Submit one MIPS assembly language file (as an attachment replying to
the official email announcing this assignment). Name your file as
sieve_yourname.s where
yourname is either your username or the name you generally go
by. (I do not care which - as long as I can easily distinguish your
programs. For example, mine could be sieve_msiff.s or
sieve_mike.s.)
Before proceeding further you should familiarize yourself with the basics of the Sieve of Eratosthenes, for example here.
Download this C version of the sieve. You can
compile it using gcc and run it like this:
$ gcc -o sieve sieve.c
$ ./sieve
Enter number up to which to perform sieve: 20
2
3
5
7
11
13
17
19
8 primes found.For your assembly code, rather than work from scratch, you should start with this MIPS program. It assembles in MARS, though it is not yet close to working correctly.
You will notice that I have included two auxiliary functions which
should be used to shield the rest of the code from syscall
operations of MARS which will be used: for printing integers and
printing newline characters. (The main code, which has been supplied for
you, makes direct use of syscalls, but you should not have to modify any
of that.)
For example:
# print_int: displays supplied integer (in $a0) on console
print_int:
li $v0, 1
syscall
...
jr $raThe point of these wrapper functions is that you should write the
rest of your code to act as if these functions are in a library where
you cannot see the code and, therefore, must assume the conventions of
saving and restoring appropriate registers whenever you call them. The
existence of these wrapper functions means you should not use
the syscall operation in the rest of your code.
You should use MARS early and often to test your code.
Unless otherwise indicated you should confine your programs to the following MIPS commands:
beq bne slt slti
add addi sub
sll srl sra
and andi or ori nor
j jal jr
lw lb lbu sw sbplus the pseudoinstructions (la, li and
move). As mentioned, I have used syscall in
the library routines, you should not need it elsewhere. (Note: you most
likely will not come close to needing all the MIPS instructions listed
above.)
Your assembly-language program should be well documented - that could mean a short comment after almost every line and, certainly, larger comments as a prologue to each function.
Your task is to complete the implementation of the three functions:
fill_buffer, sieve, and
print_primes.
Optimize, optimize, optimize!