"Name"     = 'Enter the name of the grammar'
"Author"   = 'Enter your name'
"Version"  = 'The version of the grammar and/or language'
"About"    = 'A short description of the grammar'

"Start Symbol" = <Start>

! -------------------------------------------------
! Character Sets
! -------------------------------------------------

{WS}           = {Whitespace} - {CR} - {LF}
               
! ===================================================================
! Comments
! ===================================================================

Comment Start = '/*'
Comment End   = '*/'
Comment Line  = ';'    
                 
! -------------------------------------------------
! Terminals
! -------------------------------------------------

! The following defines the Whitespace terminal using the {WS}
! set - which excludes the carriage return and line feed 
! characters

Whitespace    = {WS}+
NewLine       = {CR}{LF}|{CR} 


Opcode        = nop
OpcodeCBA     = moveh|add|sub|and|or|xor|bic|asr|lsr|lsl|fadd_fead|fsub_fead|fmul_fead|fdiv_fead|mul_fead
OpcodeBA      = cmplo|cmplos|cmple|cmples|rqld|rqldw|jmp|cmpeq|fcmpeq|fcmpne|fcmpgt|fcmpgte|fcmplt|fcmplte|fead  
OpcodeBAS     = st|stw  
OpcodeCA      = move|gpc
OpcodeCB      = fsqrt_fead|fitof_fead|fftoi_fead|fabs_fead
OpcodeA       = br
OpcodeC       = ld|ldw|ldws|mul|fadd|fsub|fmul|fdiv|fsqrt|fitof|fftoi|fabs                          
             
Cc            = ev|ts|tc|ne
Command       = word|org          
    
Comma         = [,]                          
Register      = ([r]|[R])[012345678]+              
Identifier    = {Letter}{Letter}{AlphaNumeric}*      
Integer       = [0123456789]+                             
HexInteger    = [$][0123456789ABDEFabcdef]+  
BinInteger    = [%][01]+ 
                            
! -------------------------------------------------
! Rules
! -------------------------------------------------
   
<Start>   ::= <Lines>

<Lines>   ::= <Line> <Lines>
           
<Label>   ::= Identifier
         
<Line>    ::= <Statement> NewLine
           | NewLine
  
<Immidiate> ::= <Expression> 
              
<Expression>   ::= <Expression> '+' <Mult Exp> 
                 | <Expression> '-' <Mult Exp> 
                 | <Expression> '&' <Mult Exp> 
                 | <Expression> '|' <Mult Exp> 
                 | <Mult Exp> 

<Mult Exp>    ::= <Mult Exp> '*' <Negate Exp> 
                | <Mult Exp> '/' <Negate Exp> 
                | <Negate Exp> 

<Shr>         ::= '>' <Shr>
                |
                
<Negate Exp>  ::= '-' <Value> 
                | <Shr> <Value> 
                | <Value> 

<Value>       ::= Integer
                | HexInteger 
                | BinInteger
                | <Label>
                | '(' <Expression> ')'
             
<Statement> ::= <Label> 
              | <Label> <Operation>
              | <Operation> 
              
<Condition> ::= '.' Cc
              |
              
<Operation>   ::= OpcodeCBA <Condition> <Destination> Comma <Source B> Comma <Source A> !cba
                | OpcodeBA  <Condition> <Source B> Comma <Source A> !ba
                | OpcodeBAS  <Condition> <Source B> Comma <Source A> Comma <Value> !bas
                | OpcodeCA  <Condition> <Destination> Comma <Source A> !ca
                | OpcodeCB  <Condition> <Destination> Comma <Source B> !cb
                | OpcodeA   <Condition> <Source A> !a
                | OpcodeC   <Condition> <Destination> !c
                | Opcode    <Condition> !no param
                | Command   <Immidiate>
                
<Destination> ::= Register
                | 'hold'

<Source B>    ::= Register
                | 'last'
                
<Source A>    ::= Register
                | <Immidiate>