implemented splice operator

acse/Acse.lex

@@ -88,6 +88,8 @@ ID       [a-zA-Z_][a-zA-Z0-9_]*
 "&&"              { return ANDAND; }
 "||"              { return OROR; }
 ","               { return COMMA; }
+"$"               { return DOLLAR; }
+"@"               { return AT; }    
 
 "do"              { return DO; }
 "else"            { return ELSE; }

acse/Acse.y

@@ -129,6 +129,8 @@ t_io_infos *file_infos;    /* input and output files used by the compiler */
 %token <intval> TYPE
 %token <svalue> IDENTIFIER
 %token <intval> NUMBER
+%token <label> DOLLAR
+%token <label> AT
 
 %type <expr> exp
 %type <decl> declaration
@@ -147,6 +149,7 @@ t_io_infos *file_infos;    /* input and output files used by the compiler */
 %left AND_OP
 %left EQ NOTEQ
 %left LT GT LTEQ GTEQ
+%left DOLLAR AT
 %left SHL_OP SHR_OP
 %left MINUS PLUS
 %left MUL_OP DIV_OP
@@ -565,6 +568,53 @@ exp: NUMBER      { $$ = create_expression ($1, IMMEDIATE); }
                                  (program, exp_r0, $2, SUB);
                         }
                      }
+   | exp DOLLAR exp AT exp {
+                    int e_c;
+                    if ($5.expression_type != IMMEDIATE)
+                        yyerror();
+                    if ($5.value < 0)
+                        yyerror();
+                    if ($5.value > 32)
+                        e_c = 0;
+                    else
+                        e_c = 32 - $5.value;
+                    
+                    int r_e2 = gen_load_immediate(program, 0);
+                    int r_index = gen_load_immediate(program, e_c);
+
+                    $4 = newLabel(program);
+                    $2 = assignNewLabel(program);
+                    
+                    gen_beq_instruction(program, $4, 0);
+                    gen_shli_instruction(program, r_e2, r_e2, 1);
+                    gen_addi_instruction(program, r_e2, r_e2, 1);
+                    gen_subi_instruction(program, r_index, r_index, 1);
+                    
+                    gen_bt_instruction(program, $2, 0);
+                    assignLabel(program, $4);
+                    int r_e1 = getNewRegister(program);
+                    gen_notb_instruction(program, r_e1, r_e2);
+
+                    if ($1.expression_type == IMMEDIATE)
+                        gen_andb_instruction(program, r_e1, r_e1,
+                            gen_load_immediate(program, $1.value), 
+                            CG_DIRECT_ALL);
+                    else
+                        gen_andb_instruction(program, r_e1, r_e1, $1.value, 
+                                            CG_DIRECT_ALL);
+                    
+                    if ($3.expression_type == IMMEDIATE)
+                        gen_andb_instruction(program, r_e2, r_e2,
+                            gen_load_immediate(program, $3.value), 
+                            CG_DIRECT_ALL);
+                    else
+                        gen_andb_instruction(program, r_e2, r_e2, $3.value, 
+                                            CG_DIRECT_ALL);
+
+                    gen_orb_instruction(program, r_e1, r_e1, r_e2, 
+                                        CG_DIRECT_ALL);
+                    $$ = create_expression(r_e1, REGISTER);
+                }    
 ;
 
 %%

tests/splice/splice.src

@@ -0,0 +1,8 @@
+int a, b, splice;
+
+read(a);
+read(b);
+
+splice = a $ b @ 16;
+
+write(splice);