Any changes in code generation since 1.4?

[ggutierrez]

Does the code generation have been updated in version 2.0?. In concrete I would like to know if the same program will be translated to the same set of VM instructions in 1.4 and 2.0 versions.

[sjrd]

There were changes, yes. Most notably because the instruction set is slightly different.
Most of the transformations are clearly visible here:
https://github.com/mozart/mozart2/blob/master/lib/compiler/Assembler.oz#L854

For example:

• There is one more kind of registers: K registers, which are bound to the CodeArea, and basically contain literal constants, or in general any compile-time value spliced into the program (e.g., builtins)
• deallocateL does not exist anymore. Locals are deallocated implicitly on return and tailCall instructions.
• putConstant/setConstant disappeared, since arbitrary constants can be spliced in K registers

There were also changes to the object system. Most notably, self is no special value anymore, it's a normal parameter.

The locking mechanisms were lifted in user space, with methods written in Oz rather than supported by VM instructions.

There might be other stuff I forgot.