README

Akshat Gupta
Compiler Project 2
7849305349
akshatgu@usc.edu

This has been implemented in python (and has been tested on python-2.5)

To execute the program please run the blocker.py along with the source file
Eg.
xyzzy$ python blocker.py eg1.c

This command will take in eg1.c prase it and write the intermidiate code in inter_suif.txt
After this blocks and other graphs are created and the output is written in inter.txt

The Register Allocation details are written out in reg_alloc.txt
For number of registers and adding constraints please edit the reg_parameters.py

Notes and deviation from spec:
	1.>  Since number of blocks are not fixed random number are used to find the number of iterations for a block if it belongs to a natural loop. The values can be found in reg_alloc.txt
	2.>  The register constraint needs to be applied on to the variables used in C.
	3.>  There are two maps for register constraints ... Please remember that the registers corresponding follow a "and" condition
	4.>  If a variable is used that has not been declared it is assumed to be a constant and no error is generated.
	5.>  Once the code has been spilled, it is never spilled again to make sure there is no infinite loop. To do this its spill cost is changed to -infinity.
	6.>  The AdjMtx is not being written to file as it becomes messy.
For parsing Lyx and Yacc bindings for python have been used. 

Ouput: 	reg_alloc.txt