CS360 Midterm Exam: October 8, 2003.

CS360 Midterm Exam: October 8, 2003. Question 1

Match the following four pieces of C code to their proper assembler, as converted by an unoptimized compiler:

Procedure 1
int f(int a1, int *a2) { int i; i = a1 + *a2; return i-1; }
Procedure 2
int f(int *a1, int *a2) { int i; *a1 = i + *a2; return *a1-1; }
Procedure 3
int f(int *a1, int *a2) { int i; i = a1[1] + a2[i]; return i-1; }
Procedure 4
int f(int a1, int *a2) { int i; return g(a2, h(&a1))-1; }

Answer A
f: push #4 ld [fp] -> %r0 ld [fp+16] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp+12] ld [fp+12] -> %r0 add %r0, %gm1 -> %r0 ret
Answer B
f: push #4 ld [fp+12] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ret
Answer C
f: push #4 ld [fp+12] -> %r0 st %r0 -> [sp]-- jsr h pop #4 st %r0 -> [sp]-- ld [fp+16] -> %r0 st %r0 -> [sp]-- jsr g pop #8 add %r0, %gm1 -> %r0 ret
Answer D
f: push #4 mov #12 -> %r0 add %r0, %fp -> %r0 st %r0 -> [sp]-- jsr h pop #4 st %r0 -> [sp]-- ld [fp+16] -> %r0 st %r0 -> [sp]-- jsr g pop #8 add %r0, %gm1 -> %r0 ret

Answer E
f: push #4 ld [fp+12] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] add %r0, %gm1 -> %r0 ret
Answer F
f: push #4 ld [fp+12] -> %r0 ld [r0] -> %r0 ld [fp+16] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ret
Answer G
f: push #4 ld [fp] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp+12] ld [fp+12] -> %r0 add %r0, %gm1 -> %r0 ret
Answer H
f: push #4 ld [fp+12] -> %r0 ld [fp+16] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ret

Answer I
f: ld [fp+12] -> %r0 st %r0 -> [sp]-- jsr h st %r0 -> [sp]-- ld [fp+16] -> %r0 st %r0 -> [sp]-- jsr g add %r0, %gm1 -> %r0 ret
Answer J
f: push #4 st %r2 -> [sp]-- ld [fp+12] -> %r0 mov #4 -> %r1 add %r0, %r1 -> %r0 ld [r0] -> %r0 ld [fp] -> %r1 mov #4 -> %r2 mul %r1, %r2 -> %r1 ld [fp+16] -> %r2 add %r1, %r2 -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ld ++[sp] -> %r2 ret
Answer K
f: st %r2 -> [sp]-- push #4 ld [fp+12] -> %r0 mov #4 -> %r1 add %r0, %r1 -> %r0 ld [r0] -> %r0 ld [fp] -> %r1 mov #4 -> %r2 mul %r1, %r2 -> %r1 ld [fp+16] -> %r2 add %r1, %r2 -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ld ++[sp] -> %r2 ret
Answer L
f: push #4 st %r2 -> [sp]-- ld [fp+12] -> %r0 mov #4 -> %r1 add %r0, %r1 -> %r0 ld [fp] -> %r1 mov #4 -> %r2 mul %r1, %r2 -> %r1 ld [fp+16] -> %r2 add %r1, %r2 -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ld ++[sp] -> %r2 ret

Answer M
f: push #4 st %g0 -> [fp] ld [fp] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 ld [fp+12] -> %r1 st %r0 -> [r1] ld [fp+12] -> %r0 ld [r0] -> %r0 add %r0, %gm1 -> %r0 ret
Answer N
f: mov #12 -> %r0 add %r0, %fp -> %r0 st %r0 -> [sp]-- jsr h st %r0 -> [sp]-- ld [fp+16] -> %r0 st %r0 -> [sp]-- jsr g add %r0, %gm1 -> %r0 ret
Answer O
f: st %r2 -> [sp]-- push #4 ld [fp+12] -> %r0 mov #4 -> %r1 add %r0, %r1 -> %r0 ld [fp] -> %r1 mov #4 -> %r2 mul %r1, %r2 -> %r1 ld [fp+16] -> %r2 add %r1, %r2 -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ld [sp] -> 5r2 ret
Answer P
f: push #4 ld [fp] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 ld [fp+12] -> %r1 st %r0 -> [r1] ld [fp+12] -> %r0 ld [r0] -> %r0 add %r0, %gm1 -> %r0 ret

Answer A f: push #4 ld [fp] -> %r0 ld [fp+16] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp+12] ld [fp+12] -> %r0 add %r0, %gm1 -> %r0 ret	Answer B f: push #4 ld [fp+12] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ret	Answer C f: push #4 ld [fp+12] -> %r0 st %r0 -> [sp]-- jsr h pop #4 st %r0 -> [sp]-- ld [fp+16] -> %r0 st %r0 -> [sp]-- jsr g pop #8 add %r0, %gm1 -> %r0 ret	Answer D f: push #4 mov #12 -> %r0 add %r0, %fp -> %r0 st %r0 -> [sp]-- jsr h pop #4 st %r0 -> [sp]-- ld [fp+16] -> %r0 st %r0 -> [sp]-- jsr g pop #8 add %r0, %gm1 -> %r0 ret
Answer E f: push #4 ld [fp+12] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] add %r0, %gm1 -> %r0 ret	Answer F f: push #4 ld [fp+12] -> %r0 ld [r0] -> %r0 ld [fp+16] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ret	Answer G f: push #4 ld [fp] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp+12] ld [fp+12] -> %r0 add %r0, %gm1 -> %r0 ret	Answer H f: push #4 ld [fp+12] -> %r0 ld [fp+16] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ret
Answer I f: ld [fp+12] -> %r0 st %r0 -> [sp]-- jsr h st %r0 -> [sp]-- ld [fp+16] -> %r0 st %r0 -> [sp]-- jsr g add %r0, %gm1 -> %r0 ret	Answer J f: push #4 st %r2 -> [sp]-- ld [fp+12] -> %r0 mov #4 -> %r1 add %r0, %r1 -> %r0 ld [r0] -> %r0 ld [fp] -> %r1 mov #4 -> %r2 mul %r1, %r2 -> %r1 ld [fp+16] -> %r2 add %r1, %r2 -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ld ++[sp] -> %r2 ret	Answer K f: st %r2 -> [sp]-- push #4 ld [fp+12] -> %r0 mov #4 -> %r1 add %r0, %r1 -> %r0 ld [r0] -> %r0 ld [fp] -> %r1 mov #4 -> %r2 mul %r1, %r2 -> %r1 ld [fp+16] -> %r2 add %r1, %r2 -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ld ++[sp] -> %r2 ret	Answer L f: push #4 st %r2 -> [sp]-- ld [fp+12] -> %r0 mov #4 -> %r1 add %r0, %r1 -> %r0 ld [fp] -> %r1 mov #4 -> %r2 mul %r1, %r2 -> %r1 ld [fp+16] -> %r2 add %r1, %r2 -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ld ++[sp] -> %r2 ret
Answer M f: push #4 st %g0 -> [fp] ld [fp] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 ld [fp+12] -> %r1 st %r0 -> [r1] ld [fp+12] -> %r0 ld [r0] -> %r0 add %r0, %gm1 -> %r0 ret	Answer N f: mov #12 -> %r0 add %r0, %fp -> %r0 st %r0 -> [sp]-- jsr h st %r0 -> [sp]-- ld [fp+16] -> %r0 st %r0 -> [sp]-- jsr g add %r0, %gm1 -> %r0 ret	Answer O f: st %r2 -> [sp]-- push #4 ld [fp+12] -> %r0 mov #4 -> %r1 add %r0, %r1 -> %r0 ld [fp] -> %r1 mov #4 -> %r2 mul %r1, %r2 -> %r1 ld [fp+16] -> %r2 add %r1, %r2 -> %r1 add %r0, %r1 -> %r0 st %r0 -> [fp] ld [fp] -> %r0 add %r0, %gm1 -> %r0 ld [sp] -> 5r2 ret	Answer P f: push #4 ld [fp] -> %r0 ld [fp+16] -> %r1 ld [r1] -> %r1 add %r0, %r1 -> %r0 ld [fp+12] -> %r1 st %r0 -> [r1] ld [fp+12] -> %r0 ld [r0] -> %r0 add %r0, %gm1 -> %r0 ret