28.2.19 __builtin_ed

Description

Squares sqr, returning it as the result. Also prefetches data for future square operation by computing **xptr - **yptr and storing the result in *distance.

xincr and yincr may be the literal values: -6, -4, -2, 0, 2, 4, 6 or an integer value.

For example:

 volatile register int result asm("A");
 int *xmemory, *ymemory;
 int distance;

 result = __builtin_ed(distance,
                       &xmemory, 2,
                       &ymemory, 2,
                       &distance);

might generate:

ed w4*w4, A, [w8]+=2, [W10]+=2, w4

Prototype

int __builtin_ed(int sqr, int **xptr, int xincr, int **yptr, int yincr, int *distance);

Argument

sqr – Integer squared value.

xptr – Integer pointer to pointer to x prefetch.

xincr – Integer increment value of x prefetch.

yptr – Integer pointer to pointer to y prefetch.

yincr – Integer increment value of y prefetch.

distance – Integer pointer to distance.

Return Value

Returns the squared result to an accumulator.

Assembler Operator/ Machine Instruction

ed

Error Messages

An error message will be displayed if:

  • the result is not an accumulator register
  • xptr is null
  • yptr is null
  • distance is null