Romeo Intermediate Language Specification

Author....... Kevin P. Albrecht
Version...... 1.00
Date......... 4 Feb 2004

General

- all programs must end with 'stop'
- in this document, guarantees by the parser are in
  square brackets

Operations

Special

nop
line            number: (line number), a: (filename)
jump            a: (statement index number)
stop

cond            a: (boolean), b: (jump to if a<>0), c: (jump to if a=0)
                TYPE(a): int, rat

call            a: (jump to)
                pushes return address on call stack
ret             jump to address on top of call stack

asc             a: destination string
                b: integer value to convert to the ASCII character of

rand            a: destination to place randomly generated integer

Type Conversion

- converts puts converted value of 'b' into 'a'
- 'xir' means int->rat

xir
xis
xri
xrs
xsi
xsr

Assignment

set             a: b                  TYPE: int, rat, str

Stack

- stack calls are typesafe

pushl           local_stack << a      TYPE: int, rat, str
popl            local_stack >> a      TYPE: int, rat, str
pushr           return_stack << a     TYPE: int, rat, str
popr            return_stack >> a     TYPE: int, rat, str

Unary Arithmetic

neg             a: -b                 TYPE: int, rat; [ a.type == b.type ]

Binary Arithmetic

add             a: b + c              TYPE: int, rat
sub             a: b - c              TYPE: int, rat
mult            a: b * c              TYPE: int, rat
div             a: b / c              TYPE: int, rat
pow             a: b ^ c              TYPE: int, rat; a.type == b.type
mod             a: b mod c            TYPE: int

eq              a: b = c              TYPE: int, rat
neq             a: b <> c             TYPE: int, rat
lt              a: b < c              TYPE: int, rat
gt              a: b > c              TYPE: int, rat
lteq            a: b <= c             TYPE: int, rat
gteq            a: b >= c             TYPE: int, rat

or              a: b or c             TYPE: int, rat
and             a: b and c            TYPE: int, rat

Unary Arithmetic

cat             a: b (concatenate) c  TYPE: str
seq             a: b = c              TYPE: str
sneq            a: b <> c             TYPE: str

Console

cin             a: (input)            TYPE: int, rat, str
  - loops until non-blank line is input.
cout            (output): a           TYPE: int, rat, str
  - does not output a newline character by default.

File Input/Output

fio IO_TYPE:int B C

  IO_TYPE   OPERATION     B                   C 
  -------   -----------   -----------------   --------------
  0         open input    dest handle (int)   filename (str)
  1         open output   dest handle (int)   filename (str)
  2         close         handle (int)        NULL
  3         read          handle (int)        dest line (str)
  4         write         handle (int)        line (str)