2.1 Conditions

This problem occurs if the following seven conditions are satisfied:

(1)	Optimizing option "-OR" is used at compilation.
(2)	An if statement exist whose controlling expression makes the comparison of a parameter in a calling function or an auto variable with a 0 (zero).
(3)	The type of the parameter or variable in (2) is any of those; char, signed char, unsigned char, int, unsigned int, short, and unsigned short NOTES: 1. The problem arises regardless of whether the parameter or variable is qualified as volatile or not. 2. The problem arises if an address operator is used as the parameter or variable.
(4)	In both the program statements, A and B, that are executed if the controlling expression of the if statement in (2) is satisfied and if not satisfied respectively, the same function, C, is called.
(5)	The return value from the function C is of type int, float, or pointer.
(6)	The function C does not have any argument passed to the stack.
(7)	In both the program statements A and B, the processing from the conditional jump to the function call is the same.

2.2 Example

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char sub(void);               // Conditions (5) and (6)

char func(int dummy, char c)
{
    if (c == 0) {            // Conditions (2) and (3)
            return sub();    // Conditions (4) and (7)
    }

    sub();                   // Conditions (4) and (7)
    return 0;
}
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--------------------------------------------------
char sub(void);

char func(int dummy, char c)
{
    if (c == 0) {
            asm();           // Dummy asm()
            return sub();
    }

    sub();
    return 0;
}
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