- The accuracy of the floating-point operations and of the library
functions in
`<math.h>`

and`<complex.h>`

that return floating-point results (5.2.4.2.2). - The rounding behaviors characterized by non-standard values
of
`FLT_ROUNDS`

(5.2.4.2.2). - The evaluation methods characterized by non-standard negative
values of
`FLT_EVAL_METHOD`

(5.2.4.2.2). - The direction of rounding when an integer is converted to a floating-point number that cannot exactly represent the original value (6.3.1.4).
- The direction of rounding when a floating-point number is converted to a narrower floating-point number (6.3.1.5).
- How the nearest representable value or the larger or smaller representable value immediately adjacent to the nearest representable value is chosen for certain floating constants (6.4.4.2).
- Whether and how floating expressions are contracted when not
disallowed by the
`FP_CONTRACT`

pragma (6.5). - The default state for the
`FENV_ACCESS`

pragma (7.6.1). - Additional floating-point exceptions, rounding modes, environments, and classifications, and their macro names (7.6, 7.12).
- The default state for the
`FP_CONTRACT`

pragma (7.12.2). - Whether the “inexact” floating-point exception can be raised when the rounded result actually does equal the mathematical result in an IEC 60559 conformant implementation (F.9).
- Whether the “underflow” (and “inexact”) floating-point exception can be raised when a result is tiny but not inexact in an IEC 60559 conformant implementation (F.9).