed:

LIR type error (start of writer pipeline):
in instruction with opcode: qeq
in argument 1 with opcode: ld
argument has type int32, expected int64
One way to debug this: change the failing NanoAssertMsgf(0, ...) call to a
printf(...) call and rerun with verbose output. If you're lucky, this error
message will appear before the block containing the erroneous instruction.

: 0 (./nanojit/LIR.cpp:2321)
Aborted