Assignment Solution Sketch

1
Assignment Solution Sketch

• Translation to
• MSIL and Javabyte Code

2

• Constant Expression Infix to postfix
• 2 3 4
• ( 2 (3 4 ) )
• 2 3 4
• Evaluating postfix expression using stack
• 2
• 2 3 4
• 2 12
• 14

3

• Evaluating postfix expression using stack
• 2
• 2 3 4
• 2 12
• 14
• Compiling constant expression for a stack machine
• Push 2
• Push 3
• Push 4
• Mul
• Add

4

• Generalizing to expressions with variables
• i j k
• Push i
• Push j
• Push k
• Mul
• Add
• Conversion to abstract syntax tree
• i
• j k

5

• Generalizing to expressions with variables
• i j k
• Push i
• Push j
• Push k
• Mul
• Add
• Byte code generation for static f(int i,j,k)
• ldarg.0
• ldarg.1
• ldarg.2
• mul
• add

6
Byte code for i j k for static f(int
i,j,k)

• Right associative
• ldarg.0
• ldarg.1
• ldarg.2
• add
• add

• Left associative
• ldarg.0
• ldarg.1
• add
• ldarg.2
• add

7

• Introducing numeric types with real variables
  a b
• Push a
• Push b
• Add
• Byte code generation for static f(double a,b)
• ldarg.0
• ldarg.1
• add

8

• Mixing int and double variables (requiring
  coercion code) for static f(double a,int i, j)
• i j a
• ldarg.1
• conv.r8
• ldarg.2
• conv.r8
• ldarg.0
• mul
• add

9

• Translation algorithm essence
• trans (e1 e2)
• trans(e1)
• type coercion code?
• trans(e2)
• type coercion code?
• trans()
• Map grammar rules to control structures
• E.g., alternatives, while-loop, etc

10

• Mixing int and double variables (requiring
  coercion code) for static f(double a,int i, j)
• i j a
• iload_2
• i2d
• iload_3
• i2d
• dload_0
• dmul
• dadd