- initial import

git-svn-id: http://moon:8086/svn/mips@1 a8ebac50-d88d-4704-bea3-6648445a41b3
2014-07-20 15:01:37 +00:00
commit 26291bca3d
1549 changed files with 3997969 additions and 0 deletions
@@ -0,0 +1,131 @@
+		.file	"test_asm.S"
+	
+		.section .rodata
+		.data
+text:		.asciz		"Hallo, Welt!"
+space:		.asciz		" "
+crlf:		.asciz		"\n"
+
+		.text
+		.globl main
+main:
+		.set	noreorder
+		move	$t0, $0
+
+loop:		la	$a0, text
+		li	$v0, 4
+		syscall
+
+		la	$a0, space
+		li	$v0, 4
+		syscall
+
+		move	$a0, $t0
+		li	$v0, 1
+		syscall
+
+		la	$a0, crlf
+		li	$v0, 4
+		syscall
+
+		j	fibo
+		addiu	$t0, 1
+		nop		
+		.set	reorder
+
+		.data
+in_string:	.asciiz		"Input a positive integer:\n\n"
+out_string:	.asciiz		"The Fibonacci number is:\n\n"
+
+
+		.text
+fibo:
+		addu $fp,$sp,28
+	# print out prompt
+		li	$v0, 4			# system call code for printing string = 4
+		la	$a0, in_string		# load address of string to be printed into $a0
+		syscall				# call operating system to perform print operation
+
+	# read integer into $s0
+		li	$v0, 5			# system call code for read integer = 5
+		syscall				# call operating system
+		move	$s0, $v0		# value read from keyboard returned in register $v0; transfer to $s0
+
+		sw	$s0,($sp)		# push argument for Fib on stack
+		addi	$sp,$sp,-4		#   and decrement stack pointer
+		jal	Fib			# jump to subroutine
+		addi	$sp,$sp,4		# increment stack pointer
+		lw	$s1,($sp)		#   and pop result from stack
+		
+	# print out prompt
+		li	$v0, 4			# system call code for printing string = 4
+		la	$a0, in_string		# load address of string to be printed into $a0
+		syscall				# call operating system
+
+	# print out result (stored in $s1)
+		li	$v0, 1			# system call code for printing integer = 1
+		move	$a0, $s1		# move integer to be printed into $a0:  $a0 = $s1
+		syscall				# call operating system to perform print
+
+	# exit program
+		li	$v0, 10			# system call code for exit = 10
+		syscall				# call operating system
+
+	# blank line at end to keep SPIM happy!
+
+
+##################################################################################
+# Fibonacci subroutine
+# input:  integer n, on stack
+# output: Fib(n), nth Fibonacci number
+# description: recursively computes   Fib(n)  =  Fib(n-1) + Fib(n-2),  Fib(1) = Fib(2) = 1.
+# uses: $t0, $t1
+##################################################################################
+
+
+Fib:
+						# procedure prologue:
+		sw	$ra,($sp)		# save return address on stack, since recursive,
+		addi	$sp,$sp,-4		#   and decrement stack pointer
+		sw	$fp,($sp)		# save previous frame pointer on stack
+		addi	$sp,$sp,-4		#   and decrement stack pointer
+		add	$fp,$sp,12		# set frame pointer to point at base of stack frame
+
+		lw	$t0,($fp)		# copy argument to $t0:  $t0 = n
+		li	$t1, 2	
+		bgt	$t0,$t1,do_recurse	# if argument n >= 2, branch to recursive sequence
+		li	$t0, 1			#   else set result to 1 (base cases  n = 1 and  n = 2)
+		b	epilogue		# branch to end
+
+do_recurse:	addi	$t0,$t0,-1		# $t0 = n-1
+		sw	$t0,($sp)		# push argument n-1 on stack
+		addi	$sp,$sp,-4		#   and decrement stack pointer
+		jal	Fib			# call Fibonacci with argument n-1
+						# leave result on stack for now
+		lw	$t0,($fp)		# re-copy argument to $t0:  $t0 = n
+		addi	$t0,$t0,-2		# $t0 = n-2
+		sw	$t0,($sp)		# push argument n-2 on stack
+		addi	$sp,$sp,-4		#   and decrement stack pointer
+		jal	Fib			# call Fibonacci with argument n-2
+		addi	$sp,$sp,4		# increment stack pointer
+		lw	$t0,($sp)		#   and pop result of Fib(n-2) from stack into $t0
+		addi	$sp,$sp,4		# increment stack pointer
+		lw	$t1,($sp)		#   and pop result of Fib(n-1) from stack into $t1
+		add	$t0,$t0,$t1		# $t0 = Fib(n-2) + Fib(n-1); have result
+
+epilogue:					# procedure epilogue: $t0 holds result
+		addi	$sp,$sp,4		# increment stack pointer
+		lw	$fp,($sp)		#   and pop saved frame pointer into $fp
+		addi	$sp,$sp,4		# increment stack pointer
+		lw	$ra,($sp)		#   and pop return address into $ra
+		addi	$sp,$sp,4		# increment stack pointer
+						#   to pop argument (n) from stack (discard)
+		sw	$t0,($sp)		# push result onto stack
+		addi	$sp,$sp,-4		#   and decrement stack pointer
+		jr	$ra			# return to caller
+
+##################################################################################
+# end of Fibonacci
+##################################################################################
+
+