28.2.42 __builtin_fbcl

Architecture

dsPIC33A, dsPIC33C/E/F, dsPIC30

Description

Finds the first bit change from left (Msb) in value. This is useful for dynamic scaling of fixed-point data. An example for dsPIC33E:

 int16_t result, value;
 result = __builtin_fbcl(value);

might generate:

 fbcl w4, w5

Prototype

int __builtin_fbcl(int value);

For dsPIC33A, int is int32_t. For dsPIC33C/E/F or dsPIC30, int is int16_t.

Argument

value – Integer number to check for change.

Return Value

Returns a literal value sign extended to represent the number of bits to shift left.

Machine Instruction

fbcl

Error Messages

None