Add initial lexer and parser support for shifting values. Every use of this

will lead to it being rejected though.

llvm-svn: 21335

utils/TableGen/FileLexer.l

@@ -195,6 +195,11 @@ field          { return FIELD; }
 let            { return LET; }
 in             { return IN; }
 
+!sra           { return SRATOK; }
+!srl           { return SRLTOK; }
+!shl           { return SHLTOK; }
+
+
 {Identifier}   { Filelval.StrVal = new std::string(yytext, yytext+yyleng);
                  return ID; }
 ${Identifier}  { Filelval.StrVal = new std::string(yytext+1, yytext+yyleng);

utils/TableGen/FileParser.y

@@ -189,6 +189,7 @@ using namespace llvm;
 };
 
 %token INT BIT STRING BITS LIST CODE DAG CLASS DEF FIELD LET IN
+%token SHLTOK SRATOK SRLTOK
 %token <IntVal>      INTVAL
 %token <StrVal>      ID VARNAME STRVAL CODEFRAGMENT
 
@@ -308,6 +309,24 @@ Value : INTVAL {
       exit(1);
     }
     delete $3;
+  } | SHLTOK '(' Value ',' Value ')' {
+    $$ = $3->getBinaryOp(Init::SHL, $5);
+    if ($$ == 0) {
+      err() << "Cannot shift values '" << *$3 << "' and '" << *$5 << "'!\n";
+      exit(1);
+    }
+  } | SRATOK '(' Value ',' Value ')' {
+    $$ = $3->getBinaryOp(Init::SRA, $5);
+    if ($$ == 0) {
+      err() << "Cannot shift values '" << *$3 << "' and '" << *$5 << "'!\n";
+      exit(1);
+    }
+  } | SRLTOK '(' Value ',' Value ')' {
+    $$ = $3->getBinaryOp(Init::SRL, $5);
+    if ($$ == 0) {
+      err() << "Cannot shift values '" << *$3 << "' and '" << *$5 << "'!\n";
+      exit(1);
+    }
   };
 
 OptVarName : /* empty */ {

utils/TableGen/Record.h

@@ -463,6 +463,11 @@ struct Init {
   virtual Init *getFieldInit(Record &R, const std::string &FieldName) const {
     return 0;
   }
+  
+  enum BinaryOp { SHL, SRA, SRL };
+  virtual Init *getBinaryOp(BinaryOp Op, Init *RHS) {
+    return 0;
+  }
 
   /// resolveReferences - This method is used by classes that refer to other
   /// variables which may not be defined at the time they expression is formed.