Everything
4.1.1 Unspecified Behavior

This section describes behavior that is not specified by the ANSI standard.

(1)

Execution environment - initialization of static storage

Static data is output during compilation as a data section.

(2)

Meanings of character displays - backspace (\b), horizontal tab (\t), vertical tab (\t)

This is dependent on the design of the display device.

(3)

Types - floating point

Conforms to IEEE754*.

Note

IEEE: Institute of Electrical and Electronics Engineers
IEEE754 is a system for handling floating-point calculations, providing a uniform standard for data formats, numerical ranges, and the like handled.

(4)

Expressions - evaluation order

In general, expressions are evaluated from left to right. The behavior when optimization has been applied, however, is undefined. Options or other settings could change the order of evaluation, so please do not code expressions with side effects.

(5)

Function calls - parameter evaluation order

In general, function arguments are evaluated from first to last. The behavior when optimization has been applied, however, is undefined. Options or other settings could change the order of evaluation, so please do not code expressions with side effects.

(6)

Structure and union specifiers

These are adjusted so that they do no span bit field type alignment boundaries. If packing has been conducting using options or a #pragma, then bit fields are packed, and not adjusted to alignment boundaries.

(7)

Function definitions - storage of formal parameters

These are assigned to the stack and register. For details, refer to section 9.1.3 Rules Concerning Setting and Referencing Parameters.

(8)

# operator

These are evaluated left to right.