1. 1 Code Generation (cont’d.)

2. 2 Save to Register A 1. 2 already in Register A, or 2. already in Register A, or 3. 2 and both are not in Register A

3. 3 Code Generation (cont’d.) Node Specifier S( 1 ) save to rA

4. 4

5. 5 Code Generation (cont’d.)

6. 6

7. 7 Code Generation (cont’d.) 9 and 10 S( ) := S( ) = S(SUMSQ) REGA = S( ) <> rA =S(MEAN)

8. 8 Code Generation (cont’d.) 10

9. 9 S( 2 ) <> rA = S(MEAN) Call GETA( 2 ) GETA(SUMSQ) Generate [SUB S(MEAN)=T2] S( 1 ) := rA REGA := 1

10. 10 Code Generation (cont’d.) 11 S( ) := S( ):= S(SUMSQ) S( ) <> rA S( ) := S(MEAN l )

11. 11 Code Generation (cont’d.) 11 S( 2 ) <> rA S( ) <> rA Call GETA(MEAN) Generate [MUL MEAN] S(MEAN) := rA REGA:= MEAN

12. 12 Code Generation (cont’d.) 11 S( 2 ) <> rA Call GETA(SUMSQ) Generate [DIV #100] S( 1 ) := rA REGA := 1

13. 13 Code Generation (cont’d.) 12 S( ) := S(SUMSQ) S( ) := S(MEAN l ) S( ) := S(MEAN r ) S( ) := S(#100)

14. 14

15. 15 Code Generation (cont’d.) REGA = NULL Generate [LDA SUMSQ] S(SUMSQ) := rA REGA := SUMSQ REGA <> NULL = SUMSQ S(MEAN) <> rA = S(SUMSQ) Generate [STA T1] S(SUMSQ) = T1 Generate [LDA MEAN] S(MEAN) := rA REGA := MEAN REGA <> NULL = MEAN S(SUMSQ) <> rA = S(MEAN) Generate [STA T2] S(MEAN) = T2 Generate [LDA S(SUMSQ)=T1] S(SUMSQ) := rA REGA := SUMSQ

16. 16 Code Generation (cont’d.) I

17. 17 Code Generation (cont’d.) 1, 2, and 3

18. 18 Code Generation (cont’d.) 4, 5, and 7

19. 19 8, 14, 15

20. 20 Code Generation (cont’d.) 16 and 17

21. 21 Code Generation (cont’d.)

22. 22 Code Generation (cont’d.)

23. 23

24. 24

25. 25

26. 26

27. 27

28. 28

29. 29

30. 30

31. 31 LDASUMSQ DIV#100 STAT1 LDAMEAN MULMEAN STAT2 LDAT1 SUBT2 STAT3 LDAT3 STAVARIANCE

32. 32 T2 LDAMEAN MULMEAN STAT2 LDASUMSQ DIV#100 STAT1 LDAT1 SUBT2 STAT3 LDAT3 STAVARIANCE

33. 33 T2

34. 34

35. 35

36. 36

37. 37 3*(6-1)=3*5=15

38. 38

39. 39 3*(I-1) Content of Address of A A(3*(I-1))=5

40. 40

41. 41 3*((I-0)*(6-1+1)+(J-1))=5

42. 42 3*((I-1)*(10-1+1)+(2J-1-1)) 3*(i1(i8)*10 3*(i2(i9) +i3(i10)-1-1 +i4(i11)-1 +i5 3*i6(i12) i7(i13)

43. 43

44. 44

45. 45

46. 46 Machine-Independent Compiler Features

47. 47 Machine-Independent Compiler Features Storage Allocation Static Allocation: cannot be used for recursive call Dynamic Allocation: Activation Record

48. 48

49. 49

50. 50

51. 51

52. 52

53. 53

54. 54

55. 55 P-Code Compliers

56. 56 Compiler-Compilers

57. 57 http://ptt.cc/google.wmv