SLIDE 1
FOX Garbage Collection FOX / GC Example 1 ex1: garbage at end let - - PowerPoint PPT Presentation
FOX Garbage Collection FOX / GC Example 1 ex1: garbage at end let - - PowerPoint PPT Presentation
FOX Garbage Collection FOX / GC Example 1 ex1: garbage at end let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1) ebp 0x00 0x04 0x08 0x0c 0x10 0x14 0x18 0x1c 0x20 0x24 esi
SLIDE 2
SLIDE 3
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
ebp
0x04 0x08 0x0c 0x10 0x14 0x18 0x1c 0x20 0x24
esi
ex1: garbage at end
SLIDE 4
1
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
ebp x
2
0x04 0x08 0x0c 0x10 0x14 0x18 0x1c 0x20 0x24 0x01
esi
ex1: garbage at end
SLIDE 5
1
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
ebp x
2
0x04 0x08 0x0c 0x10 0x14 0x18 0x1c 0x20 0x24
10 20
0x01
tmp
0x09
esi
ex1: garbage at end
SLIDE 6
1
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
ebp x
2
0x04 0x08 0x0c 0x10 0x14 0x18 0x1c 0x20 0x24
10 20
0x01
y
30
esi
ex1: garbage at end
SLIDE 7
1
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
ebp x
2
0x04 0x08 0x0c 0x10 0x14 0x18 0x1c 0x20 0x24
10 20
0x01
y
30
esi p0
31
ex1: garbage at end
SLIDE 8
1
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
ebp x
2
0x04 0x08 0x0c 0x10 0x14 0x18 0x1c 0x20 0x24
10 20
0x01
y
30
esi p0
31
p1
32
ex1: garbage at end
SLIDE 9
1
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
ebp x
2
0x04 0x08 0x0c 0x10 0x14 0x18 0x1c 0x20 0x24
10 20
0x01
y
30
esi p0
31
p1
32
31 32 Result (eax) = 0x11
ex1: garbage at end
SLIDE 10
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp esi
ex1: garbage at end
Suppose we had a smaller, 4-word heap
SLIDE 11
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp x
0x01
y
30
p0
31
p1
32
1 2 10 20
esi
ex1: garbage at end
SLIDE 12
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp x
0x01
y
30
p0
31
p1
32
1 2 10 20
esi
Out of memory! Can’t allocate (p0, p1)
ex1: garbage at end
SLIDE 13
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp x
0x01
y
30
p0
31
p1
32
1 2 10 20
esi
(10, 20) is “garbage”
Q: How to determine if cell is garbage?
ex1: garbage at end
SLIDE 14
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp x
0x01
y
30
p0
31
p1
32
1 2
esi
(10, 20) is “garbage”
ex1: garbage at end
SLIDE 15
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp x
0x01
y
30
p0
31
p1
32
1 2
esi
ex1: garbage at end
SLIDE 16
0x00
let x = (1, 2) , y = let tmp = (10, 20) in tmp[0] + tmp[1] , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp x
0x01
y
30
p0
31
p1
32
1 2
esi
31 32 Result (eax) = 0x09
ex1: garbage at end
SLIDE 17
FOX / GC Example 2
SLIDE 18
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp esi
ex2: garbage in the middle
Start with a 4-word heap
SLIDE 19
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
10 20
esi tmp
0x01
SLIDE 20
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20
SLIDE 21
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
SLIDE 22
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
SLIDE 23
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
SLIDE 24
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
Out of memory! Can’t allocate (p0, p1)
SLIDE 25
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
Lets reclaim & recycle garbage!
SLIDE 26
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
QUIZ: Which cells are garbage?
(A) 0x00, 0x04 (B) 0x04, 0x08 (C) 0x08, 0x0c (D) None (E) All
Lets reclaim & recycle garbage!
SLIDE 27
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
QUIZ: Which cells are garbage? Those that are not reachable from stack
Lets reclaim & recycle garbage!
SLIDE 28
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
QUIZ: Which cells are garbage? Those that are not reachable from stack
Lets reclaim & recycle garbage!
SLIDE 29
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
Q: How to reclaim space? Why is it not enough to rewind esi?
Lets reclaim & recycle garbage!
SLIDE 30
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
Why is it not enough to rewind esi?
Lets reclaim & recycle garbage!
Want free space to be contiguous (i.e. go to end of heap)
SLIDE 31
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
10 20 1 2
x
0x09
p0
31
p1
32
Solution: Compaction
Lets reclaim & recycle garbage!
Copy “live” cells into “garbage” …
SLIDE 32
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
1 2
x
0x09
p0
31
p1
32
Solution: Compaction
Lets reclaim & recycle garbage!
Copy “live” cells into “garbage” …
SLIDE 33
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
1 2
x
0x09
p0
31
p1
32
Solution: Compaction
Lets reclaim & recycle garbage!
Copy “live” cells into “garbage” …
SLIDE 34
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
1 2
x
0x09
p0
31
p1
32
Solution: Compaction
Lets reclaim & recycle garbage!
Copy “live” cells into “garbage” …
SLIDE 35
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
1 2
x
0x09
p0
31
p1
32
Solution: Compaction
Lets reclaim & recycle garbage!
Copy “live” cells into “garbage” … then rewind esi!
SLIDE 36
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
esi y
30
1 2
x
0x09
p0
31
p1
32
Yay! Have space for (p0, p1)
SLIDE 37
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
y
30
1 2
x
0x09
p0
31
p1
32
Yay! Have space for (p0, p1)
esi
31 32
SLIDE 38
0x00
let y = let tmp = (10, 20) in tmp[0] + tmp[1] , x = (1, 2) , p0 = x[0] + y , p1 = x[1] + y in (p0, p1)
0x04 0x08 0x0c 0x10
ebp
ex2: garbage in the middle
y
30
1 2
x
0x09
p0
31
p1
32
esi
31 32 Result (eax) = 0x09
SLIDE 39
FOX / GC Example 3
SLIDE 40
0x00 0x04 0x08 0x0c 0x10
ebp esi
ex3: garbage in the middle (with stack)
esp
3 local vars x,y,z
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + y + z
SLIDE 41
0x00 0x04 0x08 0x0c 0x10
esi
ex3: garbage in the middle (with stack)
ebp esp q
20
p
10
retaddr0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + y + z
SLIDE 42
0x00 0x04 0x08 0x0c 0x10
esi
ex3: garbage in the middle (with stack)
ebp0 esp q
20
p
10
retaddr0
ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + y + z
SLIDE 43
0x00 0x04 0x08 0x0c 0x10
esi
ex3: garbage in the middle (with stack)
ebp0 esp q
20
p
10
retaddr0
ebp ebp0
1 local var (tmp)
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + y + z
SLIDE 44
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0 esp q
20
p
10
retaddr0
ebp ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + y + z
SLIDE 45
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0 esp q
20
p
10
retaddr0
ebp ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + y + z
tmp
0x01
SLIDE 46
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0 esp q
20
p
10
retaddr0
ebp ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + y + z
tmp
0x01
Return (eax) = 30
SLIDE 47
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
Return (eax) = 30
ebp esp y
30
SLIDE 48
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
ebp esp y
30
SLIDE 49
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
ebp esp y
30
30 31
SLIDE 50
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
ebp esp y
30
30 31
x
0x09
SLIDE 51
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
ebp esp y
30
30 31
x
0x09
SLIDE 52
0x00 0x04 0x08 0x0c 0x10
ex3: garbage in the middle (with stack)
ebp0
10 20
esi
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
ebp y
30
30 31
x
0x09
esp q
200
p
100
retaddr1
SLIDE 53
ex3: garbage in the middle (with stack)
ebp0 esp q p
retaddr1
ebp ebp0
1 local var (tmp)
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
10 20
esi
30 31
200 100
SLIDE 54
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
10 20
esi
30 31
retaddr1
200 100
SLIDE 55
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
10 20
esi
30 31 Lets reclaim & recycle garbage!
retaddr1
200 100
SLIDE 56
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
10 20
esi
30 31 Lets reclaim & recycle garbage!
QUIZ: Which cells are garbage?
(A) 0x00, 0x04 (B) 0x04, 0x08 (C) 0x08, 0x0c (D) None (E) All
retaddr1
200 100
SLIDE 57
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
10 20
esi
30 31 Lets reclaim & recycle garbage!
Those that are not reachable from any stack frame QUIZ: Which cells are garbage?
retaddr1
200 100
SLIDE 58
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
10 20
esi
30 31 Lets reclaim & recycle garbage!
Those that are not reachable from any stack frame QUIZ: Which cells are garbage?
Traverse Stack from top (esp) to bottom (ebp0) to mark reachable cells.
retaddr1
200 100
SLIDE 59
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
10 20
esi
30 31 Lets reclaim & recycle garbage!
QUIZ: Which cells are garbage?
Traverse Stack from top (esp) to bottom (ebp0) to mark reachable cells.
retaddr1
200 100
SLIDE 60
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
esi
30 31
Compact the live cells
retaddr1
200 100
SLIDE 61
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
esi
31
Compact the live cells
retaddr1
200 100
30
SLIDE 62
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
esi
31
Compact the live cells
retaddr1
200 100
30
SLIDE 63
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
esi
31
Compact the live cells
retaddr1
200 100
30
SLIDE 64
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
31
Compact the live cells … then rewind esi
retaddr1
200 100
30
esi
SLIDE 65
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
esi
31
Compact the live cells … then rewind esi
retaddr1
200 100
30
SLIDE 66
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
esi
31
retaddr1
200 100
30
Problem???
SLIDE 67
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09 0x00 0x04 0x08 0x0c 0x10
esi
31
retaddr1
200 100
30
Problem! Have to REDIRECT existing pointers
SLIDE 68
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09
retaddr1
200 100 0x00 0x04 0x08 0x0c 0x10
esi
30 31
SLIDE 69
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09
retaddr1
200 100 0x00 0x04 0x08 0x0c 0x10
esi
30 31
- 1. Compute FORWARD addrs
(i.e. new compacted addrs)
SLIDE 70
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x09
retaddr1
200 100
- 1. Compute FORWARD addrs
e.g. 0x09 —> 0x01
0x00 0x04 0x08 0x0c 0x10
esi
30 31
SLIDE 71
0x09 0x01
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
retaddr1
200 100
- 1. Compute FORWARD addrs
e.g. 0x09 —> 0x01
- 2. REDIRECT addrs on stack
0x00 0x04 0x08 0x0c 0x10
esi
30 31
SLIDE 72
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x01
retaddr1
200 100
- 1. Compute FORWARD addrs
e.g. 0x09 —> 0x01
- 2. REDIRECT addrs on stack
- 3. COMPACT cells on heap
0x00 0x04 0x08 0x0c 0x10
esi
30 31
SLIDE 73
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x01
retaddr1
200 100
- 1. Compute FORWARD addrs
e.g. 0x09 —> 0x01
- 2. REDIRECT addrs on stack
- 3. COMPACT cells on heap
0x00 0x04 0x08 0x0c 0x10
esi
30 31
SLIDE 74
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x01
retaddr1
200 100 0x00 0x04 0x08 0x0c 0x10
esi
30 31 Yay! Have space for (p, q)
SLIDE 75
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x01 0x00 0x04 0x08 0x0c 0x10
esi
31
retaddr1
200 100
30 Yay! Have space for (p, q) 200 100
SLIDE 76
ex3: garbage in the middle (with stack)
ebp0 esp q p ebp ebp0
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x01 0x00 0x04 0x08 0x0c 0x10
esi
31
retaddr1
200 100
30 200 100
tmp
0x09
Return (eax) = 300
SLIDE 77
ex3: garbage in the middle (with stack)
esp ebp
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x01 0x00 0x04 0x08 0x0c 0x10
esi
31 30 200 100 Return (eax) = 300
z
300
SLIDE 78
ex3: garbage in the middle (with stack)
esp ebp
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x01 0x00 0x04 0x08 0x0c 0x10
esi
31 30 200 100
z
300
SLIDE 79
ex3: garbage in the middle (with stack)
esp ebp
def foo(p, q): let tmp = (p, q) in tmp[0] + tmp[1] let y = foo(10, 20) , x = (y, y + 1) , z = foo(100, 200) in x[0] + z
y
30
x
0x01 0x00 0x04 0x08 0x0c 0x10
esi
31 30 200 100
z
300
Return (eax) = 30+300 = 330
SLIDE 80
FOX / GC Example 4
SLIDE 81
ex4: recursive data
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
SLIDE 82
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
call range(0, 3)
ex4: recursive data
SLIDE 83
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
1 2
false
0x09 0x11
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
QUIZ: What is heap when range(0,3) returns? (A) (B)
ex4: recursive data
SLIDE 84
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
l1
0x11
ex4: recursive data
SLIDE 85
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3
Result sum(0x11) = 3
ex4: recursive data
SLIDE 86
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3
ex4: recursive data
SLIDE 87
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3
call range(3,6)
ex4: recursive data
SLIDE 88
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3
call range(3,6)
5 4 3
false
0x21 0x19
QUIZ: What is the value of l? (A) 0x18 (B) 0x19 (C) 0x28 (D) 0x29 (E) 0x30
l
???
ex4: recursive data
SLIDE 89
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3 5 4 3
false
0x21 0x19
l
0x29
Yikes! Out of Memory!
ex4: recursive data
SLIDE 90
esp ebp
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3 5 4 3
false
0x21 0x19
l
0x29
QUIZ: Which cells are “live” on the heap? (A) 0x00 (B) 0x08 (C) 0x10 (D) 0x18 (E) 0x20 (F) 0x28
ex4: recursive data
SLIDE 91
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3 5 4 3
false
0x21 0x19
l
0x29
- 2. Compute FORWARD addrs
- 3. REDIRECT addrs on stack
- 4. COMPACT cells on heap
- 1. MARK live addrs
ex4: recursive data
SLIDE 92
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3 5 4 3
false
0x21 0x19
l
0x29
1.MARK live addrs
reachable from stack ex4: recursive data
SLIDE 93
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
false
0x09 0x01
t1
3 5 4 3
false
0x21 0x19
l
1.MARK live addrs
reachable from stack
0x29
ex4: recursive data
SLIDE 94
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 95
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 96
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 97
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 98
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 99
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 100
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 101
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 102
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 103
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
fwd
- rig
ex4: recursive data
SLIDE 104
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
2.Compute FORWARD addrs
Where should we store the forward addrs? ex4: recursive data
SLIDE 105
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
3.REDIRECT addrs on stack
ex4: recursive data
SLIDE 106
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x29
3.REDIRECT addrs on stack
ex4: recursive data
SLIDE 107
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x11
3.REDIRECT addrs on stack
ex4: recursive data
SLIDE 108
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x11
3.REDIRECT addrs on stack and heap!
ex4: recursive data
SLIDE 109
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x19
l
0x11
3.REDIRECT addrs on stack and heap!
ex4: recursive data
SLIDE 110
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x01
l
0x11
3.REDIRECT addrs on stack and heap!
ex4: recursive data
SLIDE 111
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x21 0x01
l
0x11
3.REDIRECT addrs on stack and heap!
ex4: recursive data
SLIDE 112
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
4.COMPACT cells on heap
Copy cell to forward addr! ex4: recursive data
SLIDE 113
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
4.COMPACT cells on heap
Copy cell to forward addr! ex4: recursive data
SLIDE 114
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
4.COMPACT cells on heap
Copy cell to forward addr! ex4: recursive data
SLIDE 115
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
4.COMPACT cells on heap
Copy cell to forward addr! ex4: recursive data
SLIDE 116
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
4.COMPACT cells on heap
Copy cell to forward addr! ex4: recursive data
SLIDE 117
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
4.COMPACT cells on heap
Copy cell to forward addr! ex4: recursive data
SLIDE 118
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
4.COMPACT cells on heap
Copy cell to forward addr! ex4: recursive data
SLIDE 119
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
GC Complete!
Have space for (1000, l)
ex4: recursive data
SLIDE 120
esp ebp
def range(i, j): if (j <= i): false else: (i,range(i+1, j)) def sum(l): if l == false: 0 else: l[0] + sum(l[1]) let t1 = let l1 = range(0, 3) in sum(l1) , l = range(t1, t1 + 3) in (1000, l)
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
t1
3 5 4 3
false
0x09 0x01
l
0x11
GC Complete!
Have space for (1000, l)
1000 0x11
ex4: recursive data
SLIDE 121
esp ebp
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
0x09 0x01
t1
3 5 4 3
false
0x21 0x19
l
0x29
QUIZ: What should print(0x11) show? (A) (0, (1, (2, false))) (B) (3, (4, (5, false))) (C) (0, (1, (2, (3, (4, (5, false)))))) (D) (3, (4, (5, (0, (1, (2, false)))))) (E) (2, (1, (0, (3, (4, (5, false))))))
0x29
ex4: recursive data
SLIDE 122
esp ebp
0x00 0x04 0x08 0x0c 0x10
esi
0x14 0x18 0x1c 0x20 0x24 0x28 0x2c 0x30
2 1
0x09 0x01
t1
3 5 4 3
false
0x21 0x19
l
0x29
QUIZ: Which cells are “live” on the heap? (A) 0x00 (B) 0x08 (C) 0x10 (D) 0x18 (E) 0x20 (F) 0x28
0x29
ex4: recursive data