28.2.48 __builtin_ff1r_16
Architecture
dsPIC33A, dsPIC33C/E/F, dsPIC30
Description:
Finds the first one-bit from the right. The most right bit is numbered bit 1, increasing towards the most significant bit.
Example:
int result;
int16_t val_1 = 2048;
int16_t val_2 = -2048;
result = __builtin_ff1r_16(val_1);
result = __builtin_ff1r_16(val_2);The first one-bit for 2048 == 0x0800 == 0b0000.1000.0000.0000 is 13. The first one-bit for -2048 == 0xF800 == 0b1111.1000.0000.0000 is 13.
Prototype
int __builtin_ff1r_16(int16_t x);Arguments
x - value to inspect
Return Value
Returns the position of the first one-bit from the right (least-significant bit). The value is
sign-extended to an int.
Machine Instruction
ff1rError Messages
None.