Description
Part 1: Reading
Compilers – Principles, Techniques, & Tools, 2nd Edition, Sections 8.5 to 8.9, 9.1 to 9.2.
Homework Exercises – laboratory assignment and answer the questions at the end of the
assignment.
Introduction
In the last assignment you optimize the code generation by improving QUAD generation and/or
optimized the QUAD linked list. In this assignment you modify the calculator program to generate
PIC 16F1827 assembler code. You support QUAD to TUPLE generation for expressions and IFELSE statements and add support for indirect array quads. You test your code generator with the
previous test files. You update the compiler and implement the
For extra credit (10) you update the code generator or write your own version. For additional extra
credit (5) you download MPLAB IDE software, compile and simulate your output code.
Part 2: Laboratory
From a console window, make a directory on your computer in your EECS337 directory under
your Case ID and call it hw12.
mkdir ~/EECS337/caseid/hw12/ ; where caseid is YOUR Case ID, enter all in lower case
Change directory to the hw12 directory.
cd ~/EECS337/caseid/hw12/
Download a copy of: hw12_caseid.tar file to the hw12 directory from http://blackboard.case.edu/
in the EECS337 homework assignment area. To untar the tar file type the command:
tar xvf hw12_caseid.tar
The following files will be created in the current working directory.
codegen.c
codegen2.c
Makefile
hw12_test.sh
Copy the following files from the assignment 10 directory to this directory with the commands:
cp ../hw11/lex.l .
cp ../hw11/main.c .
cp ../hw11/quad.c .
cp ../hw11/symbol_table.c .
cp ../hw11/yacc.y .
cp ../hw11/yystype.h .
Optional: If you did not complete the last assignment you can download the hw11solutions.tar file
from the assignment directory and use that as your starting code. Use the command “tar xvf
hw11solutions.tar”. The hw11/ directory will be created with the files. In that case edit all the files
and change “caseid” to your Case ID.
You are now ready to solve the laboratory assignment.
Part 3: Laboratory Assignment
Edit the yystype.h file and add to the top of the file the PIC instructions and the TUPLE structure
definition.
/*
* define pic instructions
*/
#define I_LABEL 0
#define I_MOV 1
#define I_ADD 2
#define I_AND 3
#define I_IOR 4
#define I_SUB 5
#define I_XOR 6
#define I_COMF 7
#define I_DECF 8
#define I_DECFSZ 9
#define I_INCF 10
#define I_INCFSZ 11
#define I_RLF 12
#define I_RRF 13
#define I_SWAPF 14
#define I_BCF 15
#define I_BSF 16
#define I_BTFSC 17
#define I_BTFSS 18
#define I_CALL 19
#define I_GOTO 20
#define I_TRIS 21
#define I_CLR 22
#define I_RETLW 23
#define I_CLRWDT 24
#define I_NOP 25
#define I_OPTION 26
#define I_RETFIE 27
#define I_RETURN 28
#define I_SLEEP 29
/*
* define a tuple structure
* supports: CONSTANT STRING_LITERAL IDENTIFIER types
*/
#define TUPLE struct tuple
TUPLE
{
TUPLE *next;
int token;
unsigned char value;
int address;
#define MASK_VALUE 0x0001
#define MASK_ADDRESS 0x0002
#define MASK_LABEL 0x0004
#define MASK_W_REG 0x0008
#define MASK_F_REG 0x0010
#define MASK_INSTR 0x0020
int mask;
char *buffer;
int length;
int level;
};
Add to the bottom of the symbol table data structure the field to hold the PIC physical address.
int address;
Add to the bottom of the data structure the field to hold the PIC physical address and define the
values for the maximum and minimum PIC 16F1827 address ranges.
#define TOP_MEMORY 0x0020
#define BOTTOM_MEMORY 0x007f
int address;
Before the bottom of the file (#endif) add the external declarations below for the code generator.
/*
* external variables and functions from codegen.c
*/
extern void code_generator_pic_prefix( void);
extern void code_generator_pic_postfix( void);
extern void code_generator_operand_postfix( TUPLE *tuple);
extern void code_generator_operand( TUPLE *tuple);
extern void code_generator_instr_postfix( TUPLE *tuple);
extern void code_generator_instr( TUPLE *tuple);
extern void code_generator_pic16f1827( TUPLE *tuple_list);
extern void code_generator_instr_test( void);
/*
* external variables and functions from codegen2.c
*/
extern void code_generator_pic_address( void);
extern TUPLE *generate_quad_instruction( int instruction, int type, int index);
extern TUPLE *generate_quad_operand( int type, int index);
extern TUPLE *generate_quad_destination( int type, int index);
extern TUPLE *generate_quad( QUAD *quad);
extern TUPLE *generate_quad_2_tuple( QUAD *quad_list);
Save the yystype.h file
Edit the main.c and add to the ‘+’ flags section the code below. This flag prints out examples of
the PIC code generator instructions.
else if( !strncmp( command, “+test”, strlen( command)))
{
code_generator_instr_test();
exit( 0);
}
Save the main.c file.
Edit the symbol_table.c file and add the code to allocate the PIC physical address. In the
new_symbol function add one line of code to each CHAR, SHORT, INT and LONG specifiers.
/*
* allocate the PIC physical address
*/
data.st[ identifier].address = get_address( 1); //char
data.st[ identifier].address = get_address( 2); //short
data.st[ identifier].address = get_address( 4); // int
data.st[ identifier].address = get_address( 8); //long
Save the symbol_table.c file
Edit the lex.l file and delete the line that has [\n] and add the new line character to the white
space regular expression [ \n\t]. From now on we want to generate the whole file or until we type
$ on the command line. Save the lex.l file.
[ \t\n] { /* ignore white characters */ }
Edit the yacc.y file and at the top change the include files, the global TUPLE variable and the new
%start file for the start symbol.
#include
#include
#include
#include
#include
#include “yystype.h”
#include “y.tab.h”
#include “codegen.c”
#include “codegen2.c”
TUPLE *tuple_list;
%}
%start file
Change the top-level productions to use the productions shown below.
file : lines
{
/*
* print the quad list
*/
print_quad_list( $1.quad );
/*
* generate the tuple from quad list
*/
tuple_list = generate_quad_2_tuple( $1.quad);
/*
* free the quad list
*/
free_quad_list( $1.quad);
/*
* call the code generator
*/
code_generator_pic16f1827( tuple_list);
}
;
lines : lines stmts
{
$$.quad = end_quad_list( $1.quad);
if( $$.quad)
{
$$.quad->next = $2.quad;
$$.quad = $1.quad;
}
else
$$.quad = $2.quad;
}
| lines decls
{
$$.quad = end_quad_list( $1.quad);
if( $$.quad)
{
$$.quad->next = $2.quad;
$$.quad = $1.quad;
}
else
$$.quad = $2.quad;
}
| stmts
| decls
;
decls : type ident ‘;’
{
new_symbol( $1.index, $2.index, 0);
$$.quad = (QUAD*)0;
}
| type ident ‘[‘ number ‘]’ ‘;’
{
new_symbol( $1.index, $2.index, $4.index);
$$.quad = (QUAD*)0;
}
;
Save the yacc.y file.
Build the calc program and fix any errors using the commands: make clean and make
To test your version, type:
./calc +symbol and enter the lines below.
for caseid start time: Mon Nov 18 10:45:08 2013
Enter calculator expression and $ to exit
char a;
a = 10;
$
a = 10
; automatic code generation for PIC16F1827
; EECS337 Compiler Design
; by: caseid, date: Fall 2013
; for PIC16F1827 processor
; CPU configuration
list p=16f1827 ; list directive to define processor
#include ; processor specific variable definitions
__CONFIG _CONFIG1, _FOSC_INTOSC & _WDTE_OFF & _PWRTE_OFF & _MCLRE_ON &
_CP_OFF & _CPD_OFF & _BOREN_OFF & _CLKOUTEN_ON & _IESO_OFF & _FCMEN_OFF
__CONFIG _CONFIG2, _WRT_OFF & _PLLEN_OFF & _STVREN_OFF & _BORV_19 &
_LVP_OFF
; generate symbol table:
a_ EQU 0x20
; generate temporary addresses:
; power-up or reset vector
org 0x0000 ; processor reset vector
pagesel init
goto init ; skip interrupt vector space (reserved)
; interrupt vector
org 0x04
inter: ; on interrupt PC set to 0x04 and automatically clears GIE
retfie ; return from interrupt and automatically sets GIE
; beginning of program code
org 0x08
init:
; On reset all ports are inputs.
movlb 1 ; switch to bank 1 memory
; clrf TRISA ; set PORTA to all outputs
clrf TRISB ; set PORTB to all outputs
movlb 0 ; switch to bank 0 memory
mloop:
; read from the standard input (stdin)
movf PORTA,w
nop
movlw 0xa
movwf a_
goto mloop
; only standard library function
printf:
movwf PORTB ; output w to standard output (stdout)
return
end ; end of program code
symbol table:
index: 1 identifier: a length: 2 specifier: char
index: 2 constant: 10 length: 3 format: decimal
Test using the test files using the commands below. Determine what is missing from the code
generation and expand the compiler to generate the correct output.
./calc +symbol ../hw09/math21.txt
Part 4: Output Generation
When all your lab assignments have been completed execute the homework script file
“./hw12_test.sh” using the command below.
./hw12_test.sh &> hw12_test.txt
Print out the hw12_test.txt file and put your name, assignment number and date on it. Turn in the
file for the assignment and answer the questions at the end of the assignment.
Your final directory structure for the calc compiler should be as below (using your Case ID):
EECS337/caseid/hw12/Makefile
EECS337/caseid/hw12/calc
EECS337/caseid/hw12/codegen.c
EECS337/caseid/hw12/codegen2.c
EECS337/caseid/hw12/hw12_caseid.tar
EECS337/caseid/hw12/hw12_test.sh
EECS337/caseid/hw12/hw12_test.txt
EECS337/caseid/hw12/lex.l
EECS337/caseid/hw12/main.c
EECS337/caseid/hw12/quad.c
EECS337/caseid/hw12/symbol_table.c
EECS337/caseid/hw12/yacc.y
EECS337/caseid/hw12/yystype.h
Part 5A: Extra Credit (10 points)
Update or write your own version of a PIC code generator and edit the hw12_test.sh file and
remove the comments to test the other mathXX.txt files. Attempt to support as many test files as
possible. When the extra credit code is complete and working then execute the homework script
file “./hw12_test.sh” using the command below.
./hw12_test.sh &> hw12_test.txt
Print out this version of the hw12_test.txt file. Mark this output with EXTRA CREDIT and put
your name, assignment number, date on it and turn it in instead of the file from Part 4. Upload
ONLY your updated/new code generator file to blackboard in the assignment area. Submit it with
the comments hw12 with your CaseID on the title line. The extra credit will be graded on-line and
your score will be added to your assignment score.
Part 5B: Extra Credit (5 points)
Test the output of your compiler using MPLAB, public domain software for the Microchip PIC
microprocessor. Install MPLAB on your computer or use one of the computers in the lab. If you
have not used MPLAB, you will need a copy of the MPLAB User Guide, Part 2 – MPLAB IDE
Tutorial. You can download a version of the guide from https://blackboard.case.edu or from the
Microchip website.
The software is designed as a standard Integrated Development Software (IDE) application. As
an engineer you will use a number of different IDEs in your career. Most IDE applications have
the same type of operations. You typically download the software to a target computer and install
the applications. You may need to register the software with the company. Most companies allow
their software to be downloaded and used for free but with reduced functionality. When you need
to upgrade to the full version you purchase the software. Otherwise you are free to use the
software in your education, research or development.
Step 1. [Optional step] Install the software
To install the software on your computer go to the Microchip www.microchip.com website.
In the menu bar under DESIGN SUPPORT click on the MPLAB X IDE link. Below the three
MPLAB X buttons find the MPLAB IDE v8 for Legacy Demos button and click on the link.
On the next page scroll to the bottom and click on the MPLAB IDE v8.92 link and download the
zip file. Then click on the MPLAB IDE User’s Guide and download the file.
Unzip the MPLAB_IDE_8_92.zip file. Change directory into the MPLAB_IDE_8_92 and double
click the setup.exe. Open the User’s Guide and follow Part 2 – 4.2 MPLAB IDE FEATURES AND
INSTALLATION. Follow the instructions to install the software onto your computer. You may need
to reboot the computer after installing the software.
Step 2. Work through the tutorial
Execute MPLAB. Follow the steps in Part 4.2.2 of the MPLAB IDE Tutorial and when using the
Project Wizard use the following information:
Step One: Select a device: and pick PIC16F1827. Click Next.
Step Two: Select a language toolsuite: Use the Microchip MPASM Assembler (mpasmwin.exe)
v5.51. It should be listed under: C:\Program Files\Microchip\MPASM Suite\MPASMWIN.exe.
Click Next.
Step Three: Create New Project File: Use the Browse… button to change to your
EECS337/caseid/hw11/ directory using your Case ID. Then enter the file name (Design12). Click
Next.
Step Four: Add the Math24.asm the file to your project. Click Finish to create the work space.
Step Five: Now build the assembler program “Project>Build All” function. Pick Absolute code, if it
ask you. You should see the output window have no build errors and then you can continue on
with the lab.
Under the Debugger->Select Tool pick the MPLAB SIM (simulator) version. The debug buttons
should now be part of Run the program using the “Animate” button (two arrows) and watch the
instructions execute. Press the “Reset” button (page loop) and watch the process jump to the
start of program memory. You can stop execution (pause), set break points and run (single arrow)
the program. View the register files and print out a window snap shot showing your code running
inside the software.
Print out this snap shot file showing your program execution. Mark this output with EXTRA
CREDIT and put your name, assignment number, date on it and turn it in. Answer the questions
at the end of the assignment.
Part 6: Laboratory Questions (do any 4 questions)
1) If you wrote your own code generator then explain the code you designed.
2) If you changed the hw12_test.sh file then explain how many extra files you were able to
support.
3) Change the symbol table to use the CBLOCK ENDC instructions instead of the EQU
statements. See the example below.
cblock 0x20 ; define gpr variable register locations
myvar1 ; user variables allocated contiguously
myvar2 ;
myvar3 ;
endc
sample1 equ 0x7d ; sample user registers
sample2 equ 0x7e ;
sample3 equ 0x7f ;
4) Update the quad to tuple function to support the array type. Explain the code you
designed and the change in the output.
5) Identify and fix a bug in the current software. Explain the code you designed and the how
it changed the output.
6) Identify and fix another bug in the current software. Explain the code you designed and
the how it changed the output.
7) Add a new instruction into the current code generator. Explain the code you designed
and the change in the output.
8) Add another new instruction into the current code generator. Explain the code you
designed and the change in the output.
