[fpc-devel] Some Opcodes missing in internal assembler for mips32r2

Sergei Gorelkin sergei_gorelkin at mail.ru
Tue May 28 21:31:51 CEST 2013

28.05.2013 22:50, Michael Ring пишет:
> I am currently writing/porting startup code for the pic32 chips, the inline assembler of fpc seems
> to lack support for some opcodes, any idea how I can workarround this?
> With grep I found for example mtc1 in opcode.inc, but mtc0 is missing, this opcode is important for
> the initialization of the pic32 chips.
> Is it easy to implement those missing op-codes in the internal assembler, if yes, could some
> fpc-crack give me a hint on what to change where?
Since assembler reader for MIPS is at a very early stage, adding opcodes isn't difficult:

1) Add the opcode enum to mips/opcode.inc and its string representation to mips/strinst.inc.
2) For 'ext' and 'ins' you'll need to add the appropriate overloaded constructor to taicpu class in 
mips/aasmcpu.pas (they are going to be the first opcodes with 4 operands)
3) Modify taicpu.spilling_get_operation_type method (in mips/aasmcpu.pas) to reflect which operands 
are read/written by newly added opcodes.

A more difficult task will be to restrict opcodes to CPU type and operands to opcodes.

> Those are the missing opcodes:
> beqz
> ehb
> ext
> ins
> mfc0
> mtc0
> sdbbp
> wrpgpr
Note that 'beqz reg,label' is just a shorter representation of 'beq  reg,$zero,label', not a 
separate opcode (unlike bgtz/bltz/blez/bgez which are really missing).


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