The Postfix reference guide contains information about the structure and operations of the stack machine.
The original stack machine was created by Santos (2004). Is was composed by a set of macros to be used with printf functions. Each macro would “take” as arguments, either a number or a string. This was a simple and effective approach but was limited in its expressiveness.
The current postfix code generator class maintains the stack machine abstraction, but does not rely on macros. Instead, it defines an interface to be used by semantic analysers, as defined by a strategy pattern (Gamma et al., 1995). Specific implementations provide the realization of the postfix commands for a particular target machine. Since it is written in C++, it's very easy to extend to new needs and implementations (new target machines).
The following groups of operations are available in the Postfix interface:
text data rodata bss align label extrn globl const str char id byte double
addr addra addrv local loca locv load load2 ldchr store store2 stchr alloc dup swap push dpush pop dpop int sp
add dadd sub dsub mul dmul div ddiv neg dneg mod gt ge lt le eq ne dcmp d2i d2f i2d f2d incr decr
rotl rotr shtl shtru shtrs and or not xor
call ret start enter leave trash jmp jz jnz branch leap nil nop