Cirrus Logic CS485 Manual de usuario descargar pdf (Pagina 28)

CS485G Spring 2015 28

8. Loop example

1 void zincr(myArrayType z) {

2 int i;

3 for (i = 0; i < ZLEN; i+=1)

4 z[i] += 1;

5 }

# assume d = z

movl $0, %eax # a = 0

.L4: # loop:

addl $1, (%edx,%eax,4) # z[i] += 1

addl $1, %eax # i+=1

cmpl $5, %eax # i:5

jl .L4 # if < goto loop

28 Nested arrays

1 #define PCOUNT 4

2 myArrayType pgh[PCOUNT] =

3 {{1, 5, 2, 0, 6 },

4 {1, 5, 2, 1, 3 },

5 {1, 5, 2, 1, 7 },

6 {1, 5, 2, 2, 1 }};

2. The values are placed contiguously from some location x to x +

4*PCOUNT*ZLEN - 1 = x + 79. This ordering is guaranteed.

3. pgh is an array of 4 elements.

4. Each of those elements is an array of 5 sub-elements.

5. Each of those sub-elements is an integer occupying 4 bytes.

6. Equivalent declaration: int pgh[PCOUNT][ZLEN];

7. C code: return pgh[index] (the return type is int *)

# assume a = index

leal (%eax,%eax,4),%eax # a = 5

index

leal pgh(,%eax,4),%eax # a = pgh + (20

index)

1 2 ... 23 24 25 26 27 28 29 30 31 32 33 ... 66 67

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Cirrus Logic CS485 Manual de usuario Pagina 28