Updated asm_v2 to support jump instructions to addresses greater than 2048

[mmdiego]

Updated asm_v2 to support jump instructions (jump, call, conditional jump, close loop, wait, end) to addresses greater than 2048. Jump instructions with an immediate argument limit the argument to 11 bits; if the target label is more than 2048 lines into the program, the target address needs to be stored in a scratch register.

Since the program address of a label is not known until after macro expansion, and since replacing a jump-to-immediate with a jump-to-register adds an instruction, deciding which type of jump instruction to use needs to happen after macro expansion and needs to be done iteratively. This PR doesn't do that, and instead uses jump-to-register everywhere if the tProc program memory is more than 2048 words (in other words, if there is any possibility of exceeding the jump-to-immediate limit, whether or not that's actually happening). This adds extra instructions and execution time, but the impact should be negligible for typical programs.

We'll do this correctly later.

[meeg]

At first glance . . . it looks like the if prog.p_addr >= 2**11: tests check whether the jump instruction is past line 2048, right? But the important test is whether the target label is past line 2048, isn't it?

[mmdiego]

At first glance . . . it looks like the if prog.p_addr >= 2**11: tests check whether the jump instruction is past line 2048, right? But the important test is whether the target label is past line 2048, isn't it?

Yes, I think you are right, I wanted to add a check to avoid using always the register (that was my first approach) I'll see if I can change it.

[mmdiego]

Replaced if prog.p_addr >= 2**11 with if prog.tproccfg['pmem_size'] > 2**11

We'll go with this solution for now and see if it can be improved later