MPLAB C Compiler for PIC24 MCUs and dsPIC DSCs ... - Microchip

16-Bit C Compiler User’s Guide
__builtin_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
__builtin_edac
Description: Squares sqr and sums with the nominated accumulator register,
returning it as the result. Also prefetchs 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:
register int result asm("A");
int *xmemory, *ymemory;
int distance;
result = __builtin_ed(distance,
&xmemory, 2,
&ymemory, 2,
&distance);
Prototype:
might generate:
ed w4*w4, A, [w8]+=2, [W10]+=2, w4
int __builtin_edac(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 specified accumulator.
Assembler Operator
/ Machine
Instruction:
edac
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
__builtin_fbcl
Description: Finds the first bit change from left in value. This is useful for dynamic
scaling of fixed-point data. For example:
int result, value;
result = __builtin_fbcl(value);
might generate:
fbcl w4, w5
Prototype: int __builtin_fbcl(int value);
DS51284G-page 148 © 2008 Microchip Technology Inc.