From 522dafe05a03e48a5c7989fcc816f0a38df225b8 Mon Sep 17 00:00:00 2001
From: Claudio Maggioni <claudio@maggioni.xyz>
Date: Fri, 30 Nov 2018 15:13:38 +0100
Subject: [PATCH] HW9: bonus (now working)

---
 Homework 9/bonus.jas | 189 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 189 insertions(+)
 create mode 100644 Homework 9/bonus.jas

diff --git a/Homework 9/bonus.jas b/Homework 9/bonus.jas
new file mode 100644
index 0000000..29af16f
--- /dev/null
+++ b/Homework 9/bonus.jas	
@@ -0,0 +1,189 @@
+.constant
+OBJREF 0x40
+.end-constant
+
+.main
+.var
+a
+b
+min
+.end-var
+  LDC_W OBJREF
+  INVOKEVIRTUAL getnum
+  ISTORE a
+  LDC_W OBJREF
+  INVOKEVIRTUAL getnum
+  ISTORE b
+  ILOAD a
+  ILOAD b
+  LDC_W OBJREF
+  INVOKEVIRTUAL min
+  HALT
+.end-main
+
+.method min(x,y)
+.var
+.end-var
+  ILOAD x
+  ILOAD y
+  ISUB
+  IFLT returny
+  ILOAD x
+  IRETURN
+returny:
+  ILOAD y
+  IRETURN 
+.end-method
+
+.method getnum()
+.var
+a
+.end-var
+
+	BIPUSH 0x0		// initialize a
+        ISTORE a
+geta:	IN			// read key press
+	DUP			// duplicate key for comparison
+	BIPUSH 0xa		// if key = cr,
+	IF_ICMPEQ return	//   return
+	DUP
+	BIPUSH 0x30		// if key < "0"
+	ISUB			//
+	IFLT geta4		//   goto geta4 (key is not a hex digit)
+    	DUP
+	BIPUSH 0x3a		// else if key < ":"
+	ISUB			//
+	IFLT geta2		//   goto geta2 (key is numeric character - "0"-"9")
+	DUP
+	BIPUSH 0x41		// else if key < "A"
+	ISUB			//
+	IFLT geta4		//   goto geta4 (key is not a hex digit)
+	DUP
+	BIPUSH 0x46		// else if key > "F"
+	SWAP			//  
+	ISUB			//
+	IFLT geta4		//   goto geta4 (key is not a hex digit)
+	DUP			// else (key is letter - "A"-"F")
+	OUT			//   print key
+	BIPUSH 0x37		//   convert key from character to number
+	ISUB			//
+	GOTO geta3		//   goto geta3
+geta2:  DUP
+	OUT			// print key (numeric character)
+	BIPUSH 0x30		// convert key from character to number
+	ISUB
+geta3:  ILOAD a			// shift a left 8 bits
+	DUP
+	IADD
+	DUP
+	IADD
+	DUP
+	IADD
+	DUP
+	IADD
+	IADD			// add key to a
+	ISTORE a
+	GOTO geta		// get next key
+
+geta4:	POP			// pop invalid character
+	GOTO geta		// get next key
+
+return: OUT			// print cr
+	ILOAD a			// load a as return value
+	IRETURN			// return
+.end-method
+
+.method print( total ) 		// print converts a number into a string of
+				//   characters and prints them.  All of the characters
+				//   are pushed onto the stack, least significant
+				//   digit first, then popped off and printed.
+.var
+place
+index
+.end-var
+
+print: 	BIPUSH 0x9		// there are 8 nibbles in each integer--setting
+				//   this as nine pushes 10 characters onto the
+ 				//   stack, thus a total of ten printed digits,
+				//   but setting this less does not remove the
+				//   two leading zeros, just removes significant
+				//   digits
+	ISTORE index
+	BIPUSH 0x1		// comparison bit
+	ISTORE place
+print1:	BIPUSH 0x0
+	ILOAD index		// index = index - 1
+	BIPUSH 0x1
+	ISUB
+	DUP
+	IFEQ pall		// if index = 0  goto pall
+	ISTORE index
+	ILOAD total		// else
+	ILOAD place		//
+	IAND			//   if 1st bit of current nibble is zero (total & place)
+	IFEQ print2		//     goto print2
+	BIPUSH 0x1		//   else set first bit of character
+	IADD
+print2: ILOAD place		//   place = place << 1 
+	DUP
+	IADD
+	ISTORE place
+	ILOAD total
+	ILOAD place
+	IAND			//   if 2nd bit of current nibble is zero (total & place)
+	IFEQ print3		//     goto print3
+	BIPUSH 0x2		//   else set second bit of character
+	IADD	
+print3: ILOAD place		//   place = place << 1
+	DUP
+	IADD
+	ISTORE place
+	ILOAD total
+	ILOAD place
+	IAND			//   if 3rd bit of current nibble is zero (total & place)
+	IFEQ print4		//     goto print4
+	BIPUSH 0x4		//   else set second bit of character
+	IADD	
+print4: ILOAD place		//   place = place << 1
+	DUP
+	IADD
+	ISTORE place
+	ILOAD total
+	ILOAD place
+	IAND			//   if 4th bit of current nibble is zero (total & place)
+	IFEQ print5		//     goto print5
+	BIPUSH 0x8		//   else set second bit of character
+	IADD	
+print5: ILOAD place		//   place = place << 1
+	DUP
+	IADD
+	ISTORE place
+	GOTO print1
+	
+pall:   POP			// Pop off leading 0's
+	POP
+	BIPUSH 0x9
+	ISTORE index
+pall1:	ILOAD index		// index = index - 1
+	BIPUSH 0x1
+	ISUB
+	DUP
+	IFEQ return		// if index = 0  return
+	ISTORE index
+	DUP
+	BIPUSH 0xa		// else if character < 0xa goto pall1
+	ISUB
+	IFLT pall2
+	BIPUSH 0x37		// else convert character to "A"-"F"
+	IADD
+	OUT			// print character
+	GOTO pall1		// goto pall (prepare & print next character)
+pall2:	BIPUSH 0x30		// convert character to "0"-"9"
+	IADD
+	OUT			// print character
+	GOTO pall1		// goto pall1 (prepare & print next character)
+return:	BIPUSH 0xa		// print cr
+	OUT
+	IRETURN			// no return value
+.end-method
+