When ICS came out, there were several new extended-width bytecodes introduced. Most of these were for instructions to support jumbo ids. Here are some of these new instructions, taken from my ics/dalvik/opcode-gen/bytecode.txt:
# # Extended-width opcodes # op 00ff const-class/jumbo 41c y type-ref continue|throw op 01ff check-cast/jumbo 41c n type-ref continue|throw op 02ff instance-of/jumbo 52c y type-ref continue|throw op 03ff new-instance/jumbo 41c y type-ref continue|throw op 04ff new-array/jumbo 52c y type-ref continue|throw op 05ff filled-new-array/jumbo 5rc n type-ref continue|throw op 06ff iget/jumbo 52c y field-ref continue|throw ...
However, on the JB code, I can't find any reference to these new bytecodes. In my jellybean version of bytecodes.txt, the last opcode ends in 0xfe:
op fc +iput-object-volatile 22c n field-ref optimized|continue|throw op fd +sget-object-volatile 21c y field-ref optimized|continue|throw op fe +sput-object-volatile 21c n field-ref optimized|continue|throw # unused: op ff
Are these new instructions not supported on JellyBean?
Also, I can't even seem to find the original dalvik bytecode documentation in jellybean. This is the dir listing of my dalvik/docs folder:
$ ls -a dalvik/docs | cat . .. dalvik-constraints.css dalvik-constraints.html debugger.html debugmon.html dexopt.html embedded-vm-control.html heap-profiling.html hello-world.html java-bytecode.css java-bytecode.html java-constraints.css java-constraints.html porting-guide.html porting-proto.c.txt prettify.css prettify.js verifier.html
Or, maybe, I just downloaded from the wrong branch? I'm using the jb-4.1.1_r4 branch.Answer1:
I implemented the
dx side of these new instructions before leaving Google, but the runtime side of them had yet to be done. I guess nobody ever finished the work, but left the spec docs alone.