PicC 9.50 dsPIC Manual.pdf

Error and Warning Messagesperformed on the first pass of the loop; only on the subsequent passes. This may not reduce codesize, but it will speed program execution.(758) constant conditional branch: possible use of = instead of == (Code Generator)There is an expression inside an if or other conditional construct, where a constant is being assignedto a variable. This may mean you have inadvertently used an assignment = instead of a compare ==,e.g.:int a, b;if(a = 4) /* this can never be false; always perform the true statement */b = 6;will assign the value 4 to a, then , as the value of the assignment is always true, the comparison canbe omitted and the assignment to b always made. Did you mean:if(a == 4) /* this can never be false; always perform the true statement */b = 6;which checks to see if a is equal to 4.(759) expression generates no code (Code Generator)This expression generates no output code. Check for things like leaving off the parentheses in afunction call, e.g.:int fred;fred; /* this is valid, but has no effect at all */Some devices require that special function register need to be read to clear hardware flags. Toaccommodate this, in some instances the code generator does produce code for a statement whichonly consists of a variable ID. This may happen for variables which are qualified as volatile.Typically the output code will read the variable, but not do anything with the value read.(760) portion of expression has no effect (Code Generator)Part of this expression has no side effects, and no effect on the value of the expression, e.g.:int a, b, c;a = b,c; /* “b” has no effect, was that meant to be a comma? */308