Difference between revisions of "GenAsm (language)"

From Mill Computing Wiki
Jump to: navigation, search
m (Added missing semicolons to some of the later expressions, to make it more conformant. The angle-bracket expressions still aren't proper EBNF, though)
Line 67:Line 67:
 
     number        ::=  decimal | hexadecimal | float;
 
     number        ::=  decimal | hexadecimal | float;
 
     decimal        ::=  digit, { digit };
 
     decimal        ::=  digit, { digit };
     hexadecimal    ::=  hexBase, hexDigit, { hexDigit }
+
     hexadecimal    ::=  hexBase, hexDigit, { hexDigit };
     hexBase        ::=  "0x" | "0X"
+
     hexBase        ::=  "0x" | "0X";
     hexDigit      ::=  decDigit | <"a"-"f"> | <"A"-"F">
+
     hexDigit      ::=  decDigit | <"a"-"f"> | <"A"-"F">;
 
     float          ::=  decimal, ".", [decimal], [exponent] |
 
     float          ::=  decimal, ".", [decimal], [exponent] |
                         decimal, ["." [decimal]], exponent
+
                         decimal, ["." [decimal]], exponent;
 
     exponent      ::=  "e", [sign], decimal |
 
     exponent      ::=  "e", [sign], decimal |
                         "E", [sign], decimal
+
                         "E", [sign], decimal;
     sign          ::=  "+" | "-"
+
     sign          ::=  "+" | "-";
 
     comment        ::=  "//", {<char>}, <EOL> | "/*", {<char>}, "*/";
 
     comment        ::=  "//", {<char>}, <EOL> | "/*", {<char>}, "*/";

Revision as of 02:46, 6 January 2015

The genAsm assembly language is a low-level dataflow language for writing programs to be executed on the Mill processors. The language is accepted by the genAsm assembler, which create ELF files suitable as input to the prelinker or specializer. The assembler is intended for use when high-level language compilers are unable to provide a desired access to Mill hardware facilities.

Syntax in EBNF:

  " ... "   terminal keyword or symbol
  ::=       is defined as
  |         alternatives
  [ ... ]   option (zero or one times
  { ... }   repetition (zero or more times)
  ,         sequence (in order left-to-right)
  ;         end of definition
  
   program        ::=  "module", moduleId, serial;
   serial         ::=  [expDef], {";", [expDef]};
   expDef         ::=  expression |
                       definition |
                       join, [expDef];
   definition     ::=  functionDef | labelDef;
   functionDef    ::=  ["inline"], "func", identifier, formals, [results], funcBody;
   funcBody       ::=  ":", expression | "outcall" | "forward";
   formals        ::=  "(", [formal, {",", formal}], ")";
   formal         ::=  widthTag, identifier;
   widthTag       ::=  "b" | "h" | "w" | "d" | "q" | "bv" | "hv" | "wv" | "dv" | "qv";
   results        ::=  widthPack;
   widthPack      ::=  "{", [widthTag, {",", widthTag}], "}";
   labelDef       ::=  "label", [widthPack], identifier, "forward";
   expression     ::=  secondary | 
                       expression, binding | 
                       expression, gang, [secondary] |
                       expression, ["inline"], funcId, [secondary] |
                       expression, join |
                       expression, "?", expression, ":", expression;
   secondary      ::=  primary | 
                       secondary, "(", [expression, {",", expression}], ")"
                       secondary, widthPack;
   primary        ::=  widthTag |
                       [widthTag, ":"] number  | 
                       boundId | 
                       ebbId |
                       ["inline"], funcId | 
                       gang |
                       "(", expression, ")" |
                       "begin", serial, "end" |
                       ifClause;
   binding        ::=  "-:" identifier | 
                       "-:", idenPack;
   idenPack       ::=  "{", identifier, {",", identifier}, "}";
   gang           ::=  opId ["." opId];
   opId           ::=  identifier;
   ebbId          ::=  identifier;
   join           ::=  ebbId, ":";
   ifClause       ::=  "if", predPart, thenPart, {elifPart}, [elsePart], "fi";
   predPart       ::=  serial;
   thenPart       ::=  "then", serial;
   elifPart       ::=  "elif", serial;
   elsePart       ::=  "else", serial;
   boundId        ::=  identifier;
   funcId         ::=  identifier;
   moduleId       ::=  identifier;
   identifier     ::=  [qualification], name;
   qualification  ::=  [qualification], name, "::";
   name           ::=  alpha, {alnum};
   alnum          ::=  decDigit | alpha;
   alpha          ::=  "_" | <"a"-"z"> | <"A"-"Z">;
   decDigit       ::=  <"0"-"9">;
   number         ::=  decimal | hexadecimal | float;
   decimal        ::=  digit, { digit };
   hexadecimal    ::=  hexBase, hexDigit, { hexDigit };
   hexBase        ::=  "0x" | "0X";
   hexDigit       ::=  decDigit | <"a"-"f"> | <"A"-"F">;
   float          ::=  decimal, ".", [decimal], [exponent] |
                       decimal, ["." [decimal]], exponent;
   exponent       ::=  "e", [sign], decimal |
                       "E", [sign], decimal;
   sign           ::=  "+" | "-";
   comment        ::=  "//", {<char>}, <EOL> | "/*", {<char>}, "*/";